Cached search

- Send models etag
- Refresh models on 412
- This wires `ModelsManager` to `ModelFamily` so we don't mutate it
mid-turn

.codespellignore

@@ -1,2 +1,3 @@
 iTerm
+iTerm2
 psuedo

.codespellrc

@@ -3,4 +3,4 @@
 skip = .git*,vendor,*-lock.yaml,*.lock,.codespellrc,*test.ts,*.jsonl,frame*.txt
 check-hidden = true
 ignore-regex = ^\s*"image/\S+": ".*|\b(afterAll)\b
-ignore-words-list = ratatui,ser
+ignore-words-list = ratatui,ser,iTerm,iterm2,iterm

.github/actions/macos-code-sign/action.yml

@@ -4,6 +4,14 @@ inputs:
   target:
     description: Rust compilation target triple (e.g. aarch64-apple-darwin).
     required: true
+  sign-binaries:
+    description: Whether to sign and notarize the macOS binaries.
+    required: false
+    default: "true"
+  sign-dmg:
+    description: Whether to sign and notarize the macOS dmg.
+    required: false
+    default: "true"
   apple-certificate:
     description: Base64-encoded Apple signing certificate (P12).
     required: true
@@ -107,6 +115,7 @@ runs:
         echo "::add-mask::$APPLE_CODESIGN_IDENTITY"
 
     - name: Sign macOS binaries
+      if: ${{ inputs.sign-binaries == 'true' }}
       shell: bash
       run: |
         set -euo pipefail
@@ -127,6 +136,7 @@ runs:
         done
 
     - name: Notarize macOS binaries
+      if: ${{ inputs.sign-binaries == 'true' }}
       shell: bash
       env:
         APPLE_NOTARIZATION_KEY_P8: ${{ inputs.apple-notarization-key-p8 }}
@@ -149,6 +159,8 @@ runs:
         }
         trap cleanup_notary EXIT
 
+        source "$GITHUB_ACTION_PATH/notary_helpers.sh"
+
         notarize_binary() {
           local binary="$1"
           local source_path="codex-rs/target/${{ inputs.target }}/release/${binary}"
@@ -162,32 +174,54 @@ runs:
           rm -f "$archive_path"
           ditto -c -k --keepParent "$source_path" "$archive_path"
 
-          submission_json=$(xcrun notarytool submit "$archive_path" \
-            --key "$notary_key_path" \
-            --key-id "$APPLE_NOTARIZATION_KEY_ID" \
-            --issuer "$APPLE_NOTARIZATION_ISSUER_ID" \
-            --output-format json \
-            --wait)
-
-          status=$(printf '%s\n' "$submission_json" | jq -r '.status // "Unknown"')
-          submission_id=$(printf '%s\n' "$submission_json" | jq -r '.id // ""')
-
-          if [[ -z "$submission_id" ]]; then
-            echo "Failed to retrieve submission ID for $binary"
-            exit 1
-          fi
-
-          echo "::notice title=Notarization::$binary submission ${submission_id} completed with status ${status}"
-
-          if [[ "$status" != "Accepted" ]]; then
-            echo "Notarization failed for ${binary} (submission ${submission_id}, status ${status})"
-            exit 1
-          fi
+          notarize_submission "$binary" "$archive_path" "$notary_key_path"
         }
 
         notarize_binary "codex"
         notarize_binary "codex-responses-api-proxy"
 
+    - name: Sign and notarize macOS dmg
+      if: ${{ inputs.sign-dmg == 'true' }}
+      shell: bash
+      env:
+        APPLE_NOTARIZATION_KEY_P8: ${{ inputs.apple-notarization-key-p8 }}
+        APPLE_NOTARIZATION_KEY_ID: ${{ inputs.apple-notarization-key-id }}
+        APPLE_NOTARIZATION_ISSUER_ID: ${{ inputs.apple-notarization-issuer-id }}
+      run: |
+        set -euo pipefail
+
+        for var in APPLE_CODESIGN_IDENTITY APPLE_NOTARIZATION_KEY_P8 APPLE_NOTARIZATION_KEY_ID APPLE_NOTARIZATION_ISSUER_ID; do
+          if [[ -z "${!var:-}" ]]; then
+            echo "$var is required"
+            exit 1
+          fi
+        done
+
+        notary_key_path="${RUNNER_TEMP}/notarytool.key.p8"
+        echo "$APPLE_NOTARIZATION_KEY_P8" | base64 -d > "$notary_key_path"
+        cleanup_notary() {
+          rm -f "$notary_key_path"
+        }
+        trap cleanup_notary EXIT
+
+        source "$GITHUB_ACTION_PATH/notary_helpers.sh"
+
+        dmg_path="codex-rs/target/${{ inputs.target }}/release/codex-${{ inputs.target }}.dmg"
+
+        if [[ ! -f "$dmg_path" ]]; then
+          echo "dmg $dmg_path not found"
+          exit 1
+        fi
+
+        keychain_args=()
+        if [[ -n "${APPLE_CODESIGN_KEYCHAIN:-}" && -f "${APPLE_CODESIGN_KEYCHAIN}" ]]; then
+          keychain_args+=(--keychain "${APPLE_CODESIGN_KEYCHAIN}")
+        fi
+
+        codesign --force --timestamp --sign "$APPLE_CODESIGN_IDENTITY" "${keychain_args[@]}" "$dmg_path"
+        notarize_submission "codex-${{ inputs.target }}.dmg" "$dmg_path" "$notary_key_path"
+        xcrun stapler staple "$dmg_path"
+
     - name: Remove signing keychain
       if: ${{ always() }}
       shell: bash

.github/actions/macos-code-sign/notary_helpers.sh

@@ -0,0 +1,46 @@
+#!/usr/bin/env bash
+
+notarize_submission() {
+  local label="$1"
+  local path="$2"
+  local notary_key_path="$3"
+
+  if [[ -z "${APPLE_NOTARIZATION_KEY_ID:-}" || -z "${APPLE_NOTARIZATION_ISSUER_ID:-}" ]]; then
+    echo "APPLE_NOTARIZATION_KEY_ID and APPLE_NOTARIZATION_ISSUER_ID are required for notarization"
+    exit 1
+  fi
+
+  if [[ -z "$notary_key_path" || ! -f "$notary_key_path" ]]; then
+    echo "Notary key file $notary_key_path not found"
+    exit 1
+  fi
+
+  if [[ ! -f "$path" ]]; then
+    echo "Notarization payload $path not found"
+    exit 1
+  fi
+
+  local submission_json
+  submission_json=$(xcrun notarytool submit "$path" \
+    --key "$notary_key_path" \
+    --key-id "$APPLE_NOTARIZATION_KEY_ID" \
+    --issuer "$APPLE_NOTARIZATION_ISSUER_ID" \
+    --output-format json \
+    --wait)
+
+  local status submission_id
+  status=$(printf '%s\n' "$submission_json" | jq -r '.status // "Unknown"')
+  submission_id=$(printf '%s\n' "$submission_json" | jq -r '.id // ""')
+
+  if [[ -z "$submission_id" ]]; then
+    echo "Failed to retrieve submission ID for $label"
+    exit 1
+  fi
+
+  echo "::notice title=Notarization::$label submission ${submission_id} completed with status ${status}"
+
+  if [[ "$status" != "Accepted" ]]; then
+    echo "Notarization failed for ${label} (submission ${submission_id}, status ${status})"
+    exit 1
+  fi
+}

.github/workflows/cargo-deny.yml

@@ -20,7 +20,7 @@ jobs:
         uses: dtolnay/rust-toolchain@stable
 
       - name: Run cargo-deny
-        uses: EmbarkStudios/cargo-deny-action@v1
+        uses: EmbarkStudios/cargo-deny-action@v2
         with:
           rust-version: stable
           manifest-path: ./codex-rs/Cargo.toml

.github/workflows/ci.yml

@@ -37,7 +37,7 @@ jobs:
         run: |
           set -euo pipefail
           # Use a rust-release version that includes all native binaries.
-          CODEX_VERSION=0.74.0-alpha.3
+          CODEX_VERSION=0.74.0
           OUTPUT_DIR="${RUNNER_TEMP}"
           python3 ./scripts/stage_npm_packages.py \
             --release-version "$CODEX_VERSION" \

.github/workflows/rust-release-prepare.yml

@@ -41,7 +41,7 @@ jobs:
           curl --http1.1 --fail --show-error --location "${headers[@]}" "${url}" | jq '.' > codex-rs/core/models.json
 
       - name: Open pull request (if changed)
-        uses: peter-evans/create-pull-request@v7
+        uses: peter-evans/create-pull-request@v8
         with:
           commit-message: "Update models.json"
           title: "Update models.json"

.github/workflows/rust-release.yml

@@ -128,11 +128,72 @@ jobs:
           account-name: ${{ secrets.AZURE_TRUSTED_SIGNING_ACCOUNT_NAME }}
           certificate-profile-name: ${{ secrets.AZURE_TRUSTED_SIGNING_CERTIFICATE_PROFILE_NAME }}
 
-      - if: ${{ matrix.runner == 'macos-15-xlarge' }}
-        name: MacOS code signing
+      - if: ${{ runner.os == 'macOS' }}
+        name: MacOS code signing (binaries)
         uses: ./.github/actions/macos-code-sign
         with:
           target: ${{ matrix.target }}
+          sign-binaries: "true"
+          sign-dmg: "false"
+          apple-certificate: ${{ secrets.APPLE_CERTIFICATE_P12 }}
+          apple-certificate-password: ${{ secrets.APPLE_CERTIFICATE_PASSWORD }}
+          apple-notarization-key-p8: ${{ secrets.APPLE_NOTARIZATION_KEY_P8 }}
+          apple-notarization-key-id: ${{ secrets.APPLE_NOTARIZATION_KEY_ID }}
+          apple-notarization-issuer-id: ${{ secrets.APPLE_NOTARIZATION_ISSUER_ID }}
+
+      - if: ${{ runner.os == 'macOS' }}
+        name: Build macOS dmg
+        shell: bash
+        run: |
+          set -euo pipefail
+
+          target="${{ matrix.target }}"
+          release_dir="target/${target}/release"
+          dmg_root="${RUNNER_TEMP}/codex-dmg-root"
+          volname="Codex (${target})"
+          dmg_path="${release_dir}/codex-${target}.dmg"
+
+          # The previous "MacOS code signing (binaries)" step signs + notarizes the
+          # built artifacts in `${release_dir}`. This step packages *those same*
+          # signed binaries into a dmg.
+          codex_binary_path="${release_dir}/codex"
+          proxy_binary_path="${release_dir}/codex-responses-api-proxy"
+
+          rm -rf "$dmg_root"
+          mkdir -p "$dmg_root"
+
+          if [[ ! -f "$codex_binary_path" ]]; then
+            echo "Binary $codex_binary_path not found"
+            exit 1
+          fi
+          if [[ ! -f "$proxy_binary_path" ]]; then
+            echo "Binary $proxy_binary_path not found"
+            exit 1
+          fi
+
+          ditto "$codex_binary_path" "${dmg_root}/codex"
+          ditto "$proxy_binary_path" "${dmg_root}/codex-responses-api-proxy"
+
+          rm -f "$dmg_path"
+          hdiutil create \
+            -volname "$volname" \
+            -srcfolder "$dmg_root" \
+            -format UDZO \
+            -ov \
+            "$dmg_path"
+
+          if [[ ! -f "$dmg_path" ]]; then
+            echo "dmg $dmg_path not found after build"
+            exit 1
+          fi
+
+      - if: ${{ runner.os == 'macOS' }}
+        name: MacOS code signing (dmg)
+        uses: ./.github/actions/macos-code-sign
+        with:
+          target: ${{ matrix.target }}
+          sign-binaries: "false"
+          sign-dmg: "true"
           apple-certificate: ${{ secrets.APPLE_CERTIFICATE_P12 }}
           apple-certificate-password: ${{ secrets.APPLE_CERTIFICATE_PASSWORD }}
           apple-notarization-key-p8: ${{ secrets.APPLE_NOTARIZATION_KEY_P8 }}
@@ -160,6 +221,10 @@ jobs:
             cp target/${{ matrix.target }}/release/codex-responses-api-proxy.sigstore "$dest/codex-responses-api-proxy-${{ matrix.target }}.sigstore"
           fi
 
+          if [[ "${{ matrix.target }}" == *apple-darwin ]]; then
+            cp target/${{ matrix.target }}/release/codex-${{ matrix.target }}.dmg "$dest/codex-${{ matrix.target }}.dmg"
+          fi
+
       - if: ${{ matrix.runner == 'windows-11-arm' }}
         name: Install zstd
         shell: powershell
@@ -194,7 +259,7 @@ jobs:
             base="$(basename "$f")"
             # Skip files that are already archives (shouldn't happen, but be
             # safe).
-            if [[ "$base" == *.tar.gz || "$base" == *.zip ]]; then
+            if [[ "$base" == *.tar.gz || "$base" == *.zip || "$base" == *.dmg ]]; then
               continue
             fi
 

.gitignore

@@ -85,3 +85,8 @@ CHANGELOG.ignore.md
 # nix related
 .direnv
 .envrc
+
+# Python bytecode files
+__pycache__/
+*.pyc
+

AGENTS.md

@@ -77,6 +77,12 @@ If you don’t have the tool:
 - Prefer deep equals comparisons whenever possible. Perform `assert_eq!()` on entire objects, rather than individual fields.
 - Avoid mutating process environment in tests; prefer passing environment-derived flags or dependencies from above.
 
+### Spawning workspace binaries in tests (Cargo vs Buck2)
+
+- Prefer `codex_utils_cargo_bin::cargo_bin("...")` over `assert_cmd::Command::cargo_bin(...)` or `escargot` when tests need to spawn first-party binaries.
+  - Under Buck2, `CARGO_BIN_EXE_*` may be project-relative (e.g. `buck-out/...`), which breaks if a test changes its working directory. `codex_utils_cargo_bin::cargo_bin` resolves to an absolute path first.
+- When locating fixture files under Buck2, avoid `env!("CARGO_MANIFEST_DIR")` (Buck codegen sets it to `"."`). Prefer deriving paths from `codex_utils_cargo_bin::buck_project_root()` when needed.
+
 ### Integration tests (core)
 
 - Prefer the utilities in `core_test_support::responses` when writing end-to-end Codex tests.

codex-cli/scripts/install_native_deps.py

@@ -2,6 +2,7 @@
 """Install Codex native binaries (Rust CLI plus ripgrep helpers)."""
 
 import argparse
+from contextlib import contextmanager
 import json
 import os
 import shutil
@@ -12,6 +13,7 @@ import zipfile
 from dataclasses import dataclass
 from concurrent.futures import ThreadPoolExecutor, as_completed
 from pathlib import Path
+import sys
 from typing import Iterable, Sequence
 from urllib.parse import urlparse
 from urllib.request import urlopen
@@ -77,6 +79,45 @@ RG_TARGET_PLATFORM_PAIRS: list[tuple[str, str]] = [
 RG_TARGET_TO_PLATFORM = {target: platform for target, platform in RG_TARGET_PLATFORM_PAIRS}
 DEFAULT_RG_TARGETS = [target for target, _ in RG_TARGET_PLATFORM_PAIRS]
 
+# urllib.request.urlopen() defaults to no timeout (can hang indefinitely), which is painful in CI.
+DOWNLOAD_TIMEOUT_SECS = 60
+
+
+def _gha_enabled() -> bool:
+    # GitHub Actions supports "workflow commands" (e.g. ::group:: / ::error::) that make logs
+    # much easier to scan: groups collapse noisy sections and error annotations surface the
+    # failure in the UI without changing the actual exception/traceback output.
+    return os.environ.get("GITHUB_ACTIONS") == "true"
+
+
+def _gha_escape(value: str) -> str:
+    # Workflow commands require percent/newline escaping.
+    return value.replace("%", "%25").replace("\r", "%0D").replace("\n", "%0A")
+
+
+def _gha_error(*, title: str, message: str) -> None:
+    # Emit a GitHub Actions error annotation. This does not replace stdout/stderr logs; it just
+    # adds a prominent summary line to the job UI so the root cause is easier to spot.
+    if not _gha_enabled():
+        return
+    print(
+        f"::error title={_gha_escape(title)}::{_gha_escape(message)}",
+        flush=True,
+    )
+
+
+@contextmanager
+def _gha_group(title: str):
+    # Wrap a block in a collapsible log group on GitHub Actions. Outside of GHA this is a no-op
+    # so local output remains unchanged.
+    if _gha_enabled():
+        print(f"::group::{_gha_escape(title)}", flush=True)
+    try:
+        yield
+    finally:
+        if _gha_enabled():
+            print("::endgroup::", flush=True)
+
 
 def parse_args() -> argparse.Namespace:
     parser = argparse.ArgumentParser(description="Install native Codex binaries.")
@@ -131,18 +172,20 @@ def main() -> int:
     workflow_id = workflow_url.rstrip("/").split("/")[-1]
     print(f"Downloading native artifacts from workflow {workflow_id}...")
 
-    with tempfile.TemporaryDirectory(prefix="codex-native-artifacts-") as artifacts_dir_str:
-        artifacts_dir = Path(artifacts_dir_str)
-        _download_artifacts(workflow_id, artifacts_dir)
-        install_binary_components(
-            artifacts_dir,
-            vendor_dir,
-            [BINARY_COMPONENTS[name] for name in components if name in BINARY_COMPONENTS],
-        )
+    with _gha_group(f"Download native artifacts from workflow {workflow_id}"):
+        with tempfile.TemporaryDirectory(prefix="codex-native-artifacts-") as artifacts_dir_str:
+            artifacts_dir = Path(artifacts_dir_str)
+            _download_artifacts(workflow_id, artifacts_dir)
+            install_binary_components(
+                artifacts_dir,
+                vendor_dir,
+                [BINARY_COMPONENTS[name] for name in components if name in BINARY_COMPONENTS],
+            )
 
     if "rg" in components:
-        print("Fetching ripgrep binaries...")
-        fetch_rg(vendor_dir, DEFAULT_RG_TARGETS, manifest_path=RG_MANIFEST)
+        with _gha_group("Fetch ripgrep binaries"):
+            print("Fetching ripgrep binaries...")
+            fetch_rg(vendor_dir, DEFAULT_RG_TARGETS, manifest_path=RG_MANIFEST)
 
     print(f"Installed native dependencies into {vendor_dir}")
     return 0
@@ -203,7 +246,14 @@ def fetch_rg(
 
         for future in as_completed(future_map):
             target = future_map[future]
-            results[target] = future.result()
+            try:
+                results[target] = future.result()
+            except Exception as exc:
+                _gha_error(
+                    title="ripgrep install failed",
+                    message=f"target={target} error={exc!r}",
+                )
+                raise RuntimeError(f"Failed to install ripgrep for target {target}.") from exc
             print(f"  installed ripgrep for {target}")
 
     return [results[target] for target in targets]
@@ -301,6 +351,8 @@ def _fetch_single_rg(
     url = providers[0]["url"]
     archive_format = platform_info.get("format", "zst")
     archive_member = platform_info.get("path")
+    digest = platform_info.get("digest")
+    expected_size = platform_info.get("size")
 
     dest_dir = vendor_dir / target / "path"
     dest_dir.mkdir(parents=True, exist_ok=True)
@@ -313,10 +365,32 @@ def _fetch_single_rg(
         tmp_dir = Path(tmp_dir_str)
         archive_filename = os.path.basename(urlparse(url).path)
         download_path = tmp_dir / archive_filename
-        _download_file(url, download_path)
+        print(
+            f"  downloading ripgrep for {target} ({platform_key}) from {url}",
+            flush=True,
+        )
+        try:
+            _download_file(url, download_path)
+        except Exception as exc:
+            _gha_error(
+                title="ripgrep download failed",
+                message=f"target={target} platform={platform_key} url={url} error={exc!r}",
+            )
+            raise RuntimeError(
+                "Failed to download ripgrep "
+                f"(target={target}, platform={platform_key}, format={archive_format}, "
+                f"expected_size={expected_size!r}, digest={digest!r}, url={url}, dest={download_path})."
+            ) from exc
 
         dest.unlink(missing_ok=True)
-        extract_archive(download_path, archive_format, archive_member, dest)
+        try:
+            extract_archive(download_path, archive_format, archive_member, dest)
+        except Exception as exc:
+            raise RuntimeError(
+                "Failed to extract ripgrep "
+                f"(target={target}, platform={platform_key}, format={archive_format}, "
+                f"member={archive_member!r}, url={url}, archive={download_path})."
+            ) from exc
 
     if not is_windows:
         dest.chmod(0o755)
@@ -326,7 +400,9 @@ def _fetch_single_rg(
 
 def _download_file(url: str, dest: Path) -> None:
     dest.parent.mkdir(parents=True, exist_ok=True)
-    with urlopen(url) as response, open(dest, "wb") as out:
+    dest.unlink(missing_ok=True)
+
+    with urlopen(url, timeout=DOWNLOAD_TIMEOUT_SECS) as response, open(dest, "wb") as out:
         shutil.copyfileobj(response, out)
 
 

codex-rs/Cargo.lock

@@ -329,12 +329,12 @@ name = "app_test_support"
 version = "0.0.0"
 dependencies = [
  "anyhow",
- "assert_cmd",
  "base64",
  "chrono",
  "codex-app-server-protocol",
  "codex-core",
  "codex-protocol",
+ "codex-utils-cargo-bin",
  "core_test_support",
  "serde",
  "serde_json",
@@ -365,6 +365,12 @@ dependencies = [
  "x11rb",
 ]
 
+[[package]]
+name = "arc-swap"
+version = "1.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "69f7f8c3906b62b754cd5326047894316021dcfe5a194c8ea52bdd94934a3457"
+
 [[package]]
 name = "arrayvec"
 version = "0.7.6"
@@ -883,9 +889,9 @@ dependencies = [
 
 [[package]]
 name = "clap"
-version = "4.5.47"
+version = "4.5.53"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7eac00902d9d136acd712710d71823fb8ac8004ca445a89e73a41d45aa712931"
+checksum = "c9e340e012a1bf4935f5282ed1436d1489548e8f72308207ea5df0e23d2d03f8"
 dependencies = [
  "clap_builder",
  "clap_derive",
@@ -893,9 +899,9 @@ dependencies = [
 
 [[package]]
 name = "clap_builder"
-version = "4.5.47"
+version = "4.5.53"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2ad9bbf750e73b5884fb8a211a9424a1906c1e156724260fdae972f31d70e1d6"
+checksum = "d76b5d13eaa18c901fd2f7fca939fefe3a0727a953561fefdf3b2922b8569d00"
 dependencies = [
  "anstream",
  "anstyle",
@@ -915,9 +921,9 @@ dependencies = [
 
 [[package]]
 name = "clap_derive"
-version = "4.5.47"
+version = "4.5.49"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bbfd7eae0b0f1a6e63d4b13c9c478de77c2eb546fba158ad50b4203dc24b9f9c"
+checksum = "2a0b5487afeab2deb2ff4e03a807ad1a03ac532ff5a2cee5d86884440c7f7671"
 dependencies = [
  "heck",
  "proc-macro2",
@@ -987,7 +993,6 @@ version = "0.0.0"
 dependencies = [
  "anyhow",
  "app_test_support",
- "assert_cmd",
  "base64",
  "chrono",
  "codex-app-server-protocol",
@@ -1058,6 +1063,7 @@ dependencies = [
  "anyhow",
  "assert_cmd",
  "assert_matches",
+ "codex-utils-cargo-bin",
  "pretty_assertions",
  "similar",
  "tempfile",
@@ -1154,6 +1160,8 @@ dependencies = [
  "codex-stdio-to-uds",
  "codex-tui",
  "codex-tui2",
+ "codex-utils-absolute-path",
+ "codex-utils-cargo-bin",
  "codex-windows-sandbox",
  "ctor 0.5.0",
  "libc",
@@ -1244,6 +1252,8 @@ dependencies = [
  "codex-lmstudio",
  "codex-ollama",
  "codex-protocol",
+ "codex-utils-absolute-path",
+ "pretty_assertions",
  "serde",
  "toml 0.9.5",
 ]
@@ -1253,6 +1263,7 @@ name = "codex-core"
 version = "0.0.0"
 dependencies = [
  "anyhow",
+ "arc-swap",
  "assert_cmd",
  "assert_matches",
  "async-channel",
@@ -1275,6 +1286,7 @@ dependencies = [
  "codex-protocol",
  "codex-rmcp-client",
  "codex-utils-absolute-path",
+ "codex-utils-cargo-bin",
  "codex-utils-pty",
  "codex-utils-readiness",
  "codex-utils-string",
@@ -1291,6 +1303,7 @@ dependencies = [
  "futures",
  "http 1.3.1",
  "image",
+ "include_dir",
  "indexmap 2.12.0",
  "keyring",
  "landlock",
@@ -1315,17 +1328,15 @@ dependencies = [
  "sha2",
  "shlex",
  "similar",
- "strum_macros 0.27.2",
  "tempfile",
  "test-case",
  "test-log",
  "thiserror 2.0.17",
  "time",
  "tokio",
- "tokio-test",
  "tokio-util",
  "toml 0.9.5",
- "toml_edit",
+ "toml_edit 0.24.0+spec-1.1.0",
  "tracing",
  "tracing-subscriber",
  "tracing-test",
@@ -1351,6 +1362,7 @@ dependencies = [
  "codex-core",
  "codex-protocol",
  "codex-utils-absolute-path",
+ "codex-utils-cargo-bin",
  "core_test_support",
  "libc",
  "mcp-types",
@@ -1376,11 +1388,11 @@ name = "codex-exec-server"
 version = "0.0.0"
 dependencies = [
  "anyhow",
- "assert_cmd",
  "async-trait",
  "clap",
  "codex-core",
  "codex-execpolicy",
+ "codex-utils-cargo-bin",
  "exec_server_test_support",
  "libc",
  "maplit",
@@ -1453,6 +1465,7 @@ dependencies = [
  "clap",
  "ignore",
  "nucleo-matcher",
+ "pretty_assertions",
  "serde",
  "serde_json",
  "tokio",
@@ -1538,7 +1551,6 @@ name = "codex-mcp-server"
 version = "0.0.0"
 dependencies = [
  "anyhow",
- "assert_cmd",
  "codex-arg0",
  "codex-common",
  "codex-core",
@@ -1662,8 +1674,8 @@ dependencies = [
  "axum",
  "codex-keyring-store",
  "codex-protocol",
+ "codex-utils-cargo-bin",
  "dirs",
- "escargot",
  "futures",
  "keyring",
  "mcp-types",
@@ -1690,6 +1702,7 @@ version = "0.0.0"
 dependencies = [
  "anyhow",
  "assert_cmd",
+ "codex-utils-cargo-bin",
  "pretty_assertions",
  "tempfile",
  "uds_windows",
@@ -1746,6 +1759,7 @@ dependencies = [
  "supports-color 3.0.2",
  "tempfile",
  "textwrap 0.16.2",
+ "thiserror 2.0.17",
  "tokio",
  "tokio-stream",
  "tokio-util",
@@ -1760,6 +1774,9 @@ dependencies = [
  "url",
  "uuid",
  "vt100",
+ "which",
+ "windows-sys 0.52.0",
+ "winsplit",
 ]
 
 [[package]]
@@ -1852,6 +1869,14 @@ dependencies = [
  "tokio",
 ]
 
+[[package]]
+name = "codex-utils-cargo-bin"
+version = "0.0.0"
+dependencies = [
+ "assert_cmd",
+ "thiserror 2.0.17",
+]
+
 [[package]]
 name = "codex-utils-image"
 version = "0.0.0"
@@ -1913,6 +1938,7 @@ dependencies = [
  "codex-utils-absolute-path",
  "dirs-next",
  "dunce",
+ "pretty_assertions",
  "rand 0.8.5",
  "serde",
  "serde_json",
@@ -2054,6 +2080,7 @@ dependencies = [
  "codex-core",
  "codex-protocol",
  "codex-utils-absolute-path",
+ "codex-utils-cargo-bin",
  "notify",
  "pretty_assertions",
  "regex-lite",
@@ -2205,6 +2232,16 @@ dependencies = [
  "darling_macro 0.21.3",
 ]
 
+[[package]]
+name = "darling"
+version = "0.23.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "25ae13da2f202d56bd7f91c25fba009e7717a1e4a1cc98a76d844b65ae912e9d"
+dependencies = [
+ "darling_core 0.23.0",
+ "darling_macro 0.23.0",
+]
+
 [[package]]
 name = "darling_core"
 version = "0.20.11"
@@ -2233,6 +2270,19 @@ dependencies = [
  "syn 2.0.104",
 ]
 
+[[package]]
+name = "darling_core"
+version = "0.23.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9865a50f7c335f53564bb694ef660825eb8610e0a53d3e11bf1b0d3df31e03b0"
+dependencies = [
+ "ident_case",
+ "proc-macro2",
+ "quote",
+ "strsim 0.11.1",
+ "syn 2.0.104",
+]
+
 [[package]]
 name = "darling_macro"
 version = "0.20.11"
@@ -2255,6 +2305,17 @@ dependencies = [
  "syn 2.0.104",
 ]
 
+[[package]]
+name = "darling_macro"
+version = "0.23.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ac3984ec7bd6cfa798e62b4a642426a5be0e68f9401cfc2a01e3fa9ea2fcdb8d"
+dependencies = [
+ "darling_core 0.23.0",
+ "quote",
+ "syn 2.0.104",
+]
+
 [[package]]
 name = "dbus"
 version = "0.9.9"
@@ -2739,8 +2800,8 @@ name = "exec_server_test_support"
 version = "0.0.0"
 dependencies = [
  "anyhow",
- "assert_cmd",
  "codex-core",
+ "codex-utils-cargo-bin",
  "rmcp",
  "serde_json",
  "tokio",
@@ -3366,7 +3427,7 @@ dependencies = [
  "libc",
  "percent-encoding",
  "pin-project-lite",
- "socket2 0.5.10",
+ "socket2 0.6.1",
  "system-configuration",
  "tokio",
  "tower-service",
@@ -3589,6 +3650,25 @@ version = "0.1.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e8a5a9a0ff0086c7a148acb942baaabeadf9504d10400b5a05645853729b9cd2"
 
+[[package]]
+name = "include_dir"
+version = "0.7.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "923d117408f1e49d914f1a379a309cffe4f18c05cf4e3d12e613a15fc81bd0dd"
+dependencies = [
+ "include_dir_macros",
+]
+
+[[package]]
+name = "include_dir_macros"
+version = "0.7.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7cab85a7ed0bd5f0e76d93846e0147172bed2e2d3f859bcc33a8d9699cad1a75"
+dependencies = [
+ "proc-macro2",
+ "quote",
+]
+
 [[package]]
 name = "indenter"
 version = "0.3.3"
@@ -3687,17 +3767,6 @@ dependencies = [
  "rustversion",
 ]
 
-[[package]]
-name = "io-uring"
-version = "0.7.9"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d93587f37623a1a17d94ef2bc9ada592f5465fe7732084ab7beefabe5c77c0c4"
-dependencies = [
- "bitflags 2.10.0",
- "cfg-if",
- "libc",
-]
-
 [[package]]
 name = "ipnet"
 version = "2.11.0"
@@ -3897,9 +3966,9 @@ dependencies = [
 
 [[package]]
 name = "landlock"
-version = "0.4.2"
+version = "0.4.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b3d2ef408b88e913bfc6594f5e693d57676f6463ded7d8bf994175364320c706"
+checksum = "49fefd6652c57d68aaa32544a4c0e642929725bdc1fd929367cdeb673ab81088"
 dependencies = [
  "enumflags2",
  "libc",
@@ -4089,9 +4158,9 @@ name = "mcp_test_support"
 version = "0.0.0"
 dependencies = [
  "anyhow",
- "assert_cmd",
  "codex-core",
  "codex-mcp-server",
+ "codex-utils-cargo-bin",
  "core_test_support",
  "mcp-types",
  "os_info",
@@ -4579,9 +4648,9 @@ dependencies = [
 
 [[package]]
 name = "openssl-sys"
-version = "0.9.109"
+version = "0.9.111"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "90096e2e47630d78b7d1c20952dc621f957103f8bc2c8359ec81290d75238571"
+checksum = "82cab2d520aa75e3c58898289429321eb788c3106963d0dc886ec7a5f4adc321"
 dependencies = [
  "cc",
  "libc",
@@ -5038,7 +5107,7 @@ version = "3.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "219cb19e96be00ab2e37d6e299658a0cfa83e52429179969b0f0121b4ac46983"
 dependencies = [
- "toml_edit",
+ "toml_edit 0.23.10+spec-1.0.0",
 ]
 
 [[package]]
@@ -5052,9 +5121,9 @@ dependencies = [
 
 [[package]]
 name = "process-wrap"
-version = "8.2.1"
+version = "9.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a3ef4f2f0422f23a82ec9f628ea2acd12871c81a9362b02c43c1aa86acfc3ba1"
+checksum = "5e5fd83ab7fa55fd06f5e665e3fc52b8bca451c0486b8ea60ad649cd1c10a5da"
 dependencies = [
  "futures",
  "indexmap 2.12.0",
@@ -5152,7 +5221,7 @@ dependencies = [
  "quinn-udp",
  "rustc-hash",
  "rustls",
- "socket2 0.5.10",
+ "socket2 0.6.1",
  "thiserror 2.0.17",
  "tokio",
  "tracing",
@@ -5189,7 +5258,7 @@ dependencies = [
  "cfg_aliases 0.2.1",
  "libc",
  "once_cell",
- "socket2 0.5.10",
+ "socket2 0.6.1",
  "tracing",
  "windows-sys 0.60.2",
 ]
@@ -5383,9 +5452,9 @@ dependencies = [
 
 [[package]]
 name = "regex-lite"
-version = "0.1.7"
+version = "0.1.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "943f41321c63ef1c92fd763bfe054d2668f7f225a5c29f0105903dc2fc04ba30"
+checksum = "8d942b98df5e658f56f20d592c7f868833fe38115e65c33003d8cd224b0155da"
 
 [[package]]
 name = "regex-syntax"
@@ -5464,9 +5533,9 @@ dependencies = [
 
 [[package]]
 name = "rmcp"
-version = "0.10.0"
+version = "0.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "38b18323edc657390a6ed4d7a9110b0dec2dc3ed128eb2a123edfbafabdbddc5"
+checksum = "528d42f8176e6e5e71ea69182b17d1d0a19a6b3b894b564678b74cd7cab13cfa"
 dependencies = [
  "async-trait",
  "base64",
@@ -5499,11 +5568,11 @@ dependencies = [
 
 [[package]]
 name = "rmcp-macros"
-version = "0.10.0"
+version = "0.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c75d0a62676bf8c8003c4e3c348e2ceb6a7b3e48323681aaf177fdccdac2ce50"
+checksum = "e3f81daaa494eb8e985c9462f7d6ce1ab05e5299f48aafd76cdd3d8b060e6f59"
 dependencies = [
- "darling 0.21.3",
+ "darling 0.23.0",
  "proc-macro2",
  "quote",
  "serde_json",
@@ -6668,9 +6737,9 @@ dependencies = [
 
 [[package]]
 name = "test-log"
-version = "0.2.18"
+version = "0.2.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1e33b98a582ea0be1168eba097538ee8dd4bbe0f2b01b22ac92ea30054e5be7b"
+checksum = "37d53ac171c92a39e4769491c4b4dde7022c60042254b5fc044ae409d34a24d4"
 dependencies = [
  "env_logger",
  "test-log-macros",
@@ -6679,9 +6748,9 @@ dependencies = [
 
 [[package]]
 name = "test-log-macros"
-version = "0.2.18"
+version = "0.2.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "451b374529930d7601b1eef8d32bc79ae870b6079b069401709c2a8bf9e75f36"
+checksum = "be35209fd0781c5401458ab66e4f98accf63553e8fae7425503e92fdd319783b"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -6852,29 +6921,26 @@ checksum = "1f3ccbac311fea05f86f61904b462b55fb3df8837a366dfc601a0161d0532f20"
 
 [[package]]
 name = "tokio"
-version = "1.47.1"
+version = "1.48.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "89e49afdadebb872d3145a5638b59eb0691ea23e46ca484037cfab3b76b95038"
+checksum = "ff360e02eab121e0bc37a2d3b4d4dc622e6eda3a8e5253d5435ecf5bd4c68408"
 dependencies = [
- "backtrace",
  "bytes",
- "io-uring",
  "libc",
  "mio",
  "parking_lot",
  "pin-project-lite",
  "signal-hook-registry",
- "slab",
  "socket2 0.6.1",
  "tokio-macros",
- "windows-sys 0.59.0",
+ "windows-sys 0.61.1",
 ]
 
 [[package]]
 name = "tokio-macros"
-version = "2.5.0"
+version = "2.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6e06d43f1345a3bcd39f6a56dbb7dcab2ba47e68e8ac134855e7e2bdbaf8cab8"
+checksum = "af407857209536a95c8e56f8231ef2c2e2aff839b22e07a1ffcbc617e9db9fa5"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -6967,18 +7033,30 @@ dependencies = [
 
 [[package]]
 name = "toml_datetime"
-version = "0.7.3"
+version = "0.7.5+spec-1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f2cdb639ebbc97961c51720f858597f7f24c4fc295327923af55b74c3c724533"
+checksum = "92e1cfed4a3038bc5a127e35a2d360f145e1f4b971b551a2ba5fd7aedf7e1347"
 dependencies = [
  "serde_core",
 ]
 
 [[package]]
 name = "toml_edit"
-version = "0.23.7"
+version = "0.23.10+spec-1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6485ef6d0d9b5d0ec17244ff7eb05310113c3f316f2d14200d4de56b3cb98f8d"
+checksum = "84c8b9f757e028cee9fa244aea147aab2a9ec09d5325a9b01e0a49730c2b5269"
+dependencies = [
+ "indexmap 2.12.0",
+ "toml_datetime",
+ "toml_parser",
+ "winnow",
+]
+
+[[package]]
+name = "toml_edit"
+version = "0.24.0+spec-1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8c740b185920170a6d9191122cafef7010bd6270a3824594bff6784c04d7f09e"
 dependencies = [
  "indexmap 2.12.0",
  "toml_datetime",
@@ -6989,18 +7067,18 @@ dependencies = [
 
 [[package]]
 name = "toml_parser"
-version = "1.0.4"
+version = "1.0.6+spec-1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c0cbe268d35bdb4bb5a56a2de88d0ad0eb70af5384a99d648cd4b3d04039800e"
+checksum = "a3198b4b0a8e11f09dd03e133c0280504d0801269e9afa46362ffde1cbeebf44"
 dependencies = [
  "winnow",
 ]
 
 [[package]]
 name = "toml_writer"
-version = "1.0.4"
+version = "1.0.6+spec-1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "df8b2b54733674ad286d16267dcfc7a71ed5c776e4ac7aa3c3e2561f7c637bf2"
+checksum = "ab16f14aed21ee8bfd8ec22513f7287cd4a91aa92e44edfe2c17ddd004e92607"
 
 [[package]]
 name = "tonic"
@@ -7168,9 +7246,9 @@ dependencies = [
 
 [[package]]
 name = "tracing-subscriber"
-version = "0.3.20"
+version = "0.3.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2054a14f5307d601f88daf0553e1cbf472acc4f2c51afab632431cdcd72124d5"
+checksum = "2f30143827ddab0d256fd843b7a66d164e9f271cfa0dde49142c5ca0ca291f1e"
 dependencies = [
  "matchers",
  "nu-ansi-term",
@@ -8315,6 +8393,12 @@ version = "0.0.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d135d17ab770252ad95e9a872d365cf3090e3be864a34ab46f48555993efc904"
 
+[[package]]
+name = "winsplit"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3ab703352da6a72f35c39a533526393725640575bb211f61987a2748323ad956"
+
 [[package]]
 name = "wiremock"
 version = "0.6.5"

codex-rs/Cargo.toml

@@ -36,6 +36,7 @@ members = [
     "tui",
     "tui2",
     "utils/absolute-path",
+    "utils/cargo-bin",
     "utils/git",
     "utils/cache",
     "utils/image",
@@ -93,6 +94,7 @@ codex-tui = { path = "tui" }
 codex-tui2 = { path = "tui2" }
 codex-utils-absolute-path = { path = "utils/absolute-path" }
 codex-utils-cache = { path = "utils/cache" }
+codex-utils-cargo-bin = { path = "utils/cargo-bin" }
 codex-utils-image = { path = "utils/image" }
 codex-utils-json-to-toml = { path = "utils/json-to-toml" }
 codex-utils-pty = { path = "utils/pty" }
@@ -141,11 +143,12 @@ icu_locale_core = "2.1"
 icu_provider = { version = "2.1", features = ["sync"] }
 ignore = "0.4.23"
 image = { version = "^0.25.9", default-features = false }
+include_dir = "0.7.4"
 indexmap = "2.12.0"
 insta = "1.44.3"
 itertools = "0.14.0"
 keyring = { version = "3.6", default-features = false }
-landlock = "0.4.1"
+landlock = "0.4.4"
 lazy_static = "1"
 libc = "0.2.177"
 log = "0.4"
@@ -175,9 +178,9 @@ rand = "0.9"
 ratatui = "0.29.0"
 ratatui-macros = "0.6.0"
 regex = "1.12.2"
-regex-lite = "0.1.7"
+regex-lite = "0.1.8"
 reqwest = "0.12"
-rmcp = { version = "0.10.0", default-features = false }
+rmcp = { version = "0.12.0", default-features = false }
 schemars = "0.8.22"
 seccompiler = "0.5.0"
 sentry = "0.46.0"
@@ -197,7 +200,7 @@ strum_macros = "0.27.2"
 supports-color = "3.0.2"
 sys-locale = "0.3.2"
 tempfile = "3.23.0"
-test-log = "0.2.18"
+test-log = "0.2.19"
 textwrap = "0.16.2"
 thiserror = "2.0.17"
 time = "0.3"
@@ -207,11 +210,11 @@ tokio-stream = "0.1.17"
 tokio-test = "0.4"
 tokio-util = "0.7.16"
 toml = "0.9.5"
-toml_edit = "0.23.5"
+toml_edit = "0.24.0"
 tonic = "0.13.1"
 tracing = "0.1.43"
 tracing-appender = "0.2.3"
-tracing-subscriber = "0.3.20"
+tracing-subscriber = "0.3.22"
 tracing-test = "0.2.5"
 tree-sitter = "0.25.10"
 tree-sitter-bash = "0.25"

codex-rs/app-server-protocol/src/protocol/common.rs

@@ -539,6 +539,7 @@ server_notification_definitions! {
     ReasoningSummaryPartAdded => "item/reasoning/summaryPartAdded" (v2::ReasoningSummaryPartAddedNotification),
     ReasoningTextDelta => "item/reasoning/textDelta" (v2::ReasoningTextDeltaNotification),
     ContextCompacted => "thread/compacted" (v2::ContextCompactedNotification),
+    DeprecationNotice => "deprecationNotice" (v2::DeprecationNoticeNotification),
 
     /// Notifies the user of world-writable directories on Windows, which cannot be protected by the sandbox.
     WindowsWorldWritableWarning => "windows/worldWritableWarning" (v2::WindowsWorldWritableWarningNotification),

codex-rs/app-server-protocol/src/protocol/v2.rs

@@ -18,6 +18,7 @@ use codex_protocol::plan_tool::StepStatus as CorePlanStepStatus;
 use codex_protocol::protocol::AskForApproval as CoreAskForApproval;
 use codex_protocol::protocol::CodexErrorInfo as CoreCodexErrorInfo;
 use codex_protocol::protocol::CreditsSnapshot as CoreCreditsSnapshot;
+use codex_protocol::protocol::NetworkAccess as CoreNetworkAccess;
 use codex_protocol::protocol::RateLimitSnapshot as CoreRateLimitSnapshot;
 use codex_protocol::protocol::RateLimitWindow as CoreRateLimitWindow;
 use codex_protocol::protocol::SessionSource as CoreSessionSource;
@@ -208,6 +209,7 @@ v2_enum_from_core!(
     }
 );
 
+// TODO(mbolin): Support in-repo layer.
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, JsonSchema, TS)]
 #[serde(tag = "type", rename_all = "camelCase")]
 #[ts(tag = "type")]
@@ -216,17 +218,78 @@ pub enum ConfigLayerSource {
     /// Managed preferences layer delivered by MDM (macOS only).
     #[serde(rename_all = "camelCase")]
     #[ts(rename_all = "camelCase")]
-    Mdm { domain: String, key: String },
+    Mdm {
+        domain: String,
+        key: String,
+    },
+
     /// Managed config layer from a file (usually `managed_config.toml`).
     #[serde(rename_all = "camelCase")]
     #[ts(rename_all = "camelCase")]
-    System { file: AbsolutePathBuf },
-    /// Session-layer overrides supplied via `-c`/`--config`.
-    SessionFlags,
-    /// User config layer from a file (usually `config.toml`).
+    System {
+        /// This is the path to the system config.toml file, though it is not
+        /// guaranteed to exist.
+        file: AbsolutePathBuf,
+    },
+
+    /// User config layer from $CODEX_HOME/config.toml. This layer is special
+    /// in that it is expected to be:
+    /// - writable by the user
+    /// - generally outside the workspace directory
     #[serde(rename_all = "camelCase")]
     #[ts(rename_all = "camelCase")]
-    User { file: AbsolutePathBuf },
+    User {
+        /// This is the path to the user's config.toml file, though it is not
+        /// guaranteed to exist.
+        file: AbsolutePathBuf,
+    },
+
+    /// Path to a .codex/ folder within a project. There could be multiple of
+    /// these between `cwd` and the project/repo root.
+    #[serde(rename_all = "camelCase")]
+    #[ts(rename_all = "camelCase")]
+    Project {
+        dot_codex_folder: AbsolutePathBuf,
+    },
+
+    /// Session-layer overrides supplied via `-c`/`--config`.
+    SessionFlags,
+
+    /// `managed_config.toml` was designed to be a config that was loaded
+    /// as the last layer on top of everything else. This scheme did not quite
+    /// work out as intended, but we keep this variant as a "best effort" while
+    /// we phase out `managed_config.toml` in favor of `requirements.toml`.
+    #[serde(rename_all = "camelCase")]
+    #[ts(rename_all = "camelCase")]
+    LegacyManagedConfigTomlFromFile {
+        file: AbsolutePathBuf,
+    },
+
+    LegacyManagedConfigTomlFromMdm,
+}
+
+impl ConfigLayerSource {
+    /// A settings from a layer with a higher precedence will override a setting
+    /// from a layer with a lower precedence.
+    pub fn precedence(&self) -> i16 {
+        match self {
+            ConfigLayerSource::Mdm { .. } => 0,
+            ConfigLayerSource::System { .. } => 10,
+            ConfigLayerSource::User { .. } => 20,
+            ConfigLayerSource::Project { .. } => 25,
+            ConfigLayerSource::SessionFlags => 30,
+            ConfigLayerSource::LegacyManagedConfigTomlFromFile { .. } => 40,
+            ConfigLayerSource::LegacyManagedConfigTomlFromMdm => 50,
+        }
+    }
+}
+
+/// Compares [ConfigLayerSource] by precedence, so `A < B` means settings from
+/// layer `A` will be overridden by settings from layer `B`.
+impl PartialOrd for ConfigLayerSource {
+    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
+        Some(self.precedence().cmp(&other.precedence()))
+    }
 }
 
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Default, JsonSchema, TS)]
@@ -344,7 +407,7 @@ pub struct ConfigWriteResponse {
     pub status: WriteStatus,
     pub version: String,
     /// Canonical path to the config file that was written.
-    pub file_path: String,
+    pub file_path: AbsolutePathBuf,
     pub overridden_metadata: Option<OverriddenMetadata>,
 }
 
@@ -357,6 +420,7 @@ pub enum ConfigWriteErrorCode {
     ConfigValidationError,
     ConfigPathNotFound,
     ConfigSchemaUnknownKey,
+    UserLayerNotFound,
 }
 
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
@@ -422,6 +486,15 @@ pub enum ApprovalDecision {
     Cancel,
 }
 
+#[derive(Serialize, Deserialize, Debug, Default, Clone, PartialEq, Eq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
+pub enum NetworkAccess {
+    #[default]
+    Restricted,
+    Enabled,
+}
+
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, JsonSchema, TS)]
 #[serde(tag = "type", rename_all = "camelCase")]
 #[ts(tag = "type")]
@@ -431,6 +504,12 @@ pub enum SandboxPolicy {
     ReadOnly,
     #[serde(rename_all = "camelCase")]
     #[ts(rename_all = "camelCase")]
+    ExternalSandbox {
+        #[serde(default)]
+        network_access: NetworkAccess,
+    },
+    #[serde(rename_all = "camelCase")]
+    #[ts(rename_all = "camelCase")]
     WorkspaceWrite {
         #[serde(default)]
         writable_roots: Vec<AbsolutePathBuf>,
@@ -450,6 +529,14 @@ impl SandboxPolicy {
                 codex_protocol::protocol::SandboxPolicy::DangerFullAccess
             }
             SandboxPolicy::ReadOnly => codex_protocol::protocol::SandboxPolicy::ReadOnly,
+            SandboxPolicy::ExternalSandbox { network_access } => {
+                codex_protocol::protocol::SandboxPolicy::ExternalSandbox {
+                    network_access: match network_access {
+                        NetworkAccess::Restricted => CoreNetworkAccess::Restricted,
+                        NetworkAccess::Enabled => CoreNetworkAccess::Enabled,
+                    },
+                }
+            }
             SandboxPolicy::WorkspaceWrite {
                 writable_roots,
                 network_access,
@@ -472,6 +559,14 @@ impl From<codex_protocol::protocol::SandboxPolicy> for SandboxPolicy {
                 SandboxPolicy::DangerFullAccess
             }
             codex_protocol::protocol::SandboxPolicy::ReadOnly => SandboxPolicy::ReadOnly,
+            codex_protocol::protocol::SandboxPolicy::ExternalSandbox { network_access } => {
+                SandboxPolicy::ExternalSandbox {
+                    network_access: match network_access {
+                        CoreNetworkAccess::Restricted => NetworkAccess::Restricted,
+                        CoreNetworkAccess::Enabled => NetworkAccess::Enabled,
+                    },
+                }
+            }
             codex_protocol::protocol::SandboxPolicy::WorkspaceWrite {
                 writable_roots,
                 network_access,
@@ -980,6 +1075,10 @@ pub struct SkillsListParams {
     /// When empty, defaults to the current session working directory.
     #[serde(default, skip_serializing_if = "Vec::is_empty")]
     pub cwds: Vec<PathBuf>,
+
+    /// When true, bypass the skills cache and re-scan skills from disk.
+    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
+    pub force_reload: bool,
 }
 
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
@@ -996,7 +1095,8 @@ pub struct SkillsListResponse {
 pub enum SkillScope {
     User,
     Repo,
-    Public,
+    System,
+    Admin,
 }
 
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
@@ -1005,6 +1105,9 @@ pub enum SkillScope {
 pub struct SkillMetadata {
     pub name: String,
     pub description: String,
+    #[ts(optional)]
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub short_description: Option<String>,
     pub path: PathBuf,
     pub scope: SkillScope,
 }
@@ -1031,6 +1134,7 @@ impl From<CoreSkillMetadata> for SkillMetadata {
         Self {
             name: value.name,
             description: value.description,
+            short_description: value.short_description,
             path: value.path,
             scope: value.scope.into(),
         }
@@ -1042,7 +1146,8 @@ impl From<CoreSkillScope> for SkillScope {
         match value {
             CoreSkillScope::User => Self::User,
             CoreSkillScope::Repo => Self::Repo,
-            CoreSkillScope::Public => Self::Public,
+            CoreSkillScope::System => Self::System,
+            CoreSkillScope::Admin => Self::Admin,
         }
     }
 }
@@ -1169,6 +1274,8 @@ pub struct Turn {
 pub struct TurnError {
     pub message: String,
     pub codex_error_info: Option<CodexErrorInfo>,
+    #[serde(default)]
+    pub additional_details: Option<String>,
 }
 
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
@@ -1841,6 +1948,16 @@ pub struct AccountLoginCompletedNotification {
     pub error: Option<String>,
 }
 
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
+pub struct DeprecationNoticeNotification {
+    /// Concise summary of what is deprecated.
+    pub summary: String,
+    /// Optional extra guidance, such as migration steps or rationale.
+    pub details: Option<String>,
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -1850,11 +1967,30 @@ mod tests {
     use codex_protocol::items::TurnItem;
     use codex_protocol::items::UserMessageItem;
     use codex_protocol::items::WebSearchItem;
+    use codex_protocol::protocol::NetworkAccess as CoreNetworkAccess;
     use codex_protocol::user_input::UserInput as CoreUserInput;
     use pretty_assertions::assert_eq;
     use serde_json::json;
     use std::path::PathBuf;
 
+    #[test]
+    fn sandbox_policy_round_trips_external_sandbox_network_access() {
+        let v2_policy = SandboxPolicy::ExternalSandbox {
+            network_access: NetworkAccess::Enabled,
+        };
+
+        let core_policy = v2_policy.to_core();
+        assert_eq!(
+            core_policy,
+            codex_protocol::protocol::SandboxPolicy::ExternalSandbox {
+                network_access: CoreNetworkAccess::Enabled,
+            }
+        );
+
+        let back_to_v2 = SandboxPolicy::from(core_policy);
+        assert_eq!(back_to_v2, v2_policy);
+    }
+
     #[test]
     fn core_turn_item_into_thread_item_converts_supported_variants() {
         let user_item = TurnItem::UserMessage(UserMessageItem {
@@ -1939,6 +2075,30 @@ mod tests {
         );
     }
 
+    #[test]
+    fn skills_list_params_serialization_uses_force_reload() {
+        assert_eq!(
+            serde_json::to_value(SkillsListParams {
+                cwds: Vec::new(),
+                force_reload: false,
+            })
+            .unwrap(),
+            json!({}),
+        );
+
+        assert_eq!(
+            serde_json::to_value(SkillsListParams {
+                cwds: vec![PathBuf::from("/repo")],
+                force_reload: true,
+            })
+            .unwrap(),
+            json!({
+                "cwds": ["/repo"],
+                "forceReload": true,
+            }),
+        );
+    }
+
     #[test]
     fn codex_error_info_serializes_http_status_code_in_camel_case() {
         let value = CodexErrorInfo::ResponseTooManyFailedAttempts {

codex-rs/app-server/Cargo.toml

@@ -48,7 +48,6 @@ uuid = { workspace = true, features = ["serde", "v7"] }
 
 [dev-dependencies]
 app_test_support = { workspace = true }
-assert_cmd = { workspace = true }
 base64 = { workspace = true }
 core_test_support = { workspace = true }
 mcp-types = { workspace = true }

codex-rs/app-server/README.md

@@ -77,7 +77,7 @@ Example (from OpenAI's official VSCode extension):
 - `review/start` — kick off Codex’s automated reviewer for a thread; responds like `turn/start` and emits `item/started`/`item/completed` notifications with `enteredReviewMode` and `exitedReviewMode` items, plus a final assistant `agentMessage` containing the review.
 - `command/exec` — run a single command under the server sandbox without starting a thread/turn (handy for utilities and validation).
 - `model/list` — list available models (with reasoning effort options).
-- `skills/list` — list skills for one or more `cwd` values.
+- `skills/list` — list skills for one or more `cwd` values (optional `forceReload`).
 - `mcpServer/oauth/login` — start an OAuth login for a configured MCP server; returns an `authorization_url` and later emits `mcpServer/oauthLogin/completed` once the browser flow finishes.
 - `mcpServerStatus/list` — enumerate configured MCP servers with their tools, resources, resource templates, and auth status; supports cursor+limit pagination.
 - `feedback/upload` — submit a feedback report (classification + optional reason/logs and conversation_id); returns the tracking thread id.
@@ -172,7 +172,7 @@ You can optionally specify config overrides on the new turn. If specified, these
     "cwd": "/Users/me/project",
     "approvalPolicy": "unlessTrusted",
     "sandboxPolicy": {
-        "mode": "workspaceWrite",
+        "type": "workspaceWrite",
         "writableRoots": ["/Users/me/project"],
         "networkAccess": true
     },
@@ -285,10 +285,12 @@ Run a standalone command (argv vector) in the server’s sandbox without creatin
 { "id": 32, "result": { "exitCode": 0, "stdout": "...", "stderr": "" } }
 ```
 
+- For clients that are already sandboxed externally, set `sandboxPolicy` to `{"type":"externalSandbox","networkAccess":"enabled"}` (or omit `networkAccess` to keep it restricted). Codex will not enforce its own sandbox in this mode; it tells the model it has full file-system access and passes the `networkAccess` state through `environment_context`.
+
 Notes:
 
 - Empty `command` arrays are rejected.
-- `sandboxPolicy` accepts the same shape used by `turn/start` (e.g., `dangerFullAccess`, `readOnly`, `workspaceWrite` with flags).
+- `sandboxPolicy` accepts the same shape used by `turn/start` (e.g., `dangerFullAccess`, `readOnly`, `workspaceWrite` with flags, `externalSandbox` with `networkAccess` `restricted|enabled`).
 - When omitted, `timeoutMs` falls back to the server default.
 
 ## Events
@@ -300,7 +302,7 @@ Event notifications are the server-initiated event stream for thread lifecycles,
 The app-server streams JSON-RPC notifications while a turn is running. Each turn starts with `turn/started` (initial `turn`) and ends with `turn/completed` (final `turn` status). Token usage events stream separately via `thread/tokenUsage/updated`. Clients subscribe to the events they care about, rendering each item incrementally as updates arrive. The per-item lifecycle is always: `item/started` → zero or more item-specific deltas → `item/completed`.
 
 - `turn/started` — `{ turn }` with the turn id, empty `items`, and `status: "inProgress"`.
-- `turn/completed` — `{ turn }` where `turn.status` is `completed`, `interrupted`, or `failed`; failures carry `{ error: { message, codexErrorInfo? } }`.
+- `turn/completed` — `{ turn }` where `turn.status` is `completed`, `interrupted`, or `failed`; failures carry `{ error: { message, codexErrorInfo?, additionalDetails? } }`.
 - `turn/diff/updated` — `{ threadId, turnId, diff }` represents the up-to-date snapshot of the turn-level unified diff, emitted after every FileChange item. `diff` is the latest aggregated unified diff across every file change in the turn. UIs can render this to show the full "what changed" view without stitching individual `fileChange` items.
 - `turn/plan/updated` — `{ turnId, explanation?, plan }` whenever the agent shares or changes its plan; each `plan` entry is `{ step, status }` with `status` in `pending`, `inProgress`, or `completed`.
 
@@ -350,7 +352,7 @@ There are additional item-specific events:
 
 ### Errors
 
-`error` event is emitted whenever the server hits an error mid-turn (for example, upstream model errors or quota limits). Carries the same `{ error: { message, codexErrorInfo? } }` payload as `turn.status: "failed"` and may precede that terminal notification.
+`error` event is emitted whenever the server hits an error mid-turn (for example, upstream model errors or quota limits). Carries the same `{ error: { message, codexErrorInfo?, additionalDetails? } }` payload as `turn.status: "failed"` and may precede that terminal notification.
 
 `codexErrorInfo` maps to the `CodexErrorInfo` enum. Common values:
 

codex-rs/app-server/src/bespoke_event_handling.rs

@@ -15,6 +15,7 @@ use codex_app_server_protocol::CommandExecutionRequestApprovalParams;
 use codex_app_server_protocol::CommandExecutionRequestApprovalResponse;
 use codex_app_server_protocol::CommandExecutionStatus;
 use codex_app_server_protocol::ContextCompactedNotification;
+use codex_app_server_protocol::DeprecationNoticeNotification;
 use codex_app_server_protocol::ErrorNotification;
 use codex_app_server_protocol::ExecCommandApprovalParams;
 use codex_app_server_protocol::ExecCommandApprovalResponse;
@@ -283,6 +284,15 @@ pub(crate) async fn apply_bespoke_event_handling(
                 .send_server_notification(ServerNotification::ContextCompacted(notification))
                 .await;
         }
+        EventMsg::DeprecationNotice(event) => {
+            let notification = DeprecationNoticeNotification {
+                summary: event.summary,
+                details: event.details,
+            };
+            outgoing
+                .send_server_notification(ServerNotification::DeprecationNotice(notification))
+                .await;
+        }
         EventMsg::ReasoningContentDelta(event) => {
             let notification = ReasoningSummaryTextDeltaNotification {
                 thread_id: conversation_id.to_string(),
@@ -330,6 +340,7 @@ pub(crate) async fn apply_bespoke_event_handling(
             let turn_error = TurnError {
                 message: ev.message,
                 codex_error_info: ev.codex_error_info.map(V2CodexErrorInfo::from),
+                additional_details: None,
             };
             handle_error(conversation_id, turn_error.clone(), &turn_summary_store).await;
             outgoing
@@ -347,6 +358,7 @@ pub(crate) async fn apply_bespoke_event_handling(
             let turn_error = TurnError {
                 message: ev.message,
                 codex_error_info: ev.codex_error_info.map(V2CodexErrorInfo::from),
+                additional_details: ev.additional_details,
             };
             outgoing
                 .send_server_notification(ServerNotification::Error(ErrorNotification {
@@ -1330,6 +1342,7 @@ mod tests {
             TurnError {
                 message: "boom".to_string(),
                 codex_error_info: Some(V2CodexErrorInfo::InternalServerError),
+                additional_details: None,
             },
             &turn_summary_store,
         )
@@ -1341,6 +1354,7 @@ mod tests {
             Some(TurnError {
                 message: "boom".to_string(),
                 codex_error_info: Some(V2CodexErrorInfo::InternalServerError),
+                additional_details: None,
             })
         );
         Ok(())
@@ -1388,6 +1402,7 @@ mod tests {
             TurnError {
                 message: "oops".to_string(),
                 codex_error_info: None,
+                additional_details: None,
             },
             &turn_summary_store,
         )
@@ -1429,6 +1444,7 @@ mod tests {
             TurnError {
                 message: "bad".to_string(),
                 codex_error_info: Some(V2CodexErrorInfo::Other),
+                additional_details: None,
             },
             &turn_summary_store,
         )
@@ -1457,6 +1473,7 @@ mod tests {
                     Some(TurnError {
                         message: "bad".to_string(),
                         codex_error_info: Some(V2CodexErrorInfo::Other),
+                        additional_details: None,
                     })
                 );
             }
@@ -1681,6 +1698,7 @@ mod tests {
             TurnError {
                 message: "a1".to_string(),
                 codex_error_info: Some(V2CodexErrorInfo::BadRequest),
+                additional_details: None,
             },
             &turn_summary_store,
         )
@@ -1700,6 +1718,7 @@ mod tests {
             TurnError {
                 message: "b1".to_string(),
                 codex_error_info: None,
+                additional_details: None,
             },
             &turn_summary_store,
         )
@@ -1736,6 +1755,7 @@ mod tests {
                     Some(TurnError {
                         message: "a1".to_string(),
                         codex_error_info: Some(V2CodexErrorInfo::BadRequest),
+                        additional_details: None,
                     })
                 );
             }
@@ -1756,6 +1776,7 @@ mod tests {
                     Some(TurnError {
                         message: "b1".to_string(),
                         codex_error_info: None,
+                        additional_details: None,
                     })
                 );
             }

codex-rs/app-server/src/codex_message_processor.rs

@@ -282,7 +282,7 @@ impl CodexMessageProcessor {
     }
 
     async fn load_latest_config(&self) -> Result<Config, JSONRPCErrorError> {
-        Config::load_with_cli_overrides(self.cli_overrides.clone(), ConfigOverrides::default())
+        Config::load_with_cli_overrides(self.cli_overrides.clone())
             .await
             .map_err(|err| JSONRPCErrorError {
                 code: INTERNAL_ERROR_CODE,
@@ -1186,10 +1186,22 @@ impl CodexMessageProcessor {
             arg0: None,
         };
 
-        let effective_policy = params
-            .sandbox_policy
-            .map(|policy| policy.to_core())
-            .unwrap_or_else(|| self.config.sandbox_policy.clone());
+        let requested_policy = params.sandbox_policy.map(|policy| policy.to_core());
+        let effective_policy = match requested_policy {
+            Some(policy) => match self.config.sandbox_policy.can_set(&policy) {
+                Ok(()) => policy,
+                Err(err) => {
+                    let error = JSONRPCErrorError {
+                        code: INVALID_REQUEST_ERROR_CODE,
+                        message: format!("invalid sandbox policy: {err}"),
+                        data: None,
+                    };
+                    self.outgoing.send_error(request_id, error).await;
+                    return;
+                }
+            },
+            None => self.config.sandbox_policy.get().clone(),
+        };
 
         let codex_linux_sandbox_exe = self.config.codex_linux_sandbox_exe.clone();
         let outgoing = self.outgoing.clone();
@@ -1980,16 +1992,6 @@ impl CodexMessageProcessor {
             }
         };
 
-        if !config.features.enabled(Feature::RmcpClient) {
-            let error = JSONRPCErrorError {
-                code: INVALID_REQUEST_ERROR_CODE,
-                message: "OAuth login is only supported when [features].rmcp_client is true in config.toml".to_string(),
-                data: None,
-            };
-            self.outgoing.send_error(request_id, error).await;
-            return;
-        }
-
         let McpServerOauthLoginParams {
             name,
             scopes,
@@ -2640,36 +2642,27 @@ impl CodexMessageProcessor {
     }
 
     async fn skills_list(&self, request_id: RequestId, params: SkillsListParams) {
-        let SkillsListParams { cwds } = params;
+        let SkillsListParams { cwds, force_reload } = params;
         let cwds = if cwds.is_empty() {
             vec![self.config.cwd.clone()]
         } else {
             cwds
         };
 
-        let data = if self.config.features.enabled(Feature::Skills) {
-            let skills_manager = self.conversation_manager.skills_manager();
-            cwds.into_iter()
-                .map(|cwd| {
-                    let outcome = skills_manager.skills_for_cwd(&cwd);
-                    let errors = errors_to_info(&outcome.errors);
-                    let skills = skills_to_info(&outcome.skills);
-                    codex_app_server_protocol::SkillsListEntry {
-                        cwd,
-                        skills,
-                        errors,
-                    }
-                })
-                .collect()
-        } else {
-            cwds.into_iter()
-                .map(|cwd| codex_app_server_protocol::SkillsListEntry {
+        let skills_manager = self.conversation_manager.skills_manager();
+        let data = cwds
+            .into_iter()
+            .map(|cwd| {
+                let outcome = skills_manager.skills_for_cwd_with_options(&cwd, force_reload);
+                let errors = errors_to_info(&outcome.errors);
+                let skills = skills_to_info(&outcome.skills);
+                codex_app_server_protocol::SkillsListEntry {
                     cwd,
-                    skills: Vec::new(),
-                    errors: Vec::new(),
-                })
-                .collect()
-        };
+                    skills,
+                    errors,
+                }
+            })
+            .collect();
         self.outgoing
             .send_response(request_id, SkillsListResponse { data })
             .await;
@@ -3328,6 +3321,7 @@ fn skills_to_info(
         .map(|skill| codex_app_server_protocol::SkillMetadata {
             name: skill.name.clone(),
             description: skill.description.clone(),
+            short_description: skill.short_description.clone(),
             path: skill.path.clone(),
             scope: skill.scope.into(),
         })
@@ -3348,7 +3342,7 @@ fn errors_to_info(
 
 async fn derive_config_from_params(
     overrides: ConfigOverrides,
-    cli_overrides: Option<std::collections::HashMap<String, serde_json::Value>>,
+    cli_overrides: Option<HashMap<String, serde_json::Value>>,
 ) -> std::io::Result<Config> {
     let cli_overrides = cli_overrides
         .unwrap_or_default()
@@ -3356,7 +3350,7 @@ async fn derive_config_from_params(
         .map(|(k, v)| (k, json_to_toml(v)))
         .collect();
 
-    Config::load_with_cli_overrides(cli_overrides, overrides).await
+    Config::load_with_cli_overrides_and_harness_overrides(cli_overrides, overrides).await
 }
 
 async fn read_summary_from_rollout(

codex-rs/app-server/src/fuzzy_file_search.rs

@@ -1,6 +1,5 @@
 use std::num::NonZero;
 use std::num::NonZeroUsize;
-use std::path::Path;
 use std::path::PathBuf;
 use std::sync::Arc;
 use std::sync::atomic::AtomicBool;
@@ -63,11 +62,7 @@ pub(crate) async fn run_fuzzy_file_search(
             Ok(Ok((root, res))) => {
                 for m in res.matches {
                     let path = m.path;
-                    //TODO(shijie): Move file name generation to file_search lib.
-                    let file_name = Path::new(&path)
-                        .file_name()
-                        .map(|name| name.to_string_lossy().into_owned())
-                        .unwrap_or_else(|| path.clone());
+                    let file_name = file_search::file_name_from_path(&path);
                     let result = FuzzyFileSearchResult {
                         root: root.clone(),
                         path,

codex-rs/app-server/src/lib.rs

@@ -2,7 +2,6 @@
 
 use codex_common::CliConfigOverrides;
 use codex_core::config::Config;
-use codex_core::config::ConfigOverrides;
 use std::io::ErrorKind;
 use std::io::Result as IoResult;
 use std::path::PathBuf;
@@ -81,12 +80,11 @@ pub async fn run_main(
             format!("error parsing -c overrides: {e}"),
         )
     })?;
-    let config =
-        Config::load_with_cli_overrides(cli_kv_overrides.clone(), ConfigOverrides::default())
-            .await
-            .map_err(|e| {
-                std::io::Error::new(ErrorKind::InvalidData, format!("error loading config: {e}"))
-            })?;
+    let config = Config::load_with_cli_overrides(cli_kv_overrides.clone())
+        .await
+        .map_err(|e| {
+            std::io::Error::new(ErrorKind::InvalidData, format!("error loading config: {e}"))
+        })?;
 
     let feedback = CodexFeedback::new();
 

codex-rs/app-server/tests/common/Cargo.toml

@@ -9,12 +9,12 @@ path = "lib.rs"
 
 [dependencies]
 anyhow = { workspace = true }
-assert_cmd = { workspace = true }
 base64 = { workspace = true }
 chrono = { workspace = true }
 codex-app-server-protocol = { workspace = true }
 codex-core = { workspace = true, features = ["test-support"] }
 codex-protocol = { workspace = true }
+codex-utils-cargo-bin = { workspace = true }
 serde = { workspace = true }
 serde_json = { workspace = true }
 tokio = { workspace = true, features = [

codex-rs/app-server/tests/common/mcp_process.rs

@@ -11,7 +11,6 @@ use tokio::process::ChildStdin;
 use tokio::process::ChildStdout;
 
 use anyhow::Context;
-use assert_cmd::prelude::*;
 use codex_app_server_protocol::AddConversationListenerParams;
 use codex_app_server_protocol::ArchiveConversationParams;
 use codex_app_server_protocol::CancelLoginAccountParams;
@@ -49,7 +48,6 @@ use codex_app_server_protocol::ThreadResumeParams;
 use codex_app_server_protocol::ThreadStartParams;
 use codex_app_server_protocol::TurnInterruptParams;
 use codex_app_server_protocol::TurnStartParams;
-use std::process::Command as StdCommand;
 use tokio::process::Command;
 
 pub struct McpProcess {
@@ -78,12 +76,8 @@ impl McpProcess {
         codex_home: &Path,
         env_overrides: &[(&str, Option<&str>)],
     ) -> anyhow::Result<Self> {
-        // Use assert_cmd to locate the binary path and then switch to tokio::process::Command
-        let std_cmd = StdCommand::cargo_bin("codex-app-server")
-            .context("should find binary for codex-mcp-server")?;
-
-        let program = std_cmd.get_program().to_owned();
-
+        let program = codex_utils_cargo_bin::cargo_bin("codex-app-server")
+            .context("should find binary for codex-app-server")?;
         let mut cmd = Command::new(program);
 
         cmd.stdin(Stdio::piped());

codex-rs/app-server/tests/common/models_cache.rs

@@ -1,12 +1,10 @@
 use chrono::DateTime;
 use chrono::Utc;
-use codex_core::openai_models::model_presets::all_model_presets;
-use codex_protocol::openai_models::ClientVersion;
+use codex_core::models_manager::model_presets::all_model_presets;
 use codex_protocol::openai_models::ConfigShellToolType;
 use codex_protocol::openai_models::ModelInfo;
 use codex_protocol::openai_models::ModelPreset;
 use codex_protocol::openai_models::ModelVisibility;
-use codex_protocol::openai_models::ReasoningSummaryFormat;
 use codex_protocol::openai_models::TruncationPolicyConfig;
 use serde_json::json;
 use std::path::Path;
@@ -25,7 +23,6 @@ fn preset_to_info(preset: &ModelPreset, priority: i32) -> ModelInfo {
         } else {
             ModelVisibility::Hide
         },
-        minimal_client_version: ClientVersion(0, 1, 0),
         supported_in_api: true,
         priority,
         upgrade: preset.upgrade.as_ref().map(|u| u.id.clone()),
@@ -37,11 +34,11 @@ fn preset_to_info(preset: &ModelPreset, priority: i32) -> ModelInfo {
         truncation_policy: TruncationPolicyConfig::bytes(10_000),
         supports_parallel_tool_calls: false,
         context_window: None,
-        reasoning_summary_format: ReasoningSummaryFormat::None,
         experimental_supported_tools: Vec::new(),
     }
 }
 
+// todo(aibrahim): fix the priorities to be the opposite here.
 /// Write a models_cache.json file to the codex home directory.
 /// This prevents ModelsManager from making network requests to refresh models.
 /// The cache will be treated as fresh (within TTL) and used instead of fetching from the network.

codex-rs/app-server/tests/suite/v2/config_rpc.rs

@@ -18,6 +18,7 @@ use codex_app_server_protocol::RequestId;
 use codex_app_server_protocol::SandboxMode;
 use codex_app_server_protocol::ToolsV2;
 use codex_app_server_protocol::WriteStatus;
+use codex_core::config_loader::SYSTEM_CONFIG_TOML_FILE_UNIX;
 use codex_utils_absolute_path::AbsolutePathBuf;
 use pretty_assertions::assert_eq;
 use serde_json::json;
@@ -73,9 +74,7 @@ sandbox_mode = "workspace-write"
         }
     );
     let layers = layers.expect("layers present");
-    assert_eq!(layers.len(), 2);
-    assert_eq!(layers[0].name, ConfigLayerSource::SessionFlags);
-    assert_eq!(layers[1].name, ConfigLayerSource::User { file: user_file });
+    assert_layers_user_then_optional_system(&layers, user_file)?;
 
     Ok(())
 }
@@ -137,9 +136,7 @@ view_image = false
     );
 
     let layers = layers.expect("layers present");
-    assert_eq!(layers.len(), 2);
-    assert_eq!(layers[0].name, ConfigLayerSource::SessionFlags);
-    assert_eq!(layers[1].name, ConfigLayerSource::User { file: user_file });
+    assert_layers_user_then_optional_system(&layers, user_file)?;
 
     Ok(())
 }
@@ -211,7 +208,7 @@ writable_roots = [{}]
     assert_eq!(config.model.as_deref(), Some("gpt-system"));
     assert_eq!(
         origins.get("model").expect("origin").name,
-        ConfigLayerSource::System {
+        ConfigLayerSource::LegacyManagedConfigTomlFromFile {
             file: managed_file.clone(),
         }
     );
@@ -219,7 +216,7 @@ writable_roots = [{}]
     assert_eq!(config.approval_policy, Some(AskForApproval::Never));
     assert_eq!(
         origins.get("approval_policy").expect("origin").name,
-        ConfigLayerSource::System {
+        ConfigLayerSource::LegacyManagedConfigTomlFromFile {
             file: managed_file.clone(),
         }
     );
@@ -242,7 +239,7 @@ writable_roots = [{}]
             .get("sandbox_workspace_write.writable_roots.0")
             .expect("origin")
             .name,
-        ConfigLayerSource::System {
+        ConfigLayerSource::LegacyManagedConfigTomlFromFile {
             file: managed_file.clone(),
         }
     );
@@ -259,28 +256,23 @@ writable_roots = [{}]
     );
 
     let layers = layers.expect("layers present");
-    assert_eq!(layers.len(), 3);
-    assert_eq!(
-        layers[0].name,
-        ConfigLayerSource::System { file: managed_file }
-    );
-    assert_eq!(layers[1].name, ConfigLayerSource::SessionFlags);
-    assert_eq!(layers[2].name, ConfigLayerSource::User { file: user_file });
+    assert_layers_managed_user_then_optional_system(&layers, managed_file, user_file)?;
 
     Ok(())
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
 async fn config_value_write_replaces_value() -> Result<()> {
-    let codex_home = TempDir::new()?;
+    let temp_dir = TempDir::new()?;
+    let codex_home = temp_dir.path().canonicalize()?;
     write_config(
-        &codex_home,
+        &temp_dir,
         r#"
 model = "gpt-old"
 "#,
     )?;
 
-    let mut mcp = McpProcess::new(codex_home.path()).await?;
+    let mut mcp = McpProcess::new(&codex_home).await?;
     timeout(DEFAULT_READ_TIMEOUT, mcp.initialize()).await??;
 
     let read_id = mcp
@@ -311,13 +303,7 @@ model = "gpt-old"
     )
     .await??;
     let write: ConfigWriteResponse = to_response(write_resp)?;
-    let expected_file_path = codex_home
-        .path()
-        .join("config.toml")
-        .canonicalize()
-        .unwrap()
-        .display()
-        .to_string();
+    let expected_file_path = AbsolutePathBuf::resolve_path_against_base("config.toml", codex_home)?;
 
     assert_eq!(write.status, WriteStatus::Ok);
     assert_eq!(write.file_path, expected_file_path);
@@ -380,16 +366,17 @@ model = "gpt-old"
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
 async fn config_batch_write_applies_multiple_edits() -> Result<()> {
-    let codex_home = TempDir::new()?;
-    write_config(&codex_home, "")?;
+    let tmp_dir = TempDir::new()?;
+    let codex_home = tmp_dir.path().canonicalize()?;
+    write_config(&tmp_dir, "")?;
 
-    let mut mcp = McpProcess::new(codex_home.path()).await?;
+    let mut mcp = McpProcess::new(&codex_home).await?;
     timeout(DEFAULT_READ_TIMEOUT, mcp.initialize()).await??;
 
     let writable_root = test_tmp_path_buf();
     let batch_id = mcp
         .send_config_batch_write_request(ConfigBatchWriteParams {
-            file_path: Some(codex_home.path().join("config.toml").display().to_string()),
+            file_path: Some(codex_home.join("config.toml").display().to_string()),
             edits: vec![
                 ConfigEdit {
                     key_path: "sandbox_mode".to_string(),
@@ -415,13 +402,7 @@ async fn config_batch_write_applies_multiple_edits() -> Result<()> {
     .await??;
     let batch_write: ConfigWriteResponse = to_response(batch_resp)?;
     assert_eq!(batch_write.status, WriteStatus::Ok);
-    let expected_file_path = codex_home
-        .path()
-        .join("config.toml")
-        .canonicalize()
-        .unwrap()
-        .display()
-        .to_string();
+    let expected_file_path = AbsolutePathBuf::resolve_path_against_base("config.toml", codex_home)?;
     assert_eq!(batch_write.file_path, expected_file_path);
 
     let read_id = mcp
@@ -446,3 +427,50 @@ async fn config_batch_write_applies_multiple_edits() -> Result<()> {
 
     Ok(())
 }
+
+fn assert_layers_user_then_optional_system(
+    layers: &[codex_app_server_protocol::ConfigLayer],
+    user_file: AbsolutePathBuf,
+) -> Result<()> {
+    if cfg!(unix) {
+        let system_file = AbsolutePathBuf::from_absolute_path(SYSTEM_CONFIG_TOML_FILE_UNIX)?;
+        assert_eq!(layers.len(), 2);
+        assert_eq!(layers[0].name, ConfigLayerSource::User { file: user_file });
+        assert_eq!(
+            layers[1].name,
+            ConfigLayerSource::System { file: system_file }
+        );
+    } else {
+        assert_eq!(layers.len(), 1);
+        assert_eq!(layers[0].name, ConfigLayerSource::User { file: user_file });
+    }
+    Ok(())
+}
+
+fn assert_layers_managed_user_then_optional_system(
+    layers: &[codex_app_server_protocol::ConfigLayer],
+    managed_file: AbsolutePathBuf,
+    user_file: AbsolutePathBuf,
+) -> Result<()> {
+    if cfg!(unix) {
+        let system_file = AbsolutePathBuf::from_absolute_path(SYSTEM_CONFIG_TOML_FILE_UNIX)?;
+        assert_eq!(layers.len(), 3);
+        assert_eq!(
+            layers[0].name,
+            ConfigLayerSource::LegacyManagedConfigTomlFromFile { file: managed_file }
+        );
+        assert_eq!(layers[1].name, ConfigLayerSource::User { file: user_file });
+        assert_eq!(
+            layers[2].name,
+            ConfigLayerSource::System { file: system_file }
+        );
+    } else {
+        assert_eq!(layers.len(), 2);
+        assert_eq!(
+            layers[0].name,
+            ConfigLayerSource::LegacyManagedConfigTomlFromFile { file: managed_file }
+        );
+        assert_eq!(layers[1].name, ConfigLayerSource::User { file: user_file });
+    }
+    Ok(())
+}

codex-rs/app-server/tests/suite/v2/model_list.rs

@@ -47,33 +47,6 @@ async fn list_models_returns_all_models_with_large_limit() -> Result<()> {
     } = to_response::<ModelListResponse>(response)?;
 
     let expected_models = vec![
-        Model {
-            id: "gpt-5.1".to_string(),
-            model: "gpt-5.1".to_string(),
-            display_name: "gpt-5.1".to_string(),
-            description: "Broad world knowledge with strong general reasoning.".to_string(),
-            supported_reasoning_efforts: vec![
-                ReasoningEffortOption {
-                    reasoning_effort: ReasoningEffort::Low,
-                    description: "Balances speed with some reasoning; useful for straightforward \
-                                   queries and short explanations"
-                        .to_string(),
-                },
-                ReasoningEffortOption {
-                    reasoning_effort: ReasoningEffort::Medium,
-                    description: "Provides a solid balance of reasoning depth and latency for \
-                         general-purpose tasks"
-                        .to_string(),
-                },
-                ReasoningEffortOption {
-                    reasoning_effort: ReasoningEffort::High,
-                    description: "Maximizes reasoning depth for complex or ambiguous problems"
-                        .to_string(),
-                },
-            ],
-            default_reasoning_effort: ReasoningEffort::Medium,
-            is_default: true,
-        },
         Model {
             id: "gpt-5.2".to_string(),
             model: "gpt-5.2".to_string(),
@@ -105,7 +78,7 @@ async fn list_models_returns_all_models_with_large_limit() -> Result<()> {
                 },
             ],
             default_reasoning_effort: ReasoningEffort::Medium,
-            is_default: false,
+            is_default: true,
         },
         Model {
             id: "gpt-5.1-codex-mini".to_string(),
@@ -127,33 +100,37 @@ async fn list_models_returns_all_models_with_large_limit() -> Result<()> {
             is_default: false,
         },
         Model {
-            id: "gpt-5.1-codex".to_string(),
-            model: "gpt-5.1-codex".to_string(),
-            display_name: "gpt-5.1-codex".to_string(),
-            description: "Optimized for codex.".to_string(),
+            id: "gpt-5.1-codex-max".to_string(),
+            model: "gpt-5.1-codex-max".to_string(),
+            display_name: "gpt-5.1-codex-max".to_string(),
+            description: "Codex-optimized flagship for deep and fast reasoning.".to_string(),
             supported_reasoning_efforts: vec![
                 ReasoningEffortOption {
                     reasoning_effort: ReasoningEffort::Low,
-                    description: "Fastest responses with limited reasoning".to_string(),
+                    description: "Fast responses with lighter reasoning".to_string(),
                 },
                 ReasoningEffortOption {
                     reasoning_effort: ReasoningEffort::Medium,
-                    description: "Dynamically adjusts reasoning based on the task".to_string(),
+                    description: "Balances speed and reasoning depth for everyday tasks"
+                        .to_string(),
                 },
                 ReasoningEffortOption {
                     reasoning_effort: ReasoningEffort::High,
-                    description: "Maximizes reasoning depth for complex or ambiguous problems"
-                        .to_string(),
+                    description: "Greater reasoning depth for complex problems".to_string(),
+                },
+                ReasoningEffortOption {
+                    reasoning_effort: ReasoningEffort::XHigh,
+                    description: "Extra high reasoning depth for complex problems".to_string(),
                 },
             ],
             default_reasoning_effort: ReasoningEffort::Medium,
             is_default: false,
         },
         Model {
-            id: "gpt-5.1-codex-max".to_string(),
-            model: "gpt-5.1-codex-max".to_string(),
-            display_name: "gpt-5.1-codex-max".to_string(),
-            description: "Latest Codex-optimized flagship for deep and fast reasoning.".to_string(),
+            id: "gpt-5.2-codex".to_string(),
+            model: "gpt-5.2-codex".to_string(),
+            display_name: "gpt-5.2-codex".to_string(),
+            description: "Latest frontier agentic coding model.".to_string(),
             supported_reasoning_efforts: vec![
                 ReasoningEffortOption {
                     reasoning_effort: ReasoningEffort::Low,
@@ -210,7 +187,7 @@ async fn list_models_pagination_works() -> Result<()> {
     } = to_response::<ModelListResponse>(first_response)?;
 
     assert_eq!(first_items.len(), 1);
-    assert_eq!(first_items[0].id, "gpt-5.1");
+    assert_eq!(first_items[0].id, "gpt-5.2");
     let next_cursor = first_cursor.ok_or_else(|| anyhow!("cursor for second page"))?;
 
     let second_request = mcp
@@ -232,7 +209,7 @@ async fn list_models_pagination_works() -> Result<()> {
     } = to_response::<ModelListResponse>(second_response)?;
 
     assert_eq!(second_items.len(), 1);
-    assert_eq!(second_items[0].id, "gpt-5.2");
+    assert_eq!(second_items[0].id, "gpt-5.1-codex-mini");
     let third_cursor = second_cursor.ok_or_else(|| anyhow!("cursor for third page"))?;
 
     let third_request = mcp
@@ -254,7 +231,7 @@ async fn list_models_pagination_works() -> Result<()> {
     } = to_response::<ModelListResponse>(third_response)?;
 
     assert_eq!(third_items.len(), 1);
-    assert_eq!(third_items[0].id, "gpt-5.1-codex-mini");
+    assert_eq!(third_items[0].id, "gpt-5.1-codex-max");
     let fourth_cursor = third_cursor.ok_or_else(|| anyhow!("cursor for fourth page"))?;
 
     let fourth_request = mcp
@@ -276,30 +253,8 @@ async fn list_models_pagination_works() -> Result<()> {
     } = to_response::<ModelListResponse>(fourth_response)?;
 
     assert_eq!(fourth_items.len(), 1);
-    assert_eq!(fourth_items[0].id, "gpt-5.1-codex");
-    let fifth_cursor = fourth_cursor.ok_or_else(|| anyhow!("cursor for fifth page"))?;
-
-    let fifth_request = mcp
-        .send_list_models_request(ModelListParams {
-            limit: Some(1),
-            cursor: Some(fifth_cursor.clone()),
-        })
-        .await?;
-
-    let fifth_response: JSONRPCResponse = timeout(
-        DEFAULT_TIMEOUT,
-        mcp.read_stream_until_response_message(RequestId::Integer(fifth_request)),
-    )
-    .await??;
-
-    let ModelListResponse {
-        data: fifth_items,
-        next_cursor: fifth_cursor,
-    } = to_response::<ModelListResponse>(fifth_response)?;
-
-    assert_eq!(fifth_items.len(), 1);
-    assert_eq!(fifth_items[0].id, "gpt-5.1-codex-max");
-    assert!(fifth_cursor.is_none());
+    assert_eq!(fourth_items[0].id, "gpt-5.2-codex");
+    assert!(fourth_cursor.is_none());
     Ok(())
 }
 

codex-rs/apply-patch/Cargo.toml

@@ -25,5 +25,6 @@ tree-sitter-bash = { workspace = true }
 [dev-dependencies]
 assert_cmd = { workspace = true }
 assert_matches = { workspace = true }
+codex-utils-cargo-bin = { workspace = true }
 pretty_assertions = { workspace = true }
 tempfile = { workspace = true }

codex-rs/apply-patch/tests/suite/cli.rs

@@ -1,8 +1,13 @@
-use assert_cmd::prelude::*;
+use assert_cmd::Command;
 use std::fs;
-use std::process::Command;
 use tempfile::tempdir;
 
+fn apply_patch_command() -> anyhow::Result<Command> {
+    Ok(Command::new(codex_utils_cargo_bin::cargo_bin(
+        "apply_patch",
+    )?))
+}
+
 #[test]
 fn test_apply_patch_cli_add_and_update() -> anyhow::Result<()> {
     let tmp = tempdir()?;
@@ -16,8 +21,7 @@ fn test_apply_patch_cli_add_and_update() -> anyhow::Result<()> {
 +hello
 *** End Patch"#
     );
-    Command::cargo_bin("apply_patch")
-        .expect("should find apply_patch binary")
+    apply_patch_command()?
         .arg(add_patch)
         .current_dir(tmp.path())
         .assert()
@@ -34,8 +38,7 @@ fn test_apply_patch_cli_add_and_update() -> anyhow::Result<()> {
 +world
 *** End Patch"#
     );
-    Command::cargo_bin("apply_patch")
-        .expect("should find apply_patch binary")
+    apply_patch_command()?
         .arg(update_patch)
         .current_dir(tmp.path())
         .assert()
@@ -59,10 +62,9 @@ fn test_apply_patch_cli_stdin_add_and_update() -> anyhow::Result<()> {
 +hello
 *** End Patch"#
     );
-    let mut cmd =
-        assert_cmd::Command::cargo_bin("apply_patch").expect("should find apply_patch binary");
-    cmd.current_dir(tmp.path());
-    cmd.write_stdin(add_patch)
+    apply_patch_command()?
+        .current_dir(tmp.path())
+        .write_stdin(add_patch)
         .assert()
         .success()
         .stdout(format!("Success. Updated the following files:\nA {file}\n"));
@@ -77,10 +79,9 @@ fn test_apply_patch_cli_stdin_add_and_update() -> anyhow::Result<()> {
 +world
 *** End Patch"#
     );
-    let mut cmd =
-        assert_cmd::Command::cargo_bin("apply_patch").expect("should find apply_patch binary");
-    cmd.current_dir(tmp.path());
-    cmd.write_stdin(update_patch)
+    apply_patch_command()?
+        .current_dir(tmp.path())
+        .write_stdin(update_patch)
         .assert()
         .success()
         .stdout(format!("Success. Updated the following files:\nM {file}\n"));

codex-rs/apply-patch/tests/suite/scenarios.rs

@@ -1,4 +1,3 @@
-use assert_cmd::prelude::*;
 use pretty_assertions::assert_eq;
 use std::collections::BTreeMap;
 use std::fs;
@@ -9,7 +8,8 @@ use tempfile::tempdir;
 
 #[test]
 fn test_apply_patch_scenarios() -> anyhow::Result<()> {
-    for scenario in fs::read_dir("tests/fixtures/scenarios")? {
+    let scenarios_dir = Path::new(env!("CARGO_MANIFEST_DIR")).join("tests/fixtures/scenarios");
+    for scenario in fs::read_dir(scenarios_dir)? {
         let scenario = scenario?;
         let path = scenario.path();
         if path.is_dir() {
@@ -36,7 +36,7 @@ fn run_apply_patch_scenario(dir: &Path) -> anyhow::Result<()> {
     // Run apply_patch in the temporary directory. We intentionally do not assert
     // on the exit status here; the scenarios are specified purely in terms of
     // final filesystem state, which we compare below.
-    Command::cargo_bin("apply_patch")?
+    Command::new(codex_utils_cargo_bin::cargo_bin("apply_patch")?)
         .arg(patch)
         .current_dir(tmp.path())
         .output()?;
@@ -82,11 +82,15 @@ fn snapshot_dir_recursive(
             continue;
         };
         let rel = stripped.to_path_buf();
-        let file_type = entry.file_type()?;
-        if file_type.is_dir() {
+
+        // Under Buck2, files in `__srcs` are often materialized as symlinks.
+        // Use `metadata()` (follows symlinks) so our fixture snapshots work
+        // under both Cargo and Buck2.
+        let metadata = fs::metadata(&path)?;
+        if metadata.is_dir() {
             entries.insert(rel.clone(), Entry::Dir);
             snapshot_dir_recursive(base, &path, entries)?;
-        } else if file_type.is_file() {
+        } else if metadata.is_file() {
             let contents = fs::read(&path)?;
             entries.insert(rel, Entry::File(contents));
         }
@@ -98,12 +102,14 @@ fn copy_dir_recursive(src: &Path, dst: &Path) -> anyhow::Result<()> {
     for entry in fs::read_dir(src)? {
         let entry = entry?;
         let path = entry.path();
-        let file_type = entry.file_type()?;
         let dest_path = dst.join(entry.file_name());
-        if file_type.is_dir() {
+
+        // See note in `snapshot_dir_recursive` about Buck2 symlink trees.
+        let metadata = fs::metadata(&path)?;
+        if metadata.is_dir() {
             fs::create_dir_all(&dest_path)?;
             copy_dir_recursive(&path, &dest_path)?;
-        } else if file_type.is_file() {
+        } else if metadata.is_file() {
             if let Some(parent) = dest_path.parent() {
                 fs::create_dir_all(parent)?;
             }

codex-rs/apply-patch/tests/suite/tool.rs

@@ -5,13 +5,13 @@ use std::path::Path;
 use tempfile::tempdir;
 
 fn run_apply_patch_in_dir(dir: &Path, patch: &str) -> anyhow::Result<assert_cmd::assert::Assert> {
-    let mut cmd = Command::cargo_bin("apply_patch")?;
+    let mut cmd = Command::new(codex_utils_cargo_bin::cargo_bin("apply_patch")?);
     cmd.current_dir(dir);
     Ok(cmd.arg(patch).assert())
 }
 
 fn apply_patch_command(dir: &Path) -> anyhow::Result<Command> {
-    let mut cmd = Command::cargo_bin("apply_patch")?;
+    let mut cmd = Command::new(codex_utils_cargo_bin::cargo_bin("apply_patch")?);
     cmd.current_dir(dir);
     Ok(cmd)
 }

codex-rs/chatgpt/src/apply_command.rs

@@ -3,7 +3,6 @@ use std::path::PathBuf;
 use clap::Parser;
 use codex_common::CliConfigOverrides;
 use codex_core::config::Config;
-use codex_core::config::ConfigOverrides;
 
 use crate::chatgpt_token::init_chatgpt_token_from_auth;
 use crate::get_task::GetTaskResponse;
@@ -28,7 +27,6 @@ pub async fn run_apply_command(
             .config_overrides
             .parse_overrides()
             .map_err(anyhow::Error::msg)?,
-        ConfigOverrides::default(),
     )
     .await?;
 

codex-rs/cli/Cargo.toml

@@ -37,13 +37,13 @@ codex-rmcp-client = { workspace = true }
 codex-stdio-to-uds = { workspace = true }
 codex-tui = { workspace = true }
 codex-tui2 = { workspace = true }
+codex-utils-absolute-path = { workspace = true }
 ctor = { workspace = true }
 libc = { workspace = true }
 owo-colors = { workspace = true }
-regex-lite = { workspace = true}
+regex-lite = { workspace = true }
 serde_json = { workspace = true }
 supports-color = { workspace = true }
-toml = { workspace = true }
 tokio = { workspace = true, features = [
     "io-std",
     "macros",
@@ -51,6 +51,7 @@ tokio = { workspace = true, features = [
     "rt-multi-thread",
     "signal",
 ] }
+toml = { workspace = true }
 tracing = { workspace = true }
 
 [target.'cfg(target_os = "windows")'.dependencies]
@@ -59,6 +60,7 @@ codex_windows_sandbox = { package = "codex-windows-sandbox", path = "../windows-
 [dev-dependencies]
 assert_cmd = { workspace = true }
 assert_matches = { workspace = true }
+codex-utils-cargo-bin = { workspace = true }
 predicates = { workspace = true }
 pretty_assertions = { workspace = true }
 tempfile = { workspace = true }

codex-rs/cli/src/debug_sandbox.rs

@@ -109,7 +109,7 @@ async fn run_command_under_sandbox(
     log_denials: bool,
 ) -> anyhow::Result<()> {
     let sandbox_mode = create_sandbox_mode(full_auto);
-    let config = Config::load_with_cli_overrides(
+    let config = Config::load_with_cli_overrides_and_harness_overrides(
         config_overrides
             .parse_overrides()
             .map_err(anyhow::Error::msg)?,
@@ -140,7 +140,7 @@ async fn run_command_under_sandbox(
             use codex_windows_sandbox::run_windows_sandbox_capture;
             use codex_windows_sandbox::run_windows_sandbox_capture_elevated;
 
-            let policy_str = serde_json::to_string(&config.sandbox_policy)?;
+            let policy_str = serde_json::to_string(config.sandbox_policy.get())?;
 
             let sandbox_cwd = sandbox_policy_cwd.clone();
             let cwd_clone = cwd.clone();
@@ -216,7 +216,7 @@ async fn run_command_under_sandbox(
             spawn_command_under_seatbelt(
                 command,
                 cwd,
-                &config.sandbox_policy,
+                config.sandbox_policy.get(),
                 sandbox_policy_cwd.as_path(),
                 stdio_policy,
                 env,
@@ -232,7 +232,7 @@ async fn run_command_under_sandbox(
                 codex_linux_sandbox_exe,
                 command,
                 cwd,
-                &config.sandbox_policy,
+                config.sandbox_policy.get(),
                 sandbox_policy_cwd.as_path(),
                 stdio_policy,
                 env,

codex-rs/cli/src/login.rs

@@ -6,7 +6,6 @@ use codex_core::auth::CLIENT_ID;
 use codex_core::auth::login_with_api_key;
 use codex_core::auth::logout;
 use codex_core::config::Config;
-use codex_core::config::ConfigOverrides;
 use codex_login::ServerOptions;
 use codex_login::run_device_code_login;
 use codex_login::run_login_server;
@@ -210,8 +209,7 @@ async fn load_config_or_exit(cli_config_overrides: CliConfigOverrides) -> Config
         }
     };
 
-    let config_overrides = ConfigOverrides::default();
-    match Config::load_with_cli_overrides(cli_overrides, config_overrides).await {
+    match Config::load_with_cli_overrides(cli_overrides).await {
         Ok(config) => config,
         Err(e) => {
             eprintln!("Error loading configuration: {e}");

codex-rs/cli/src/main.rs

@@ -44,6 +44,7 @@ use codex_core::features::Feature;
 use codex_core::features::FeatureOverrides;
 use codex_core::features::Features;
 use codex_core::features::is_known_feature_key;
+use codex_utils_absolute_path::AbsolutePathBuf;
 
 /// Codex CLI
 ///
@@ -631,7 +632,11 @@ async fn cli_main(codex_linux_sandbox_exe: Option<PathBuf>) -> anyhow::Result<()
                     ..Default::default()
                 };
 
-                let config = Config::load_with_cli_overrides(cli_kv_overrides, overrides).await?;
+                let config = Config::load_with_cli_overrides_and_harness_overrides(
+                    cli_kv_overrides,
+                    overrides,
+                )
+                .await?;
                 for def in codex_core::features::FEATURES.iter() {
                     let name = def.key;
                     let stage = stage_str(def.stage);
@@ -683,7 +688,13 @@ async fn is_tui2_enabled(cli: &TuiCli) -> std::io::Result<bool> {
         .map_err(|e| std::io::Error::new(std::io::ErrorKind::InvalidInput, e))?;
 
     let codex_home = find_codex_home()?;
-    let config_toml = load_config_as_toml_with_cli_overrides(&codex_home, cli_kv_overrides).await?;
+    let cwd = cli.cwd.clone();
+    let config_cwd = match cwd.as_deref() {
+        Some(path) => AbsolutePathBuf::from_absolute_path(path)?,
+        None => AbsolutePathBuf::current_dir()?,
+    };
+    let config_toml =
+        load_config_as_toml_with_cli_overrides(&codex_home, &config_cwd, cli_kv_overrides).await?;
     let config_profile = config_toml.get_config_profile(cli.config_profile.clone())?;
     let overrides = FeatureOverrides::default();
     let features = Features::from_config(&config_toml, &config_profile, overrides);

codex-rs/cli/src/mcp_cmd.rs

@@ -8,21 +8,17 @@ use clap::ArgGroup;
 use codex_common::CliConfigOverrides;
 use codex_common::format_env_display::format_env_display;
 use codex_core::config::Config;
-use codex_core::config::ConfigOverrides;
 use codex_core::config::edit::ConfigEditsBuilder;
 use codex_core::config::find_codex_home;
 use codex_core::config::load_global_mcp_servers;
 use codex_core::config::types::McpServerConfig;
 use codex_core::config::types::McpServerTransportConfig;
-use codex_core::features::Feature;
 use codex_core::mcp::auth::compute_auth_statuses;
 use codex_core::protocol::McpAuthStatus;
 use codex_rmcp_client::delete_oauth_tokens;
 use codex_rmcp_client::perform_oauth_login;
 use codex_rmcp_client::supports_oauth_login;
 
-/// [experimental] Launch Codex as an MCP server or manage configured MCP servers.
-///
 /// Subcommands:
 /// - `serve`  — run the MCP server on stdio
 /// - `list`   — list configured servers (with `--json`)
@@ -40,24 +36,11 @@ pub struct McpCli {
 
 #[derive(Debug, clap::Subcommand)]
 pub enum McpSubcommand {
-    /// [experimental] List configured MCP servers.
     List(ListArgs),
-
-    /// [experimental] Show details for a configured MCP server.
     Get(GetArgs),
-
-    /// [experimental] Add a global MCP server entry.
     Add(AddArgs),
-
-    /// [experimental] Remove a global MCP server entry.
     Remove(RemoveArgs),
-
-    /// [experimental] Authenticate with a configured MCP server via OAuth.
-    /// Requires features.rmcp_client = true in config.toml.
     Login(LoginArgs),
-
-    /// [experimental] Remove stored OAuth credentials for a server.
-    /// Requires features.rmcp_client = true in config.toml.
     Logout(LogoutArgs),
 }
 
@@ -200,7 +183,7 @@ async fn run_add(config_overrides: &CliConfigOverrides, add_args: AddArgs) -> Re
     let overrides = config_overrides
         .parse_overrides()
         .map_err(anyhow::Error::msg)?;
-    let config = Config::load_with_cli_overrides(overrides, ConfigOverrides::default())
+    let config = Config::load_with_cli_overrides(overrides)
         .await
         .context("failed to load configuration")?;
 
@@ -283,24 +266,17 @@ async fn run_add(config_overrides: &CliConfigOverrides, add_args: AddArgs) -> Re
     {
         match supports_oauth_login(&url).await {
             Ok(true) => {
-                if !config.features.enabled(Feature::RmcpClient) {
-                    println!(
-                        "MCP server supports login. Add `features.rmcp_client = true` \
-                         to your config.toml and run `codex mcp login {name}` to login."
-                    );
-                } else {
-                    println!("Detected OAuth support. Starting OAuth flow…");
-                    perform_oauth_login(
-                        &name,
-                        &url,
-                        config.mcp_oauth_credentials_store_mode,
-                        http_headers.clone(),
-                        env_http_headers.clone(),
-                        &Vec::new(),
-                    )
-                    .await?;
-                    println!("Successfully logged in.");
-                }
+                println!("Detected OAuth support. Starting OAuth flow…");
+                perform_oauth_login(
+                    &name,
+                    &url,
+                    config.mcp_oauth_credentials_store_mode,
+                    http_headers.clone(),
+                    env_http_headers.clone(),
+                    &Vec::new(),
+                )
+                .await?;
+                println!("Successfully logged in.");
             }
             Ok(false) => {}
             Err(_) => println!(
@@ -349,16 +325,10 @@ async fn run_login(config_overrides: &CliConfigOverrides, login_args: LoginArgs)
     let overrides = config_overrides
         .parse_overrides()
         .map_err(anyhow::Error::msg)?;
-    let config = Config::load_with_cli_overrides(overrides, ConfigOverrides::default())
+    let config = Config::load_with_cli_overrides(overrides)
         .await
         .context("failed to load configuration")?;
 
-    if !config.features.enabled(Feature::RmcpClient) {
-        bail!(
-            "OAuth login is only supported when [features].rmcp_client is true in config.toml. See https://github.com/openai/codex/blob/main/docs/config.md#feature-flags for details."
-        );
-    }
-
     let LoginArgs { name, scopes } = login_args;
 
     let Some(server) = config.mcp_servers.get(&name) else {
@@ -392,7 +362,7 @@ async fn run_logout(config_overrides: &CliConfigOverrides, logout_args: LogoutAr
     let overrides = config_overrides
         .parse_overrides()
         .map_err(anyhow::Error::msg)?;
-    let config = Config::load_with_cli_overrides(overrides, ConfigOverrides::default())
+    let config = Config::load_with_cli_overrides(overrides)
         .await
         .context("failed to load configuration")?;
 
@@ -421,7 +391,7 @@ async fn run_list(config_overrides: &CliConfigOverrides, list_args: ListArgs) ->
     let overrides = config_overrides
         .parse_overrides()
         .map_err(anyhow::Error::msg)?;
-    let config = Config::load_with_cli_overrides(overrides, ConfigOverrides::default())
+    let config = Config::load_with_cli_overrides(overrides)
         .await
         .context("failed to load configuration")?;
 
@@ -678,7 +648,7 @@ async fn run_get(config_overrides: &CliConfigOverrides, get_args: GetArgs) -> Re
     let overrides = config_overrides
         .parse_overrides()
         .map_err(anyhow::Error::msg)?;
-    let config = Config::load_with_cli_overrides(overrides, ConfigOverrides::default())
+    let config = Config::load_with_cli_overrides(overrides)
         .await
         .context("failed to load configuration")?;
 

codex-rs/cli/tests/execpolicy.rs

@@ -24,7 +24,7 @@ prefix_rule(
 "#,
     )?;
 
-    let output = Command::cargo_bin("codex")?
+    let output = Command::new(codex_utils_cargo_bin::cargo_bin("codex")?)
         .env("CODEX_HOME", codex_home.path())
         .args([
             "execpolicy",

codex-rs/cli/tests/mcp_add_remove.rs

@@ -8,7 +8,7 @@ use pretty_assertions::assert_eq;
 use tempfile::TempDir;
 
 fn codex_command(codex_home: &Path) -> Result<assert_cmd::Command> {
-    let mut cmd = assert_cmd::Command::cargo_bin("codex")?;
+    let mut cmd = assert_cmd::Command::new(codex_utils_cargo_bin::cargo_bin("codex")?);
     cmd.env("CODEX_HOME", codex_home);
     Ok(cmd)
 }

codex-rs/cli/tests/mcp_list.rs

@@ -12,7 +12,7 @@ use serde_json::json;
 use tempfile::TempDir;
 
 fn codex_command(codex_home: &Path) -> Result<assert_cmd::Command> {
-    let mut cmd = assert_cmd::Command::cargo_bin("codex")?;
+    let mut cmd = assert_cmd::Command::new(codex_utils_cargo_bin::cargo_bin("codex")?);
     cmd.env("CODEX_HOME", codex_home);
     Ok(cmd)
 }

codex-rs/cloud-tasks/Cargo.toml

@@ -37,6 +37,9 @@ unicode-width = { workspace = true }
 owo-colors = { workspace = true, features = ["supports-colors"] }
 supports-color = { workspace = true }
 
+[dependencies.async-trait]
+workspace = true
+
 [dev-dependencies]
 async-trait = { workspace = true }
 pretty_assertions = { workspace = true }

codex-rs/cloud-tasks/src/cli.rs

@@ -34,10 +34,6 @@ pub struct ExecCommand {
     #[arg(long = "env", value_name = "ENV_ID")]
     pub environment: String,
 
-    /// Git branch to run in Codex Cloud.
-    #[arg(long = "branch", value_name = "BRANCH", default_value = "main")]
-    pub branch: String,
-
     /// Number of assistant attempts (best-of-N).
     #[arg(
         long = "attempts",
@@ -45,6 +41,10 @@ pub struct ExecCommand {
         value_parser = parse_attempts
     )]
     pub attempts: usize,
+
+    /// Git branch to run in Codex Cloud (defaults to current branch).
+    #[arg(long = "branch", value_name = "BRANCH")]
+    pub branch: Option<String>,
 }
 
 fn parse_attempts(input: &str) -> Result<usize, String> {

codex-rs/cloud-tasks/src/lib.rs

@@ -104,6 +104,54 @@ async fn init_backend(user_agent_suffix: &str) -> anyhow::Result<BackendContext>
     })
 }
 
+#[async_trait::async_trait]
+trait GitInfoProvider {
+    async fn default_branch_name(&self, path: &std::path::Path) -> Option<String>;
+
+    async fn current_branch_name(&self, path: &std::path::Path) -> Option<String>;
+}
+
+struct RealGitInfo;
+
+#[async_trait::async_trait]
+impl GitInfoProvider for RealGitInfo {
+    async fn default_branch_name(&self, path: &std::path::Path) -> Option<String> {
+        codex_core::git_info::default_branch_name(path).await
+    }
+
+    async fn current_branch_name(&self, path: &std::path::Path) -> Option<String> {
+        codex_core::git_info::current_branch_name(path).await
+    }
+}
+
+async fn resolve_git_ref(branch_override: Option<&String>) -> String {
+    resolve_git_ref_with_git_info(branch_override, &RealGitInfo).await
+}
+
+async fn resolve_git_ref_with_git_info(
+    branch_override: Option<&String>,
+    git_info: &impl GitInfoProvider,
+) -> String {
+    if let Some(branch) = branch_override {
+        let branch = branch.trim();
+        if !branch.is_empty() {
+            return branch.to_string();
+        }
+    }
+
+    if let Ok(cwd) = std::env::current_dir() {
+        if let Some(branch) = git_info.current_branch_name(&cwd).await {
+            branch
+        } else if let Some(branch) = git_info.default_branch_name(&cwd).await {
+            branch
+        } else {
+            "main".to_string()
+        }
+    } else {
+        "main".to_string()
+    }
+}
+
 async fn run_exec_command(args: crate::cli::ExecCommand) -> anyhow::Result<()> {
     let crate::cli::ExecCommand {
         query,
@@ -114,11 +162,12 @@ async fn run_exec_command(args: crate::cli::ExecCommand) -> anyhow::Result<()> {
     let ctx = init_backend("codex_cloud_tasks_exec").await?;
     let prompt = resolve_query_input(query)?;
     let env_id = resolve_environment_id(&ctx, &environment).await?;
+    let git_ref = resolve_git_ref(branch.as_ref()).await;
     let created = codex_cloud_tasks_client::CloudBackend::create_task(
         &*ctx.backend,
         &env_id,
         &prompt,
-        &branch,
+        &git_ref,
         false,
         attempts,
     )
@@ -1362,17 +1411,7 @@ pub async fn run_main(cli: Cli, _codex_linux_sandbox_exe: Option<PathBuf>) -> an
                                                 let backend = Arc::clone(&backend);
                                                 let best_of_n = page.best_of_n;
                                                 tokio::spawn(async move {
-                                                    let git_ref = if let Ok(cwd) = std::env::current_dir() {
-                                                        if let Some(branch) = codex_core::git_info::default_branch_name(&cwd).await {
-                                                            branch
-                                                        } else if let Some(branch) = codex_core::git_info::current_branch_name(&cwd).await {
-                                                            branch
-                                                        } else {
-                                                            "main".to_string()
-                                                        }
-                                                    } else {
-                                                        "main".to_string()
-                                                    };
+                                                    let git_ref = resolve_git_ref(None).await;
 
                                                     let result = codex_cloud_tasks_client::CloudBackend::create_task(&*backend, &env, &text, &git_ref, false, best_of_n).await;
                                                     let evt = match result {
@@ -1991,6 +2030,7 @@ fn pretty_lines_from_error(raw: &str) -> Vec<String> {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::resolve_git_ref_with_git_info;
     use codex_cloud_tasks_client::DiffSummary;
     use codex_cloud_tasks_client::MockClient;
     use codex_cloud_tasks_client::TaskId;
@@ -2005,6 +2045,85 @@ mod tests {
     use ratatui::buffer::Buffer;
     use ratatui::layout::Rect;
 
+    struct StubGitInfo {
+        default_branch: Option<String>,
+        current_branch: Option<String>,
+    }
+
+    impl StubGitInfo {
+        fn new(default_branch: Option<String>, current_branch: Option<String>) -> Self {
+            Self {
+                default_branch,
+                current_branch,
+            }
+        }
+    }
+
+    #[async_trait::async_trait]
+    impl super::GitInfoProvider for StubGitInfo {
+        async fn default_branch_name(&self, _path: &std::path::Path) -> Option<String> {
+            self.default_branch.clone()
+        }
+
+        async fn current_branch_name(&self, _path: &std::path::Path) -> Option<String> {
+            self.current_branch.clone()
+        }
+    }
+
+    #[tokio::test]
+    async fn branch_override_is_used_when_provided() {
+        let git_ref = resolve_git_ref_with_git_info(
+            Some(&"feature/override".to_string()),
+            &StubGitInfo::new(None, None),
+        )
+        .await;
+
+        assert_eq!(git_ref, "feature/override");
+    }
+
+    #[tokio::test]
+    async fn trims_override_whitespace() {
+        let git_ref = resolve_git_ref_with_git_info(
+            Some(&"  feature/spaces  ".to_string()),
+            &StubGitInfo::new(None, None),
+        )
+        .await;
+
+        assert_eq!(git_ref, "feature/spaces");
+    }
+
+    #[tokio::test]
+    async fn prefers_current_branch_when_available() {
+        let git_ref = resolve_git_ref_with_git_info(
+            None,
+            &StubGitInfo::new(
+                Some("default-main".to_string()),
+                Some("feature/current".to_string()),
+            ),
+        )
+        .await;
+
+        assert_eq!(git_ref, "feature/current");
+    }
+
+    #[tokio::test]
+    async fn falls_back_to_current_branch_when_default_is_missing() {
+        let git_ref = resolve_git_ref_with_git_info(
+            None,
+            &StubGitInfo::new(None, Some("develop".to_string())),
+        )
+        .await;
+
+        assert_eq!(git_ref, "develop");
+    }
+
+    #[tokio::test]
+    async fn falls_back_to_main_when_no_git_info_is_available() {
+        let git_ref = resolve_git_ref_with_git_info(None, &StubGitInfo::new(None, None)).await;
+
+        assert_eq!(git_ref, "main");
+    }
+
     #[test]
     fn format_task_status_lines_with_diff_and_label() {
         let now = Utc::now();

codex-rs/cloud-tasks/src/util.rs

@@ -5,7 +5,6 @@ use chrono::Utc;
 use reqwest::header::HeaderMap;
 
 use codex_core::config::Config;
-use codex_core::config::ConfigOverrides;
 use codex_login::AuthManager;
 
 pub fn set_user_agent_suffix(suffix: &str) {
@@ -62,9 +61,7 @@ pub fn extract_chatgpt_account_id(token: &str) -> Option<String> {
 
 pub async fn load_auth_manager() -> Option<AuthManager> {
     // TODO: pass in cli overrides once cloud tasks properly support them.
-    let config = Config::load_with_cli_overrides(Vec::new(), ConfigOverrides::default())
-        .await
-        .ok()?;
+    let config = Config::load_with_cli_overrides(Vec::new()).await.ok()?;
     Some(AuthManager::new(
         config.codex_home,
         false,

codex-rs/codex-api/src/common.rs

@@ -59,6 +59,7 @@ pub enum ResponseEvent {
         summary_index: i64,
     },
     RateLimits(RateLimitSnapshot),
+    ModelsEtag(String),
 }
 
 #[derive(Debug, Serialize, Clone)]

codex-rs/codex-api/src/endpoint/chat.rs

@@ -152,6 +152,9 @@ impl Stream for AggregatedStream {
                 Poll::Ready(Some(Ok(ResponseEvent::RateLimits(snapshot)))) => {
                     return Poll::Ready(Some(Ok(ResponseEvent::RateLimits(snapshot))));
                 }
+                Poll::Ready(Some(Ok(ResponseEvent::ModelsEtag(etag)))) => {
+                    return Poll::Ready(Some(Ok(ResponseEvent::ModelsEtag(etag))));
+                }
                 Poll::Ready(Some(Ok(ResponseEvent::Completed {
                     response_id,
                     token_usage,

codex-rs/codex-api/src/endpoint/models.rs

@@ -5,6 +5,7 @@ use crate::provider::Provider;
 use crate::telemetry::run_with_request_telemetry;
 use codex_client::HttpTransport;
 use codex_client::RequestTelemetry;
+use codex_protocol::openai_models::ModelInfo;
 use codex_protocol::openai_models::ModelsResponse;
 use http::HeaderMap;
 use http::Method;
@@ -41,7 +42,7 @@ impl<T: HttpTransport, A: AuthProvider> ModelsClient<T, A> {
         &self,
         client_version: &str,
         extra_headers: HeaderMap,
-    ) -> Result<ModelsResponse, ApiError> {
+    ) -> Result<(Vec<ModelInfo>, Option<String>), ApiError> {
         let builder = || {
             let mut req = self.provider.build_request(Method::GET, self.path());
             req.headers.extend(extra_headers.clone());
@@ -66,7 +67,7 @@ impl<T: HttpTransport, A: AuthProvider> ModelsClient<T, A> {
             .and_then(|value| value.to_str().ok())
             .map(ToString::to_string);
 
-        let ModelsResponse { models, etag } = serde_json::from_slice::<ModelsResponse>(&resp.body)
+        let ModelsResponse { models } = serde_json::from_slice::<ModelsResponse>(&resp.body)
             .map_err(|e| {
                 ApiError::Stream(format!(
                     "failed to decode models response: {e}; body: {}",
@@ -74,9 +75,7 @@ impl<T: HttpTransport, A: AuthProvider> ModelsClient<T, A> {
                 ))
             })?;
 
-        let etag = header_etag.unwrap_or(etag);
-
-        Ok(ModelsResponse { models, etag })
+        Ok((models, header_etag))
     }
 }
 
@@ -102,16 +101,15 @@ mod tests {
     struct CapturingTransport {
         last_request: Arc<Mutex<Option<Request>>>,
         body: Arc<ModelsResponse>,
+        etag: Option<String>,
     }
 
     impl Default for CapturingTransport {
         fn default() -> Self {
             Self {
                 last_request: Arc::new(Mutex::new(None)),
-                body: Arc::new(ModelsResponse {
-                    models: Vec::new(),
-                    etag: String::new(),
-                }),
+                body: Arc::new(ModelsResponse { models: Vec::new() }),
+                etag: None,
             }
         }
     }
@@ -122,8 +120,8 @@ mod tests {
             *self.last_request.lock().unwrap() = Some(req);
             let body = serde_json::to_vec(&*self.body).unwrap();
             let mut headers = HeaderMap::new();
-            if !self.body.etag.is_empty() {
-                headers.insert(ETAG, self.body.etag.parse().unwrap());
+            if let Some(etag) = &self.etag {
+                headers.insert(ETAG, etag.parse().unwrap());
             }
             Ok(Response {
                 status: StatusCode::OK,
@@ -166,14 +164,12 @@ mod tests {
 
     #[tokio::test]
     async fn appends_client_version_query() {
-        let response = ModelsResponse {
-            models: Vec::new(),
-            etag: String::new(),
-        };
+        let response = ModelsResponse { models: Vec::new() };
 
         let transport = CapturingTransport {
             last_request: Arc::new(Mutex::new(None)),
             body: Arc::new(response),
+            etag: None,
         };
 
         let client = ModelsClient::new(
@@ -182,12 +178,12 @@ mod tests {
             DummyAuth,
         );
 
-        let result = client
+        let (models, _) = client
             .list_models("0.99.0", HeaderMap::new())
             .await
             .expect("request should succeed");
 
-        assert_eq!(result.models.len(), 0);
+        assert_eq!(models.len(), 0);
 
         let url = transport
             .last_request
@@ -227,17 +223,16 @@ mod tests {
                     "truncation_policy": {"mode": "bytes", "limit": 10_000},
                     "supports_parallel_tool_calls": false,
                     "context_window": null,
-                    "reasoning_summary_format": "none",
                     "experimental_supported_tools": [],
                 }))
                 .unwrap(),
             ],
-            etag: String::new(),
         };
 
         let transport = CapturingTransport {
             last_request: Arc::new(Mutex::new(None)),
             body: Arc::new(response),
+            etag: None,
         };
 
         let client = ModelsClient::new(
@@ -246,27 +241,25 @@ mod tests {
             DummyAuth,
         );
 
-        let result = client
+        let (models, _) = client
             .list_models("0.99.0", HeaderMap::new())
             .await
             .expect("request should succeed");
 
-        assert_eq!(result.models.len(), 1);
-        assert_eq!(result.models[0].slug, "gpt-test");
-        assert_eq!(result.models[0].supported_in_api, true);
-        assert_eq!(result.models[0].priority, 1);
+        assert_eq!(models.len(), 1);
+        assert_eq!(models[0].slug, "gpt-test");
+        assert_eq!(models[0].supported_in_api, true);
+        assert_eq!(models[0].priority, 1);
     }
 
     #[tokio::test]
     async fn list_models_includes_etag() {
-        let response = ModelsResponse {
-            models: Vec::new(),
-            etag: "\"abc\"".to_string(),
-        };
+        let response = ModelsResponse { models: Vec::new() };
 
         let transport = CapturingTransport {
             last_request: Arc::new(Mutex::new(None)),
             body: Arc::new(response),
+            etag: Some("\"abc\"".to_string()),
         };
 
         let client = ModelsClient::new(
@@ -275,12 +268,12 @@ mod tests {
             DummyAuth,
         );
 
-        let result = client
+        let (models, etag) = client
             .list_models("0.1.0", HeaderMap::new())
             .await
             .expect("request should succeed");
 
-        assert_eq!(result.models.len(), 0);
-        assert_eq!(result.etag, "\"abc\"");
+        assert_eq!(models.len(), 0);
+        assert_eq!(etag, Some("\"abc\"".to_string()));
     }
 }

codex-rs/codex-api/src/sse/responses.rs

@@ -51,11 +51,19 @@ pub fn spawn_response_stream(
     telemetry: Option<Arc<dyn SseTelemetry>>,
 ) -> ResponseStream {
     let rate_limits = parse_rate_limit(&stream_response.headers);
+    let models_etag = stream_response
+        .headers
+        .get("X-Models-Etag")
+        .and_then(|v| v.to_str().ok())
+        .map(ToString::to_string);
     let (tx_event, rx_event) = mpsc::channel::<Result<ResponseEvent, ApiError>>(1600);
     tokio::spawn(async move {
         if let Some(snapshot) = rate_limits {
             let _ = tx_event.send(Ok(ResponseEvent::RateLimits(snapshot))).await;
         }
+        if let Some(etag) = models_etag {
+            let _ = tx_event.send(Ok(ResponseEvent::ModelsEtag(etag))).await;
+        }
         process_sse(stream_response.bytes, tx_event, idle_timeout, telemetry).await;
     });
 

codex-rs/codex-api/tests/models_integration.rs

@@ -4,14 +4,12 @@ use codex_api::provider::Provider;
 use codex_api::provider::RetryConfig;
 use codex_api::provider::WireApi;
 use codex_client::ReqwestTransport;
-use codex_protocol::openai_models::ClientVersion;
 use codex_protocol::openai_models::ConfigShellToolType;
 use codex_protocol::openai_models::ModelInfo;
 use codex_protocol::openai_models::ModelVisibility;
 use codex_protocol::openai_models::ModelsResponse;
 use codex_protocol::openai_models::ReasoningEffort;
 use codex_protocol::openai_models::ReasoningEffortPreset;
-use codex_protocol::openai_models::ReasoningSummaryFormat;
 use codex_protocol::openai_models::TruncationPolicyConfig;
 use http::HeaderMap;
 use http::Method;
@@ -75,7 +73,6 @@ async fn models_client_hits_models_endpoint() {
             ],
             shell_type: ConfigShellToolType::ShellCommand,
             visibility: ModelVisibility::List,
-            minimal_client_version: ClientVersion(0, 1, 0),
             supported_in_api: true,
             priority: 1,
             upgrade: None,
@@ -87,10 +84,8 @@ async fn models_client_hits_models_endpoint() {
             truncation_policy: TruncationPolicyConfig::bytes(10_000),
             supports_parallel_tool_calls: false,
             context_window: None,
-            reasoning_summary_format: ReasoningSummaryFormat::None,
             experimental_supported_tools: Vec::new(),
         }],
-        etag: String::new(),
     };
 
     Mock::given(method("GET"))
@@ -106,13 +101,13 @@ async fn models_client_hits_models_endpoint() {
     let transport = ReqwestTransport::new(reqwest::Client::new());
     let client = ModelsClient::new(transport, provider(&base_url), DummyAuth);
 
-    let result = client
+    let (models, _) = client
         .list_models("0.1.0", HeaderMap::new())
         .await
         .expect("models request should succeed");
 
-    assert_eq!(result.models.len(), 1);
-    assert_eq!(result.models[0].slug, "gpt-test");
+    assert_eq!(models.len(), 1);
+    assert_eq!(models[0].slug, "gpt-test");
 
     let received = server
         .received_requests()

codex-rs/common/Cargo.toml

@@ -21,3 +21,10 @@ toml = { workspace = true, optional = true }
 cli = ["clap", "serde", "toml"]
 elapsed = []
 sandbox_summary = []
+
+[dev-dependencies]
+clap = { workspace = true, features = ["derive", "wrap_help"] }
+codex-utils-absolute-path = { workspace = true }
+pretty_assertions = { workspace = true }
+serde = { workspace = true }
+toml = { workspace = true }

codex-rs/common/src/config_summary.rs

@@ -10,7 +10,10 @@ pub fn create_config_summary_entries(config: &Config, model: &str) -> Vec<(&'sta
         ("model", model.to_string()),
         ("provider", config.model_provider_id.clone()),
         ("approval", config.approval_policy.value().to_string()),
-        ("sandbox", summarize_sandbox_policy(&config.sandbox_policy)),
+        (
+            "sandbox",
+            summarize_sandbox_policy(config.sandbox_policy.get()),
+        ),
     ];
     if config.model_provider.wire_api == WireApi::Responses {
         let reasoning_effort = config

codex-rs/common/src/sandbox_mode_cli_arg.rs

@@ -26,3 +26,22 @@ impl From<SandboxModeCliArg> for SandboxMode {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use pretty_assertions::assert_eq;
+
+    #[test]
+    fn maps_cli_args_to_protocol_modes() {
+        assert_eq!(SandboxMode::ReadOnly, SandboxModeCliArg::ReadOnly.into());
+        assert_eq!(
+            SandboxMode::WorkspaceWrite,
+            SandboxModeCliArg::WorkspaceWrite.into()
+        );
+        assert_eq!(
+            SandboxMode::DangerFullAccess,
+            SandboxModeCliArg::DangerFullAccess.into()
+        );
+    }
+}

codex-rs/common/src/sandbox_summary.rs

@@ -1,9 +1,17 @@
+use codex_core::protocol::NetworkAccess;
 use codex_core::protocol::SandboxPolicy;
 
 pub fn summarize_sandbox_policy(sandbox_policy: &SandboxPolicy) -> String {
     match sandbox_policy {
         SandboxPolicy::DangerFullAccess => "danger-full-access".to_string(),
         SandboxPolicy::ReadOnly => "read-only".to_string(),
+        SandboxPolicy::ExternalSandbox { network_access } => {
+            let mut summary = "external-sandbox".to_string();
+            if matches!(network_access, NetworkAccess::Enabled) {
+                summary.push_str(" (network access enabled)");
+            }
+            summary
+        }
         SandboxPolicy::WorkspaceWrite {
             writable_roots,
             network_access,
@@ -34,3 +42,45 @@ pub fn summarize_sandbox_policy(sandbox_policy: &SandboxPolicy) -> String {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use codex_utils_absolute_path::AbsolutePathBuf;
+    use pretty_assertions::assert_eq;
+
+    #[test]
+    fn summarizes_external_sandbox_without_network_access_suffix() {
+        let summary = summarize_sandbox_policy(&SandboxPolicy::ExternalSandbox {
+            network_access: NetworkAccess::Restricted,
+        });
+        assert_eq!(summary, "external-sandbox");
+    }
+
+    #[test]
+    fn summarizes_external_sandbox_with_enabled_network() {
+        let summary = summarize_sandbox_policy(&SandboxPolicy::ExternalSandbox {
+            network_access: NetworkAccess::Enabled,
+        });
+        assert_eq!(summary, "external-sandbox (network access enabled)");
+    }
+
+    #[test]
+    fn workspace_write_summary_still_includes_network_access() {
+        let root = if cfg!(windows) { "C:\\repo" } else { "/repo" };
+        let writable_root = AbsolutePathBuf::try_from(root).unwrap();
+        let summary = summarize_sandbox_policy(&SandboxPolicy::WorkspaceWrite {
+            writable_roots: vec![writable_root.clone()],
+            network_access: true,
+            exclude_tmpdir_env_var: true,
+            exclude_slash_tmp: true,
+        });
+        assert_eq!(
+            summary,
+            format!(
+                "workspace-write [workdir, {}] (network access enabled)",
+                writable_root.to_string_lossy()
+            )
+        );
+    }
+}

codex-rs/core/Cargo.toml

@@ -16,6 +16,7 @@ workspace = true
 anyhow = { workspace = true }
 async-channel = { workspace = true }
 async-trait = { workspace = true }
+arc-swap = "1.7.1"
 base64 = { workspace = true }
 chardetng = { workspace = true }
 chrono = { workspace = true, features = ["serde"] }
@@ -43,6 +44,7 @@ env-flags = { workspace = true }
 eventsource-stream = { workspace = true }
 futures = { workspace = true }
 http = { workspace = true }
+include_dir = { workspace = true }
 indexmap = { workspace = true }
 keyring = { workspace = true, features = ["crypto-rust"] }
 libc = { workspace = true }
@@ -60,7 +62,6 @@ sha1 = { workspace = true }
 sha2 = { workspace = true }
 shlex = { workspace = true }
 similar = { workspace = true }
-strum_macros = { workspace = true }
 tempfile = { workspace = true }
 test-case = "3.3.1"
 test-log = { workspace = true }
@@ -122,6 +123,7 @@ assert_cmd = { workspace = true }
 assert_matches = { workspace = true }
 codex-arg0 = { workspace = true }
 codex-core = { path = ".", features = ["deterministic_process_ids"] }
+codex-utils-cargo-bin = { workspace = true }
 core_test_support = { workspace = true }
 ctor = { workspace = true }
 escargot = { workspace = true }
@@ -131,7 +133,6 @@ predicates = { workspace = true }
 pretty_assertions = { workspace = true }
 serial_test = { workspace = true }
 tempfile = { workspace = true }
-tokio-test = { workspace = true }
 tracing-subscriber = { workspace = true }
 tracing-test = { workspace = true, features = ["no-env-filter"] }
 walkdir = { workspace = true }

codex-rs/core/gpt-5.2-codex_prompt.md

@@ -0,0 +1,117 @@
+You are Codex, based on GPT-5. You are running as a coding agent in the Codex CLI on a user's computer.
+
+## General
+
+- When searching for text or files, prefer using `rg` or `rg --files` respectively because `rg` is much faster than alternatives like `grep`. (If the `rg` command is not found, then use alternatives.)
+
+## Editing constraints
+
+- Default to ASCII when editing or creating files. Only introduce non-ASCII or other Unicode characters when there is a clear justification and the file already uses them.
+- Add succinct code comments that explain what is going on if code is not self-explanatory. You should not add comments like "Assigns the value to the variable", but a brief comment might be useful ahead of a complex code block that the user would otherwise have to spend time parsing out. Usage of these comments should be rare.
+- Try to use apply_patch for single file edits, but it is fine to explore other options to make the edit if it does not work well. Do not use apply_patch for changes that are auto-generated (i.e. generating package.json or running a lint or format command like gofmt) or when scripting is more efficient (such as search and replacing a string across a codebase).
+- You may be in a dirty git worktree.
+    * NEVER revert existing changes you did not make unless explicitly requested, since these changes were made by the user.
+    * If asked to make a commit or code edits and there are unrelated changes to your work or changes that you didn't make in those files, don't revert those changes.
+    * If the changes are in files you've touched recently, you should read carefully and understand how you can work with the changes rather than reverting them.
+    * If the changes are in unrelated files, just ignore them and don't revert them.
+- Do not amend a commit unless explicitly requested to do so.
+- While you are working, you might notice unexpected changes that you didn't make. If this happens, STOP IMMEDIATELY and ask the user how they would like to proceed.
+- **NEVER** use destructive commands like `git reset --hard` or `git checkout --` unless specifically requested or approved by the user.
+
+## Plan tool
+
+When using the planning tool:
+- Skip using the planning tool for straightforward tasks (roughly the easiest 25%).
+- Do not make single-step plans.
+- When you made a plan, update it after having performed one of the sub-tasks that you shared on the plan.
+
+## Codex CLI harness, sandboxing, and approvals
+
+The Codex CLI harness supports several different configurations for sandboxing and escalation approvals that the user can choose from.
+
+Filesystem sandboxing defines which files can be read or written. The options for `sandbox_mode` are:
+- **read-only**: The sandbox only permits reading files.
+- **workspace-write**: The sandbox permits reading files, and editing files in `cwd` and `writable_roots`. Editing files in other directories requires approval.
+- **danger-full-access**: No filesystem sandboxing - all commands are permitted.
+
+Network sandboxing defines whether network can be accessed without approval. Options for `network_access` are:
+- **restricted**: Requires approval
+- **enabled**: No approval needed
+
+Approvals are your mechanism to get user consent to run shell commands without the sandbox. Possible configuration options for `approval_policy` are
+- **untrusted**: The harness will escalate most commands for user approval, apart from a limited allowlist of safe "read" commands.
+- **on-failure**: The harness will allow all commands to run in the sandbox (if enabled), and failures will be escalated to the user for approval to run again without the sandbox.
+- **on-request**: Commands will be run in the sandbox by default, and you can specify in your tool call if you want to escalate a command to run without sandboxing. (Note that this mode is not always available. If it is, you'll see parameters for it in the `shell` command description.)
+- **never**: This is a non-interactive mode where you may NEVER ask the user for approval to run commands. Instead, you must always persist and work around constraints to solve the task for the user. You MUST do your utmost best to finish the task and validate your work before yielding. If this mode is paired with `danger-full-access`, take advantage of it to deliver the best outcome for the user. Further, in this mode, your default testing philosophy is overridden: Even if you don't see local patterns for testing, you may add tests and scripts to validate your work. Just remove them before yielding.
+
+When you are running with `approval_policy == on-request`, and sandboxing enabled, here are scenarios where you'll need to request approval:
+- You need to run a command that writes to a directory that requires it (e.g. running tests that write to /var)
+- You need to run a GUI app (e.g., open/xdg-open/osascript) to open browsers or files.
+- You are running sandboxed and need to run a command that requires network access (e.g. installing packages)
+- If you run a command that is important to solving the user's query, but it fails because of sandboxing, rerun the command with approval. ALWAYS proceed to use the `sandbox_permissions` and `justification` parameters - do not message the user before requesting approval for the command.
+- You are about to take a potentially destructive action such as an `rm` or `git reset` that the user did not explicitly ask for
+- (for all of these, you should weigh alternative paths that do not require approval)
+
+When `sandbox_mode` is set to read-only, you'll need to request approval for any command that isn't a read.
+
+You will be told what filesystem sandboxing, network sandboxing, and approval mode are active in a developer or user message. If you are not told about this, assume that you are running with workspace-write, network sandboxing enabled, and approval on-failure.
+
+Although they introduce friction to the user because your work is paused until the user responds, you should leverage them when necessary to accomplish important work. If the completing the task requires escalated permissions, Do not let these settings or the sandbox deter you from attempting to accomplish the user's task unless it is set to "never", in which case never ask for approvals.
+
+When requesting approval to execute a command that will require escalated privileges:
+  - Provide the `sandbox_permissions` parameter with the value `"require_escalated"`
+  - Include a short, 1 sentence explanation for why you need escalated permissions in the justification parameter
+
+## Special user requests
+
+- If the user makes a simple request (such as asking for the time) which you can fulfill by running a terminal command (such as `date`), you should do so.
+- If the user asks for a "review", default to a code review mindset: prioritise identifying bugs, risks, behavioural regressions, and missing tests. Findings must be the primary focus of the response - keep summaries or overviews brief and only after enumerating the issues. Present findings first (ordered by severity with file/line references), follow with open questions or assumptions, and offer a change-summary only as a secondary detail. If no findings are discovered, state that explicitly and mention any residual risks or testing gaps.
+
+## Frontend tasks
+When doing frontend design tasks, avoid collapsing into "AI slop" or safe, average-looking layouts.
+Aim for interfaces that feel intentional, bold, and a bit surprising.
+- Typography: Use expressive, purposeful fonts and avoid default stacks (Inter, Roboto, Arial, system).
+- Color & Look: Choose a clear visual direction; define CSS variables; avoid purple-on-white defaults. No purple bias or dark mode bias.
+- Motion: Use a few meaningful animations (page-load, staggered reveals) instead of generic micro-motions.
+- Background: Don't rely on flat, single-color backgrounds; use gradients, shapes, or subtle patterns to build atmosphere.
+- Overall: Avoid boilerplate layouts and interchangeable UI patterns. Vary themes, type families, and visual languages across outputs.
+- Ensure the page loads properly on both desktop and mobile
+
+Exception: If working within an existing website or design system, preserve the established patterns, structure, and visual language.
+
+## Presenting your work and final message
+
+You are producing plain text that will later be styled by the CLI. Follow these rules exactly. Formatting should make results easy to scan, but not feel mechanical. Use judgment to decide how much structure adds value.
+
+- Default: be very concise; friendly coding teammate tone.
+- Ask only when needed; suggest ideas; mirror the user's style.
+- For substantial work, summarize clearly; follow final‑answer formatting.
+- Skip heavy formatting for simple confirmations.
+- Don't dump large files you've written; reference paths only.
+- No "save/copy this file" - User is on the same machine.
+- Offer logical next steps (tests, commits, build) briefly; add verify steps if you couldn't do something.
+- For code changes:
+  * Lead with a quick explanation of the change, and then give more details on the context covering where and why a change was made. Do not start this explanation with "summary", just jump right in.
+  * If there are natural next steps the user may want to take, suggest them at the end of your response. Do not make suggestions if there are no natural next steps.
+  * When suggesting multiple options, use numeric lists for the suggestions so the user can quickly respond with a single number.
+- The user does not command execution outputs. When asked to show the output of a command (e.g. `git show`), relay the important details in your answer or summarize the key lines so the user understands the result.
+
+### Final answer structure and style guidelines
+
+- Plain text; CLI handles styling. Use structure only when it helps scanability.
+- Headers: optional; short Title Case (1-3 words) wrapped in **…**; no blank line before the first bullet; add only if they truly help.
+- Bullets: use - ; merge related points; keep to one line when possible; 4–6 per list ordered by importance; keep phrasing consistent.
+- Monospace: backticks for commands/paths/env vars/code ids and inline examples; use for literal keyword bullets; never combine with **.
+- Code samples or multi-line snippets should be wrapped in fenced code blocks; include an info string as often as possible.
+- Structure: group related bullets; order sections general → specific → supporting; for subsections, start with a bolded keyword bullet, then items; match complexity to the task.
+- Tone: collaborative, concise, factual; present tense, active voice; self‑contained; no "above/below"; parallel wording.
+- Don'ts: no nested bullets/hierarchies; no ANSI codes; don't cram unrelated keywords; keep keyword lists short—wrap/reformat if long; avoid naming formatting styles in answers.
+- Adaptation: code explanations → precise, structured with code refs; simple tasks → lead with outcome; big changes → logical walkthrough + rationale + next actions; casual one-offs → plain sentences, no headers/bullets.
+- File References: When referencing files in your response follow the below rules:
+  * Use inline code to make file paths clickable.
+  * Each reference should have a stand alone path. Even if it's the same file.
+  * Accepted: absolute, workspace‑relative, a/ or b/ diff prefixes, or bare filename/suffix.
+  * Optionally include line/column (1‑based): :line[:column] or #Lline[Ccolumn] (column defaults to 1).
+  * Do not use URIs like file://, vscode://, or https://.
+  * Do not provide range of lines
+  * Examples: src/app.ts, src/app.ts:42, b/server/index.js#L10, C:\repo\project\main.rs:12:5

codex-rs/core/src/auth.rs

@@ -636,8 +636,7 @@ mod tests {
     use crate::auth::storage::FileAuthStorage;
     use crate::auth::storage::get_auth_file;
     use crate::config::Config;
-    use crate::config::ConfigOverrides;
-    use crate::config::ConfigToml;
+    use crate::config::ConfigBuilder;
     use crate::token_data::IdTokenInfo;
     use crate::token_data::KnownPlan as InternalKnownPlan;
     use crate::token_data::PlanType as InternalPlanType;
@@ -862,17 +861,16 @@ mod tests {
         Ok(fake_jwt)
     }
 
-    fn build_config(
+    async fn build_config(
         codex_home: &Path,
         forced_login_method: Option<ForcedLoginMethod>,
         forced_chatgpt_workspace_id: Option<String>,
     ) -> Config {
-        let mut config = Config::load_from_base_config_with_overrides(
-            ConfigToml::default(),
-            ConfigOverrides::default(),
-            codex_home.to_path_buf(),
-        )
-        .expect("config should load");
+        let mut config = ConfigBuilder::default()
+            .codex_home(codex_home.to_path_buf())
+            .build()
+            .await
+            .expect("config should load");
         config.forced_login_method = forced_login_method;
         config.forced_chatgpt_workspace_id = forced_chatgpt_workspace_id;
         config
@@ -915,7 +913,7 @@ mod tests {
         login_with_api_key(codex_home.path(), "sk-test", AuthCredentialsStoreMode::File)
             .expect("seed api key");
 
-        let config = build_config(codex_home.path(), Some(ForcedLoginMethod::Chatgpt), None);
+        let config = build_config(codex_home.path(), Some(ForcedLoginMethod::Chatgpt), None).await;
 
         let err = super::enforce_login_restrictions(&config)
             .await
@@ -941,7 +939,7 @@ mod tests {
         )
         .expect("failed to write auth file");
 
-        let config = build_config(codex_home.path(), None, Some("org_mine".to_string()));
+        let config = build_config(codex_home.path(), None, Some("org_mine".to_string())).await;
 
         let err = super::enforce_login_restrictions(&config)
             .await
@@ -967,7 +965,7 @@ mod tests {
         )
         .expect("failed to write auth file");
 
-        let config = build_config(codex_home.path(), None, Some("org_mine".to_string()));
+        let config = build_config(codex_home.path(), None, Some("org_mine".to_string())).await;
 
         super::enforce_login_restrictions(&config)
             .await
@@ -985,7 +983,7 @@ mod tests {
         login_with_api_key(codex_home.path(), "sk-test", AuthCredentialsStoreMode::File)
             .expect("seed api key");
 
-        let config = build_config(codex_home.path(), None, Some("org_mine".to_string()));
+        let config = build_config(codex_home.path(), None, Some("org_mine".to_string())).await;
 
         super::enforce_login_restrictions(&config)
             .await
@@ -1002,7 +1000,7 @@ mod tests {
         let _guard = EnvVarGuard::set(CODEX_API_KEY_ENV_VAR, "sk-env");
         let codex_home = tempdir().unwrap();
 
-        let config = build_config(codex_home.path(), Some(ForcedLoginMethod::Chatgpt), None);
+        let config = build_config(codex_home.path(), Some(ForcedLoginMethod::Chatgpt), None).await;
 
         let err = super::enforce_login_restrictions(&config)
             .await

codex-rs/core/src/bash.rs

@@ -46,6 +46,7 @@ pub fn try_parse_word_only_commands_sequence(tree: &Tree, src: &str) -> Option<V
         "string_content",
         "raw_string",
         "number",
+        "concatenation",
     ];
     // Allow only safe punctuation / operator tokens; anything else causes reject.
     const ALLOWED_PUNCT_TOKENS: &[&str] = &["&&", "||", ";", "|", "\"", "'"];
@@ -158,6 +159,48 @@ fn parse_plain_command_from_node(cmd: tree_sitter::Node, src: &str) -> Option<Ve
                     return None;
                 }
             }
+            "concatenation" => {
+                // Handle concatenated arguments like -g"*.py"
+                let mut concatenated = String::new();
+                let mut concat_cursor = child.walk();
+                for part in child.named_children(&mut concat_cursor) {
+                    match part.kind() {
+                        "word" | "number" => {
+                            concatenated
+                                .push_str(part.utf8_text(src.as_bytes()).ok()?.to_owned().as_str());
+                        }
+                        "string" => {
+                            if part.child_count() == 3
+                                && part.child(0)?.kind() == "\""
+                                && part.child(1)?.kind() == "string_content"
+                                && part.child(2)?.kind() == "\""
+                            {
+                                concatenated.push_str(
+                                    part.child(1)?
+                                        .utf8_text(src.as_bytes())
+                                        .ok()?
+                                        .to_owned()
+                                        .as_str(),
+                                );
+                            } else {
+                                return None;
+                            }
+                        }
+                        "raw_string" => {
+                            let raw_string = part.utf8_text(src.as_bytes()).ok()?;
+                            let stripped = raw_string
+                                .strip_prefix('\'')
+                                .and_then(|s| s.strip_suffix('\''))?;
+                            concatenated.push_str(stripped);
+                        }
+                        _ => return None,
+                    }
+                }
+                if concatenated.is_empty() {
+                    return None;
+                }
+                words.push(concatenated);
+            }
             _ => return None,
         }
     }
@@ -256,4 +299,47 @@ mod tests {
         let parsed = parse_shell_lc_plain_commands(&command).unwrap();
         assert_eq!(parsed, vec![vec!["ls".to_string()]]);
     }
+
+    #[test]
+    fn accepts_concatenated_flag_and_value() {
+        // Test case: -g"*.py" (flag directly concatenated with quoted value)
+        let cmds = parse_seq("rg -n \"foo\" -g\"*.py\"").unwrap();
+        assert_eq!(
+            cmds,
+            vec![vec![
+                "rg".to_string(),
+                "-n".to_string(),
+                "foo".to_string(),
+                "-g*.py".to_string(),
+            ]]
+        );
+    }
+
+    #[test]
+    fn accepts_concatenated_flag_with_single_quotes() {
+        let cmds = parse_seq("grep -n 'pattern' -g'*.txt'").unwrap();
+        assert_eq!(
+            cmds,
+            vec![vec![
+                "grep".to_string(),
+                "-n".to_string(),
+                "pattern".to_string(),
+                "-g*.txt".to_string(),
+            ]]
+        );
+    }
+
+    #[test]
+    fn rejects_concatenation_with_variable_substitution() {
+        // Environment variables in concatenated strings should be rejected
+        assert!(parse_seq("rg -g\"$VAR\" pattern").is_none());
+        assert!(parse_seq("rg -g\"${VAR}\" pattern").is_none());
+    }
+
+    #[test]
+    fn rejects_concatenation_with_command_substitution() {
+        // Command substitution in concatenated strings should be rejected
+        assert!(parse_seq("rg -g\"$(pwd)\" pattern").is_none());
+        assert!(parse_seq("rg -g\"$(echo '*.py')\" pattern").is_none());
+    }
 }

codex-rs/core/src/client.rs

@@ -49,7 +49,7 @@ use crate::features::FEATURES;
 use crate::flags::CODEX_RS_SSE_FIXTURE;
 use crate::model_provider_info::ModelProviderInfo;
 use crate::model_provider_info::WireApi;
-use crate::openai_models::model_family::ModelFamily;
+use crate::models_manager::model_family::ModelFamily;
 use crate::tools::spec::create_tools_json_for_chat_completions_api;
 use crate::tools::spec::create_tools_json_for_responses_api;
 

codex-rs/core/src/client_common.rs

@@ -1,6 +1,6 @@
 use crate::client_common::tools::ToolSpec;
 use crate::error::Result;
-use crate::openai_models::model_family::ModelFamily;
+use crate::models_manager::model_family::ModelFamily;
 pub use codex_api::common::ResponseEvent;
 use codex_apply_patch::APPLY_PATCH_TOOL_INSTRUCTIONS;
 use codex_protocol::models::ResponseItem;
@@ -193,10 +193,8 @@ pub(crate) mod tools {
         Function(ResponsesApiTool),
         #[serde(rename = "local_shell")]
         LocalShell {},
-        // TODO: Understand why we get an error on web_search although the API docs say it's supported.
-        // https://platform.openai.com/docs/guides/tools-web-search?api-mode=responses#:~:text=%7B%20type%3A%20%22web_search%22%20%7D%2C
         #[serde(rename = "web_search")]
-        WebSearch {},
+        WebSearch(WebSearchTool),
         #[serde(rename = "custom")]
         Freeform(FreeformTool),
     }
@@ -206,7 +204,7 @@ pub(crate) mod tools {
             match self {
                 ToolSpec::Function(tool) => tool.name.as_str(),
                 ToolSpec::LocalShell {} => "local_shell",
-                ToolSpec::WebSearch {} => "web_search",
+                ToolSpec::WebSearch(_) => "web_search",
                 ToolSpec::Freeform(tool) => tool.name.as_str(),
             }
         }
@@ -236,6 +234,11 @@ pub(crate) mod tools {
         pub(crate) strict: bool,
         pub(crate) parameters: JsonSchema,
     }
+
+    #[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
+    pub struct WebSearchTool {
+        pub(crate) external_web_access: bool,
+    }
 }
 
 pub struct ResponseStream {
@@ -259,7 +262,7 @@ mod tests {
     use pretty_assertions::assert_eq;
 
     use crate::config::test_config;
-    use crate::openai_models::models_manager::ModelsManager;
+    use crate::models_manager::manager::ModelsManager;
 
     use super::*;
 

codex-rs/core/src/codex.rs

@@ -13,11 +13,11 @@ use crate::compact;
 use crate::compact::run_inline_auto_compact_task;
 use crate::compact::should_use_remote_compact_task;
 use crate::compact_remote::run_inline_remote_auto_compact_task;
-use crate::exec_policy::load_exec_policy_for_features;
+use crate::exec_policy::ExecPolicyManager;
 use crate::features::Feature;
 use crate::features::Features;
-use crate::openai_models::model_family::ModelFamily;
-use crate::openai_models::models_manager::ModelsManager;
+use crate::models_manager::manager::ModelsManager;
+use crate::models_manager::model_family::ModelFamily;
 use crate::parse_command::parse_command;
 use crate::parse_turn_item;
 use crate::stream_events_utils::HandleOutputCtx;
@@ -78,7 +78,6 @@ use crate::client_common::ResponseEvent;
 use crate::compact::collect_user_messages;
 use crate::config::Config;
 use crate::config::Constrained;
-use crate::config::ConstraintError;
 use crate::config::ConstraintResult;
 use crate::config::GhostSnapshotConfig;
 use crate::config::types::ShellEnvironmentPolicy;
@@ -149,7 +148,6 @@ use crate::user_instructions::UserInstructions;
 use crate::user_notification::UserNotification;
 use crate::util::backoff;
 use codex_async_utils::OrCancelExt;
-use codex_execpolicy::Policy as ExecPolicy;
 use codex_otel::otel_manager::OtelManager;
 use codex_protocol::config_types::ReasoningSummary as ReasoningSummaryConfig;
 use codex_protocol::models::ContentItem;
@@ -219,11 +217,10 @@ impl Codex {
         let (tx_sub, rx_sub) = async_channel::bounded(SUBMISSION_CHANNEL_CAPACITY);
         let (tx_event, rx_event) = async_channel::unbounded();
 
-        let loaded_skills = if config.features.enabled(Feature::Skills) {
-            Some(skills_manager.skills_for_cwd(&config.cwd))
-        } else {
-            None
-        };
+        let loaded_skills = config
+            .features
+            .enabled(Feature::Skills)
+            .then(|| skills_manager.skills_for_cwd(&config.cwd));
 
         if let Some(outcome) = &loaded_skills {
             for err in &outcome.errors {
@@ -243,14 +240,15 @@ impl Codex {
         )
         .await;
 
-        let exec_policy = load_exec_policy_for_features(&config.features, &config.codex_home)
+        let exec_policy = ExecPolicyManager::load(&config.features, &config.config_layer_stack)
             .await
             .map_err(|err| CodexErr::Fatal(format!("failed to load execpolicy: {err}")))?;
-        let exec_policy = Arc::new(RwLock::new(exec_policy));
 
         let config = Arc::new(config);
         if config.features.enabled(Feature::RemoteModels)
-            && let Err(err) = models_manager.refresh_available_models(&config).await
+            && let Err(err) = models_manager
+                .refresh_available_models_with_cache(&config)
+                .await
         {
             error!("failed to refresh available models: {err:?}");
         }
@@ -268,7 +266,6 @@ impl Codex {
             sandbox_policy: config.sandbox_policy.clone(),
             cwd: config.cwd.clone(),
             original_config_do_not_use: Arc::clone(&config),
-            exec_policy,
             session_source,
         };
 
@@ -280,6 +277,7 @@ impl Codex {
             config.clone(),
             auth_manager.clone(),
             models_manager.clone(),
+            exec_policy,
             tx_event.clone(),
             conversation_history,
             session_source_clone,
@@ -373,7 +371,6 @@ pub(crate) struct TurnContext {
     pub(crate) final_output_json_schema: Option<Value>,
     pub(crate) codex_linux_sandbox_exe: Option<PathBuf>,
     pub(crate) tool_call_gate: Arc<ReadinessFlag>,
-    pub(crate) exec_policy: Arc<RwLock<ExecPolicy>>,
     pub(crate) truncation_policy: TruncationPolicy,
 }
 
@@ -417,7 +414,7 @@ pub(crate) struct SessionConfiguration {
     /// When to escalate for approval for execution
     approval_policy: Constrained<AskForApproval>,
     /// How to sandbox commands executed in the system
-    sandbox_policy: SandboxPolicy,
+    sandbox_policy: Constrained<SandboxPolicy>,
 
     /// Working directory that should be treated as the *root* of the
     /// session. All relative paths supplied by the model as well as the
@@ -428,9 +425,6 @@ pub(crate) struct SessionConfiguration {
     /// operate deterministically.
     cwd: PathBuf,
 
-    /// Execpolicy policy, applied only when enabled by feature flag.
-    exec_policy: Arc<RwLock<ExecPolicy>>,
-
     // TODO(pakrym): Remove config from here
     original_config_do_not_use: Arc<Config>,
     /// Source of the session (cli, vscode, exec, mcp, ...)
@@ -453,7 +447,7 @@ impl SessionConfiguration {
             next_configuration.approval_policy.set(approval_policy)?;
         }
         if let Some(sandbox_policy) = updates.sandbox_policy.clone() {
-            next_configuration.sandbox_policy = sandbox_policy;
+            next_configuration.sandbox_policy.set(sandbox_policy)?;
         }
         if let Some(cwd) = updates.cwd.clone() {
             next_configuration.cwd = cwd;
@@ -528,14 +522,13 @@ impl Session {
             compact_prompt: session_configuration.compact_prompt.clone(),
             user_instructions: session_configuration.user_instructions.clone(),
             approval_policy: session_configuration.approval_policy.value(),
-            sandbox_policy: session_configuration.sandbox_policy.clone(),
+            sandbox_policy: session_configuration.sandbox_policy.get().clone(),
             shell_environment_policy: per_turn_config.shell_environment_policy.clone(),
             tools_config,
             ghost_snapshot: per_turn_config.ghost_snapshot.clone(),
             final_output_json_schema: None,
             codex_linux_sandbox_exe: per_turn_config.codex_linux_sandbox_exe.clone(),
             tool_call_gate: Arc::new(ReadinessFlag::new()),
-            exec_policy: session_configuration.exec_policy.clone(),
             truncation_policy: TruncationPolicy::new(
                 per_turn_config.as_ref(),
                 model_family.truncation_policy,
@@ -549,6 +542,7 @@ impl Session {
         config: Arc<Config>,
         auth_manager: Arc<AuthManager>,
         models_manager: Arc<ModelsManager>,
+        exec_policy: ExecPolicyManager,
         tx_event: Sender<Event>,
         initial_history: InitialHistory,
         session_source: SessionSource,
@@ -645,7 +639,7 @@ impl Session {
             config.model_context_window,
             config.model_auto_compact_token_limit,
             config.approval_policy.value(),
-            config.sandbox_policy.clone(),
+            config.sandbox_policy.get().clone(),
             config.mcp_servers.keys().map(String::as_str).collect(),
             config.active_profile.clone(),
         );
@@ -668,6 +662,7 @@ impl Session {
             rollout: Mutex::new(Some(rollout_recorder)),
             user_shell: Arc::new(default_shell),
             show_raw_agent_reasoning: config.show_raw_agent_reasoning,
+            exec_policy,
             auth_manager: Arc::clone(&auth_manager),
             otel_manager,
             models_manager: Arc::clone(&models_manager),
@@ -695,7 +690,7 @@ impl Session {
                 model: session_configuration.model.clone(),
                 model_provider_id: config.model_provider_id.clone(),
                 approval_policy: session_configuration.approval_policy.value(),
-                sandbox_policy: session_configuration.sandbox_policy.clone(),
+                sandbox_policy: session_configuration.sandbox_policy.get().clone(),
                 cwd: session_configuration.cwd.clone(),
                 reasoning_effort: session_configuration.model_reasoning_effort,
                 history_log_id,
@@ -712,7 +707,7 @@ impl Session {
         // Construct sandbox_state before initialize() so it can be sent to each
         // MCP server immediately after it becomes ready (avoiding blocking).
         let sandbox_state = SandboxState {
-            sandbox_policy: session_configuration.sandbox_policy.clone(),
+            sandbox_policy: session_configuration.sandbox_policy.get().clone(),
             codex_linux_sandbox_exe: config.codex_linux_sandbox_exe.clone(),
             sandbox_cwd: session_configuration.cwd.clone(),
         };
@@ -733,30 +728,6 @@ impl Session {
         // record_initial_history can emit events. We record only after the SessionConfiguredEvent is emitted.
         sess.record_initial_history(initial_history).await;
 
-        if sess.enabled(Feature::Skills) {
-            let mut rx = sess
-                .services
-                .skills_manager
-                .subscribe_skills_update_notifications();
-            let sess = Arc::downgrade(&sess);
-            tokio::spawn(async move {
-                loop {
-                    match rx.recv().await {
-                        Ok(()) => {
-                            let Some(sess) = sess.upgrade() else {
-                                break;
-                            };
-                            let turn_context = sess.new_default_turn().await;
-                            sess.send_event(turn_context.as_ref(), EventMsg::SkillsUpdateAvailable)
-                                .await;
-                        }
-                        Err(tokio::sync::broadcast::error::RecvError::Lagged(_)) => continue,
-                        Err(tokio::sync::broadcast::error::RecvError::Closed) => break,
-                    }
-                }
-            });
-        }
-
         Ok(sess)
     }
 
@@ -861,11 +832,8 @@ impl Session {
                 Ok(())
             }
             Err(err) => {
-                let wrapped = ConstraintError {
-                    message: format!("Could not update config: {err}"),
-                };
-                warn!(%wrapped, "rejected session settings update");
-                Err(wrapped)
+                warn!("rejected session settings update: {err}");
+                Err(err)
             }
         }
     }
@@ -886,18 +854,15 @@ impl Session {
                 }
                 Err(err) => {
                     drop(state);
-                    let wrapped = ConstraintError {
-                        message: format!("Could not update config: {err}"),
-                    };
                     self.send_event_raw(Event {
                         id: sub_id.clone(),
                         msg: EventMsg::Error(ErrorEvent {
-                            message: wrapped.to_string(),
+                            message: err.to_string(),
                             codex_error_info: Some(CodexErrorInfo::BadRequest),
                         }),
                     })
                     .await;
-                    return Err(wrapped);
+                    return Err(err);
                 }
             }
         };
@@ -923,7 +888,7 @@ impl Session {
 
         if sandbox_policy_changed {
             let sandbox_state = SandboxState {
-                sandbox_policy: per_turn_config.sandbox_policy.clone(),
+                sandbox_policy: per_turn_config.sandbox_policy.get().clone(),
                 codex_linux_sandbox_exe: per_turn_config.codex_linux_sandbox_exe.clone(),
                 sandbox_cwd: per_turn_config.cwd.clone(),
             };
@@ -1057,29 +1022,24 @@ impl Session {
         amendment: &ExecPolicyAmendment,
     ) -> Result<(), ExecPolicyUpdateError> {
         let features = self.features.clone();
-        let (codex_home, current_policy) = {
-            let state = self.state.lock().await;
-            (
-                state
-                    .session_configuration
-                    .original_config_do_not_use
-                    .codex_home
-                    .clone(),
-                state.session_configuration.exec_policy.clone(),
-            )
-        };
+        let codex_home = self
+            .state
+            .lock()
+            .await
+            .session_configuration
+            .original_config_do_not_use
+            .codex_home
+            .clone();
 
         if !features.enabled(Feature::ExecPolicy) {
             error!("attempted to append execpolicy rule while execpolicy feature is disabled");
             return Err(ExecPolicyUpdateError::FeatureDisabled);
         }
 
-        crate::exec_policy::append_execpolicy_amendment_and_update(
-            &codex_home,
-            &current_policy,
-            &amendment.command,
-        )
-        .await?;
+        self.services
+            .exec_policy
+            .append_amendment_and_update(&codex_home, amendment)
+            .await?;
 
         Ok(())
     }
@@ -1464,12 +1424,14 @@ impl Session {
         message: impl Into<String>,
         codex_error: CodexErr,
     ) {
+        let additional_details = codex_error.to_string();
         let codex_error_info = CodexErrorInfo::ResponseStreamDisconnected {
             http_status_code: codex_error.http_status_code_value(),
         };
         let event = EventMsg::StreamError(StreamErrorEvent {
             message: message.into(),
             codex_error_info: Some(codex_error_info),
+            additional_details: Some(additional_details),
         });
         self.send_event(turn_context, event).await;
     }
@@ -2186,7 +2148,6 @@ async fn spawn_review_thread(
         final_output_json_schema: None,
         codex_linux_sandbox_exe: parent_turn_context.codex_linux_sandbox_exe.clone(),
         tool_call_gate: Arc::new(ReadinessFlag::new()),
-        exec_policy: parent_turn_context.exec_policy.clone(),
         truncation_policy: TruncationPolicy::new(&per_turn_config, model_family.truncation_policy),
     };
 
@@ -2212,6 +2173,7 @@ fn skills_to_info(skills: &[SkillMetadata]) -> Vec<ProtocolSkillMetadata> {
         .map(|skill| ProtocolSkillMetadata {
             name: skill.name.clone(),
             description: skill.description.clone(),
+            short_description: skill.short_description.clone(),
             path: skill.path.clone(),
             scope: skill.scope,
         })
@@ -2266,15 +2228,11 @@ pub(crate) async fn run_task(
     });
     sess.send_event(&turn_context, event).await;
 
-    let skills_outcome = if sess.enabled(Feature::Skills) {
-        Some(
-            sess.services
-                .skills_manager
-                .skills_for_cwd(&turn_context.cwd),
-        )
-    } else {
-        None
-    };
+    let skills_outcome = sess.enabled(Feature::Skills).then(|| {
+        sess.services
+            .skills_manager
+            .skills_for_cwd(&turn_context.cwd)
+    });
 
     let SkillInjections {
         items: skill_items,
@@ -2560,6 +2518,11 @@ async fn try_run_turn(
         model: turn_context.client.get_model(),
         effort: turn_context.client.get_reasoning_effort(),
         summary: turn_context.client.get_reasoning_summary(),
+        base_instructions: turn_context.base_instructions.clone(),
+        user_instructions: turn_context.user_instructions.clone(),
+        developer_instructions: turn_context.developer_instructions.clone(),
+        final_output_json_schema: turn_context.final_output_json_schema.clone(),
+        truncation_policy: Some(turn_context.truncation_policy.into()),
     });
 
     sess.persist_rollout_items(&[rollout_item]).await;
@@ -2652,6 +2615,10 @@ async fn try_run_turn(
                 // token usage is available to avoid duplicate TokenCount events.
                 sess.update_rate_limits(&turn_context, snapshot).await;
             }
+            ResponseEvent::ModelsEtag(etag) => {
+                // Update internal state with latest models etag
+                sess.services.models_manager.refresh_if_new_etag(etag).await;
+            }
             ResponseEvent::Completed {
                 response_id: _,
                 token_usage,
@@ -2778,12 +2745,12 @@ pub(crate) use tests::make_session_and_context_with_rx;
 mod tests {
     use super::*;
     use crate::CodexAuth;
-    use crate::config::ConfigOverrides;
-    use crate::config::ConfigToml;
+    use crate::config::ConfigBuilder;
     use crate::exec::ExecToolCallOutput;
     use crate::function_tool::FunctionCallError;
     use crate::shell::default_user_shell;
     use crate::tools::format_exec_output_str;
+
     use codex_protocol::models::FunctionCallOutputPayload;
 
     use crate::protocol::CompactedItem;
@@ -2806,6 +2773,7 @@ mod tests {
     use codex_app_server_protocol::AuthMode;
     use codex_protocol::models::ContentItem;
     use codex_protocol::models::ResponseItem;
+    use std::path::Path;
     use std::time::Duration;
     use tokio::time::sleep;
 
@@ -2818,9 +2786,9 @@ mod tests {
     use std::sync::Arc;
     use std::time::Duration as StdDuration;
 
-    #[test]
-    fn reconstruct_history_matches_live_compactions() {
-        let (session, turn_context) = make_session_and_context();
+    #[tokio::test]
+    async fn reconstruct_history_matches_live_compactions() {
+        let (session, turn_context) = make_session_and_context().await;
         let (rollout_items, expected) = sample_rollout(&session, &turn_context);
 
         let reconstructed = session.reconstruct_history_from_rollout(&turn_context, &rollout_items);
@@ -2828,47 +2796,40 @@ mod tests {
         assert_eq!(expected, reconstructed);
     }
 
-    #[test]
-    fn record_initial_history_reconstructs_resumed_transcript() {
-        let (session, turn_context) = make_session_and_context();
+    #[tokio::test]
+    async fn record_initial_history_reconstructs_resumed_transcript() {
+        let (session, turn_context) = make_session_and_context().await;
         let (rollout_items, expected) = sample_rollout(&session, &turn_context);
 
-        tokio_test::block_on(session.record_initial_history(InitialHistory::Resumed(
-            ResumedHistory {
+        session
+            .record_initial_history(InitialHistory::Resumed(ResumedHistory {
                 conversation_id: ConversationId::default(),
                 history: rollout_items,
                 rollout_path: PathBuf::from("/tmp/resume.jsonl"),
-            },
-        )));
+            }))
+            .await;
 
-        let actual = tokio_test::block_on(async {
-            session.state.lock().await.clone_history().get_history()
-        });
+        let actual = session.state.lock().await.clone_history().get_history();
         assert_eq!(expected, actual);
     }
 
-    #[test]
-    fn record_initial_history_reconstructs_forked_transcript() {
-        let (session, turn_context) = make_session_and_context();
+    #[tokio::test]
+    async fn record_initial_history_reconstructs_forked_transcript() {
+        let (session, turn_context) = make_session_and_context().await;
         let (rollout_items, expected) = sample_rollout(&session, &turn_context);
 
-        tokio_test::block_on(session.record_initial_history(InitialHistory::Forked(rollout_items)));
+        session
+            .record_initial_history(InitialHistory::Forked(rollout_items))
+            .await;
 
-        let actual = tokio_test::block_on(async {
-            session.state.lock().await.clone_history().get_history()
-        });
+        let actual = session.state.lock().await.clone_history().get_history();
         assert_eq!(expected, actual);
     }
 
-    #[test]
-    fn set_rate_limits_retains_previous_credits() {
+    #[tokio::test]
+    async fn set_rate_limits_retains_previous_credits() {
         let codex_home = tempfile::tempdir().expect("create temp dir");
-        let config = Config::load_from_base_config_with_overrides(
-            ConfigToml::default(),
-            ConfigOverrides::default(),
-            codex_home.path().to_path_buf(),
-        )
-        .expect("load default test config");
+        let config = build_test_config(codex_home.path()).await;
         let config = Arc::new(config);
         let model = ModelsManager::get_model_offline(config.model.as_deref());
         let session_configuration = SessionConfiguration {
@@ -2884,7 +2845,6 @@ mod tests {
             sandbox_policy: config.sandbox_policy.clone(),
             cwd: config.cwd.clone(),
             original_config_do_not_use: Arc::clone(&config),
-            exec_policy: Arc::new(RwLock::new(ExecPolicy::empty())),
             session_source: SessionSource::Exec,
         };
 
@@ -2932,15 +2892,10 @@ mod tests {
         );
     }
 
-    #[test]
-    fn set_rate_limits_updates_plan_type_when_present() {
+    #[tokio::test]
+    async fn set_rate_limits_updates_plan_type_when_present() {
         let codex_home = tempfile::tempdir().expect("create temp dir");
-        let config = Config::load_from_base_config_with_overrides(
-            ConfigToml::default(),
-            ConfigOverrides::default(),
-            codex_home.path().to_path_buf(),
-        )
-        .expect("load default test config");
+        let config = build_test_config(codex_home.path()).await;
         let config = Arc::new(config);
         let model = ModelsManager::get_model_offline(config.model.as_deref());
         let session_configuration = SessionConfiguration {
@@ -2956,7 +2911,6 @@ mod tests {
             sandbox_policy: config.sandbox_policy.clone(),
             cwd: config.cwd.clone(),
             original_config_do_not_use: Arc::clone(&config),
-            exec_policy: Arc::new(RwLock::new(ExecPolicy::empty())),
             session_source: SessionSource::Exec,
         };
 
@@ -3030,8 +2984,8 @@ mod tests {
         assert_eq!(expected, got);
     }
 
-    #[test]
-    fn includes_timed_out_message() {
+    #[tokio::test]
+    async fn includes_timed_out_message() {
         let exec = ExecToolCallOutput {
             exit_code: 0,
             stdout: StreamOutput::new(String::new()),
@@ -3040,7 +2994,7 @@ mod tests {
             duration: StdDuration::from_secs(1),
             timed_out: true,
         };
-        let (_, turn_context) = make_session_and_context();
+        let (_, turn_context) = make_session_and_context().await;
 
         let out = format_exec_output_str(&exec, turn_context.truncation_policy);
 
@@ -3113,6 +3067,14 @@ mod tests {
         })
     }
 
+    async fn build_test_config(codex_home: &Path) -> Config {
+        ConfigBuilder::default()
+            .codex_home(codex_home.to_path_buf())
+            .build()
+            .await
+            .expect("load default test config")
+    }
+
     fn otel_manager(
         conversation_id: ConversationId,
         config: &Config,
@@ -3132,20 +3094,16 @@ mod tests {
         )
     }
 
-    pub(crate) fn make_session_and_context() -> (Session, TurnContext) {
+    pub(crate) async fn make_session_and_context() -> (Session, TurnContext) {
         let (tx_event, _rx_event) = async_channel::unbounded();
         let codex_home = tempfile::tempdir().expect("create temp dir");
-        let config = Config::load_from_base_config_with_overrides(
-            ConfigToml::default(),
-            ConfigOverrides::default(),
-            codex_home.path().to_path_buf(),
-        )
-        .expect("load default test config");
+        let config = build_test_config(codex_home.path()).await;
         let config = Arc::new(config);
         let conversation_id = ConversationId::default();
         let auth_manager =
             AuthManager::from_auth_for_testing(CodexAuth::from_api_key("Test API Key"));
         let models_manager = Arc::new(ModelsManager::new(auth_manager.clone()));
+        let exec_policy = ExecPolicyManager::default();
         let model = ModelsManager::get_model_offline(config.model.as_deref());
         let session_configuration = SessionConfiguration {
             provider: config.model_provider.clone(),
@@ -3160,7 +3118,6 @@ mod tests {
             sandbox_policy: config.sandbox_policy.clone(),
             cwd: config.cwd.clone(),
             original_config_do_not_use: Arc::clone(&config),
-            exec_policy: Arc::new(RwLock::new(ExecPolicy::empty())),
             session_source: SessionSource::Exec,
         };
         let per_turn_config = Session::build_per_turn_config(&session_configuration);
@@ -3186,9 +3143,10 @@ mod tests {
             rollout: Mutex::new(None),
             user_shell: Arc::new(default_user_shell()),
             show_raw_agent_reasoning: config.show_raw_agent_reasoning,
+            exec_policy,
             auth_manager: auth_manager.clone(),
             otel_manager: otel_manager.clone(),
-            models_manager,
+            models_manager: Arc::clone(&models_manager),
             tool_approvals: Mutex::new(ApprovalStore::default()),
             skills_manager,
         };
@@ -3219,24 +3177,20 @@ mod tests {
 
     // Like make_session_and_context, but returns Arc<Session> and the event receiver
     // so tests can assert on emitted events.
-    pub(crate) fn make_session_and_context_with_rx() -> (
+    pub(crate) async fn make_session_and_context_with_rx() -> (
         Arc<Session>,
         Arc<TurnContext>,
         async_channel::Receiver<Event>,
     ) {
         let (tx_event, rx_event) = async_channel::unbounded();
         let codex_home = tempfile::tempdir().expect("create temp dir");
-        let config = Config::load_from_base_config_with_overrides(
-            ConfigToml::default(),
-            ConfigOverrides::default(),
-            codex_home.path().to_path_buf(),
-        )
-        .expect("load default test config");
+        let config = build_test_config(codex_home.path()).await;
         let config = Arc::new(config);
         let conversation_id = ConversationId::default();
         let auth_manager =
             AuthManager::from_auth_for_testing(CodexAuth::from_api_key("Test API Key"));
         let models_manager = Arc::new(ModelsManager::new(auth_manager.clone()));
+        let exec_policy = ExecPolicyManager::default();
         let model = ModelsManager::get_model_offline(config.model.as_deref());
         let session_configuration = SessionConfiguration {
             provider: config.model_provider.clone(),
@@ -3251,7 +3205,6 @@ mod tests {
             sandbox_policy: config.sandbox_policy.clone(),
             cwd: config.cwd.clone(),
             original_config_do_not_use: Arc::clone(&config),
-            exec_policy: Arc::new(RwLock::new(ExecPolicy::empty())),
             session_source: SessionSource::Exec,
         };
         let per_turn_config = Session::build_per_turn_config(&session_configuration);
@@ -3277,9 +3230,10 @@ mod tests {
             rollout: Mutex::new(None),
             user_shell: Arc::new(default_user_shell()),
             show_raw_agent_reasoning: config.show_raw_agent_reasoning,
+            exec_policy,
             auth_manager: Arc::clone(&auth_manager),
             otel_manager: otel_manager.clone(),
-            models_manager,
+            models_manager: Arc::clone(&models_manager),
             tool_approvals: Mutex::new(ApprovalStore::default()),
             skills_manager,
         };
@@ -3310,7 +3264,7 @@ mod tests {
 
     #[tokio::test]
     async fn record_model_warning_appends_user_message() {
-        let (mut session, turn_context) = make_session_and_context();
+        let (mut session, turn_context) = make_session_and_context().await;
         let mut features = Features::with_defaults();
         features.enable(Feature::ModelWarnings);
         session.features = features;
@@ -3369,7 +3323,7 @@ mod tests {
     #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
     #[test_log::test]
     async fn abort_regular_task_emits_turn_aborted_only() {
-        let (sess, tc, rx) = make_session_and_context_with_rx();
+        let (sess, tc, rx) = make_session_and_context_with_rx().await;
         let input = vec![UserInput::Text {
             text: "hello".to_string(),
         }];
@@ -3398,7 +3352,7 @@ mod tests {
 
     #[tokio::test]
     async fn abort_gracefuly_emits_turn_aborted_only() {
-        let (sess, tc, rx) = make_session_and_context_with_rx();
+        let (sess, tc, rx) = make_session_and_context_with_rx().await;
         let input = vec![UserInput::Text {
             text: "hello".to_string(),
         }];
@@ -3424,7 +3378,7 @@ mod tests {
 
     #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
     async fn abort_review_task_emits_exited_then_aborted_and_records_history() {
-        let (sess, tc, rx) = make_session_and_context_with_rx();
+        let (sess, tc, rx) = make_session_and_context_with_rx().await;
         let input = vec![UserInput::Text {
             text: "start review".to_string(),
         }];
@@ -3472,7 +3426,7 @@ mod tests {
 
     #[tokio::test]
     async fn fatal_tool_error_stops_turn_and_reports_error() {
-        let (session, turn_context, _rx) = make_session_and_context_with_rx();
+        let (session, turn_context, _rx) = make_session_and_context_with_rx().await;
         let tools = {
             session
                 .services
@@ -3635,7 +3589,7 @@ mod tests {
         use crate::turn_diff_tracker::TurnDiffTracker;
         use std::collections::HashMap;
 
-        let (session, mut turn_context_raw) = make_session_and_context();
+        let (session, mut turn_context_raw) = make_session_and_context().await;
         // Ensure policy is NOT OnRequest so the early rejection path triggers
         turn_context_raw.approval_policy = AskForApproval::OnFailure;
         let session = Arc::new(session);
@@ -3766,7 +3720,7 @@ mod tests {
         use crate::sandboxing::SandboxPermissions;
         use crate::turn_diff_tracker::TurnDiffTracker;
 
-        let (session, mut turn_context_raw) = make_session_and_context();
+        let (session, mut turn_context_raw) = make_session_and_context().await;
         turn_context_raw.approval_policy = AskForApproval::OnFailure;
         let session = Arc::new(session);
         let turn_context = Arc::new(turn_context_raw);

codex-rs/core/src/codex_delegate.rs

@@ -25,7 +25,7 @@ use crate::codex::Session;
 use crate::codex::TurnContext;
 use crate::config::Config;
 use crate::error::CodexErr;
-use crate::openai_models::models_manager::ModelsManager;
+use crate::models_manager::manager::ModelsManager;
 use codex_protocol::protocol::InitialHistory;
 
 /// Start an interactive sub-Codex conversation and return IO channels.
@@ -366,7 +366,7 @@ mod tests {
             rx_event: rx_events,
         });
 
-        let (session, ctx, _rx_evt) = crate::codex::make_session_and_context_with_rx();
+        let (session, ctx, _rx_evt) = crate::codex::make_session_and_context_with_rx().await;
 
         let (tx_out, rx_out) = bounded(1);
         tx_out

codex-rs/core/src/command_safety/is_dangerous_command.rs

@@ -21,8 +21,11 @@ pub fn requires_initial_appoval(
     match policy {
         AskForApproval::Never | AskForApproval::OnFailure => false,
         AskForApproval::OnRequest => {
-            // In DangerFullAccess, only prompt if the command looks dangerous.
-            if matches!(sandbox_policy, SandboxPolicy::DangerFullAccess) {
+            // In DangerFullAccess or ExternalSandbox, only prompt if the command looks dangerous.
+            if matches!(
+                sandbox_policy,
+                SandboxPolicy::DangerFullAccess | SandboxPolicy::ExternalSandbox { .. }
+            ) {
                 return command_might_be_dangerous(command);
             }
 
@@ -83,6 +86,7 @@ fn is_dangerous_to_call_with_exec(command: &[String]) -> bool {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use codex_protocol::protocol::NetworkAccess;
 
     fn vec_str(items: &[&str]) -> Vec<String> {
         items.iter().map(std::string::ToString::to_string).collect()
@@ -150,4 +154,23 @@ mod tests {
     fn rm_f_is_dangerous() {
         assert!(command_might_be_dangerous(&vec_str(&["rm", "-f", "/"])));
     }
+
+    #[test]
+    fn external_sandbox_only_prompts_for_dangerous_commands() {
+        let external_policy = SandboxPolicy::ExternalSandbox {
+            network_access: NetworkAccess::Restricted,
+        };
+        assert!(!requires_initial_appoval(
+            AskForApproval::OnRequest,
+            &external_policy,
+            &vec_str(&["ls"]),
+            SandboxPermissions::UseDefault,
+        ));
+        assert!(requires_initial_appoval(
+            AskForApproval::OnRequest,
+            &external_policy,
+            &vec_str(&["rm", "-rf", "/"]),
+            SandboxPermissions::UseDefault,
+        ));
+    }
 }

codex-rs/core/src/compact.rs

@@ -86,6 +86,11 @@ async fn run_compact_task_inner(
         model: turn_context.client.get_model(),
         effort: turn_context.client.get_reasoning_effort(),
         summary: turn_context.client.get_reasoning_summary(),
+        base_instructions: turn_context.base_instructions.clone(),
+        user_instructions: turn_context.user_instructions.clone(),
+        developer_instructions: turn_context.developer_instructions.clone(),
+        final_output_json_schema: turn_context.final_output_json_schema.clone(),
+        truncation_policy: Some(turn_context.truncation_policy.into()),
     });
     sess.persist_rollout_items(&[rollout_item]).await;
 

codex-rs/core/src/config/constraint.rs

@@ -4,19 +4,25 @@ use std::sync::Arc;
 use thiserror::Error;
 
 #[derive(Debug, Error, PartialEq, Eq)]
-#[error("{message}")]
-pub struct ConstraintError {
-    pub message: String,
+pub enum ConstraintError {
+    #[error("value `{candidate}` is not in the allowed set {allowed}")]
+    InvalidValue { candidate: String, allowed: String },
+
+    #[error("field `{field_name}` cannot be empty")]
+    EmptyField { field_name: String },
 }
 
 impl ConstraintError {
     pub fn invalid_value(candidate: impl Into<String>, allowed: impl Into<String>) -> Self {
-        Self {
-            message: format!(
-                "value `{}` is not in the allowed set {}",
-                candidate.into(),
-                allowed.into()
-            ),
+        Self::InvalidValue {
+            candidate: candidate.into(),
+            allowed: allowed.into(),
+        }
+    }
+
+    pub fn empty_field(field_name: impl Into<String>) -> Self {
+        Self::EmptyField {
+            field_name: field_name.into(),
         }
     }
 }
@@ -57,6 +63,32 @@ impl<T: Send + Sync> Constrained<T> {
         }
     }
 
+    pub fn allow_only(value: T) -> Self
+    where
+        T: PartialEq + Send + Sync + fmt::Debug + Clone + 'static,
+    {
+        #[expect(clippy::expect_used)]
+        Self::new(value.clone(), move |candidate| {
+            if *candidate == value {
+                Ok(())
+            } else {
+                Err(ConstraintError::invalid_value(
+                    format!("{candidate:?}"),
+                    format!("{value:?}"),
+                ))
+            }
+        })
+        .expect("initial value should always be valid")
+    }
+
+    /// Allow any value of T, using T's Default as the initial value.
+    pub fn allow_any_from_default() -> Self
+    where
+        T: Default,
+    {
+        Self::allow_any(T::default())
+    }
+
     pub fn allow_values(initial_value: T, allowed: Vec<T>) -> ConstraintResult<Self>
     where
         T: PartialEq + Send + Sync + fmt::Debug + 'static,
@@ -129,6 +161,12 @@ mod tests {
         assert_eq!(constrained.value(), -10);
     }
 
+    #[test]
+    fn constrained_allow_any_default_uses_default_value() {
+        let constrained = Constrained::<i32>::allow_any_from_default();
+        assert_eq!(constrained.value(), 0);
+    }
+
     #[test]
     fn constrained_new_rejects_invalid_initial_value() {
         let result = Constrained::new(0, |value| {

codex-rs/core/src/config/edit.rs

@@ -694,7 +694,6 @@ mod tests {
     use codex_protocol::openai_models::ReasoningEffort;
     use pretty_assertions::assert_eq;
     use tempfile::tempdir;
-    use tokio::runtime::Builder;
     use toml::Value as TomlValue;
 
     #[test]
@@ -1455,22 +1454,16 @@ model_reasoning_effort = "high"
         assert_eq!(contents, initial_expected);
     }
 
-    #[test]
-    fn blocking_set_asynchronous_helpers_available() {
-        let rt = Builder::new_current_thread()
-            .enable_all()
-            .build()
-            .expect("runtime");
+    #[tokio::test]
+    async fn blocking_set_asynchronous_helpers_available() {
         let tmp = tempdir().expect("tmpdir");
         let codex_home = tmp.path().to_path_buf();
 
-        rt.block_on(async {
-            ConfigEditsBuilder::new(&codex_home)
-                .set_hide_full_access_warning(true)
-                .apply()
-                .await
-                .expect("persist");
-        });
+        ConfigEditsBuilder::new(&codex_home)
+            .set_hide_full_access_warning(true)
+            .apply()
+            .await
+            .expect("persist");
 
         let raw = std::fs::read_to_string(codex_home.join(CONFIG_TOML_FILE)).expect("read config");
         let notice = toml::from_str::<TomlValue>(&raw)

codex-rs/core/src/config/mod.rs

@@ -8,10 +8,14 @@ use crate::config::types::OtelConfig;
 use crate::config::types::OtelConfigToml;
 use crate::config::types::OtelExporterKind;
 use crate::config::types::SandboxWorkspaceWrite;
+use crate::config::types::ScrollInputMode;
 use crate::config::types::ShellEnvironmentPolicy;
 use crate::config::types::ShellEnvironmentPolicyToml;
 use crate::config::types::Tui;
 use crate::config::types::UriBasedFileOpener;
+use crate::config_loader::ConfigLayerStack;
+use crate::config_loader::ConfigRequirements;
+use crate::config_loader::LoaderOverrides;
 use crate::config_loader::load_config_layers_state;
 use crate::features::Feature;
 use crate::features::FeatureOverrides;
@@ -34,12 +38,12 @@ use codex_protocol::config_types::SandboxMode;
 use codex_protocol::config_types::TrustLevel;
 use codex_protocol::config_types::Verbosity;
 use codex_protocol::openai_models::ReasoningEffort;
-use codex_protocol::openai_models::ReasoningSummaryFormat;
 use codex_rmcp_client::OAuthCredentialsStoreMode;
 use codex_utils_absolute_path::AbsolutePathBuf;
 use codex_utils_absolute_path::AbsolutePathBufGuard;
 use dirs::home_dir;
 use serde::Deserialize;
+use serde::Serialize;
 use similar::DiffableStr;
 use std::collections::BTreeMap;
 use std::collections::HashMap;
@@ -90,6 +94,10 @@ pub(crate) fn test_config() -> Config {
 /// Application configuration loaded from disk and merged with overrides.
 #[derive(Debug, Clone, PartialEq)]
 pub struct Config {
+    /// Provenance for how this [`Config`] was derived (merged layers + enforced
+    /// requirements).
+    pub config_layer_stack: ConfigLayerStack,
+
     /// Optional override of model selection.
     pub model: Option<String>,
 
@@ -111,7 +119,7 @@ pub struct Config {
     /// Approval policy for executing commands.
     pub approval_policy: Constrained<AskForApproval>,
 
-    pub sandbox_policy: SandboxPolicy,
+    pub sandbox_policy: Constrained<SandboxPolicy>,
 
     /// True if the user passed in an override or set a value in config.toml
     /// for either of approval_policy or sandbox_mode.
@@ -176,6 +184,58 @@ pub struct Config {
     /// Show startup tooltips in the TUI welcome screen.
     pub show_tooltips: bool,
 
+    /// Override the events-per-wheel-tick factor for TUI2 scroll normalization.
+    ///
+    /// This is the same `tui.scroll_events_per_tick` value from `config.toml`, plumbed through the
+    /// merged [`Config`] object (see [`Tui`]) so TUI2 can normalize scroll event density per
+    /// terminal.
+    pub tui_scroll_events_per_tick: Option<u16>,
+
+    /// Override the number of lines applied per wheel tick in TUI2.
+    ///
+    /// This is the same `tui.scroll_wheel_lines` value from `config.toml` (see [`Tui`]). TUI2
+    /// applies it to wheel-like scroll streams. Trackpad-like scrolling uses a separate
+    /// `tui.scroll_trackpad_lines` setting.
+    pub tui_scroll_wheel_lines: Option<u16>,
+
+    /// Override the number of lines per tick-equivalent used for trackpad scrolling in TUI2.
+    ///
+    /// This is the same `tui.scroll_trackpad_lines` value from `config.toml` (see [`Tui`]).
+    pub tui_scroll_trackpad_lines: Option<u16>,
+
+    /// Trackpad acceleration: approximate number of events required to gain +1x speed in TUI2.
+    ///
+    /// This is the same `tui.scroll_trackpad_accel_events` value from `config.toml` (see [`Tui`]).
+    pub tui_scroll_trackpad_accel_events: Option<u16>,
+
+    /// Trackpad acceleration: maximum multiplier applied to trackpad-like streams in TUI2.
+    ///
+    /// This is the same `tui.scroll_trackpad_accel_max` value from `config.toml` (see [`Tui`]).
+    pub tui_scroll_trackpad_accel_max: Option<u16>,
+
+    /// Control how TUI2 interprets mouse scroll input (wheel vs trackpad).
+    ///
+    /// This is the same `tui.scroll_mode` value from `config.toml` (see [`Tui`]).
+    pub tui_scroll_mode: ScrollInputMode,
+
+    /// Override the wheel tick detection threshold (ms) for TUI2 auto scroll mode.
+    ///
+    /// This is the same `tui.scroll_wheel_tick_detect_max_ms` value from `config.toml` (see
+    /// [`Tui`]).
+    pub tui_scroll_wheel_tick_detect_max_ms: Option<u64>,
+
+    /// Override the wheel-like end-of-stream threshold (ms) for TUI2 auto scroll mode.
+    ///
+    /// This is the same `tui.scroll_wheel_like_max_duration_ms` value from `config.toml` (see
+    /// [`Tui`]).
+    pub tui_scroll_wheel_like_max_duration_ms: Option<u64>,
+
+    /// Invert mouse scroll direction for TUI2.
+    ///
+    /// This is the same `tui.scroll_invert` value from `config.toml` (see [`Tui`]) and is applied
+    /// consistently to both mouse wheels and trackpads.
+    pub tui_scroll_invert: bool,
+
     /// The directory that should be treated as the current working directory
     /// for the session. All relative paths inside the business-logic layer are
     /// resolved against this path.
@@ -242,9 +302,6 @@ pub struct Config {
     /// Optional override to force-enable reasoning summaries for the configured model.
     pub model_supports_reasoning_summaries: Option<bool>,
 
-    /// Optional override to force reasoning summary format for the configured model.
-    pub model_reasoning_summary_format: Option<ReasoningSummaryFormat>,
-
     /// Optional verbosity control for GPT-5 models (Responses API `text.verbosity`).
     pub model_verbosity: Option<Verbosity>,
 
@@ -267,10 +324,6 @@ pub struct Config {
     /// If set to `true`, used only the experimental unified exec tool.
     pub use_experimental_unified_exec_tool: bool,
 
-    /// If set to `true`, use the experimental official Rust MCP client.
-    /// https://github.com/modelcontextprotocol/rust-sdk
-    pub use_experimental_use_rmcp_client: bool,
-
     /// Settings for ghost snapshots (used for undo).
     pub ghost_snapshot: GhostSnapshotConfig,
 
@@ -304,41 +357,119 @@ pub struct Config {
     pub otel: crate::config::types::OtelConfig,
 }
 
-impl Config {
-    pub async fn load_with_cli_overrides(
-        cli_overrides: Vec<(String, TomlValue)>,
-        overrides: ConfigOverrides,
-    ) -> std::io::Result<Self> {
-        let codex_home = find_codex_home()?;
+#[derive(Debug, Clone, Default)]
+pub struct ConfigBuilder {
+    codex_home: Option<PathBuf>,
+    cli_overrides: Option<Vec<(String, TomlValue)>>,
+    harness_overrides: Option<ConfigOverrides>,
+    loader_overrides: Option<LoaderOverrides>,
+}
 
-        let root_value = load_resolved_config(
-            &codex_home,
+impl ConfigBuilder {
+    pub fn codex_home(mut self, codex_home: PathBuf) -> Self {
+        self.codex_home = Some(codex_home);
+        self
+    }
+
+    pub fn cli_overrides(mut self, cli_overrides: Vec<(String, TomlValue)>) -> Self {
+        self.cli_overrides = Some(cli_overrides);
+        self
+    }
+
+    pub fn harness_overrides(mut self, harness_overrides: ConfigOverrides) -> Self {
+        self.harness_overrides = Some(harness_overrides);
+        self
+    }
+
+    pub fn loader_overrides(mut self, loader_overrides: LoaderOverrides) -> Self {
+        self.loader_overrides = Some(loader_overrides);
+        self
+    }
+
+    pub async fn build(self) -> std::io::Result<Config> {
+        let Self {
+            codex_home,
             cli_overrides,
-            crate::config_loader::LoaderOverrides::default(),
+            harness_overrides,
+            loader_overrides,
+        } = self;
+        let codex_home = codex_home.map_or_else(find_codex_home, std::io::Result::Ok)?;
+        let cli_overrides = cli_overrides.unwrap_or_default();
+        let harness_overrides = harness_overrides.unwrap_or_default();
+        let loader_overrides = loader_overrides.unwrap_or_default();
+        let cwd = match harness_overrides.cwd.as_deref() {
+            Some(path) => AbsolutePathBuf::try_from(path)?,
+            None => AbsolutePathBuf::current_dir()?,
+        };
+        let config_layer_stack =
+            load_config_layers_state(&codex_home, Some(cwd), &cli_overrides, loader_overrides)
+                .await?;
+        let merged_toml = config_layer_stack.effective_config();
+
+        // Note that each layer in ConfigLayerStack should have resolved
+        // relative paths to absolute paths based on the parent folder of the
+        // respective config file, so we should be safe to deserialize without
+        // AbsolutePathBufGuard here.
+        let config_toml: ConfigToml = merged_toml
+            .try_into()
+            .map_err(|e| std::io::Error::new(std::io::ErrorKind::InvalidData, e))?;
+        Config::load_config_with_layer_stack(
+            config_toml,
+            harness_overrides,
+            codex_home,
+            config_layer_stack,
         )
-        .await?;
-
-        let cfg = deserialize_config_toml_with_base(root_value, &codex_home).map_err(|e| {
-            tracing::error!("Failed to deserialize overridden config: {e}");
-            e
-        })?;
-
-        Self::load_from_base_config_with_overrides(cfg, overrides, codex_home)
     }
 }
 
+impl Config {
+    /// This is the preferred way to create an instance of [Config].
+    pub async fn load_with_cli_overrides(
+        cli_overrides: Vec<(String, TomlValue)>,
+    ) -> std::io::Result<Self> {
+        ConfigBuilder::default()
+            .cli_overrides(cli_overrides)
+            .build()
+            .await
+    }
+
+    /// This is a secondary way of creating [Config], which is appropriate when
+    /// the harness is meant to be used with a specific configuration that
+    /// ignores user settings. For example, the `codex exec` subcommand is
+    /// designed to use [AskForApproval::Never] exclusively.
+    ///
+    /// Further, [ConfigOverrides] contains some options that are not supported
+    /// in [ConfigToml], such as `cwd` and `codex_linux_sandbox_exe`.
+    pub async fn load_with_cli_overrides_and_harness_overrides(
+        cli_overrides: Vec<(String, TomlValue)>,
+        harness_overrides: ConfigOverrides,
+    ) -> std::io::Result<Self> {
+        ConfigBuilder::default()
+            .cli_overrides(cli_overrides)
+            .harness_overrides(harness_overrides)
+            .build()
+            .await
+    }
+}
+
+/// DEPRECATED: Use [Config::load_with_cli_overrides()] instead because working
+/// with [ConfigToml] directly means that [ConfigRequirements] have not been
+/// applied yet, which risks failing to enforce required constraints.
 pub async fn load_config_as_toml_with_cli_overrides(
     codex_home: &Path,
+    cwd: &AbsolutePathBuf,
     cli_overrides: Vec<(String, TomlValue)>,
 ) -> std::io::Result<ConfigToml> {
-    let root_value = load_resolved_config(
+    let config_layer_stack = load_config_layers_state(
         codex_home,
-        cli_overrides,
-        crate::config_loader::LoaderOverrides::default(),
+        Some(cwd.clone()),
+        &cli_overrides,
+        LoaderOverrides::default(),
     )
     .await?;
 
-    let cfg = deserialize_config_toml_with_base(root_value, codex_home).map_err(|e| {
+    let merged_toml = config_layer_stack.effective_config();
+    let cfg = deserialize_config_toml_with_base(merged_toml, codex_home).map_err(|e| {
         tracing::error!("Failed to deserialize overridden config: {e}");
         e
     })?;
@@ -346,15 +477,6 @@ pub async fn load_config_as_toml_with_cli_overrides(
     Ok(cfg)
 }
 
-async fn load_resolved_config(
-    codex_home: &Path,
-    cli_overrides: Vec<(String, TomlValue)>,
-    overrides: crate::config_loader::LoaderOverrides,
-) -> std::io::Result<TomlValue> {
-    let layers = load_config_layers_state(codex_home, &cli_overrides, overrides).await?;
-    Ok(layers.effective_config())
-}
-
 fn deserialize_config_toml_with_base(
     root_value: TomlValue,
     config_base_dir: &Path,
@@ -370,13 +492,22 @@ fn deserialize_config_toml_with_base(
 pub async fn load_global_mcp_servers(
     codex_home: &Path,
 ) -> std::io::Result<BTreeMap<String, McpServerConfig>> {
-    let root_value = load_resolved_config(
-        codex_home,
-        Vec::new(),
-        crate::config_loader::LoaderOverrides::default(),
-    )
-    .await?;
-    let Some(servers_value) = root_value.get("mcp_servers") else {
+    // In general, Config::load_with_cli_overrides() should be used to load the
+    // full config with requirements.toml applied, but in this case, we need
+    // access to the raw TOML in order to warn the user about deprecated fields.
+    //
+    // Note that a more precise way to do this would be to audit the individual
+    // config layers for deprecated fields rather than reporting on the merged
+    // result.
+    let cli_overrides = Vec::<(String, TomlValue)>::new();
+    // There is no cwd/project context for this query, so this will not include
+    // MCP servers defined in in-repo .codex/ folders.
+    let cwd: Option<AbsolutePathBuf> = None;
+    let config_layer_stack =
+        load_config_layers_state(codex_home, cwd, &cli_overrides, LoaderOverrides::default())
+            .await?;
+    let merged_toml = config_layer_stack.effective_config();
+    let Some(servers_value) = merged_toml.get("mcp_servers") else {
         return Ok(BTreeMap::new());
     };
 
@@ -535,7 +666,7 @@ pub fn set_default_oss_provider(codex_home: &Path, provider: &str) -> std::io::R
 }
 
 /// Base config deserialized from ~/.codex/config.toml.
-#[derive(Deserialize, Debug, Clone, Default, PartialEq)]
+#[derive(Serialize, Deserialize, Debug, Clone, Default, PartialEq)]
 pub struct ConfigToml {
     /// Optional override of model selection.
     pub model: Option<String>,
@@ -651,9 +782,6 @@ pub struct ConfigToml {
     /// Override to force-enable reasoning summaries for the configured model.
     pub model_supports_reasoning_summaries: Option<bool>,
 
-    /// Override to force reasoning summary format for the configured model.
-    pub model_reasoning_summary_format: Option<ReasoningSummaryFormat>,
-
     /// Base URL for requests to ChatGPT (as opposed to the OpenAI API).
     pub chatgpt_base_url: Option<String>,
 
@@ -670,6 +798,11 @@ pub struct ConfigToml {
     #[serde(default)]
     pub ghost_snapshot: Option<GhostSnapshotToml>,
 
+    /// Markers used to detect the project root when searching parent
+    /// directories for `.codex` folders. Defaults to [".git"] when unset.
+    #[serde(default)]
+    pub project_root_markers: Option<Vec<String>>,
+
     /// When `true`, checks for Codex updates on startup and surfaces update prompts.
     /// Set to `false` only if your Codex updates are centrally managed.
     /// Defaults to `true`.
@@ -694,7 +827,6 @@ pub struct ConfigToml {
     pub experimental_instructions_file: Option<AbsolutePathBuf>,
     pub experimental_compact_prompt_file: Option<AbsolutePathBuf>,
     pub experimental_use_unified_exec_tool: Option<bool>,
-    pub experimental_use_rmcp_client: Option<bool>,
     pub experimental_use_freeform_apply_patch: Option<bool>,
     /// Preferred OSS provider for local models, e.g. "lmstudio" or "ollama".
     pub oss_provider: Option<String>,
@@ -725,7 +857,7 @@ impl From<ConfigToml> for UserSavedConfig {
     }
 }
 
-#[derive(Deserialize, Debug, Clone, PartialEq, Eq)]
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq)]
 pub struct ProjectConfig {
     pub trust_level: Option<TrustLevel>,
 }
@@ -740,7 +872,7 @@ impl ProjectConfig {
     }
 }
 
-#[derive(Deserialize, Debug, Clone, Default, PartialEq)]
+#[derive(Serialize, Deserialize, Debug, Clone, Default, PartialEq)]
 pub struct ToolsToml {
     #[serde(default, alias = "web_search_request")]
     pub web_search: Option<bool>,
@@ -759,7 +891,7 @@ impl From<ToolsToml> for Tools {
     }
 }
 
-#[derive(Deserialize, Debug, Clone, Default, PartialEq, Eq)]
+#[derive(Serialize, Deserialize, Debug, Clone, Default, PartialEq, Eq)]
 pub struct GhostSnapshotToml {
     /// Exclude untracked files larger than this many bytes from ghost snapshots.
     #[serde(alias = "ignore_untracked_files_over_bytes")]
@@ -927,13 +1059,24 @@ pub fn resolve_oss_provider(
 }
 
 impl Config {
-    /// Meant to be used exclusively for tests: `load_with_overrides()` should
-    /// be used in all other cases.
-    pub fn load_from_base_config_with_overrides(
+    #[cfg(test)]
+    fn load_from_base_config_with_overrides(
         cfg: ConfigToml,
         overrides: ConfigOverrides,
         codex_home: PathBuf,
     ) -> std::io::Result<Self> {
+        // Note this ignores requirements.toml enforcement for tests.
+        let config_layer_stack = ConfigLayerStack::default();
+        Self::load_config_with_layer_stack(cfg, overrides, codex_home, config_layer_stack)
+    }
+
+    fn load_config_with_layer_stack(
+        cfg: ConfigToml,
+        overrides: ConfigOverrides,
+        codex_home: PathBuf,
+        config_layer_stack: ConfigLayerStack,
+    ) -> std::io::Result<Self> {
+        let requirements = config_layer_stack.requirements().clone();
         let user_instructions = Self::load_instructions(Some(&codex_home));
 
         // Destructure ConfigOverrides fully to ensure all overrides are applied.
@@ -1038,7 +1181,8 @@ impl Config {
                     AskForApproval::default()
                 }
             });
-        let approval_policy = Constrained::allow_any(approval_policy);
+        // TODO(dylan): We should be able to leverage ConfigLayerStack so that
+        // we can reliably check this at every config level.
         let did_user_set_custom_approval_policy_or_sandbox_mode = approval_policy_override
             .is_some()
             || config_profile.approval_policy.is_some()
@@ -1099,7 +1243,6 @@ impl Config {
         let include_apply_patch_tool_flag = features.enabled(Feature::ApplyPatchFreeform);
         let tools_web_search_request = features.enabled(Feature::WebSearchRequest);
         let use_experimental_unified_exec_tool = features.enabled(Feature::UnifiedExec);
-        let use_experimental_use_rmcp_client = features.enabled(Feature::RmcpClient);
 
         let forced_chatgpt_workspace_id =
             cfg.forced_chatgpt_workspace_id.as_ref().and_then(|value| {
@@ -1155,6 +1298,20 @@ impl Config {
 
         let check_for_update_on_startup = cfg.check_for_update_on_startup.unwrap_or(true);
 
+        // Ensure that every field of ConfigRequirements is applied to the final
+        // Config.
+        let ConfigRequirements {
+            approval_policy: mut constrained_approval_policy,
+            sandbox_policy: mut constrained_sandbox_policy,
+        } = requirements;
+
+        constrained_approval_policy
+            .set(approval_policy)
+            .map_err(|e| std::io::Error::new(std::io::ErrorKind::InvalidInput, format!("{e}")))?;
+        constrained_sandbox_policy
+            .set(sandbox_policy)
+            .map_err(|e| std::io::Error::new(std::io::ErrorKind::InvalidInput, format!("{e}")))?;
+
         let config = Self {
             model,
             review_model,
@@ -1163,8 +1320,8 @@ impl Config {
             model_provider_id,
             model_provider,
             cwd: resolved_cwd,
-            approval_policy,
-            sandbox_policy,
+            approval_policy: constrained_approval_policy,
+            sandbox_policy: constrained_sandbox_policy,
             did_user_set_custom_approval_policy_or_sandbox_mode,
             forced_auto_mode_downgraded_on_windows,
             shell_environment_policy,
@@ -1197,6 +1354,7 @@ impl Config {
                 .collect(),
             tool_output_token_limit: cfg.tool_output_token_limit,
             codex_home,
+            config_layer_stack,
             history,
             file_opener: cfg.file_opener.unwrap_or(UriBasedFileOpener::VsCode),
             codex_linux_sandbox_exe,
@@ -1214,7 +1372,6 @@ impl Config {
                 .or(cfg.model_reasoning_summary)
                 .unwrap_or_default(),
             model_supports_reasoning_summaries: cfg.model_supports_reasoning_summaries,
-            model_reasoning_summary_format: cfg.model_reasoning_summary_format.clone(),
             model_verbosity: config_profile.model_verbosity.or(cfg.model_verbosity),
             chatgpt_base_url: config_profile
                 .chatgpt_base_url
@@ -1225,7 +1382,6 @@ impl Config {
             include_apply_patch_tool: include_apply_patch_tool_flag,
             tools_web_search_request,
             use_experimental_unified_exec_tool,
-            use_experimental_use_rmcp_client,
             ghost_snapshot,
             features,
             active_profile: active_profile_name,
@@ -1241,6 +1397,27 @@ impl Config {
                 .unwrap_or_default(),
             animations: cfg.tui.as_ref().map(|t| t.animations).unwrap_or(true),
             show_tooltips: cfg.tui.as_ref().map(|t| t.show_tooltips).unwrap_or(true),
+            tui_scroll_events_per_tick: cfg.tui.as_ref().and_then(|t| t.scroll_events_per_tick),
+            tui_scroll_wheel_lines: cfg.tui.as_ref().and_then(|t| t.scroll_wheel_lines),
+            tui_scroll_trackpad_lines: cfg.tui.as_ref().and_then(|t| t.scroll_trackpad_lines),
+            tui_scroll_trackpad_accel_events: cfg
+                .tui
+                .as_ref()
+                .and_then(|t| t.scroll_trackpad_accel_events),
+            tui_scroll_trackpad_accel_max: cfg
+                .tui
+                .as_ref()
+                .and_then(|t| t.scroll_trackpad_accel_max),
+            tui_scroll_mode: cfg.tui.as_ref().map(|t| t.scroll_mode).unwrap_or_default(),
+            tui_scroll_wheel_tick_detect_max_ms: cfg
+                .tui
+                .as_ref()
+                .and_then(|t| t.scroll_wheel_tick_detect_max_ms),
+            tui_scroll_wheel_like_max_duration_ms: cfg
+                .tui
+                .as_ref()
+                .and_then(|t| t.scroll_wheel_like_max_duration_ms),
+            tui_scroll_invert: cfg.tui.as_ref().map(|t| t.scroll_invert).unwrap_or(false),
             otel: {
                 let t: OtelConfigToml = cfg.otel.unwrap_or_default();
                 let log_user_prompt = t.log_user_prompt.unwrap_or(false);
@@ -1413,8 +1590,23 @@ persistence = "none"
             .expect("TUI config without notifications should succeed");
         let tui = parsed.tui.expect("config should include tui section");
 
-        assert_eq!(tui.notifications, Notifications::Enabled(true));
-        assert!(tui.show_tooltips);
+        assert_eq!(
+            tui,
+            Tui {
+                notifications: Notifications::Enabled(true),
+                animations: true,
+                show_tooltips: true,
+                scroll_events_per_tick: None,
+                scroll_wheel_lines: None,
+                scroll_trackpad_lines: None,
+                scroll_trackpad_accel_events: None,
+                scroll_trackpad_accel_max: None,
+                scroll_mode: ScrollInputMode::Auto,
+                scroll_wheel_tick_detect_max_ms: None,
+                scroll_wheel_like_max_duration_ms: None,
+                scroll_invert: false,
+            }
+        );
     }
 
     #[test]
@@ -1586,12 +1778,12 @@ trust_level = "trusted"
                 config.forced_auto_mode_downgraded_on_windows,
                 "expected workspace-write request to be downgraded on Windows"
             );
-            match config.sandbox_policy {
-                SandboxPolicy::ReadOnly => {}
+            match config.sandbox_policy.get() {
+                &SandboxPolicy::ReadOnly => {}
                 other => panic!("expected read-only policy on Windows, got {other:?}"),
             }
         } else {
-            match config.sandbox_policy {
+            match config.sandbox_policy.get() {
                 SandboxPolicy::WorkspaceWrite { writable_roots, .. } => {
                     assert_eq!(
                         writable_roots
@@ -1723,8 +1915,8 @@ trust_level = "trusted"
         )?;
 
         assert!(matches!(
-            config.sandbox_policy,
-            SandboxPolicy::DangerFullAccess
+            config.sandbox_policy.get(),
+            &SandboxPolicy::DangerFullAccess
         ));
         assert!(config.did_user_set_custom_approval_policy_or_sandbox_mode);
 
@@ -1760,11 +1952,14 @@ trust_level = "trusted"
         )?;
 
         if cfg!(target_os = "windows") {
-            assert!(matches!(config.sandbox_policy, SandboxPolicy::ReadOnly));
+            assert!(matches!(
+                config.sandbox_policy.get(),
+                SandboxPolicy::ReadOnly
+            ));
             assert!(config.forced_auto_mode_downgraded_on_windows);
         } else {
             assert!(matches!(
-                config.sandbox_policy,
+                config.sandbox_policy.get(),
                 SandboxPolicy::WorkspaceWrite { .. }
             ));
             assert!(!config.forced_auto_mode_downgraded_on_windows);
@@ -1800,7 +1995,6 @@ trust_level = "trusted"
         let codex_home = TempDir::new()?;
         let cfg = ConfigToml {
             experimental_use_unified_exec_tool: Some(true),
-            experimental_use_rmcp_client: Some(true),
             experimental_use_freeform_apply_patch: Some(true),
             ..Default::default()
         };
@@ -1813,12 +2007,10 @@ trust_level = "trusted"
 
         assert!(config.features.enabled(Feature::ApplyPatchFreeform));
         assert!(config.features.enabled(Feature::UnifiedExec));
-        assert!(config.features.enabled(Feature::RmcpClient));
 
         assert!(config.include_apply_patch_tool);
 
         assert!(config.use_experimental_unified_exec_tool);
-        assert!(config.use_experimental_use_rmcp_client);
 
         Ok(())
     }
@@ -1854,18 +2046,23 @@ trust_level = "trusted"
         std::fs::write(&config_path, "mcp_oauth_credentials_store = \"file\"\n")?;
         std::fs::write(&managed_path, "mcp_oauth_credentials_store = \"keyring\"\n")?;
 
-        let overrides = crate::config_loader::LoaderOverrides {
+        let overrides = LoaderOverrides {
             managed_config_path: Some(managed_path.clone()),
             #[cfg(target_os = "macos")]
             managed_preferences_base64: None,
         };
 
-        let root_value = load_resolved_config(codex_home.path(), Vec::new(), overrides).await?;
-        let cfg =
-            deserialize_config_toml_with_base(root_value, codex_home.path()).map_err(|e| {
-                tracing::error!("Failed to deserialize overridden config: {e}");
-                e
-            })?;
+        let cwd = AbsolutePathBuf::try_from(codex_home.path())?;
+        let config_layer_stack =
+            load_config_layers_state(codex_home.path(), Some(cwd), &Vec::new(), overrides).await?;
+        let cfg = deserialize_config_toml_with_base(
+            config_layer_stack.effective_config(),
+            codex_home.path(),
+        )
+        .map_err(|e| {
+            tracing::error!("Failed to deserialize overridden config: {e}");
+            e
+        })?;
         assert_eq!(
             cfg.mcp_oauth_credentials_store,
             Some(OAuthCredentialsStoreMode::Keyring),
@@ -1969,24 +2166,29 @@ trust_level = "trusted"
         )?;
         std::fs::write(&managed_path, "model = \"managed_config\"\n")?;
 
-        let overrides = crate::config_loader::LoaderOverrides {
+        let overrides = LoaderOverrides {
             managed_config_path: Some(managed_path),
             #[cfg(target_os = "macos")]
             managed_preferences_base64: None,
         };
 
-        let root_value = load_resolved_config(
+        let cwd = AbsolutePathBuf::try_from(codex_home.path())?;
+        let config_layer_stack = load_config_layers_state(
             codex_home.path(),
-            vec![("model".to_string(), TomlValue::String("cli".to_string()))],
+            Some(cwd),
+            &[("model".to_string(), TomlValue::String("cli".to_string()))],
             overrides,
         )
         .await?;
 
-        let cfg =
-            deserialize_config_toml_with_base(root_value, codex_home.path()).map_err(|e| {
-                tracing::error!("Failed to deserialize overridden config: {e}");
-                e
-            })?;
+        let cfg = deserialize_config_toml_with_base(
+            config_layer_stack.effective_config(),
+            codex_home.path(),
+        )
+        .map_err(|e| {
+            tracing::error!("Failed to deserialize overridden config: {e}");
+            e
+        })?;
 
         assert_eq!(cfg.model.as_deref(), Some("managed_config"));
         Ok(())
@@ -2955,7 +3157,7 @@ model_verbosity = "high"
                 model_provider_id: "openai".to_string(),
                 model_provider: fixture.openai_provider.clone(),
                 approval_policy: Constrained::allow_any(AskForApproval::Never),
-                sandbox_policy: SandboxPolicy::new_read_only_policy(),
+                sandbox_policy: Constrained::allow_any(SandboxPolicy::new_read_only_policy()),
                 did_user_set_custom_approval_policy_or_sandbox_mode: true,
                 forced_auto_mode_downgraded_on_windows: false,
                 shell_environment_policy: ShellEnvironmentPolicy::default(),
@@ -2970,6 +3172,7 @@ model_verbosity = "high"
                 project_doc_fallback_filenames: Vec::new(),
                 tool_output_token_limit: None,
                 codex_home: fixture.codex_home(),
+                config_layer_stack: Default::default(),
                 history: History::default(),
                 file_opener: UriBasedFileOpener::VsCode,
                 codex_linux_sandbox_exe: None,
@@ -2978,7 +3181,6 @@ model_verbosity = "high"
                 model_reasoning_effort: Some(ReasoningEffort::High),
                 model_reasoning_summary: ReasoningSummary::Detailed,
                 model_supports_reasoning_summaries: None,
-                model_reasoning_summary_format: None,
                 model_verbosity: None,
                 chatgpt_base_url: "https://chatgpt.com/backend-api/".to_string(),
                 base_instructions: None,
@@ -2989,7 +3191,6 @@ model_verbosity = "high"
                 include_apply_patch_tool: false,
                 tools_web_search_request: false,
                 use_experimental_unified_exec_tool: false,
-                use_experimental_use_rmcp_client: false,
                 ghost_snapshot: GhostSnapshotConfig::default(),
                 features: Features::with_defaults(),
                 active_profile: Some("o3".to_string()),
@@ -3001,6 +3202,15 @@ model_verbosity = "high"
                 tui_notifications: Default::default(),
                 animations: true,
                 show_tooltips: true,
+                tui_scroll_events_per_tick: None,
+                tui_scroll_wheel_lines: None,
+                tui_scroll_trackpad_lines: None,
+                tui_scroll_trackpad_accel_events: None,
+                tui_scroll_trackpad_accel_max: None,
+                tui_scroll_mode: ScrollInputMode::Auto,
+                tui_scroll_wheel_tick_detect_max_ms: None,
+                tui_scroll_wheel_like_max_duration_ms: None,
+                tui_scroll_invert: false,
                 otel: OtelConfig::default(),
             },
             o3_profile_config
@@ -3030,7 +3240,7 @@ model_verbosity = "high"
             model_provider_id: "openai-chat-completions".to_string(),
             model_provider: fixture.openai_chat_completions_provider.clone(),
             approval_policy: Constrained::allow_any(AskForApproval::UnlessTrusted),
-            sandbox_policy: SandboxPolicy::new_read_only_policy(),
+            sandbox_policy: Constrained::allow_any(SandboxPolicy::new_read_only_policy()),
             did_user_set_custom_approval_policy_or_sandbox_mode: true,
             forced_auto_mode_downgraded_on_windows: false,
             shell_environment_policy: ShellEnvironmentPolicy::default(),
@@ -3045,6 +3255,7 @@ model_verbosity = "high"
             project_doc_fallback_filenames: Vec::new(),
             tool_output_token_limit: None,
             codex_home: fixture.codex_home(),
+            config_layer_stack: Default::default(),
             history: History::default(),
             file_opener: UriBasedFileOpener::VsCode,
             codex_linux_sandbox_exe: None,
@@ -3053,7 +3264,6 @@ model_verbosity = "high"
             model_reasoning_effort: None,
             model_reasoning_summary: ReasoningSummary::default(),
             model_supports_reasoning_summaries: None,
-            model_reasoning_summary_format: None,
             model_verbosity: None,
             chatgpt_base_url: "https://chatgpt.com/backend-api/".to_string(),
             base_instructions: None,
@@ -3064,7 +3274,6 @@ model_verbosity = "high"
             include_apply_patch_tool: false,
             tools_web_search_request: false,
             use_experimental_unified_exec_tool: false,
-            use_experimental_use_rmcp_client: false,
             ghost_snapshot: GhostSnapshotConfig::default(),
             features: Features::with_defaults(),
             active_profile: Some("gpt3".to_string()),
@@ -3076,6 +3285,15 @@ model_verbosity = "high"
             tui_notifications: Default::default(),
             animations: true,
             show_tooltips: true,
+            tui_scroll_events_per_tick: None,
+            tui_scroll_wheel_lines: None,
+            tui_scroll_trackpad_lines: None,
+            tui_scroll_trackpad_accel_events: None,
+            tui_scroll_trackpad_accel_max: None,
+            tui_scroll_mode: ScrollInputMode::Auto,
+            tui_scroll_wheel_tick_detect_max_ms: None,
+            tui_scroll_wheel_like_max_duration_ms: None,
+            tui_scroll_invert: false,
             otel: OtelConfig::default(),
         };
 
@@ -3120,7 +3338,7 @@ model_verbosity = "high"
             model_provider_id: "openai".to_string(),
             model_provider: fixture.openai_provider.clone(),
             approval_policy: Constrained::allow_any(AskForApproval::OnFailure),
-            sandbox_policy: SandboxPolicy::new_read_only_policy(),
+            sandbox_policy: Constrained::allow_any(SandboxPolicy::new_read_only_policy()),
             did_user_set_custom_approval_policy_or_sandbox_mode: true,
             forced_auto_mode_downgraded_on_windows: false,
             shell_environment_policy: ShellEnvironmentPolicy::default(),
@@ -3135,6 +3353,7 @@ model_verbosity = "high"
             project_doc_fallback_filenames: Vec::new(),
             tool_output_token_limit: None,
             codex_home: fixture.codex_home(),
+            config_layer_stack: Default::default(),
             history: History::default(),
             file_opener: UriBasedFileOpener::VsCode,
             codex_linux_sandbox_exe: None,
@@ -3143,7 +3362,6 @@ model_verbosity = "high"
             model_reasoning_effort: None,
             model_reasoning_summary: ReasoningSummary::default(),
             model_supports_reasoning_summaries: None,
-            model_reasoning_summary_format: None,
             model_verbosity: None,
             chatgpt_base_url: "https://chatgpt.com/backend-api/".to_string(),
             base_instructions: None,
@@ -3154,7 +3372,6 @@ model_verbosity = "high"
             include_apply_patch_tool: false,
             tools_web_search_request: false,
             use_experimental_unified_exec_tool: false,
-            use_experimental_use_rmcp_client: false,
             ghost_snapshot: GhostSnapshotConfig::default(),
             features: Features::with_defaults(),
             active_profile: Some("zdr".to_string()),
@@ -3166,6 +3383,15 @@ model_verbosity = "high"
             tui_notifications: Default::default(),
             animations: true,
             show_tooltips: true,
+            tui_scroll_events_per_tick: None,
+            tui_scroll_wheel_lines: None,
+            tui_scroll_trackpad_lines: None,
+            tui_scroll_trackpad_accel_events: None,
+            tui_scroll_trackpad_accel_max: None,
+            tui_scroll_mode: ScrollInputMode::Auto,
+            tui_scroll_wheel_tick_detect_max_ms: None,
+            tui_scroll_wheel_like_max_duration_ms: None,
+            tui_scroll_invert: false,
             otel: OtelConfig::default(),
         };
 
@@ -3196,7 +3422,7 @@ model_verbosity = "high"
             model_provider_id: "openai".to_string(),
             model_provider: fixture.openai_provider.clone(),
             approval_policy: Constrained::allow_any(AskForApproval::OnFailure),
-            sandbox_policy: SandboxPolicy::new_read_only_policy(),
+            sandbox_policy: Constrained::allow_any(SandboxPolicy::new_read_only_policy()),
             did_user_set_custom_approval_policy_or_sandbox_mode: true,
             forced_auto_mode_downgraded_on_windows: false,
             shell_environment_policy: ShellEnvironmentPolicy::default(),
@@ -3211,6 +3437,7 @@ model_verbosity = "high"
             project_doc_fallback_filenames: Vec::new(),
             tool_output_token_limit: None,
             codex_home: fixture.codex_home(),
+            config_layer_stack: Default::default(),
             history: History::default(),
             file_opener: UriBasedFileOpener::VsCode,
             codex_linux_sandbox_exe: None,
@@ -3219,7 +3446,6 @@ model_verbosity = "high"
             model_reasoning_effort: Some(ReasoningEffort::High),
             model_reasoning_summary: ReasoningSummary::Detailed,
             model_supports_reasoning_summaries: None,
-            model_reasoning_summary_format: None,
             model_verbosity: Some(Verbosity::High),
             chatgpt_base_url: "https://chatgpt.com/backend-api/".to_string(),
             base_instructions: None,
@@ -3230,7 +3456,6 @@ model_verbosity = "high"
             include_apply_patch_tool: false,
             tools_web_search_request: false,
             use_experimental_unified_exec_tool: false,
-            use_experimental_use_rmcp_client: false,
             ghost_snapshot: GhostSnapshotConfig::default(),
             features: Features::with_defaults(),
             active_profile: Some("gpt5".to_string()),
@@ -3242,6 +3467,15 @@ model_verbosity = "high"
             tui_notifications: Default::default(),
             animations: true,
             show_tooltips: true,
+            tui_scroll_events_per_tick: None,
+            tui_scroll_wheel_lines: None,
+            tui_scroll_trackpad_lines: None,
+            tui_scroll_trackpad_accel_events: None,
+            tui_scroll_trackpad_accel_max: None,
+            tui_scroll_mode: ScrollInputMode::Auto,
+            tui_scroll_wheel_tick_detect_max_ms: None,
+            tui_scroll_wheel_like_max_duration_ms: None,
+            tui_scroll_invert: false,
             otel: OtelConfig::default(),
         };
 
@@ -3541,12 +3775,15 @@ trust_level = "untrusted"
         // Verify that untrusted projects still get WorkspaceWrite sandbox (or ReadOnly on Windows)
         if cfg!(target_os = "windows") {
             assert!(
-                matches!(config.sandbox_policy, SandboxPolicy::ReadOnly),
+                matches!(config.sandbox_policy.get(), SandboxPolicy::ReadOnly),
                 "Expected ReadOnly on Windows"
             );
         } else {
             assert!(
-                matches!(config.sandbox_policy, SandboxPolicy::WorkspaceWrite { .. }),
+                matches!(
+                    config.sandbox_policy.get(),
+                    SandboxPolicy::WorkspaceWrite { .. }
+                ),
                 "Expected WorkspaceWrite sandbox for untrusted project"
             );
         }

codex-rs/core/src/config/profile.rs

@@ -1,5 +1,6 @@
 use codex_utils_absolute_path::AbsolutePathBuf;
 use serde::Deserialize;
+use serde::Serialize;
 
 use crate::protocol::AskForApproval;
 use codex_protocol::config_types::ReasoningSummary;
@@ -9,7 +10,7 @@ use codex_protocol::openai_models::ReasoningEffort;
 
 /// Collection of common configuration options that a user can define as a unit
 /// in `config.toml`.
-#[derive(Debug, Clone, Default, PartialEq, Deserialize)]
+#[derive(Debug, Clone, Default, PartialEq, Serialize, Deserialize)]
 pub struct ConfigProfile {
     pub model: Option<String>,
     /// The key in the `model_providers` map identifying the
@@ -25,7 +26,6 @@ pub struct ConfigProfile {
     pub experimental_compact_prompt_file: Option<AbsolutePathBuf>,
     pub include_apply_patch_tool: Option<bool>,
     pub experimental_use_unified_exec_tool: Option<bool>,
-    pub experimental_use_rmcp_client: Option<bool>,
     pub experimental_use_freeform_apply_patch: Option<bool>,
     pub tools_web_search: Option<bool>,
     pub tools_view_image: Option<bool>,

codex-rs/core/src/config/service.rs

@@ -20,7 +20,9 @@ use codex_app_server_protocol::ConfigWriteResponse;
 use codex_app_server_protocol::MergeStrategy;
 use codex_app_server_protocol::OverriddenMetadata;
 use codex_app_server_protocol::WriteStatus;
+use codex_utils_absolute_path::AbsolutePathBuf;
 use serde_json::Value as JsonValue;
+use std::borrow::Cow;
 use std::path::Path;
 use std::path::PathBuf;
 use thiserror::Error;
@@ -130,7 +132,7 @@ impl ConfigService {
         params: ConfigReadParams,
     ) -> Result<ConfigReadResponse, ConfigServiceError> {
         let layers = self
-            .load_layers_state()
+            .load_thread_agnostic_config()
             .await
             .map_err(|err| ConfigServiceError::io("failed to read configuration layers", err))?;
 
@@ -146,7 +148,13 @@ impl ConfigService {
         Ok(ConfigReadResponse {
             config,
             origins: layers.origins(),
-            layers: params.include_layers.then(|| layers.layers_high_to_low()),
+            layers: params.include_layers.then(|| {
+                layers
+                    .layers_high_to_low()
+                    .iter()
+                    .map(|layer| layer.as_layer())
+                    .collect()
+            }),
         })
     }
 
@@ -177,7 +185,7 @@ impl ConfigService {
         &self,
     ) -> Result<codex_app_server_protocol::UserSavedConfig, ConfigServiceError> {
         let layers = self
-            .load_layers_state()
+            .load_thread_agnostic_config()
             .await
             .map_err(|err| ConfigServiceError::io("failed to load configuration", err))?;
 
@@ -194,11 +202,14 @@ impl ConfigService {
         expected_version: Option<String>,
         edits: Vec<(String, JsonValue, MergeStrategy)>,
     ) -> Result<ConfigWriteResponse, ConfigServiceError> {
-        let allowed_path = self.codex_home.join(CONFIG_TOML_FILE);
-        let provided_path = file_path
-            .as_ref()
-            .map(PathBuf::from)
-            .unwrap_or_else(|| allowed_path.clone());
+        let allowed_path =
+            AbsolutePathBuf::resolve_path_against_base(CONFIG_TOML_FILE, &self.codex_home)
+                .map_err(|err| ConfigServiceError::io("failed to resolve user config path", err))?;
+        let provided_path = match file_path {
+            Some(path) => AbsolutePathBuf::from_absolute_path(PathBuf::from(path))
+                .map_err(|err| ConfigServiceError::io("failed to resolve user config path", err))?,
+            None => allowed_path.clone(),
+        };
 
         if !paths_match(&allowed_path, &provided_path) {
             return Err(ConfigServiceError::write(
@@ -208,12 +219,16 @@ impl ConfigService {
         }
 
         let layers = self
-            .load_layers_state()
+            .load_thread_agnostic_config()
             .await
             .map_err(|err| ConfigServiceError::io("failed to load configuration", err))?;
+        let user_layer = match layers.get_user_layer() {
+            Some(layer) => Cow::Borrowed(layer),
+            None => Cow::Owned(create_empty_user_layer(&allowed_path).await?),
+        };
 
         if let Some(expected) = expected_version.as_deref()
-            && expected != layers.user.version
+            && expected != user_layer.version
         {
             return Err(ConfigServiceError::write(
                 ConfigWriteErrorCode::ConfigVersionConflict,
@@ -221,7 +236,7 @@ impl ConfigService {
             ));
         }
 
-        let mut user_config = layers.user.config.clone();
+        let mut user_config = user_layer.config.clone();
         let mut parsed_segments = Vec::new();
         let mut config_edits = Vec::new();
 
@@ -273,7 +288,7 @@ impl ConfigService {
             )
         })?;
 
-        let updated_layers = layers.with_user_config(user_config.clone());
+        let updated_layers = layers.with_user_config(&provided_path, user_config.clone());
         let effective = updated_layers.effective_config();
         validate_config(&effective).map_err(|err| {
             ConfigServiceError::write(
@@ -296,23 +311,31 @@ impl ConfigService {
             .map(|_| WriteStatus::OkOverridden)
             .unwrap_or(WriteStatus::Ok);
 
-        let file_path = provided_path
-            .canonicalize()
-            .unwrap_or(provided_path.clone())
-            .display()
-            .to_string();
-
         Ok(ConfigWriteResponse {
             status,
-            version: updated_layers.user.version.clone(),
-            file_path,
+            version: updated_layers
+                .get_user_layer()
+                .ok_or_else(|| {
+                    ConfigServiceError::write(
+                        ConfigWriteErrorCode::UserLayerNotFound,
+                        "user layer not found in updated layers",
+                    )
+                })?
+                .version
+                .clone(),
+            file_path: provided_path,
             overridden_metadata: overridden,
         })
     }
 
-    async fn load_layers_state(&self) -> std::io::Result<ConfigLayerStack> {
+    /// Loads a "thread-agnostic" config, which means the config layers do not
+    /// include any in-repo .codex/ folders because there is no cwd/project root
+    /// associated with this query.
+    async fn load_thread_agnostic_config(&self) -> std::io::Result<ConfigLayerStack> {
+        let cwd: Option<AbsolutePathBuf> = None;
         load_config_layers_state(
             &self.codex_home,
+            cwd,
             &self.cli_overrides,
             self.loader_overrides.clone(),
         )
@@ -320,6 +343,32 @@ impl ConfigService {
     }
 }
 
+async fn create_empty_user_layer(
+    config_toml: &AbsolutePathBuf,
+) -> Result<ConfigLayerEntry, ConfigServiceError> {
+    let toml_value = match tokio::fs::read_to_string(config_toml).await {
+        Ok(contents) => toml::from_str(&contents).map_err(|e| {
+            ConfigServiceError::toml("failed to parse existing user config.toml", e)
+        })?,
+        Err(e) => {
+            if e.kind() == std::io::ErrorKind::NotFound {
+                tokio::fs::write(config_toml, "").await.map_err(|e| {
+                    ConfigServiceError::io("failed to create empty user config.toml", e)
+                })?;
+                TomlValue::Table(toml::map::Map::new())
+            } else {
+                return Err(ConfigServiceError::io("failed to read user config.toml", e));
+            }
+        }
+    };
+    Ok(ConfigLayerEntry::new(
+        ConfigLayerSource::User {
+            file: config_toml.clone(),
+        },
+        toml_value,
+    ))
+}
+
 fn parse_value(value: JsonValue) -> Result<Option<TomlValue>, String> {
     if value.is_null() {
         return Ok(None);
@@ -470,15 +519,15 @@ fn validate_config(value: &TomlValue) -> Result<(), toml::de::Error> {
     Ok(())
 }
 
-fn paths_match(expected: &Path, provided: &Path) -> bool {
+fn paths_match(expected: impl AsRef<Path>, provided: impl AsRef<Path>) -> bool {
     if let (Ok(expanded_expected), Ok(expanded_provided)) = (
-        path_utils::normalize_for_path_comparison(expected),
-        path_utils::normalize_for_path_comparison(provided),
+        path_utils::normalize_for_path_comparison(&expected),
+        path_utils::normalize_for_path_comparison(&provided),
     ) {
-        return expanded_expected == expanded_provided;
+        expanded_expected == expanded_provided
+    } else {
+        expected.as_ref() == provided.as_ref()
     }
-
-    expected == provided
 }
 
 fn value_at_path<'a>(root: &'a TomlValue, segments: &[String]) -> Option<&'a TomlValue> {
@@ -501,10 +550,29 @@ fn value_at_path<'a>(root: &'a TomlValue, segments: &[String]) -> Option<&'a Tom
 
 fn override_message(layer: &ConfigLayerSource) -> String {
     match layer {
-        ConfigLayerSource::Mdm { .. } => "Overridden by managed policy (mdm)".to_string(),
-        ConfigLayerSource::System { .. } => "Overridden by managed config (system)".to_string(),
+        ConfigLayerSource::Mdm { domain, key: _ } => {
+            format!("Overridden by managed policy (MDM): {domain}")
+        }
+        ConfigLayerSource::System { file } => {
+            format!("Overridden by managed config (system): {}", file.display())
+        }
+        ConfigLayerSource::Project { dot_codex_folder } => format!(
+            "Overridden by project config: {}/{CONFIG_TOML_FILE}",
+            dot_codex_folder.display(),
+        ),
         ConfigLayerSource::SessionFlags => "Overridden by session flags".to_string(),
-        ConfigLayerSource::User { .. } => "Overridden by user config".to_string(),
+        ConfigLayerSource::User { file } => {
+            format!("Overridden by user config: {}", file.display())
+        }
+        ConfigLayerSource::LegacyManagedConfigTomlFromFile { file } => {
+            format!(
+                "Overridden by legacy managed_config.toml: {}",
+                file.display()
+            )
+        }
+        ConfigLayerSource::LegacyManagedConfigTomlFromMdm => {
+            "Overridden by legacy managed configuration from MDM".to_string()
+        }
     }
 }
 
@@ -513,7 +581,10 @@ fn compute_override_metadata(
     effective: &TomlValue,
     segments: &[String],
 ) -> Option<OverriddenMetadata> {
-    let user_value = value_at_path(&layers.user.config, segments);
+    let user_value = match layers.get_user_layer() {
+        Some(user_layer) => value_at_path(&user_layer.config, segments),
+        None => return None,
+    };
     let effective_value = value_at_path(effective, segments);
 
     if user_value.is_some() && user_value == effective_value {
@@ -524,8 +595,7 @@ fn compute_override_metadata(
         return None;
     }
 
-    let effective_layer = find_effective_layer(layers, segments);
-    let overriding_layer = effective_layer.unwrap_or_else(|| layers.user.metadata());
+    let overriding_layer = find_effective_layer(layers, segments)?;
     let message = override_message(&overriding_layer.name);
 
     Some(OverriddenMetadata {
@@ -554,23 +624,13 @@ fn find_effective_layer(
     layers: &ConfigLayerStack,
     segments: &[String],
 ) -> Option<ConfigLayerMetadata> {
-    let check =
-        |state: &ConfigLayerEntry| value_at_path(&state.config, segments).map(|_| state.metadata());
+    for layer in layers.layers_high_to_low() {
+        if let Some(meta) = value_at_path(&layer.config, segments).map(|_| layer.metadata()) {
+            return Some(meta);
+        }
+    }
 
-    if let Some(mdm) = &layers.mdm
-        && let Some(meta) = check(mdm)
-    {
-        return Some(meta);
-    }
-    if let Some(system) = &layers.system
-        && let Some(meta) = check(system)
-    {
-        return Some(meta);
-    }
-    if let Some(meta) = check(&layers.session_flags) {
-        return Some(meta);
-    }
-    check(&layers.user)
+    None
 }
 
 #[cfg(test)]
@@ -713,20 +773,46 @@ remote_compaction = true
                 .get("approval_policy")
                 .expect("origin")
                 .name,
-            ConfigLayerSource::System {
-                file: managed_file.clone(),
-            }
+            ConfigLayerSource::LegacyManagedConfigTomlFromFile {
+                file: managed_file.clone()
+            },
         );
         let layers = response.layers.expect("layers present");
-        assert_eq!(
-            layers.first().unwrap().name,
-            ConfigLayerSource::System { file: managed_file }
-        );
-        assert_eq!(layers.get(1).unwrap().name, ConfigLayerSource::SessionFlags);
-        assert_eq!(
-            layers.last().unwrap().name,
-            ConfigLayerSource::User { file: user_file }
-        );
+        if cfg!(unix) {
+            let system_file = AbsolutePathBuf::from_absolute_path(
+                crate::config_loader::SYSTEM_CONFIG_TOML_FILE_UNIX,
+            )
+            .expect("system file");
+            assert_eq!(layers.len(), 3, "expected three layers on unix");
+            assert_eq!(
+                layers.first().unwrap().name,
+                ConfigLayerSource::LegacyManagedConfigTomlFromFile {
+                    file: managed_file.clone()
+                }
+            );
+            assert_eq!(
+                layers.get(1).unwrap().name,
+                ConfigLayerSource::User {
+                    file: user_file.clone()
+                }
+            );
+            assert_eq!(
+                layers.get(2).unwrap().name,
+                ConfigLayerSource::System { file: system_file }
+            );
+        } else {
+            assert_eq!(layers.len(), 2, "expected two layers");
+            assert_eq!(
+                layers.first().unwrap().name,
+                ConfigLayerSource::LegacyManagedConfigTomlFromFile {
+                    file: managed_file.clone()
+                }
+            );
+            assert_eq!(
+                layers.get(1).unwrap().name,
+                ConfigLayerSource::User { file: user_file }
+            );
+        }
     }
 
     #[tokio::test]
@@ -779,7 +865,9 @@ remote_compaction = true
                 .get("approval_policy")
                 .expect("origin")
                 .name,
-            ConfigLayerSource::System { file: managed_file }
+            ConfigLayerSource::LegacyManagedConfigTomlFromFile {
+                file: managed_file.clone()
+            }
         );
         assert_eq!(result.status, WriteStatus::Ok);
         assert!(result.overridden_metadata.is_none());
@@ -909,14 +997,14 @@ remote_compaction = true
         assert_eq!(response.config.model.as_deref(), Some("system"));
         assert_eq!(
             response.origins.get("model").expect("origin").name,
-            ConfigLayerSource::System {
-                file: managed_file.clone(),
-            }
+            ConfigLayerSource::LegacyManagedConfigTomlFromFile {
+                file: managed_file.clone()
+            },
         );
         let layers = response.layers.expect("layers");
         assert_eq!(
             layers.first().unwrap().name,
-            ConfigLayerSource::System { file: managed_file }
+            ConfigLayerSource::LegacyManagedConfigTomlFromFile { file: managed_file }
         );
         assert_eq!(layers.get(1).unwrap().name, ConfigLayerSource::SessionFlags);
         assert_eq!(
@@ -959,7 +1047,7 @@ remote_compaction = true
         let overridden = result.overridden_metadata.expect("overridden metadata");
         assert_eq!(
             overridden.overriding_layer.name,
-            ConfigLayerSource::System { file: managed_file }
+            ConfigLayerSource::LegacyManagedConfigTomlFromFile { file: managed_file }
         );
         assert_eq!(overridden.effective_value, serde_json::json!("never"));
     }

codex-rs/core/src/config/types.rs

@@ -221,7 +221,7 @@ mod option_duration_secs {
     }
 }
 
-#[derive(Deserialize, Debug, Copy, Clone, PartialEq)]
+#[derive(Serialize, Deserialize, Debug, Copy, Clone, PartialEq)]
 pub enum UriBasedFileOpener {
     #[serde(rename = "vscode")]
     VsCode,
@@ -253,7 +253,7 @@ impl UriBasedFileOpener {
 }
 
 /// Settings that govern if and what will be written to `~/.codex/history.jsonl`.
-#[derive(Deserialize, Debug, Clone, PartialEq, Default)]
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Default)]
 pub struct History {
     /// If true, history entries will not be written to disk.
     pub persistence: HistoryPersistence,
@@ -263,7 +263,7 @@ pub struct History {
     pub max_bytes: Option<usize>,
 }
 
-#[derive(Deserialize, Debug, Copy, Clone, PartialEq, Default)]
+#[derive(Serialize, Deserialize, Debug, Copy, Clone, PartialEq, Default)]
 #[serde(rename_all = "kebab-case")]
 pub enum HistoryPersistence {
     /// Save all history entries to disk.
@@ -275,7 +275,7 @@ pub enum HistoryPersistence {
 
 // ===== OTEL configuration =====
 
-#[derive(Deserialize, Debug, Clone, PartialEq)]
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq)]
 #[serde(rename_all = "kebab-case")]
 pub enum OtelHttpProtocol {
     /// Binary payload
@@ -284,7 +284,7 @@ pub enum OtelHttpProtocol {
     Json,
 }
 
-#[derive(Deserialize, Debug, Clone, PartialEq, Default)]
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Default)]
 #[serde(rename_all = "kebab-case")]
 pub struct OtelTlsConfig {
     pub ca_certificate: Option<AbsolutePathBuf>,
@@ -293,7 +293,7 @@ pub struct OtelTlsConfig {
 }
 
 /// Which OTEL exporter to use.
-#[derive(Deserialize, Debug, Clone, PartialEq)]
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq)]
 #[serde(rename_all = "kebab-case")]
 pub enum OtelExporterKind {
     None,
@@ -315,7 +315,7 @@ pub enum OtelExporterKind {
 }
 
 /// OTEL settings loaded from config.toml. Fields are optional so we can apply defaults.
-#[derive(Deserialize, Debug, Clone, PartialEq, Default)]
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Default)]
 pub struct OtelConfigToml {
     /// Log user prompt in traces
     pub log_user_prompt: Option<bool>,
@@ -350,7 +350,7 @@ impl Default for OtelConfig {
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq, Deserialize)]
+#[derive(Serialize, Debug, Clone, PartialEq, Eq, Deserialize)]
 #[serde(untagged)]
 pub enum Notifications {
     Enabled(bool),
@@ -363,8 +363,30 @@ impl Default for Notifications {
     }
 }
 
+/// How TUI2 should interpret mouse scroll events.
+///
+/// Terminals generally encode both mouse wheels and trackpads as the same "scroll up/down" mouse
+/// button events, without a magnitude. This setting controls whether Codex uses a heuristic to
+/// infer wheel vs trackpad per stream, or forces a specific behavior.
+#[derive(Serialize, Deserialize, Debug, Clone, Copy, PartialEq, Eq)]
+#[serde(rename_all = "snake_case")]
+pub enum ScrollInputMode {
+    /// Infer wheel vs trackpad behavior per scroll stream.
+    Auto,
+    /// Always treat scroll events as mouse-wheel input (fixed lines per tick).
+    Wheel,
+    /// Always treat scroll events as trackpad input (fractional accumulation).
+    Trackpad,
+}
+
+impl Default for ScrollInputMode {
+    fn default() -> Self {
+        Self::Auto
+    }
+}
+
 /// Collection of settings that are specific to the TUI.
-#[derive(Deserialize, Debug, Clone, PartialEq, Default)]
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Default)]
 pub struct Tui {
     /// Enable desktop notifications from the TUI when the terminal is unfocused.
     /// Defaults to `true`.
@@ -380,6 +402,109 @@ pub struct Tui {
     /// Defaults to `true`.
     #[serde(default = "default_true")]
     pub show_tooltips: bool,
+
+    /// Override the *wheel* event density used to normalize TUI2 scrolling.
+    ///
+    /// Terminals generally deliver both mouse wheels and trackpads as discrete `scroll up/down`
+    /// mouse events with direction but no magnitude. Unfortunately, the *number* of raw events
+    /// per physical wheel notch varies by terminal (commonly 1, 3, or 9+). TUI2 uses this value
+    /// to normalize that raw event density into consistent "wheel tick" behavior.
+    ///
+    /// Wheel math (conceptually):
+    ///
+    /// - A single event contributes `1 / scroll_events_per_tick` tick-equivalents.
+    /// - Wheel-like streams then scale that by `scroll_wheel_lines` so one physical notch scrolls
+    ///   a fixed number of lines.
+    ///
+    /// Trackpad math is intentionally *not* fully tied to this value: in trackpad-like mode, TUI2
+    /// uses `min(scroll_events_per_tick, 3)` as the divisor so terminals with dense wheel ticks
+    /// (e.g. 9 events per notch) do not make trackpads feel artificially slow.
+    ///
+    /// Defaults are derived per terminal from [`crate::terminal::TerminalInfo`] when TUI2 starts.
+    /// See `codex-rs/tui2/docs/scroll_input_model.md` for the probe data and rationale.
+    pub scroll_events_per_tick: Option<u16>,
+
+    /// Override how many transcript lines one physical *wheel notch* should scroll in TUI2.
+    ///
+    /// This is the "classic feel" knob. Defaults to 3.
+    ///
+    /// Wheel-like per-event contribution is `scroll_wheel_lines / scroll_events_per_tick`. For
+    /// example, in a terminal that emits 9 events per notch, the default `3 / 9` yields 1/3 of a
+    /// line per event and totals 3 lines once the full notch burst arrives.
+    ///
+    /// See `codex-rs/tui2/docs/scroll_input_model.md` for details on the stream model and the
+    /// wheel/trackpad heuristic.
+    pub scroll_wheel_lines: Option<u16>,
+
+    /// Override baseline trackpad scroll sensitivity in TUI2.
+    ///
+    /// Trackpads do not have discrete notches, but terminals still emit discrete `scroll up/down`
+    /// events. In trackpad-like mode, TUI2 accumulates fractional scroll and only applies whole
+    /// lines to the viewport.
+    ///
+    /// Trackpad per-event contribution is:
+    ///
+    /// - `scroll_trackpad_lines / min(scroll_events_per_tick, 3)`
+    ///
+    /// (plus optional bounded acceleration; see `scroll_trackpad_accel_*`). The `min(..., 3)`
+    /// divisor is deliberate: `scroll_events_per_tick` is calibrated from *wheel* behavior and
+    /// can be much larger than trackpad event density, which would otherwise make trackpads feel
+    /// too slow in dense-wheel terminals.
+    ///
+    /// Defaults to 1, meaning one tick-equivalent maps to one transcript line.
+    pub scroll_trackpad_lines: Option<u16>,
+
+    /// Trackpad acceleration: approximate number of events required to gain +1x speed in TUI2.
+    ///
+    /// This keeps small swipes precise while allowing large/faster swipes to cover more content.
+    /// Defaults are chosen to address terminals where trackpad event density is comparatively low.
+    ///
+    /// Concretely, TUI2 computes an acceleration multiplier for trackpad-like streams:
+    ///
+    /// - `multiplier = clamp(1 + abs(events) / scroll_trackpad_accel_events, 1..scroll_trackpad_accel_max)`
+    ///
+    /// The multiplier is applied to the stream’s computed line delta (including any carried
+    /// fractional remainder).
+    pub scroll_trackpad_accel_events: Option<u16>,
+
+    /// Trackpad acceleration: maximum multiplier applied to trackpad-like streams.
+    ///
+    /// Set to 1 to effectively disable trackpad acceleration.
+    ///
+    /// See [`Tui::scroll_trackpad_accel_events`] for the exact multiplier formula.
+    pub scroll_trackpad_accel_max: Option<u16>,
+
+    /// Select how TUI2 interprets mouse scroll input.
+    ///
+    /// - `auto` (default): infer wheel vs trackpad per scroll stream.
+    /// - `wheel`: always use wheel behavior (fixed lines per wheel notch).
+    /// - `trackpad`: always use trackpad behavior (fractional accumulation; wheel may feel slow).
+    #[serde(default)]
+    pub scroll_mode: ScrollInputMode,
+
+    /// Auto-mode threshold: maximum time (ms) for the first tick-worth of events to arrive.
+    ///
+    /// In `scroll_mode = "auto"`, TUI2 starts a stream as trackpad-like (to avoid overshoot) and
+    /// promotes it to wheel-like if `scroll_events_per_tick` events arrive "quickly enough". This
+    /// threshold controls what "quickly enough" means.
+    ///
+    /// Most users should leave this unset; it is primarily for terminals that emit wheel ticks
+    /// batched over longer time spans.
+    pub scroll_wheel_tick_detect_max_ms: Option<u64>,
+
+    /// Auto-mode fallback: maximum duration (ms) that a very small stream is still treated as wheel-like.
+    ///
+    /// This is only used when `scroll_events_per_tick` is effectively 1 (one event per wheel
+    /// notch). In that case, we cannot observe a "tick completion time", so TUI2 treats a
+    /// short-lived, small stream (<= 2 events) as wheel-like to preserve classic wheel behavior.
+    pub scroll_wheel_like_max_duration_ms: Option<u64>,
+
+    /// Invert mouse scroll direction in TUI2.
+    ///
+    /// This flips the scroll sign after terminal detection. It is applied consistently to both
+    /// wheel and trackpad input.
+    #[serde(default)]
+    pub scroll_invert: bool,
 }
 
 const fn default_true() -> bool {
@@ -389,7 +514,7 @@ const fn default_true() -> bool {
 /// Settings for notices we display to users via the tui and app-server clients
 /// (primarily the Codex IDE extension). NOTE: these are different from
 /// notifications - notices are warnings, NUX screens, acknowledgements, etc.
-#[derive(Deserialize, Debug, Clone, PartialEq, Default)]
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Default)]
 pub struct Notice {
     /// Tracks whether the user has acknowledged the full access warning prompt.
     pub hide_full_access_warning: Option<bool>,
@@ -412,7 +537,7 @@ impl Notice {
     pub(crate) const TABLE_KEY: &'static str = "notice";
 }
 
-#[derive(Deserialize, Debug, Clone, PartialEq, Default)]
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Default)]
 pub struct SandboxWorkspaceWrite {
     #[serde(default)]
     pub writable_roots: Vec<AbsolutePathBuf>,
@@ -435,7 +560,7 @@ impl From<SandboxWorkspaceWrite> for codex_app_server_protocol::SandboxSettings
     }
 }
 
-#[derive(Deserialize, Debug, Clone, PartialEq, Default)]
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Default)]
 #[serde(rename_all = "kebab-case")]
 pub enum ShellEnvironmentPolicyInherit {
     /// "Core" environment variables for the platform. On UNIX, this would
@@ -452,7 +577,7 @@ pub enum ShellEnvironmentPolicyInherit {
 
 /// Policy for building the `env` when spawning a process via either the
 /// `shell` or `local_shell` tool.
-#[derive(Deserialize, Debug, Clone, PartialEq, Default)]
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Default)]
 pub struct ShellEnvironmentPolicyToml {
     pub inherit: Option<ShellEnvironmentPolicyInherit>,
 
@@ -474,17 +599,17 @@ pub type EnvironmentVariablePattern = WildMatchPattern<'*', '?'>;
 /// Deriving the `env` based on this policy works as follows:
 /// 1. Create an initial map based on the `inherit` policy.
 /// 2. If `ignore_default_excludes` is false, filter the map using the default
-///    exclude pattern(s), which are: `"*KEY*"` and `"*TOKEN*"`.
+///    exclude pattern(s), which are: `"*KEY*"`, `"*SECRET*"`, and `"*TOKEN*"`.
 /// 3. If `exclude` is not empty, filter the map using the provided patterns.
 /// 4. Insert any entries from `r#set` into the map.
 /// 5. If non-empty, filter the map using the `include_only` patterns.
-#[derive(Debug, Clone, PartialEq, Default)]
+#[derive(Debug, Clone, PartialEq)]
 pub struct ShellEnvironmentPolicy {
     /// Starting point when building the environment.
     pub inherit: ShellEnvironmentPolicyInherit,
 
     /// True to skip the check to exclude default environment variables that
-    /// contain "KEY" or "TOKEN" in their name.
+    /// contain "KEY", "SECRET", or "TOKEN" in their name. Defaults to true.
     pub ignore_default_excludes: bool,
 
     /// Environment variable names to exclude from the environment.
@@ -504,7 +629,7 @@ impl From<ShellEnvironmentPolicyToml> for ShellEnvironmentPolicy {
     fn from(toml: ShellEnvironmentPolicyToml) -> Self {
         // Default to inheriting the full environment when not specified.
         let inherit = toml.inherit.unwrap_or(ShellEnvironmentPolicyInherit::All);
-        let ignore_default_excludes = toml.ignore_default_excludes.unwrap_or(false);
+        let ignore_default_excludes = toml.ignore_default_excludes.unwrap_or(true);
         let exclude = toml
             .exclude
             .unwrap_or_default()
@@ -531,6 +656,19 @@ impl From<ShellEnvironmentPolicyToml> for ShellEnvironmentPolicy {
     }
 }
 
+impl Default for ShellEnvironmentPolicy {
+    fn default() -> Self {
+        Self {
+            inherit: ShellEnvironmentPolicyInherit::All,
+            ignore_default_excludes: true,
+            exclude: Vec::new(),
+            r#set: HashMap::new(),
+            include_only: Vec::new(),
+            use_profile: false,
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

codex-rs/core/src/config_loader/README.md

@@ -10,7 +10,7 @@ This module is the canonical place to **load and describe Codex configuration la
 
 Exported from `codex_core::config_loader`:
 
-- `load_config_layers_state(codex_home, cli_overrides, overrides) -> ConfigLayerStack`
+- `load_config_layers_state(codex_home, cwd_opt, cli_overrides, overrides) -> ConfigLayerStack`
 - `ConfigLayerStack`
   - `effective_config() -> toml::Value`
   - `origins() -> HashMap<String, ConfigLayerMetadata>`
@@ -37,11 +37,14 @@ Most callers want the effective config plus metadata:
 
 ```rust
 use codex_core::config_loader::{load_config_layers_state, LoaderOverrides};
+use codex_utils_absolute_path::AbsolutePathBuf;
 use toml::Value as TomlValue;
 
 let cli_overrides: Vec<(String, TomlValue)> = Vec::new();
+let cwd = AbsolutePathBuf::current_dir()?;
 let layers = load_config_layers_state(
     &codex_home,
+    Some(cwd),
     &cli_overrides,
     LoaderOverrides::default(),
 ).await?;

codex-rs/core/src/config_loader/config_requirements.rs

@@ -0,0 +1,287 @@
+use codex_protocol::config_types::SandboxMode;
+use codex_protocol::protocol::AskForApproval;
+use codex_protocol::protocol::SandboxPolicy;
+use serde::Deserialize;
+
+use crate::config::Constrained;
+use crate::config::ConstraintError;
+
+/// Normalized version of [`ConfigRequirementsToml`] after deserialization and
+/// normalization.
+#[derive(Debug, Clone, PartialEq)]
+pub struct ConfigRequirements {
+    pub approval_policy: Constrained<AskForApproval>,
+    pub sandbox_policy: Constrained<SandboxPolicy>,
+}
+
+impl Default for ConfigRequirements {
+    fn default() -> Self {
+        Self {
+            approval_policy: Constrained::allow_any_from_default(),
+            sandbox_policy: Constrained::allow_any(SandboxPolicy::ReadOnly),
+        }
+    }
+}
+
+/// Base config deserialized from /etc/codex/requirements.toml or MDM.
+#[derive(Deserialize, Debug, Clone, Default, PartialEq)]
+pub struct ConfigRequirementsToml {
+    pub allowed_approval_policies: Option<Vec<AskForApproval>>,
+    pub allowed_sandbox_modes: Option<Vec<SandboxModeRequirement>>,
+}
+
+/// Currently, `external-sandbox` is not supported in config.toml, but it is
+/// supported through programmatic use.
+#[derive(Deserialize, Debug, Clone, Copy, PartialEq)]
+pub enum SandboxModeRequirement {
+    #[serde(rename = "read-only")]
+    ReadOnly,
+
+    #[serde(rename = "workspace-write")]
+    WorkspaceWrite,
+
+    #[serde(rename = "danger-full-access")]
+    DangerFullAccess,
+
+    #[serde(rename = "external-sandbox")]
+    ExternalSandbox,
+}
+
+impl From<SandboxMode> for SandboxModeRequirement {
+    fn from(mode: SandboxMode) -> Self {
+        match mode {
+            SandboxMode::ReadOnly => SandboxModeRequirement::ReadOnly,
+            SandboxMode::WorkspaceWrite => SandboxModeRequirement::WorkspaceWrite,
+            SandboxMode::DangerFullAccess => SandboxModeRequirement::DangerFullAccess,
+        }
+    }
+}
+
+impl ConfigRequirementsToml {
+    /// For every field in `other` that is `Some`, if the corresponding field in
+    /// `self` is `None`, copy the value from `other` into `self`.
+    pub fn merge_unset_fields(&mut self, mut other: ConfigRequirementsToml) {
+        macro_rules! fill_missing_take {
+            ($base:expr, $other:expr, { $($field:ident),+ $(,)? }) => {
+                $(
+                    if $base.$field.is_none() {
+                        if let Some(value) = $other.$field.take() {
+                            $base.$field = Some(value);
+                        }
+                    }
+                )+
+            };
+        }
+
+        fill_missing_take!(self, other, { allowed_approval_policies, allowed_sandbox_modes });
+    }
+}
+
+impl TryFrom<ConfigRequirementsToml> for ConfigRequirements {
+    type Error = ConstraintError;
+
+    fn try_from(toml: ConfigRequirementsToml) -> Result<Self, Self::Error> {
+        let ConfigRequirementsToml {
+            allowed_approval_policies,
+            allowed_sandbox_modes,
+        } = toml;
+        let approval_policy: Constrained<AskForApproval> = match allowed_approval_policies {
+            Some(policies) => {
+                if let Some(first) = policies.first() {
+                    Constrained::allow_values(*first, policies)?
+                } else {
+                    return Err(ConstraintError::empty_field("allowed_approval_policies"));
+                }
+            }
+            None => Constrained::allow_any_from_default(),
+        };
+
+        // TODO(gt): `ConfigRequirementsToml` should let the author specify the
+        // default `SandboxPolicy`? Should do this for `AskForApproval` too?
+        //
+        // Currently, we force ReadOnly as the default policy because two of
+        // the other variants (WorkspaceWrite, ExternalSandbox) require
+        // additional parameters. Ultimately, we should expand the config
+        // format to allow specifying those parameters.
+        let default_sandbox_policy = SandboxPolicy::ReadOnly;
+        let sandbox_policy: Constrained<SandboxPolicy> = match allowed_sandbox_modes {
+            Some(modes) => {
+                if !modes.contains(&SandboxModeRequirement::ReadOnly) {
+                    return Err(ConstraintError::invalid_value(
+                        "allowed_sandbox_modes",
+                        "must include 'read-only' to allow any SandboxPolicy",
+                    ));
+                };
+
+                Constrained::new(default_sandbox_policy, move |candidate| {
+                    let mode = match candidate {
+                        SandboxPolicy::ReadOnly => SandboxModeRequirement::ReadOnly,
+                        SandboxPolicy::WorkspaceWrite { .. } => {
+                            SandboxModeRequirement::WorkspaceWrite
+                        }
+                        SandboxPolicy::DangerFullAccess => SandboxModeRequirement::DangerFullAccess,
+                        SandboxPolicy::ExternalSandbox { .. } => {
+                            SandboxModeRequirement::ExternalSandbox
+                        }
+                    };
+                    if modes.contains(&mode) {
+                        Ok(())
+                    } else {
+                        Err(ConstraintError::invalid_value(
+                            format!("{candidate:?}"),
+                            format!("{modes:?}"),
+                        ))
+                    }
+                })?
+            }
+            None => Constrained::allow_any(default_sandbox_policy),
+        };
+        Ok(ConfigRequirements {
+            approval_policy,
+            sandbox_policy,
+        })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use anyhow::Result;
+    use codex_protocol::protocol::NetworkAccess;
+    use codex_utils_absolute_path::AbsolutePathBuf;
+    use pretty_assertions::assert_eq;
+    use toml::from_str;
+
+    #[test]
+    fn merge_unset_fields_only_fills_missing_values() -> Result<()> {
+        let source: ConfigRequirementsToml = from_str(
+            r#"
+                allowed_approval_policies = ["on-request"]
+            "#,
+        )?;
+
+        let mut empty_target: ConfigRequirementsToml = from_str(
+            r#"
+                # intentionally left unset
+            "#,
+        )?;
+        empty_target.merge_unset_fields(source.clone());
+        assert_eq!(
+            empty_target.allowed_approval_policies,
+            Some(vec![AskForApproval::OnRequest])
+        );
+
+        let mut populated_target: ConfigRequirementsToml = from_str(
+            r#"
+                allowed_approval_policies = ["never"]
+            "#,
+        )?;
+        populated_target.merge_unset_fields(source);
+        assert_eq!(
+            populated_target.allowed_approval_policies,
+            Some(vec![AskForApproval::Never])
+        );
+        Ok(())
+    }
+
+    #[test]
+    fn deserialize_allowed_approval_policies() -> Result<()> {
+        let toml_str = r#"
+            allowed_approval_policies = ["untrusted", "on-request"]
+        "#;
+        let config: ConfigRequirementsToml = from_str(toml_str)?;
+        let requirements = ConfigRequirements::try_from(config)?;
+
+        assert_eq!(
+            requirements.approval_policy.value(),
+            AskForApproval::UnlessTrusted,
+            "currently, there is no way to specify the default value for approval policy in the toml, so it picks the first allowed value"
+        );
+        assert!(
+            requirements
+                .approval_policy
+                .can_set(&AskForApproval::UnlessTrusted)
+                .is_ok()
+        );
+        assert_eq!(
+            requirements
+                .approval_policy
+                .can_set(&AskForApproval::OnFailure),
+            Err(ConstraintError::InvalidValue {
+                candidate: "OnFailure".into(),
+                allowed: "[UnlessTrusted, OnRequest]".into(),
+            })
+        );
+        assert!(
+            requirements
+                .approval_policy
+                .can_set(&AskForApproval::OnRequest)
+                .is_ok()
+        );
+        assert_eq!(
+            requirements.approval_policy.can_set(&AskForApproval::Never),
+            Err(ConstraintError::InvalidValue {
+                candidate: "Never".into(),
+                allowed: "[UnlessTrusted, OnRequest]".into(),
+            })
+        );
+        assert!(
+            requirements
+                .sandbox_policy
+                .can_set(&SandboxPolicy::ReadOnly)
+                .is_ok()
+        );
+
+        Ok(())
+    }
+
+    #[test]
+    fn deserialize_allowed_sandbox_modes() -> Result<()> {
+        let toml_str = r#"
+            allowed_sandbox_modes = ["read-only", "workspace-write"]
+        "#;
+        let config: ConfigRequirementsToml = from_str(toml_str)?;
+        let requirements = ConfigRequirements::try_from(config)?;
+
+        let root = if cfg!(windows) { "C:\\repo" } else { "/repo" };
+        assert!(
+            requirements
+                .sandbox_policy
+                .can_set(&SandboxPolicy::ReadOnly)
+                .is_ok()
+        );
+        assert!(
+            requirements
+                .sandbox_policy
+                .can_set(&SandboxPolicy::WorkspaceWrite {
+                    writable_roots: vec![AbsolutePathBuf::from_absolute_path(root)?],
+                    network_access: false,
+                    exclude_tmpdir_env_var: false,
+                    exclude_slash_tmp: false,
+                })
+                .is_ok()
+        );
+        assert_eq!(
+            requirements
+                .sandbox_policy
+                .can_set(&SandboxPolicy::DangerFullAccess),
+            Err(ConstraintError::InvalidValue {
+                candidate: "DangerFullAccess".into(),
+                allowed: "[ReadOnly, WorkspaceWrite]".into(),
+            })
+        );
+        assert_eq!(
+            requirements
+                .sandbox_policy
+                .can_set(&SandboxPolicy::ExternalSandbox {
+                    network_access: NetworkAccess::Restricted,
+                }),
+            Err(ConstraintError::InvalidValue {
+                candidate: "ExternalSandbox { network_access: Restricted }".into(),
+                allowed: "[ReadOnly, WorkspaceWrite]".into(),
+            })
+        );
+
+        Ok(())
+    }
+}

codex-rs/core/src/config_loader/layer_io.rs

@@ -1,7 +1,7 @@
 use super::LoaderOverrides;
+#[cfg(target_os = "macos")]
 use super::macos::load_managed_admin_config_layer;
-use super::overrides::default_empty_table;
-use crate::config::CONFIG_TOML_FILE;
+use codex_utils_absolute_path::AbsolutePathBuf;
 use std::io;
 use std::path::Path;
 use std::path::PathBuf;
@@ -11,11 +11,18 @@ use toml::Value as TomlValue;
 #[cfg(unix)]
 const CODEX_MANAGED_CONFIG_SYSTEM_PATH: &str = "/etc/codex/managed_config.toml";
 
+#[derive(Debug, Clone)]
+pub(super) struct MangedConfigFromFile {
+    pub managed_config: TomlValue,
+    pub file: AbsolutePathBuf,
+}
+
 #[derive(Debug, Clone)]
 pub(super) struct LoadedConfigLayers {
-    pub base: TomlValue,
-    pub managed_config: Option<TomlValue>,
-    pub managed_preferences: Option<TomlValue>,
+    /// If present, data read from a file such as `/etc/codex/managed_config.toml`.
+    pub managed_config: Option<MangedConfigFromFile>,
+    /// If present, data read from managed preferences (macOS only).
+    pub managed_config_from_mdm: Option<TomlValue>,
 }
 
 pub(super) async fn load_config_layers_internal(
@@ -33,49 +40,52 @@ pub(super) async fn load_config_layers_internal(
         managed_config_path,
     } = overrides;
 
-    let managed_config_path =
-        managed_config_path.unwrap_or_else(|| managed_config_default_path(codex_home));
+    let managed_config_path = AbsolutePathBuf::from_absolute_path(
+        managed_config_path.unwrap_or_else(|| managed_config_default_path(codex_home)),
+    )?;
 
-    let user_config_path = codex_home.join(CONFIG_TOML_FILE);
-    let user_config = read_config_from_path(&user_config_path, true).await?;
-    let managed_config = read_config_from_path(&managed_config_path, false).await?;
+    let managed_config = read_config_from_path(&managed_config_path, false)
+        .await?
+        .map(|managed_config| MangedConfigFromFile {
+            managed_config,
+            file: managed_config_path.clone(),
+        });
 
     #[cfg(target_os = "macos")]
     let managed_preferences =
         load_managed_admin_config_layer(managed_preferences_base64.as_deref()).await?;
 
     #[cfg(not(target_os = "macos"))]
-    let managed_preferences = load_managed_admin_config_layer(None).await?;
+    let managed_preferences = None;
 
     Ok(LoadedConfigLayers {
-        base: user_config.unwrap_or_else(default_empty_table),
         managed_config,
-        managed_preferences,
+        managed_config_from_mdm: managed_preferences,
     })
 }
 
 pub(super) async fn read_config_from_path(
-    path: &Path,
+    path: impl AsRef<Path>,
     log_missing_as_info: bool,
 ) -> io::Result<Option<TomlValue>> {
-    match fs::read_to_string(path).await {
+    match fs::read_to_string(path.as_ref()).await {
         Ok(contents) => match toml::from_str::<TomlValue>(&contents) {
             Ok(value) => Ok(Some(value)),
             Err(err) => {
-                tracing::error!("Failed to parse {}: {err}", path.display());
+                tracing::error!("Failed to parse {}: {err}", path.as_ref().display());
                 Err(io::Error::new(io::ErrorKind::InvalidData, err))
             }
         },
         Err(err) if err.kind() == io::ErrorKind::NotFound => {
             if log_missing_as_info {
-                tracing::info!("{} not found, using defaults", path.display());
+                tracing::info!("{} not found, using defaults", path.as_ref().display());
             } else {
-                tracing::debug!("{} not found", path.display());
+                tracing::debug!("{} not found", path.as_ref().display());
             }
             Ok(None)
         }
         Err(err) => {
-            tracing::error!("Failed to read {}: {err}", path.display());
+            tracing::error!("Failed to read {}: {err}", path.as_ref().display());
             Err(err)
         }
     }

codex-rs/core/src/config_loader/macos.rs

@@ -1,118 +1,100 @@
+use base64::Engine;
+use base64::prelude::BASE64_STANDARD;
+use core_foundation::base::TCFType;
+use core_foundation::string::CFString;
+use core_foundation::string::CFStringRef;
+use std::ffi::c_void;
 use std::io;
+use tokio::task;
 use toml::Value as TomlValue;
 
-#[cfg(target_os = "macos")]
-mod native {
-    use super::*;
-    use base64::Engine;
-    use base64::prelude::BASE64_STANDARD;
-    use core_foundation::base::TCFType;
-    use core_foundation::string::CFString;
-    use core_foundation::string::CFStringRef;
-    use std::ffi::c_void;
-    use tokio::task;
+const MANAGED_PREFERENCES_APPLICATION_ID: &str = "com.openai.codex";
+const MANAGED_PREFERENCES_CONFIG_KEY: &str = "config_toml_base64";
 
-    pub(crate) async fn load_managed_admin_config_layer(
-        override_base64: Option<&str>,
-    ) -> io::Result<Option<TomlValue>> {
-        if let Some(encoded) = override_base64 {
-            let trimmed = encoded.trim();
-            return if trimmed.is_empty() {
-                Ok(None)
-            } else {
-                parse_managed_preferences_base64(trimmed).map(Some)
-            };
-        }
-
-        const LOAD_ERROR: &str = "Failed to load managed preferences configuration";
-
-        match task::spawn_blocking(load_managed_admin_config).await {
-            Ok(result) => result,
-            Err(join_err) => {
-                if join_err.is_cancelled() {
-                    tracing::error!("Managed preferences load task was cancelled");
-                } else {
-                    tracing::error!("Managed preferences load task failed: {join_err}");
-                }
-                Err(io::Error::other(LOAD_ERROR))
-            }
-        }
-    }
-
-    pub(super) fn load_managed_admin_config() -> io::Result<Option<TomlValue>> {
-        #[link(name = "CoreFoundation", kind = "framework")]
-        unsafe extern "C" {
-            fn CFPreferencesCopyAppValue(
-                key: CFStringRef,
-                application_id: CFStringRef,
-            ) -> *mut c_void;
-        }
-
-        const MANAGED_PREFERENCES_APPLICATION_ID: &str = "com.openai.codex";
-        const MANAGED_PREFERENCES_CONFIG_KEY: &str = "config_toml_base64";
-
-        let application_id = CFString::new(MANAGED_PREFERENCES_APPLICATION_ID);
-        let key = CFString::new(MANAGED_PREFERENCES_CONFIG_KEY);
-
-        let value_ref = unsafe {
-            CFPreferencesCopyAppValue(
-                key.as_concrete_TypeRef(),
-                application_id.as_concrete_TypeRef(),
-            )
-        };
-
-        if value_ref.is_null() {
-            tracing::debug!(
-                "Managed preferences for {} key {} not found",
-                MANAGED_PREFERENCES_APPLICATION_ID,
-                MANAGED_PREFERENCES_CONFIG_KEY
-            );
-            return Ok(None);
-        }
-
-        let value = unsafe { CFString::wrap_under_create_rule(value_ref as _) };
-        let contents = value.to_string();
-        let trimmed = contents.trim();
-
-        parse_managed_preferences_base64(trimmed).map(Some)
-    }
-
-    pub(super) fn parse_managed_preferences_base64(encoded: &str) -> io::Result<TomlValue> {
-        let decoded = BASE64_STANDARD.decode(encoded.as_bytes()).map_err(|err| {
-            tracing::error!("Failed to decode managed preferences as base64: {err}");
-            io::Error::new(io::ErrorKind::InvalidData, err)
-        })?;
-
-        let decoded_str = String::from_utf8(decoded).map_err(|err| {
-            tracing::error!("Managed preferences base64 contents were not valid UTF-8: {err}");
-            io::Error::new(io::ErrorKind::InvalidData, err)
-        })?;
-
-        match toml::from_str::<TomlValue>(&decoded_str) {
-            Ok(TomlValue::Table(parsed)) => Ok(TomlValue::Table(parsed)),
-            Ok(other) => {
-                tracing::error!(
-                    "Managed preferences TOML must have a table at the root, found {other:?}",
-                );
-                Err(io::Error::new(
-                    io::ErrorKind::InvalidData,
-                    "managed preferences root must be a table",
-                ))
-            }
-            Err(err) => {
-                tracing::error!("Failed to parse managed preferences TOML: {err}");
-                Err(io::Error::new(io::ErrorKind::InvalidData, err))
-            }
-        }
-    }
-}
-
-#[cfg(target_os = "macos")]
-pub(crate) use native::load_managed_admin_config_layer;
-
-#[cfg(not(target_os = "macos"))]
 pub(crate) async fn load_managed_admin_config_layer(
-    _override_base64: Option<&str>,
+    override_base64: Option<&str>,
 ) -> io::Result<Option<TomlValue>> {
-    Ok(None)
+    if let Some(encoded) = override_base64 {
+        let trimmed = encoded.trim();
+        return if trimmed.is_empty() {
+            Ok(None)
+        } else {
+            parse_managed_preferences_base64(trimmed).map(Some)
+        };
+    }
+
+    const LOAD_ERROR: &str = "Failed to load managed preferences configuration";
+
+    match task::spawn_blocking(load_managed_admin_config).await {
+        Ok(result) => result,
+        Err(join_err) => {
+            if join_err.is_cancelled() {
+                tracing::error!("Managed preferences load task was cancelled");
+            } else {
+                tracing::error!("Managed preferences load task failed: {join_err}");
+            }
+            Err(io::Error::other(LOAD_ERROR))
+        }
+    }
+}
+
+fn load_managed_admin_config() -> io::Result<Option<TomlValue>> {
+    #[link(name = "CoreFoundation", kind = "framework")]
+    unsafe extern "C" {
+        fn CFPreferencesCopyAppValue(key: CFStringRef, application_id: CFStringRef) -> *mut c_void;
+    }
+
+    let application_id = CFString::new(MANAGED_PREFERENCES_APPLICATION_ID);
+    let key = CFString::new(MANAGED_PREFERENCES_CONFIG_KEY);
+
+    let value_ref = unsafe {
+        CFPreferencesCopyAppValue(
+            key.as_concrete_TypeRef(),
+            application_id.as_concrete_TypeRef(),
+        )
+    };
+
+    if value_ref.is_null() {
+        tracing::debug!(
+            "Managed preferences for {} key {} not found",
+            MANAGED_PREFERENCES_APPLICATION_ID,
+            MANAGED_PREFERENCES_CONFIG_KEY
+        );
+        return Ok(None);
+    }
+
+    let value = unsafe { CFString::wrap_under_create_rule(value_ref as _) };
+    let contents = value.to_string();
+    let trimmed = contents.trim();
+
+    parse_managed_preferences_base64(trimmed).map(Some)
+}
+
+fn parse_managed_preferences_base64(encoded: &str) -> io::Result<TomlValue> {
+    let decoded = BASE64_STANDARD.decode(encoded.as_bytes()).map_err(|err| {
+        tracing::error!("Failed to decode managed preferences as base64: {err}");
+        io::Error::new(io::ErrorKind::InvalidData, err)
+    })?;
+
+    let decoded_str = String::from_utf8(decoded).map_err(|err| {
+        tracing::error!("Managed preferences base64 contents were not valid UTF-8: {err}");
+        io::Error::new(io::ErrorKind::InvalidData, err)
+    })?;
+
+    match toml::from_str::<TomlValue>(&decoded_str) {
+        Ok(TomlValue::Table(parsed)) => Ok(TomlValue::Table(parsed)),
+        Ok(other) => {
+            tracing::error!(
+                "Managed preferences TOML must have a table at the root, found {other:?}",
+            );
+            Err(io::Error::new(
+                io::ErrorKind::InvalidData,
+                "managed preferences root must be a table",
+            ))
+        }
+        Err(err) => {
+            tracing::error!("Failed to parse managed preferences TOML: {err}");
+            Err(io::Error::new(io::ErrorKind::InvalidData, err))
+        }
+    }
 }

codex-rs/core/src/config_loader/mod.rs

@@ -1,5 +1,7 @@
+mod config_requirements;
 mod fingerprint;
 mod layer_io;
+#[cfg(target_os = "macos")]
 mod macos;
 mod merge;
 mod overrides;
@@ -9,74 +11,593 @@ mod state;
 mod tests;
 
 use crate::config::CONFIG_TOML_FILE;
+use crate::config::ConfigToml;
+use crate::config_loader::config_requirements::ConfigRequirementsToml;
+use crate::config_loader::layer_io::LoadedConfigLayers;
 use codex_app_server_protocol::ConfigLayerSource;
+use codex_protocol::config_types::SandboxMode;
+use codex_protocol::protocol::AskForApproval;
 use codex_utils_absolute_path::AbsolutePathBuf;
+use codex_utils_absolute_path::AbsolutePathBufGuard;
+use serde::Deserialize;
 use std::io;
 use std::path::Path;
 use toml::Value as TomlValue;
 
+pub use config_requirements::ConfigRequirements;
 pub use merge::merge_toml_values;
 pub use state::ConfigLayerEntry;
 pub use state::ConfigLayerStack;
+pub use state::ConfigLayerStackOrdering;
 pub use state::LoaderOverrides;
 
-const MDM_PREFERENCES_DOMAIN: &str = "com.openai.codex";
-const MDM_PREFERENCES_KEY: &str = "config_toml_base64";
+/// On Unix systems, load requirements from this file path, if present.
+const DEFAULT_REQUIREMENTS_TOML_FILE_UNIX: &str = "/etc/codex/requirements.toml";
 
-/// Configuration layering pipeline (top overrides bottom):
+/// On Unix systems, load default settings from this file path, if present.
+/// Note that /etc/codex/ is treated as a "config folder," so subfolders such
+/// as skills/ and rules/ will also be honored.
+pub const SYSTEM_CONFIG_TOML_FILE_UNIX: &str = "/etc/codex/config.toml";
+
+const DEFAULT_PROJECT_ROOT_MARKERS: &[&str] = &[".git"];
+
+/// To build up the set of admin-enforced constraints, we build up from multiple
+/// configuration layers in the following order, but a constraint defined in an
+/// earlier layer cannot be overridden by a later layer:
 ///
-///        +-------------------------+
-///        | Managed preferences (*) |
-///        +-------------------------+
-///                    ^
-///                    |
-///        +-------------------------+
-///        |  managed_config.toml   |
-///        +-------------------------+
-///                    ^
-///                    |
-///        +-------------------------+
-///        |    config.toml (base)   |
-///        +-------------------------+
+/// - admin:    managed preferences (*)
+/// - system    `/etc/codex/requirements.toml`
+///
+/// For backwards compatibility, we also load from
+/// `/etc/codex/managed_config.toml` and map it to
+/// `/etc/codex/requirements.toml`.
+///
+/// Configuration is built up from multiple layers in the following order:
+///
+/// - admin:    managed preferences (*)
+/// - system    `/etc/codex/config.toml`
+/// - user      `${CODEX_HOME}/config.toml`
+/// - cwd       `${PWD}/config.toml`
+/// - tree      parent directories up to root looking for `./.codex/config.toml`
+/// - repo      `$(git rev-parse --show-toplevel)/.codex/config.toml`
+/// - runtime   e.g., --config flags, model selector in UI
 ///
 /// (*) Only available on macOS via managed device profiles.
+///
+/// See https://developers.openai.com/codex/security for details.
+///
+/// When loading the config stack for a thread, there should be a `cwd`
+/// associated with it such that `cwd` should be `Some(...)`. Only for
+/// thread-agnostic config loading (e.g., for the app server's `/config`
+/// endpoint) should `cwd` be `None`.
 pub async fn load_config_layers_state(
     codex_home: &Path,
+    cwd: Option<AbsolutePathBuf>,
     cli_overrides: &[(String, TomlValue)],
     overrides: LoaderOverrides,
 ) -> io::Result<ConfigLayerStack> {
-    let managed_config_path = overrides
-        .managed_config_path
-        .clone()
-        .unwrap_or_else(|| layer_io::managed_config_default_path(codex_home));
+    let mut config_requirements_toml = ConfigRequirementsToml::default();
 
-    let layers = layer_io::load_config_layers_internal(codex_home, overrides).await?;
-    let cli_overrides_layer = overrides::build_cli_overrides_layer(cli_overrides);
-    let user_file = AbsolutePathBuf::from_absolute_path(codex_home.join(CONFIG_TOML_FILE))?;
+    // TODO(gt): Support an entry in MDM for config requirements and use it
+    // with `config_requirements_toml.merge_unset_fields(...)`, if present.
 
-    let system = match layers.managed_config {
-        Some(cfg) => {
-            let system_file = AbsolutePathBuf::from_absolute_path(managed_config_path.clone())?;
-            Some(ConfigLayerEntry::new(
-                ConfigLayerSource::System { file: system_file },
-                cfg,
-            ))
-        }
-        None => None,
+    // Honor /etc/codex/requirements.toml.
+    if cfg!(unix) {
+        load_requirements_toml(
+            &mut config_requirements_toml,
+            DEFAULT_REQUIREMENTS_TOML_FILE_UNIX,
+        )
+        .await?;
+    }
+
+    // Make a best-effort to support the legacy `managed_config.toml` as a
+    // requirements specification.
+    let loaded_config_layers = layer_io::load_config_layers_internal(codex_home, overrides).await?;
+    load_requirements_from_legacy_scheme(
+        &mut config_requirements_toml,
+        loaded_config_layers.clone(),
+    )
+    .await?;
+
+    let mut layers = Vec::<ConfigLayerEntry>::new();
+
+    // TODO(gt): Honor managed preferences (macOS only).
+
+    // Include an entry for the "system" config folder, loading its config.toml,
+    // if it exists.
+    let system_config_toml_file = if cfg!(unix) {
+        Some(AbsolutePathBuf::from_absolute_path(
+            SYSTEM_CONFIG_TOML_FILE_UNIX,
+        )?)
+    } else {
+        // TODO(gt): Determine the path to load on Windows.
+        None
     };
+    if let Some(system_config_toml_file) = system_config_toml_file {
+        let system_layer =
+            load_config_toml_for_required_layer(&system_config_toml_file, |config_toml| {
+                ConfigLayerEntry::new(
+                    ConfigLayerSource::System {
+                        file: system_config_toml_file.clone(),
+                    },
+                    config_toml,
+                )
+            })
+            .await?;
+        layers.push(system_layer);
+    }
 
-    Ok(ConfigLayerStack {
-        user: ConfigLayerEntry::new(ConfigLayerSource::User { file: user_file }, layers.base),
-        session_flags: ConfigLayerEntry::new(ConfigLayerSource::SessionFlags, cli_overrides_layer),
-        system,
-        mdm: layers.managed_preferences.map(|cfg| {
-            ConfigLayerEntry::new(
-                ConfigLayerSource::Mdm {
-                    domain: MDM_PREFERENCES_DOMAIN.to_string(),
-                    key: MDM_PREFERENCES_KEY.to_string(),
-                },
-                cfg,
-            )
-        }),
+    // Add a layer for $CODEX_HOME/config.toml if it exists. Note if the file
+    // exists, but is malformed, then this error should be propagated to the
+    // user.
+    let user_file = AbsolutePathBuf::resolve_path_against_base(CONFIG_TOML_FILE, codex_home)?;
+    let user_layer = load_config_toml_for_required_layer(&user_file, |config_toml| {
+        ConfigLayerEntry::new(
+            ConfigLayerSource::User {
+                file: user_file.clone(),
+            },
+            config_toml,
+        )
     })
+    .await?;
+    layers.push(user_layer);
+
+    if let Some(cwd) = cwd {
+        let mut merged_so_far = TomlValue::Table(toml::map::Map::new());
+        for layer in &layers {
+            merge_toml_values(&mut merged_so_far, &layer.config);
+        }
+        let project_root_markers = project_root_markers_from_config(&merged_so_far)?
+            .unwrap_or_else(default_project_root_markers);
+
+        let project_root = find_project_root(&cwd, &project_root_markers).await?;
+        let project_layers = load_project_layers(&cwd, &project_root).await?;
+        layers.extend(project_layers);
+    }
+
+    // Add a layer for runtime overrides from the CLI or UI, if any exist.
+    if !cli_overrides.is_empty() {
+        let cli_overrides_layer = overrides::build_cli_overrides_layer(cli_overrides);
+        layers.push(ConfigLayerEntry::new(
+            ConfigLayerSource::SessionFlags,
+            cli_overrides_layer,
+        ));
+    }
+
+    // Make a best-effort to support the legacy `managed_config.toml` as a
+    // config layer on top of everything else. For fields in
+    // `managed_config.toml` that do not have an equivalent in
+    // `ConfigRequirements`, note users can still override these values on a
+    // per-turn basis in the TUI and VS Code.
+    let LoadedConfigLayers {
+        managed_config,
+        managed_config_from_mdm,
+    } = loaded_config_layers;
+    if let Some(config) = managed_config {
+        let managed_parent = config.file.as_path().parent().ok_or_else(|| {
+            io::Error::new(
+                io::ErrorKind::InvalidData,
+                format!(
+                    "Managed config file {} has no parent directory",
+                    config.file.as_path().display()
+                ),
+            )
+        })?;
+        let managed_config =
+            resolve_relative_paths_in_config_toml(config.managed_config, managed_parent)?;
+        layers.push(ConfigLayerEntry::new(
+            ConfigLayerSource::LegacyManagedConfigTomlFromFile { file: config.file },
+            managed_config,
+        ));
+    }
+    if let Some(config) = managed_config_from_mdm {
+        layers.push(ConfigLayerEntry::new(
+            ConfigLayerSource::LegacyManagedConfigTomlFromMdm,
+            config,
+        ));
+    }
+
+    ConfigLayerStack::new(layers, config_requirements_toml.try_into()?)
+}
+
+/// Attempts to load a config.toml file from `config_toml`.
+/// - If the file exists and is valid TOML, passes the parsed `toml::Value` to
+///   `create_entry` and returns the resulting layer entry.
+/// - If the file does not exist, uses an empty `Table` with `create_entry` and
+///   returns the resulting layer entry.
+/// - If there is an error reading the file or parsing the TOML, returns an
+///   error.
+async fn load_config_toml_for_required_layer(
+    config_toml: impl AsRef<Path>,
+    create_entry: impl FnOnce(TomlValue) -> ConfigLayerEntry,
+) -> io::Result<ConfigLayerEntry> {
+    let toml_file = config_toml.as_ref();
+    let toml_value = match tokio::fs::read_to_string(toml_file).await {
+        Ok(contents) => {
+            let config: TomlValue = toml::from_str(&contents).map_err(|e| {
+                io::Error::new(
+                    io::ErrorKind::InvalidData,
+                    format!("Error parsing config file {}: {e}", toml_file.display()),
+                )
+            })?;
+            let config_parent = toml_file.parent().ok_or_else(|| {
+                io::Error::new(
+                    io::ErrorKind::InvalidData,
+                    format!(
+                        "Config file {} has no parent directory",
+                        toml_file.display()
+                    ),
+                )
+            })?;
+            resolve_relative_paths_in_config_toml(config, config_parent)
+        }
+        Err(e) => {
+            if e.kind() == io::ErrorKind::NotFound {
+                Ok(TomlValue::Table(toml::map::Map::new()))
+            } else {
+                Err(io::Error::new(
+                    e.kind(),
+                    format!("Failed to read config file {}: {e}", toml_file.display()),
+                ))
+            }
+        }
+    }?;
+
+    Ok(create_entry(toml_value))
+}
+
+/// If available, apply requirements from `/etc/codex/requirements.toml` to
+/// `config_requirements_toml` by filling in any unset fields.
+async fn load_requirements_toml(
+    config_requirements_toml: &mut ConfigRequirementsToml,
+    requirements_toml_file: impl AsRef<Path>,
+) -> io::Result<()> {
+    match tokio::fs::read_to_string(&requirements_toml_file).await {
+        Ok(contents) => {
+            let requirements_config: ConfigRequirementsToml =
+                toml::from_str(&contents).map_err(|e| {
+                    io::Error::new(
+                        io::ErrorKind::InvalidData,
+                        format!(
+                            "Error parsing requirements file {}: {e}",
+                            requirements_toml_file.as_ref().display(),
+                        ),
+                    )
+                })?;
+            config_requirements_toml.merge_unset_fields(requirements_config);
+        }
+        Err(e) => {
+            if e.kind() != io::ErrorKind::NotFound {
+                return Err(io::Error::new(
+                    e.kind(),
+                    format!(
+                        "Failed to read requirements file {}: {e}",
+                        requirements_toml_file.as_ref().display(),
+                    ),
+                ));
+            }
+        }
+    }
+
+    Ok(())
+}
+
+async fn load_requirements_from_legacy_scheme(
+    config_requirements_toml: &mut ConfigRequirementsToml,
+    loaded_config_layers: LoadedConfigLayers,
+) -> io::Result<()> {
+    // In this implementation, earlier layers cannot be overwritten by later
+    // layers, so list managed_config_from_mdm first because it has the highest
+    // precedence.
+    let LoadedConfigLayers {
+        managed_config,
+        managed_config_from_mdm,
+    } = loaded_config_layers;
+    for config in [
+        managed_config_from_mdm,
+        managed_config.map(|c| c.managed_config),
+    ]
+    .into_iter()
+    .flatten()
+    {
+        let legacy_config: LegacyManagedConfigToml =
+            config.try_into().map_err(|err: toml::de::Error| {
+                io::Error::new(
+                    io::ErrorKind::InvalidData,
+                    format!("Failed to parse config requirements as TOML: {err}"),
+                )
+            })?;
+
+        let new_requirements_toml = ConfigRequirementsToml::from(legacy_config);
+        config_requirements_toml.merge_unset_fields(new_requirements_toml);
+    }
+
+    Ok(())
+}
+
+/// Reads `project_root_markers` from the [toml::Value] produced by merging
+/// `config.toml` from the config layers in the stack preceding
+/// [ConfigLayerSource::Project].
+///
+/// Invariants:
+/// - If `project_root_markers` is not specified, returns `Ok(None)`.
+/// - If `project_root_markers` is specified, returns `Ok(Some(markers))` where
+///   `markers` is a `Vec<String>` (including `Ok(Some(Vec::new()))` for an
+///   empty array, which indicates that root detection should be disabled).
+/// - Returns an error if `project_root_markers` is specified but is not an
+///   array of strings.
+fn project_root_markers_from_config(config: &TomlValue) -> io::Result<Option<Vec<String>>> {
+    let Some(table) = config.as_table() else {
+        return Ok(None);
+    };
+    let Some(markers_value) = table.get("project_root_markers") else {
+        return Ok(None);
+    };
+    let TomlValue::Array(entries) = markers_value else {
+        return Err(io::Error::new(
+            io::ErrorKind::InvalidData,
+            "project_root_markers must be an array of strings",
+        ));
+    };
+    if entries.is_empty() {
+        return Ok(Some(Vec::new()));
+    }
+    let mut markers = Vec::new();
+    for entry in entries {
+        let Some(marker) = entry.as_str() else {
+            return Err(io::Error::new(
+                io::ErrorKind::InvalidData,
+                "project_root_markers must be an array of strings",
+            ));
+        };
+        markers.push(marker.to_string());
+    }
+    Ok(Some(markers))
+}
+
+fn default_project_root_markers() -> Vec<String> {
+    DEFAULT_PROJECT_ROOT_MARKERS
+        .iter()
+        .map(ToString::to_string)
+        .collect()
+}
+
+/// Takes a `toml::Value` parsed from a config.toml file and walks through it,
+/// resolving any `AbsolutePathBuf` fields against `base_dir`, returning a new
+/// `toml::Value` with the same shape but with paths resolved.
+///
+/// This ensures that multiple config layers can be merged together correctly
+/// even if they were loaded from different directories.
+fn resolve_relative_paths_in_config_toml(
+    value_from_config_toml: TomlValue,
+    base_dir: &Path,
+) -> io::Result<TomlValue> {
+    // Use the serialize/deserialize round-trip to convert the
+    // `toml::Value` into a `ConfigToml` with `AbsolutePath
+    let _guard = AbsolutePathBufGuard::new(base_dir);
+    let Ok(resolved) = value_from_config_toml.clone().try_into::<ConfigToml>() else {
+        return Ok(value_from_config_toml);
+    };
+    drop(_guard);
+
+    let resolved_value = TomlValue::try_from(resolved).map_err(|e| {
+        io::Error::new(
+            io::ErrorKind::InvalidData,
+            format!("Failed to serialize resolved config: {e}"),
+        )
+    })?;
+
+    Ok(copy_shape_from_original(
+        &value_from_config_toml,
+        &resolved_value,
+    ))
+}
+
+/// Ensure that every field in `original` is present in the returned
+/// `toml::Value`, taking the value from `resolved` where possible. This ensures
+/// the fields that we "removed" during the serialize/deserialize round-trip in
+/// `resolve_config_paths` are preserved, out of an abundance of caution.
+fn copy_shape_from_original(original: &TomlValue, resolved: &TomlValue) -> TomlValue {
+    match (original, resolved) {
+        (TomlValue::Table(original_table), TomlValue::Table(resolved_table)) => {
+            let mut table = toml::map::Map::new();
+            for (key, original_value) in original_table {
+                let resolved_value = resolved_table.get(key).unwrap_or(original_value);
+                table.insert(
+                    key.clone(),
+                    copy_shape_from_original(original_value, resolved_value),
+                );
+            }
+            TomlValue::Table(table)
+        }
+        (TomlValue::Array(original_array), TomlValue::Array(resolved_array)) => {
+            let mut items = Vec::new();
+            for (index, original_value) in original_array.iter().enumerate() {
+                let resolved_value = resolved_array.get(index).unwrap_or(original_value);
+                items.push(copy_shape_from_original(original_value, resolved_value));
+            }
+            TomlValue::Array(items)
+        }
+        (_, resolved_value) => resolved_value.clone(),
+    }
+}
+
+async fn find_project_root(
+    cwd: &AbsolutePathBuf,
+    project_root_markers: &[String],
+) -> io::Result<AbsolutePathBuf> {
+    if project_root_markers.is_empty() {
+        return Ok(cwd.clone());
+    }
+
+    for ancestor in cwd.as_path().ancestors() {
+        for marker in project_root_markers {
+            let marker_path = ancestor.join(marker);
+            if tokio::fs::metadata(&marker_path).await.is_ok() {
+                return AbsolutePathBuf::from_absolute_path(ancestor);
+            }
+        }
+    }
+    Ok(cwd.clone())
+}
+
+/// Return the appropriate list of layers (each with
+/// [ConfigLayerSource::Project] as the source) between `cwd` and
+/// `project_root`, inclusive. The list is ordered in _increasing_ precdence,
+/// starting from folders closest to `project_root` (which is the lowest
+/// precedence) to those closest to `cwd` (which is the highest precedence).
+async fn load_project_layers(
+    cwd: &AbsolutePathBuf,
+    project_root: &AbsolutePathBuf,
+) -> io::Result<Vec<ConfigLayerEntry>> {
+    let mut dirs = cwd
+        .as_path()
+        .ancestors()
+        .scan(false, |done, a| {
+            if *done {
+                None
+            } else {
+                if a == project_root.as_path() {
+                    *done = true;
+                }
+                Some(a)
+            }
+        })
+        .collect::<Vec<_>>();
+    dirs.reverse();
+
+    let mut layers = Vec::new();
+    for dir in dirs {
+        let dot_codex = dir.join(".codex");
+        if !tokio::fs::metadata(&dot_codex)
+            .await
+            .map(|meta| meta.is_dir())
+            .unwrap_or(false)
+        {
+            continue;
+        }
+
+        let dot_codex_abs = AbsolutePathBuf::from_absolute_path(&dot_codex)?;
+        let config_file = dot_codex_abs.join(CONFIG_TOML_FILE)?;
+        match tokio::fs::read_to_string(&config_file).await {
+            Ok(contents) => {
+                let config: TomlValue = toml::from_str(&contents).map_err(|e| {
+                    io::Error::new(
+                        io::ErrorKind::InvalidData,
+                        format!(
+                            "Error parsing project config file {}: {e}",
+                            config_file.as_path().display(),
+                        ),
+                    )
+                })?;
+                let config =
+                    resolve_relative_paths_in_config_toml(config, dot_codex_abs.as_path())?;
+                layers.push(ConfigLayerEntry::new(
+                    ConfigLayerSource::Project {
+                        dot_codex_folder: dot_codex_abs,
+                    },
+                    config,
+                ));
+            }
+            Err(err) => {
+                if err.kind() == io::ErrorKind::NotFound {
+                    // If there is no config.toml file, record an empty entry
+                    // for this project layer, as this may still have subfolders
+                    // that are significant in the overall ConfigLayerStack.
+                    layers.push(ConfigLayerEntry::new(
+                        ConfigLayerSource::Project {
+                            dot_codex_folder: dot_codex_abs,
+                        },
+                        TomlValue::Table(toml::map::Map::new()),
+                    ));
+                } else {
+                    return Err(io::Error::new(
+                        err.kind(),
+                        format!(
+                            "Failed to read project config file {}: {err}",
+                            config_file.as_path().display(),
+                        ),
+                    ));
+                }
+            }
+        }
+    }
+
+    Ok(layers)
+}
+
+/// The legacy mechanism for specifying admin-enforced configuration is to read
+/// from a file like `/etc/codex/managed_config.toml` that has the same
+/// structure as `config.toml` where fields like `approval_policy` can specify
+/// exactly one value rather than a list of allowed values.
+///
+/// If present, re-interpret `managed_config.toml` as a `requirements.toml`
+/// where each specified field is treated as a constraint allowing only that
+/// value.
+#[derive(Deserialize, Debug, Clone, Default, PartialEq)]
+struct LegacyManagedConfigToml {
+    approval_policy: Option<AskForApproval>,
+    sandbox_mode: Option<SandboxMode>,
+}
+
+impl From<LegacyManagedConfigToml> for ConfigRequirementsToml {
+    fn from(legacy: LegacyManagedConfigToml) -> Self {
+        let mut config_requirements_toml = ConfigRequirementsToml::default();
+
+        let LegacyManagedConfigToml {
+            approval_policy,
+            sandbox_mode,
+        } = legacy;
+        if let Some(approval_policy) = approval_policy {
+            config_requirements_toml.allowed_approval_policies = Some(vec![approval_policy]);
+        }
+        if let Some(sandbox_mode) = sandbox_mode {
+            config_requirements_toml.allowed_sandbox_modes = Some(vec![sandbox_mode.into()]);
+        }
+        config_requirements_toml
+    }
+}
+
+// Cannot name this `mod tests` because of tests.rs in this folder.
+#[cfg(test)]
+mod unit_tests {
+    use super::*;
+    use tempfile::tempdir;
+
+    #[test]
+    fn ensure_resolve_relative_paths_in_config_toml_preserves_all_fields() -> anyhow::Result<()> {
+        let tmp = tempdir()?;
+        let base_dir = tmp.path();
+        let contents = r#"
+# This is a field recognized by config.toml that is an AbsolutePathBuf in
+# the ConfigToml struct.
+experimental_instructions_file = "./some_file.md"
+
+# This is a field recognized by config.toml.
+model = "gpt-1000"
+
+# This is a field not recognized by config.toml.
+foo = "xyzzy"
+"#;
+        let user_config: TomlValue = toml::from_str(contents)?;
+
+        let normalized_toml_value = resolve_relative_paths_in_config_toml(user_config, base_dir)?;
+        let mut expected_toml_value = toml::map::Map::new();
+        expected_toml_value.insert(
+            "experimental_instructions_file".to_string(),
+            TomlValue::String(
+                AbsolutePathBuf::resolve_path_against_base("./some_file.md", base_dir)?
+                    .as_path()
+                    .to_string_lossy()
+                    .to_string(),
+            ),
+        );
+        expected_toml_value.insert(
+            "model".to_string(),
+            TomlValue::String("gpt-1000".to_string()),
+        );
+        expected_toml_value.insert("foo".to_string(), TomlValue::String("xyzzy".to_string()));
+        assert_eq!(normalized_toml_value, TomlValue::Table(expected_toml_value));
+        Ok(())
+    }
 }

codex-rs/core/src/config_loader/state.rs

@@ -1,9 +1,12 @@
+use crate::config_loader::ConfigRequirements;
+
 use super::fingerprint::record_origins;
 use super::fingerprint::version_for_toml;
 use super::merge::merge_toml_values;
 use codex_app_server_protocol::ConfigLayer;
 use codex_app_server_protocol::ConfigLayerMetadata;
 use codex_app_server_protocol::ConfigLayerSource;
+use codex_utils_absolute_path::AbsolutePathBuf;
 use serde_json::Value as JsonValue;
 use std::collections::HashMap;
 use std::path::PathBuf;
@@ -16,7 +19,7 @@ pub struct LoaderOverrides {
     pub managed_preferences_base64: Option<String>,
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq)]
 pub struct ConfigLayerEntry {
     pub name: ConfigLayerSource,
     pub config: TomlValue,
@@ -47,34 +50,113 @@ impl ConfigLayerEntry {
             config: serde_json::to_value(&self.config).unwrap_or(JsonValue::Null),
         }
     }
+
+    // Get the `.codex/` folder associated with this config layer, if any.
+    pub fn config_folder(&self) -> Option<AbsolutePathBuf> {
+        match &self.name {
+            ConfigLayerSource::Mdm { .. } => None,
+            ConfigLayerSource::System { file } => file.parent(),
+            ConfigLayerSource::User { file } => file.parent(),
+            ConfigLayerSource::Project { dot_codex_folder } => Some(dot_codex_folder.clone()),
+            ConfigLayerSource::SessionFlags => None,
+            ConfigLayerSource::LegacyManagedConfigTomlFromFile { .. } => None,
+            ConfigLayerSource::LegacyManagedConfigTomlFromMdm => None,
+        }
+    }
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum ConfigLayerStackOrdering {
+    LowestPrecedenceFirst,
+    HighestPrecedenceFirst,
+}
+
+#[derive(Debug, Clone, Default, PartialEq)]
 pub struct ConfigLayerStack {
-    pub user: ConfigLayerEntry,
-    pub session_flags: ConfigLayerEntry,
-    pub system: Option<ConfigLayerEntry>,
-    pub mdm: Option<ConfigLayerEntry>,
+    /// Layers are listed from lowest precedence (base) to highest (top), so
+    /// later entries in the Vec override earlier ones.
+    layers: Vec<ConfigLayerEntry>,
+
+    /// Index into [layers] of the user config layer, if any.
+    user_layer_index: Option<usize>,
+
+    /// Constraints that must be enforced when deriving a [Config] from the
+    /// layers.
+    requirements: ConfigRequirements,
 }
 
 impl ConfigLayerStack {
-    pub fn with_user_config(&self, user_config: TomlValue) -> Self {
-        Self {
-            user: ConfigLayerEntry::new(self.user.name.clone(), user_config),
-            session_flags: self.session_flags.clone(),
-            system: self.system.clone(),
-            mdm: self.mdm.clone(),
+    pub fn new(
+        layers: Vec<ConfigLayerEntry>,
+        requirements: ConfigRequirements,
+    ) -> std::io::Result<Self> {
+        let user_layer_index = verify_layer_ordering(&layers)?;
+        Ok(Self {
+            layers,
+            user_layer_index,
+            requirements,
+        })
+    }
+
+    /// Returns the user config layer, if any.
+    pub fn get_user_layer(&self) -> Option<&ConfigLayerEntry> {
+        self.user_layer_index
+            .and_then(|index| self.layers.get(index))
+    }
+
+    pub fn requirements(&self) -> &ConfigRequirements {
+        &self.requirements
+    }
+
+    /// Creates a new [ConfigLayerStack] using the specified values to inject a
+    /// "user layer" into the stack. If such a layer already exists, it is
+    /// replaced; otherwise, it is inserted into the stack at the appropriate
+    /// position based on precedence rules.
+    pub fn with_user_config(&self, config_toml: &AbsolutePathBuf, user_config: TomlValue) -> Self {
+        let user_layer = ConfigLayerEntry::new(
+            ConfigLayerSource::User {
+                file: config_toml.clone(),
+            },
+            user_config,
+        );
+
+        let mut layers = self.layers.clone();
+        match self.user_layer_index {
+            Some(index) => {
+                layers[index] = user_layer;
+                Self {
+                    layers,
+                    user_layer_index: self.user_layer_index,
+                    requirements: self.requirements.clone(),
+                }
+            }
+            None => {
+                let user_layer_index = match layers
+                    .iter()
+                    .position(|layer| layer.name.precedence() > user_layer.name.precedence())
+                {
+                    Some(index) => {
+                        layers.insert(index, user_layer);
+                        index
+                    }
+                    None => {
+                        layers.push(user_layer);
+                        layers.len() - 1
+                    }
+                };
+                Self {
+                    layers,
+                    user_layer_index: Some(user_layer_index),
+                    requirements: self.requirements.clone(),
+                }
+            }
         }
     }
 
     pub fn effective_config(&self) -> TomlValue {
-        let mut merged = self.user.config.clone();
-        merge_toml_values(&mut merged, &self.session_flags.config);
-        if let Some(system) = &self.system {
-            merge_toml_values(&mut merged, &system.config);
-        }
-        if let Some(mdm) = &self.mdm {
-            merge_toml_values(&mut merged, &mdm.config);
+        let mut merged = TomlValue::Table(toml::map::Map::new());
+        for layer in &self.layers {
+            merge_toml_values(&mut merged, &layer.config);
         }
         merged
     }
@@ -83,38 +165,82 @@ impl ConfigLayerStack {
         let mut origins = HashMap::new();
         let mut path = Vec::new();
 
-        record_origins(
-            &self.user.config,
-            &self.user.metadata(),
-            &mut path,
-            &mut origins,
-        );
-        record_origins(
-            &self.session_flags.config,
-            &self.session_flags.metadata(),
-            &mut path,
-            &mut origins,
-        );
-        if let Some(system) = &self.system {
-            record_origins(&system.config, &system.metadata(), &mut path, &mut origins);
-        }
-        if let Some(mdm) = &self.mdm {
-            record_origins(&mdm.config, &mdm.metadata(), &mut path, &mut origins);
+        for layer in &self.layers {
+            record_origins(&layer.config, &layer.metadata(), &mut path, &mut origins);
         }
 
         origins
     }
 
-    pub fn layers_high_to_low(&self) -> Vec<ConfigLayer> {
-        let mut layers = Vec::new();
-        if let Some(mdm) = &self.mdm {
-            layers.push(mdm.as_layer());
+    /// Returns the highest-precedence to lowest-precedence layers, so
+    /// `ConfigLayerSource::SessionFlags` would be first, if present.
+    pub fn layers_high_to_low(&self) -> Vec<&ConfigLayerEntry> {
+        self.get_layers(ConfigLayerStackOrdering::HighestPrecedenceFirst)
+    }
+
+    /// Returns the highest-precedence to lowest-precedence layers, so
+    /// `ConfigLayerSource::SessionFlags` would be first, if present.
+    pub fn get_layers(&self, ordering: ConfigLayerStackOrdering) -> Vec<&ConfigLayerEntry> {
+        match ordering {
+            ConfigLayerStackOrdering::HighestPrecedenceFirst => self.layers.iter().rev().collect(),
+            ConfigLayerStackOrdering::LowestPrecedenceFirst => self.layers.iter().collect(),
         }
-        if let Some(system) = &self.system {
-            layers.push(system.as_layer());
-        }
-        layers.push(self.session_flags.as_layer());
-        layers.push(self.user.as_layer());
-        layers
     }
 }
+
+/// Ensures precedence ordering of config layers is correct. Returns the index
+/// of the user config layer, if any (at most one should exist).
+fn verify_layer_ordering(layers: &[ConfigLayerEntry]) -> std::io::Result<Option<usize>> {
+    if !layers.iter().map(|layer| &layer.name).is_sorted() {
+        return Err(std::io::Error::new(
+            std::io::ErrorKind::InvalidData,
+            "config layers are not in correct precedence order",
+        ));
+    }
+
+    // The previous check ensured `layers` is sorted by precedence, so now we
+    // further verify that:
+    // 1. There is at most one user config layer.
+    // 2. Project layers are ordered from root to cwd.
+    let mut user_layer_index: Option<usize> = None;
+    let mut previous_project_dot_codex_folder: Option<&AbsolutePathBuf> = None;
+    for (index, layer) in layers.iter().enumerate() {
+        if matches!(layer.name, ConfigLayerSource::User { .. }) {
+            if user_layer_index.is_some() {
+                return Err(std::io::Error::new(
+                    std::io::ErrorKind::InvalidData,
+                    "multiple user config layers found",
+                ));
+            }
+            user_layer_index = Some(index);
+        }
+
+        if let ConfigLayerSource::Project {
+            dot_codex_folder: current_project_dot_codex_folder,
+        } = &layer.name
+        {
+            if let Some(previous) = previous_project_dot_codex_folder {
+                let Some(parent) = previous.as_path().parent() else {
+                    return Err(std::io::Error::new(
+                        std::io::ErrorKind::InvalidData,
+                        "project layer has no parent directory",
+                    ));
+                };
+                if previous == current_project_dot_codex_folder
+                    || !current_project_dot_codex_folder
+                        .as_path()
+                        .ancestors()
+                        .any(|ancestor| ancestor == parent)
+                {
+                    return Err(std::io::Error::new(
+                        std::io::ErrorKind::InvalidData,
+                        "project layers are not ordered from root to cwd",
+                    ));
+                }
+            }
+            previous_project_dot_codex_folder = Some(current_project_dot_codex_folder);
+        }
+    }
+
+    Ok(user_layer_index)
+}

codex-rs/core/src/config_loader/tests.rs

@@ -1,6 +1,16 @@
 use super::LoaderOverrides;
 use super::load_config_layers_state;
 use crate::config::CONFIG_TOML_FILE;
+use crate::config::ConfigBuilder;
+use crate::config::ConfigOverrides;
+use crate::config_loader::ConfigLayerEntry;
+use crate::config_loader::ConfigRequirements;
+use crate::config_loader::config_requirements::ConfigRequirementsToml;
+use crate::config_loader::fingerprint::version_for_toml;
+use crate::config_loader::load_requirements_toml;
+use codex_protocol::protocol::AskForApproval;
+use codex_utils_absolute_path::AbsolutePathBuf;
+use pretty_assertions::assert_eq;
 use tempfile::tempdir;
 use toml::Value as TomlValue;
 
@@ -35,9 +45,15 @@ extra = true
         managed_preferences_base64: None,
     };
 
-    let state = load_config_layers_state(tmp.path(), &[] as &[(String, TomlValue)], overrides)
-        .await
-        .expect("load config");
+    let cwd = AbsolutePathBuf::try_from(tmp.path()).expect("cwd");
+    let state = load_config_layers_state(
+        tmp.path(),
+        Some(cwd),
+        &[] as &[(String, TomlValue)],
+        overrides,
+    )
+    .await
+    .expect("load config");
     let loaded = state.effective_config();
     let table = loaded.as_table().expect("top-level table expected");
 
@@ -63,17 +79,50 @@ async fn returns_empty_when_all_layers_missing() {
         managed_preferences_base64: None,
     };
 
-    let layers = load_config_layers_state(tmp.path(), &[] as &[(String, TomlValue)], overrides)
-        .await
-        .expect("load layers");
-    let base_table = layers.user.config.as_table().expect("base table expected");
+    let cwd = AbsolutePathBuf::try_from(tmp.path()).expect("cwd");
+    let layers = load_config_layers_state(
+        tmp.path(),
+        Some(cwd),
+        &[] as &[(String, TomlValue)],
+        overrides,
+    )
+    .await
+    .expect("load layers");
+    let user_layer = layers
+        .get_user_layer()
+        .expect("expected a user layer even when CODEX_HOME/config.toml does not exist");
+    assert_eq!(
+        &ConfigLayerEntry {
+            name: super::ConfigLayerSource::User {
+                file: AbsolutePathBuf::resolve_path_against_base(CONFIG_TOML_FILE, tmp.path())
+                    .expect("resolve user config.toml path")
+            },
+            config: TomlValue::Table(toml::map::Map::new()),
+            version: version_for_toml(&TomlValue::Table(toml::map::Map::new())),
+        },
+        user_layer,
+    );
+    assert_eq!(
+        user_layer.config,
+        TomlValue::Table(toml::map::Map::new()),
+        "expected empty config for user layer when config.toml does not exist"
+    );
+
+    let binding = layers.effective_config();
+    let base_table = binding.as_table().expect("base table expected");
     assert!(
         base_table.is_empty(),
         "expected empty base layer when configs missing"
     );
-    assert!(
-        layers.system.is_none(),
-        "managed config layer should be absent when file missing"
+    let num_system_layers = layers
+        .layers_high_to_low()
+        .iter()
+        .filter(|layer| matches!(layer.name, super::ConfigLayerSource::System { .. }))
+        .count();
+    let expected_system_layers = if cfg!(unix) { 1 } else { 0 };
+    assert_eq!(
+        num_system_layers, expected_system_layers,
+        "system layer should be present only on unix"
     );
 
     #[cfg(not(target_os = "macos"))]
@@ -122,9 +171,15 @@ flag = true
         managed_preferences_base64: Some(encoded),
     };
 
-    let state = load_config_layers_state(tmp.path(), &[] as &[(String, TomlValue)], overrides)
-        .await
-        .expect("load config");
+    let cwd = AbsolutePathBuf::try_from(tmp.path()).expect("cwd");
+    let state = load_config_layers_state(
+        tmp.path(),
+        Some(cwd),
+        &[] as &[(String, TomlValue)],
+        overrides,
+    )
+    .await
+    .expect("load config");
     let loaded = state.effective_config();
     let nested = loaded
         .get("nested")
@@ -136,3 +191,246 @@ flag = true
     );
     assert_eq!(nested.get("flag"), Some(&TomlValue::Boolean(false)));
 }
+
+#[tokio::test(flavor = "current_thread")]
+async fn load_requirements_toml_produces_expected_constraints() -> anyhow::Result<()> {
+    let tmp = tempdir()?;
+    let requirements_file = tmp.path().join("requirements.toml");
+    tokio::fs::write(
+        &requirements_file,
+        r#"
+allowed_approval_policies = ["never", "on-request"]
+"#,
+    )
+    .await?;
+
+    let mut config_requirements_toml = ConfigRequirementsToml::default();
+    load_requirements_toml(&mut config_requirements_toml, &requirements_file).await?;
+
+    assert_eq!(
+        config_requirements_toml.allowed_approval_policies,
+        Some(vec![AskForApproval::Never, AskForApproval::OnRequest])
+    );
+
+    let config_requirements: ConfigRequirements = config_requirements_toml.try_into()?;
+    assert_eq!(
+        config_requirements.approval_policy.value(),
+        AskForApproval::Never
+    );
+    config_requirements
+        .approval_policy
+        .can_set(&AskForApproval::Never)?;
+    assert!(
+        config_requirements
+            .approval_policy
+            .can_set(&AskForApproval::OnFailure)
+            .is_err()
+    );
+    Ok(())
+}
+
+#[tokio::test]
+async fn project_layers_prefer_closest_cwd() -> std::io::Result<()> {
+    let tmp = tempdir()?;
+    let project_root = tmp.path().join("project");
+    let nested = project_root.join("child");
+    tokio::fs::create_dir_all(nested.join(".codex")).await?;
+    tokio::fs::create_dir_all(project_root.join(".codex")).await?;
+    tokio::fs::write(project_root.join(".git"), "gitdir: here").await?;
+
+    tokio::fs::write(
+        project_root.join(".codex").join(CONFIG_TOML_FILE),
+        "foo = \"root\"\n",
+    )
+    .await?;
+    tokio::fs::write(
+        nested.join(".codex").join(CONFIG_TOML_FILE),
+        "foo = \"child\"\n",
+    )
+    .await?;
+
+    let codex_home = tmp.path().join("home");
+    tokio::fs::create_dir_all(&codex_home).await?;
+    let cwd = AbsolutePathBuf::from_absolute_path(&nested)?;
+    let layers = load_config_layers_state(
+        &codex_home,
+        Some(cwd),
+        &[] as &[(String, TomlValue)],
+        LoaderOverrides::default(),
+    )
+    .await?;
+
+    let project_layers: Vec<_> = layers
+        .layers_high_to_low()
+        .into_iter()
+        .filter_map(|layer| match &layer.name {
+            super::ConfigLayerSource::Project { dot_codex_folder } => Some(dot_codex_folder),
+            _ => None,
+        })
+        .collect();
+    assert_eq!(project_layers.len(), 2);
+    assert_eq!(project_layers[0].as_path(), nested.join(".codex").as_path());
+    assert_eq!(
+        project_layers[1].as_path(),
+        project_root.join(".codex").as_path()
+    );
+
+    let config = layers.effective_config();
+    let foo = config
+        .get("foo")
+        .and_then(TomlValue::as_str)
+        .expect("foo entry");
+    assert_eq!(foo, "child");
+    Ok(())
+}
+
+#[tokio::test]
+async fn project_paths_resolve_relative_to_dot_codex_and_override_in_order() -> std::io::Result<()>
+{
+    let tmp = tempdir()?;
+    let project_root = tmp.path().join("project");
+    let nested = project_root.join("child");
+    tokio::fs::create_dir_all(project_root.join(".codex")).await?;
+    tokio::fs::create_dir_all(nested.join(".codex")).await?;
+    tokio::fs::write(project_root.join(".git"), "gitdir: here").await?;
+
+    let root_cfg = r#"
+experimental_instructions_file = "root.txt"
+"#;
+    let nested_cfg = r#"
+experimental_instructions_file = "child.txt"
+"#;
+    tokio::fs::write(project_root.join(".codex").join(CONFIG_TOML_FILE), root_cfg).await?;
+    tokio::fs::write(nested.join(".codex").join(CONFIG_TOML_FILE), nested_cfg).await?;
+    tokio::fs::write(
+        project_root.join(".codex").join("root.txt"),
+        "root instructions",
+    )
+    .await?;
+    tokio::fs::write(
+        nested.join(".codex").join("child.txt"),
+        "child instructions",
+    )
+    .await?;
+
+    let codex_home = tmp.path().join("home");
+    tokio::fs::create_dir_all(&codex_home).await?;
+
+    let config = ConfigBuilder::default()
+        .codex_home(codex_home)
+        .harness_overrides(ConfigOverrides {
+            cwd: Some(nested.clone()),
+            ..ConfigOverrides::default()
+        })
+        .build()
+        .await?;
+
+    assert_eq!(
+        config.base_instructions.as_deref(),
+        Some("child instructions")
+    );
+
+    Ok(())
+}
+
+#[tokio::test]
+async fn project_layer_is_added_when_dot_codex_exists_without_config_toml() -> std::io::Result<()> {
+    let tmp = tempdir()?;
+    let project_root = tmp.path().join("project");
+    let nested = project_root.join("child");
+    tokio::fs::create_dir_all(&nested).await?;
+    tokio::fs::create_dir_all(project_root.join(".codex")).await?;
+    tokio::fs::write(project_root.join(".git"), "gitdir: here").await?;
+
+    let codex_home = tmp.path().join("home");
+    tokio::fs::create_dir_all(&codex_home).await?;
+    let cwd = AbsolutePathBuf::from_absolute_path(&nested)?;
+    let layers = load_config_layers_state(
+        &codex_home,
+        Some(cwd),
+        &[] as &[(String, TomlValue)],
+        LoaderOverrides::default(),
+    )
+    .await?;
+
+    let project_layers: Vec<_> = layers
+        .layers_high_to_low()
+        .into_iter()
+        .filter(|layer| matches!(layer.name, super::ConfigLayerSource::Project { .. }))
+        .collect();
+    assert_eq!(
+        vec![&ConfigLayerEntry {
+            name: super::ConfigLayerSource::Project {
+                dot_codex_folder: AbsolutePathBuf::from_absolute_path(project_root.join(".codex"))?,
+            },
+            config: TomlValue::Table(toml::map::Map::new()),
+            version: version_for_toml(&TomlValue::Table(toml::map::Map::new())),
+        }],
+        project_layers
+    );
+
+    Ok(())
+}
+
+#[tokio::test]
+async fn project_root_markers_supports_alternate_markers() -> std::io::Result<()> {
+    let tmp = tempdir()?;
+    let project_root = tmp.path().join("project");
+    let nested = project_root.join("child");
+    tokio::fs::create_dir_all(project_root.join(".codex")).await?;
+    tokio::fs::create_dir_all(nested.join(".codex")).await?;
+    tokio::fs::write(project_root.join(".hg"), "hg").await?;
+    tokio::fs::write(
+        project_root.join(".codex").join(CONFIG_TOML_FILE),
+        "foo = \"root\"\n",
+    )
+    .await?;
+    tokio::fs::write(
+        nested.join(".codex").join(CONFIG_TOML_FILE),
+        "foo = \"child\"\n",
+    )
+    .await?;
+
+    let codex_home = tmp.path().join("home");
+    tokio::fs::create_dir_all(&codex_home).await?;
+    tokio::fs::write(
+        codex_home.join(CONFIG_TOML_FILE),
+        r#"
+project_root_markers = [".hg"]
+"#,
+    )
+    .await?;
+
+    let cwd = AbsolutePathBuf::from_absolute_path(&nested)?;
+    let layers = load_config_layers_state(
+        &codex_home,
+        Some(cwd),
+        &[] as &[(String, TomlValue)],
+        LoaderOverrides::default(),
+    )
+    .await?;
+
+    let project_layers: Vec<_> = layers
+        .layers_high_to_low()
+        .into_iter()
+        .filter_map(|layer| match &layer.name {
+            super::ConfigLayerSource::Project { dot_codex_folder } => Some(dot_codex_folder),
+            _ => None,
+        })
+        .collect();
+    assert_eq!(project_layers.len(), 2);
+    assert_eq!(project_layers[0].as_path(), nested.join(".codex").as_path());
+    assert_eq!(
+        project_layers[1].as_path(),
+        project_root.join(".codex").as_path()
+    );
+
+    let merged = layers.effective_config();
+    let foo = merged
+        .get("foo")
+        .and_then(TomlValue::as_str)
+        .expect("foo entry");
+    assert_eq!(foo, "child");
+
+    Ok(())
+}

codex-rs/core/src/conversation_manager.rs

@@ -10,7 +10,7 @@ use crate::codex_conversation::CodexConversation;
 use crate::config::Config;
 use crate::error::CodexErr;
 use crate::error::Result as CodexResult;
-use crate::openai_models::models_manager::ModelsManager;
+use crate::models_manager::manager::ModelsManager;
 use crate::protocol::Event;
 use crate::protocol::EventMsg;
 use crate::protocol::SessionConfiguredEvent;
@@ -379,9 +379,9 @@ mod tests {
         assert_matches!(truncated2, InitialHistory::New);
     }
 
-    #[test]
-    fn ignores_session_prefix_messages_when_truncating() {
-        let (session, turn_context) = make_session_and_context();
+    #[tokio::test]
+    async fn ignores_session_prefix_messages_when_truncating() {
+        let (session, turn_context) = make_session_and_context().await;
         let mut items = session.build_initial_context(&turn_context);
         items.push(user_msg("feature request"));
         items.push(assistant_msg("ack"));

codex-rs/core/src/environment_context.rs

@@ -1,10 +1,6 @@
-use codex_utils_absolute_path::AbsolutePathBuf;
-use serde::Deserialize;
-use serde::Serialize;
-use strum_macros::Display as DeriveDisplay;
-
 use crate::codex::TurnContext;
 use crate::protocol::AskForApproval;
+use crate::protocol::NetworkAccess;
 use crate::protocol::SandboxPolicy;
 use crate::shell::Shell;
 use codex_protocol::config_types::SandboxMode;
@@ -12,15 +8,11 @@ use codex_protocol::models::ContentItem;
 use codex_protocol::models::ResponseItem;
 use codex_protocol::protocol::ENVIRONMENT_CONTEXT_CLOSE_TAG;
 use codex_protocol::protocol::ENVIRONMENT_CONTEXT_OPEN_TAG;
+use codex_utils_absolute_path::AbsolutePathBuf;
+use serde::Deserialize;
+use serde::Serialize;
 use std::path::PathBuf;
 
-#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, DeriveDisplay)]
-#[serde(rename_all = "kebab-case")]
-#[strum(serialize_all = "kebab-case")]
-pub enum NetworkAccess {
-    Restricted,
-    Enabled,
-}
 #[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
 #[serde(rename = "environment_context", rename_all = "snake_case")]
 pub(crate) struct EnvironmentContext {
@@ -45,12 +37,14 @@ impl EnvironmentContext {
             sandbox_mode: match sandbox_policy {
                 Some(SandboxPolicy::DangerFullAccess) => Some(SandboxMode::DangerFullAccess),
                 Some(SandboxPolicy::ReadOnly) => Some(SandboxMode::ReadOnly),
+                Some(SandboxPolicy::ExternalSandbox { .. }) => Some(SandboxMode::DangerFullAccess),
                 Some(SandboxPolicy::WorkspaceWrite { .. }) => Some(SandboxMode::WorkspaceWrite),
                 None => None,
             },
             network_access: match sandbox_policy {
                 Some(SandboxPolicy::DangerFullAccess) => Some(NetworkAccess::Enabled),
                 Some(SandboxPolicy::ReadOnly) => Some(NetworkAccess::Restricted),
+                Some(SandboxPolicy::ExternalSandbox { network_access }) => Some(network_access),
                 Some(SandboxPolicy::WorkspaceWrite { network_access, .. }) => {
                     if network_access {
                         Some(NetworkAccess::Enabled)
@@ -272,6 +266,48 @@ mod tests {
         assert_eq!(context.serialize_to_xml(), expected);
     }
 
+    #[test]
+    fn serialize_external_sandbox_environment_context() {
+        let context = EnvironmentContext::new(
+            None,
+            Some(AskForApproval::OnRequest),
+            Some(SandboxPolicy::ExternalSandbox {
+                network_access: NetworkAccess::Enabled,
+            }),
+            fake_shell(),
+        );
+
+        let expected = r#"<environment_context>
+  <approval_policy>on-request</approval_policy>
+  <sandbox_mode>danger-full-access</sandbox_mode>
+  <network_access>enabled</network_access>
+  <shell>bash</shell>
+</environment_context>"#;
+
+        assert_eq!(context.serialize_to_xml(), expected);
+    }
+
+    #[test]
+    fn serialize_external_sandbox_with_restricted_network_environment_context() {
+        let context = EnvironmentContext::new(
+            None,
+            Some(AskForApproval::OnRequest),
+            Some(SandboxPolicy::ExternalSandbox {
+                network_access: NetworkAccess::Restricted,
+            }),
+            fake_shell(),
+        );
+
+        let expected = r#"<environment_context>
+  <approval_policy>on-request</approval_policy>
+  <sandbox_mode>danger-full-access</sandbox_mode>
+  <network_access>restricted</network_access>
+  <shell>bash</shell>
+</environment_context>"#;
+
+        assert_eq!(context.serialize_to_xml(), expected);
+    }
+
     #[test]
     fn serialize_full_access_environment_context() {
         let context = EnvironmentContext::new(

codex-rs/core/src/exec.rs

@@ -135,7 +135,9 @@ pub async fn process_exec_tool_call(
     stdout_stream: Option<StdoutStream>,
 ) -> Result<ExecToolCallOutput> {
     let sandbox_type = match &sandbox_policy {
-        SandboxPolicy::DangerFullAccess => SandboxType::None,
+        SandboxPolicy::DangerFullAccess | SandboxPolicy::ExternalSandbox { .. } => {
+            SandboxType::None
+        }
         _ => get_platform_sandbox().unwrap_or(SandboxType::None),
     };
     tracing::debug!("Sandbox type: {sandbox_type:?}");
@@ -523,7 +525,10 @@ async fn exec(
 ) -> Result<RawExecToolCallOutput> {
     #[cfg(target_os = "windows")]
     if sandbox == SandboxType::WindowsRestrictedToken
-        && !matches!(sandbox_policy, SandboxPolicy::DangerFullAccess)
+        && !matches!(
+            sandbox_policy,
+            SandboxPolicy::DangerFullAccess | SandboxPolicy::ExternalSandbox { .. }
+        )
     {
         return exec_windows_sandbox(params, sandbox_policy).await;
     }

codex-rs/core/src/exec_env.rs

@@ -82,7 +82,7 @@ mod tests {
     }
 
     #[test]
-    fn test_core_inherit_and_default_excludes() {
+    fn test_core_inherit_defaults_keep_sensitive_vars() {
         let vars = make_vars(&[
             ("PATH", "/usr/bin"),
             ("HOME", "/home/user"),
@@ -90,7 +90,32 @@ mod tests {
             ("SECRET_TOKEN", "t"),
         ]);
 
-        let policy = ShellEnvironmentPolicy::default(); // inherit Core, default excludes on
+        let policy = ShellEnvironmentPolicy::default(); // inherit All, default excludes ignored
+        let result = populate_env(vars, &policy);
+
+        let expected: HashMap<String, String> = hashmap! {
+            "PATH".to_string() => "/usr/bin".to_string(),
+            "HOME".to_string() => "/home/user".to_string(),
+            "API_KEY".to_string() => "secret".to_string(),
+            "SECRET_TOKEN".to_string() => "t".to_string(),
+        };
+
+        assert_eq!(result, expected);
+    }
+
+    #[test]
+    fn test_core_inherit_with_default_excludes_enabled() {
+        let vars = make_vars(&[
+            ("PATH", "/usr/bin"),
+            ("HOME", "/home/user"),
+            ("API_KEY", "secret"),
+            ("SECRET_TOKEN", "t"),
+        ]);
+
+        let policy = ShellEnvironmentPolicy {
+            ignore_default_excludes: false, // apply KEY/SECRET/TOKEN filter
+            ..Default::default()
+        };
         let result = populate_env(vars, &policy);
 
         let expected: HashMap<String, String> = hashmap! {
@@ -162,6 +187,7 @@ mod tests {
 
         let policy = ShellEnvironmentPolicy {
             inherit: ShellEnvironmentPolicyInherit::All,
+            ignore_default_excludes: false,
             ..Default::default()
         };
 

codex-rs/core/src/exec_policy.rs

@@ -3,7 +3,11 @@ use std::path::Path;
 use std::path::PathBuf;
 use std::sync::Arc;
 
+use arc_swap::ArcSwap;
+
 use crate::command_safety::is_dangerous_command::requires_initial_appoval;
+use crate::config_loader::ConfigLayerStack;
+use crate::config_loader::ConfigLayerStackOrdering;
 use codex_execpolicy::AmendError;
 use codex_execpolicy::Decision;
 use codex_execpolicy::Error as ExecPolicyRuleError;
@@ -17,7 +21,6 @@ use codex_protocol::protocol::AskForApproval;
 use codex_protocol::protocol::SandboxPolicy;
 use thiserror::Error;
 use tokio::fs;
-use tokio::sync::RwLock;
 use tokio::task::spawn_blocking;
 
 use crate::bash::parse_shell_lc_plain_commands;
@@ -80,20 +83,141 @@ pub enum ExecPolicyUpdateError {
     FeatureDisabled,
 }
 
-pub(crate) async fn load_exec_policy_for_features(
+pub(crate) struct ExecPolicyManager {
+    policy: ArcSwap<Policy>,
+}
+
+impl ExecPolicyManager {
+    pub(crate) fn new(policy: Arc<Policy>) -> Self {
+        Self {
+            policy: ArcSwap::from(policy),
+        }
+    }
+
+    pub(crate) async fn load(
+        features: &Features,
+        config_stack: &ConfigLayerStack,
+    ) -> Result<Self, ExecPolicyError> {
+        let policy = load_exec_policy_for_features(features, config_stack).await?;
+        Ok(Self::new(Arc::new(policy)))
+    }
+
+    pub(crate) fn current(&self) -> Arc<Policy> {
+        self.policy.load_full()
+    }
+
+    pub(crate) async fn create_exec_approval_requirement_for_command(
+        &self,
+        features: &Features,
+        command: &[String],
+        approval_policy: AskForApproval,
+        sandbox_policy: &SandboxPolicy,
+        sandbox_permissions: SandboxPermissions,
+    ) -> ExecApprovalRequirement {
+        let exec_policy = self.current();
+        let commands =
+            parse_shell_lc_plain_commands(command).unwrap_or_else(|| vec![command.to_vec()]);
+        let heuristics_fallback = |cmd: &[String]| {
+            if requires_initial_appoval(approval_policy, sandbox_policy, cmd, sandbox_permissions) {
+                Decision::Prompt
+            } else {
+                Decision::Allow
+            }
+        };
+        let evaluation = exec_policy.check_multiple(commands.iter(), &heuristics_fallback);
+
+        match evaluation.decision {
+            Decision::Forbidden => ExecApprovalRequirement::Forbidden {
+                reason: FORBIDDEN_REASON.to_string(),
+            },
+            Decision::Prompt => {
+                if matches!(approval_policy, AskForApproval::Never) {
+                    ExecApprovalRequirement::Forbidden {
+                        reason: PROMPT_CONFLICT_REASON.to_string(),
+                    }
+                } else {
+                    ExecApprovalRequirement::NeedsApproval {
+                        reason: derive_prompt_reason(&evaluation),
+                        proposed_execpolicy_amendment: if features.enabled(Feature::ExecPolicy) {
+                            try_derive_execpolicy_amendment_for_prompt_rules(
+                                &evaluation.matched_rules,
+                            )
+                        } else {
+                            None
+                        },
+                    }
+                }
+            }
+            Decision::Allow => ExecApprovalRequirement::Skip {
+                // Bypass sandbox if execpolicy allows the command
+                bypass_sandbox: evaluation.matched_rules.iter().any(|rule_match| {
+                    is_policy_match(rule_match) && rule_match.decision() == Decision::Allow
+                }),
+                proposed_execpolicy_amendment: if features.enabled(Feature::ExecPolicy) {
+                    try_derive_execpolicy_amendment_for_allow_rules(&evaluation.matched_rules)
+                } else {
+                    None
+                },
+            },
+        }
+    }
+
+    pub(crate) async fn append_amendment_and_update(
+        &self,
+        codex_home: &Path,
+        amendment: &ExecPolicyAmendment,
+    ) -> Result<(), ExecPolicyUpdateError> {
+        let policy_path = default_policy_path(codex_home);
+        let prefix = amendment.command.clone();
+        spawn_blocking({
+            let policy_path = policy_path.clone();
+            let prefix = prefix.clone();
+            move || blocking_append_allow_prefix_rule(&policy_path, &prefix)
+        })
+        .await
+        .map_err(|source| ExecPolicyUpdateError::JoinBlockingTask { source })?
+        .map_err(|source| ExecPolicyUpdateError::AppendRule {
+            path: policy_path,
+            source,
+        })?;
+
+        let mut updated_policy = self.current().as_ref().clone();
+        updated_policy.add_prefix_rule(&prefix, Decision::Allow)?;
+        self.policy.store(Arc::new(updated_policy));
+        Ok(())
+    }
+}
+
+impl Default for ExecPolicyManager {
+    fn default() -> Self {
+        Self::new(Arc::new(Policy::empty()))
+    }
+}
+
+async fn load_exec_policy_for_features(
     features: &Features,
-    codex_home: &Path,
+    config_stack: &ConfigLayerStack,
 ) -> Result<Policy, ExecPolicyError> {
     if !features.enabled(Feature::ExecPolicy) {
         Ok(Policy::empty())
     } else {
-        load_exec_policy(codex_home).await
+        load_exec_policy(config_stack).await
     }
 }
 
-pub async fn load_exec_policy(codex_home: &Path) -> Result<Policy, ExecPolicyError> {
-    let policy_dir = codex_home.join(RULES_DIR_NAME);
-    let policy_paths = collect_policy_files(&policy_dir).await?;
+pub async fn load_exec_policy(config_stack: &ConfigLayerStack) -> Result<Policy, ExecPolicyError> {
+    // Iterate the layers in increasing order of precedence, adding the *.rules
+    // from each layer, so that higher-precedence layers can override
+    // rules defined in lower-precedence ones.
+    let mut policy_paths = Vec::new();
+    for layer in config_stack.get_layers(ConfigLayerStackOrdering::LowestPrecedenceFirst) {
+        if let Some(config_folder) = layer.config_folder() {
+            #[expect(clippy::expect_used)]
+            let policy_dir = config_folder.join(RULES_DIR_NAME).expect("safe join");
+            let layer_policy_paths = collect_policy_files(&policy_dir).await?;
+            policy_paths.extend(layer_policy_paths);
+        }
+    }
 
     let mut parser = PolicyParser::new();
     for policy_path in &policy_paths {
@@ -114,46 +238,15 @@ pub async fn load_exec_policy(codex_home: &Path) -> Result<Policy, ExecPolicyErr
     }
 
     let policy = parser.build();
-    tracing::debug!(
-        "loaded execpolicy from {} files in {}",
-        policy_paths.len(),
-        policy_dir.display()
-    );
+    tracing::debug!("loaded execpolicy from {} files", policy_paths.len());
 
     Ok(policy)
 }
 
-pub(crate) fn default_policy_path(codex_home: &Path) -> PathBuf {
+fn default_policy_path(codex_home: &Path) -> PathBuf {
     codex_home.join(RULES_DIR_NAME).join(DEFAULT_POLICY_FILE)
 }
 
-pub(crate) async fn append_execpolicy_amendment_and_update(
-    codex_home: &Path,
-    current_policy: &Arc<RwLock<Policy>>,
-    prefix: &[String],
-) -> Result<(), ExecPolicyUpdateError> {
-    let policy_path = default_policy_path(codex_home);
-    let prefix = prefix.to_vec();
-    spawn_blocking({
-        let policy_path = policy_path.clone();
-        let prefix = prefix.clone();
-        move || blocking_append_allow_prefix_rule(&policy_path, &prefix)
-    })
-    .await
-    .map_err(|source| ExecPolicyUpdateError::JoinBlockingTask { source })?
-    .map_err(|source| ExecPolicyUpdateError::AppendRule {
-        path: policy_path,
-        source,
-    })?;
-
-    current_policy
-        .write()
-        .await
-        .add_prefix_rule(&prefix, Decision::Allow)?;
-
-    Ok(())
-}
-
 /// Derive a proposed execpolicy amendment when a command requires user approval
 /// - If any execpolicy rule prompts, return None, because an amendment would not skip that policy requirement.
 /// - Otherwise return the first heuristics Prompt.
@@ -217,60 +310,8 @@ fn derive_prompt_reason(evaluation: &Evaluation) -> Option<String> {
     })
 }
 
-pub(crate) async fn create_exec_approval_requirement_for_command(
-    exec_policy: &Arc<RwLock<Policy>>,
-    features: &Features,
-    command: &[String],
-    approval_policy: AskForApproval,
-    sandbox_policy: &SandboxPolicy,
-    sandbox_permissions: SandboxPermissions,
-) -> ExecApprovalRequirement {
-    let commands = parse_shell_lc_plain_commands(command).unwrap_or_else(|| vec![command.to_vec()]);
-    let heuristics_fallback = |cmd: &[String]| {
-        if requires_initial_appoval(approval_policy, sandbox_policy, cmd, sandbox_permissions) {
-            Decision::Prompt
-        } else {
-            Decision::Allow
-        }
-    };
-    let policy = exec_policy.read().await;
-    let evaluation = policy.check_multiple(commands.iter(), &heuristics_fallback);
-
-    match evaluation.decision {
-        Decision::Forbidden => ExecApprovalRequirement::Forbidden {
-            reason: FORBIDDEN_REASON.to_string(),
-        },
-        Decision::Prompt => {
-            if matches!(approval_policy, AskForApproval::Never) {
-                ExecApprovalRequirement::Forbidden {
-                    reason: PROMPT_CONFLICT_REASON.to_string(),
-                }
-            } else {
-                ExecApprovalRequirement::NeedsApproval {
-                    reason: derive_prompt_reason(&evaluation),
-                    proposed_execpolicy_amendment: if features.enabled(Feature::ExecPolicy) {
-                        try_derive_execpolicy_amendment_for_prompt_rules(&evaluation.matched_rules)
-                    } else {
-                        None
-                    },
-                }
-            }
-        }
-        Decision::Allow => ExecApprovalRequirement::Skip {
-            // Bypass sandbox if execpolicy allows the command
-            bypass_sandbox: evaluation.matched_rules.iter().any(|rule_match| {
-                is_policy_match(rule_match) && rule_match.decision() == Decision::Allow
-            }),
-            proposed_execpolicy_amendment: if features.enabled(Feature::ExecPolicy) {
-                try_derive_execpolicy_amendment_for_allow_rules(&evaluation.matched_rules)
-            } else {
-                None
-            },
-        },
-    }
-}
-
-async fn collect_policy_files(dir: &Path) -> Result<Vec<PathBuf>, ExecPolicyError> {
+async fn collect_policy_files(dir: impl AsRef<Path>) -> Result<Vec<PathBuf>, ExecPolicyError> {
+    let dir = dir.as_ref();
     let mut read_dir = match fs::read_dir(dir).await {
         Ok(read_dir) => read_dir,
         Err(err) if err.kind() == ErrorKind::NotFound => return Ok(Vec::new()),
@@ -313,30 +354,54 @@ async fn collect_policy_files(dir: &Path) -> Result<Vec<PathBuf>, ExecPolicyErro
 
     policy_paths.sort();
 
+    tracing::debug!(
+        "loaded {} .rules files in {}",
+        policy_paths.len(),
+        dir.display()
+    );
     Ok(policy_paths)
 }
 
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::config_loader::ConfigLayerEntry;
+    use crate::config_loader::ConfigLayerStack;
+    use crate::config_loader::ConfigRequirements;
     use crate::features::Feature;
     use crate::features::Features;
+    use codex_app_server_protocol::ConfigLayerSource;
     use codex_protocol::protocol::AskForApproval;
     use codex_protocol::protocol::SandboxPolicy;
+    use codex_utils_absolute_path::AbsolutePathBuf;
     use pretty_assertions::assert_eq;
     use std::fs;
+    use std::path::Path;
     use std::sync::Arc;
     use tempfile::tempdir;
+    use toml::Value as TomlValue;
+
+    fn config_stack_for_dot_codex_folder(dot_codex_folder: &Path) -> ConfigLayerStack {
+        let dot_codex_folder = AbsolutePathBuf::from_absolute_path(dot_codex_folder)
+            .expect("absolute dot_codex_folder");
+        let layer = ConfigLayerEntry::new(
+            ConfigLayerSource::Project { dot_codex_folder },
+            TomlValue::Table(Default::default()),
+        );
+        ConfigLayerStack::new(vec![layer], ConfigRequirements::default()).expect("ConfigLayerStack")
+    }
 
     #[tokio::test]
     async fn returns_empty_policy_when_feature_disabled() {
         let mut features = Features::with_defaults();
         features.disable(Feature::ExecPolicy);
         let temp_dir = tempdir().expect("create temp dir");
+        let config_stack = config_stack_for_dot_codex_folder(temp_dir.path());
 
-        let policy = load_exec_policy_for_features(&features, temp_dir.path())
+        let manager = ExecPolicyManager::load(&features, &config_stack)
             .await
-            .expect("policy result");
+            .expect("manager result");
+        let policy = manager.current();
 
         let commands = [vec!["rm".to_string()]];
         assert_eq!(
@@ -367,6 +432,7 @@ mod tests {
     #[tokio::test]
     async fn loads_policies_from_policy_subdirectory() {
         let temp_dir = tempdir().expect("create temp dir");
+        let config_stack = config_stack_for_dot_codex_folder(temp_dir.path());
         let policy_dir = temp_dir.path().join(RULES_DIR_NAME);
         fs::create_dir_all(&policy_dir).expect("create policy dir");
         fs::write(
@@ -375,7 +441,7 @@ mod tests {
         )
         .expect("write policy file");
 
-        let policy = load_exec_policy(temp_dir.path())
+        let policy = load_exec_policy(&config_stack)
             .await
             .expect("policy result");
         let command = [vec!["rm".to_string()]];
@@ -394,13 +460,14 @@ mod tests {
     #[tokio::test]
     async fn ignores_policies_outside_policy_dir() {
         let temp_dir = tempdir().expect("create temp dir");
+        let config_stack = config_stack_for_dot_codex_folder(temp_dir.path());
         fs::write(
             temp_dir.path().join("root.rules"),
             r#"prefix_rule(pattern=["ls"], decision="prompt")"#,
         )
         .expect("write policy file");
 
-        let policy = load_exec_policy(temp_dir.path())
+        let policy = load_exec_policy(&config_stack)
             .await
             .expect("policy result");
         let command = [vec!["ls".to_string()]];
@@ -416,6 +483,69 @@ mod tests {
         );
     }
 
+    #[tokio::test]
+    async fn loads_policies_from_multiple_config_layers() -> anyhow::Result<()> {
+        let user_dir = tempdir()?;
+        let project_dir = tempdir()?;
+
+        let user_policy_dir = user_dir.path().join(RULES_DIR_NAME);
+        fs::create_dir_all(&user_policy_dir)?;
+        fs::write(
+            user_policy_dir.join("user.rules"),
+            r#"prefix_rule(pattern=["rm"], decision="forbidden")"#,
+        )?;
+
+        let project_policy_dir = project_dir.path().join(RULES_DIR_NAME);
+        fs::create_dir_all(&project_policy_dir)?;
+        fs::write(
+            project_policy_dir.join("project.rules"),
+            r#"prefix_rule(pattern=["ls"], decision="prompt")"#,
+        )?;
+
+        let user_config_toml =
+            AbsolutePathBuf::from_absolute_path(user_dir.path().join("config.toml"))?;
+        let project_dot_codex_folder = AbsolutePathBuf::from_absolute_path(project_dir.path())?;
+        let layers = vec![
+            ConfigLayerEntry::new(
+                ConfigLayerSource::User {
+                    file: user_config_toml,
+                },
+                TomlValue::Table(Default::default()),
+            ),
+            ConfigLayerEntry::new(
+                ConfigLayerSource::Project {
+                    dot_codex_folder: project_dot_codex_folder,
+                },
+                TomlValue::Table(Default::default()),
+            ),
+        ];
+        let config_stack = ConfigLayerStack::new(layers, ConfigRequirements::default())?;
+
+        let policy = load_exec_policy(&config_stack).await?;
+
+        assert_eq!(
+            Evaluation {
+                decision: Decision::Forbidden,
+                matched_rules: vec![RuleMatch::PrefixRuleMatch {
+                    matched_prefix: vec!["rm".to_string()],
+                    decision: Decision::Forbidden
+                }],
+            },
+            policy.check_multiple([vec!["rm".to_string()]].iter(), &|_| Decision::Allow)
+        );
+        assert_eq!(
+            Evaluation {
+                decision: Decision::Prompt,
+                matched_rules: vec![RuleMatch::PrefixRuleMatch {
+                    matched_prefix: vec!["ls".to_string()],
+                    decision: Decision::Prompt
+                }],
+            },
+            policy.check_multiple([vec!["ls".to_string()]].iter(), &|_| Decision::Allow)
+        );
+        Ok(())
+    }
+
     #[tokio::test]
     async fn evaluates_bash_lc_inner_commands() {
         let policy_src = r#"
@@ -425,7 +555,7 @@ prefix_rule(pattern=["rm"], decision="forbidden")
         parser
             .parse("test.rules", policy_src)
             .expect("parse policy");
-        let policy = Arc::new(RwLock::new(parser.build()));
+        let policy = Arc::new(parser.build());
 
         let forbidden_script = vec![
             "bash".to_string(),
@@ -433,15 +563,16 @@ prefix_rule(pattern=["rm"], decision="forbidden")
             "rm -rf /tmp".to_string(),
         ];
 
-        let requirement = create_exec_approval_requirement_for_command(
-            &policy,
-            &Features::with_defaults(),
-            &forbidden_script,
-            AskForApproval::OnRequest,
-            &SandboxPolicy::DangerFullAccess,
-            SandboxPermissions::UseDefault,
-        )
-        .await;
+        let manager = ExecPolicyManager::new(policy);
+        let requirement = manager
+            .create_exec_approval_requirement_for_command(
+                &Features::with_defaults(),
+                &forbidden_script,
+                AskForApproval::OnRequest,
+                &SandboxPolicy::DangerFullAccess,
+                SandboxPermissions::UseDefault,
+            )
+            .await;
 
         assert_eq!(
             requirement,
@@ -458,18 +589,19 @@ prefix_rule(pattern=["rm"], decision="forbidden")
         parser
             .parse("test.rules", policy_src)
             .expect("parse policy");
-        let policy = Arc::new(RwLock::new(parser.build()));
+        let policy = Arc::new(parser.build());
         let command = vec!["rm".to_string()];
 
-        let requirement = create_exec_approval_requirement_for_command(
-            &policy,
-            &Features::with_defaults(),
-            &command,
-            AskForApproval::OnRequest,
-            &SandboxPolicy::DangerFullAccess,
-            SandboxPermissions::UseDefault,
-        )
-        .await;
+        let manager = ExecPolicyManager::new(policy);
+        let requirement = manager
+            .create_exec_approval_requirement_for_command(
+                &Features::with_defaults(),
+                &command,
+                AskForApproval::OnRequest,
+                &SandboxPolicy::DangerFullAccess,
+                SandboxPermissions::UseDefault,
+            )
+            .await;
 
         assert_eq!(
             requirement,
@@ -487,18 +619,19 @@ prefix_rule(pattern=["rm"], decision="forbidden")
         parser
             .parse("test.rules", policy_src)
             .expect("parse policy");
-        let policy = Arc::new(RwLock::new(parser.build()));
+        let policy = Arc::new(parser.build());
         let command = vec!["rm".to_string()];
 
-        let requirement = create_exec_approval_requirement_for_command(
-            &policy,
-            &Features::with_defaults(),
-            &command,
-            AskForApproval::Never,
-            &SandboxPolicy::DangerFullAccess,
-            SandboxPermissions::UseDefault,
-        )
-        .await;
+        let manager = ExecPolicyManager::new(policy);
+        let requirement = manager
+            .create_exec_approval_requirement_for_command(
+                &Features::with_defaults(),
+                &command,
+                AskForApproval::Never,
+                &SandboxPolicy::DangerFullAccess,
+                SandboxPermissions::UseDefault,
+            )
+            .await;
 
         assert_eq!(
             requirement,
@@ -512,16 +645,16 @@ prefix_rule(pattern=["rm"], decision="forbidden")
     async fn exec_approval_requirement_falls_back_to_heuristics() {
         let command = vec!["cargo".to_string(), "build".to_string()];
 
-        let empty_policy = Arc::new(RwLock::new(Policy::empty()));
-        let requirement = create_exec_approval_requirement_for_command(
-            &empty_policy,
-            &Features::with_defaults(),
-            &command,
-            AskForApproval::UnlessTrusted,
-            &SandboxPolicy::ReadOnly,
-            SandboxPermissions::UseDefault,
-        )
-        .await;
+        let manager = ExecPolicyManager::default();
+        let requirement = manager
+            .create_exec_approval_requirement_for_command(
+                &Features::with_defaults(),
+                &command,
+                AskForApproval::UnlessTrusted,
+                &SandboxPolicy::ReadOnly,
+                SandboxPermissions::UseDefault,
+            )
+            .await;
 
         assert_eq!(
             requirement,
@@ -539,7 +672,7 @@ prefix_rule(pattern=["rm"], decision="forbidden")
         parser
             .parse("test.rules", policy_src)
             .expect("parse policy");
-        let policy = Arc::new(RwLock::new(parser.build()));
+        let policy = Arc::new(parser.build());
         let command = vec![
             "bash".to_string(),
             "-lc".to_string(),
@@ -547,15 +680,15 @@ prefix_rule(pattern=["rm"], decision="forbidden")
         ];
 
         assert_eq!(
-            create_exec_approval_requirement_for_command(
-                &policy,
-                &Features::with_defaults(),
-                &command,
-                AskForApproval::UnlessTrusted,
-                &SandboxPolicy::DangerFullAccess,
-                SandboxPermissions::UseDefault,
-            )
-            .await,
+            ExecPolicyManager::new(policy)
+                .create_exec_approval_requirement_for_command(
+                    &Features::with_defaults(),
+                    &command,
+                    AskForApproval::UnlessTrusted,
+                    &SandboxPolicy::DangerFullAccess,
+                    SandboxPermissions::UseDefault,
+                )
+                .await,
             ExecApprovalRequirement::NeedsApproval {
                 reason: None,
                 proposed_execpolicy_amendment: Some(ExecPolicyAmendment::new(vec![
@@ -568,14 +701,16 @@ prefix_rule(pattern=["rm"], decision="forbidden")
     #[tokio::test]
     async fn append_execpolicy_amendment_updates_policy_and_file() {
         let codex_home = tempdir().expect("create temp dir");
-        let current_policy = Arc::new(RwLock::new(Policy::empty()));
         let prefix = vec!["echo".to_string(), "hello".to_string()];
+        let manager = ExecPolicyManager::default();
 
-        append_execpolicy_amendment_and_update(codex_home.path(), &current_policy, &prefix)
+        manager
+            .append_amendment_and_update(codex_home.path(), &ExecPolicyAmendment::from(prefix))
             .await
             .expect("update policy");
+        let updated_policy = manager.current();
 
-        let evaluation = current_policy.read().await.check(
+        let evaluation = updated_policy.check(
             &["echo".to_string(), "hello".to_string(), "world".to_string()],
             &|_| Decision::Allow,
         );
@@ -599,10 +734,11 @@ prefix_rule(pattern=["rm"], decision="forbidden")
     #[tokio::test]
     async fn append_execpolicy_amendment_rejects_empty_prefix() {
         let codex_home = tempdir().expect("create temp dir");
-        let current_policy = Arc::new(RwLock::new(Policy::empty()));
+        let manager = ExecPolicyManager::default();
 
-        let result =
-            append_execpolicy_amendment_and_update(codex_home.path(), &current_policy, &[]).await;
+        let result = manager
+            .append_amendment_and_update(codex_home.path(), &ExecPolicyAmendment::from(vec![]))
+            .await;
 
         assert!(matches!(
             result,
@@ -617,16 +753,16 @@ prefix_rule(pattern=["rm"], decision="forbidden")
     async fn proposed_execpolicy_amendment_is_present_for_single_command_without_policy_match() {
         let command = vec!["cargo".to_string(), "build".to_string()];
 
-        let empty_policy = Arc::new(RwLock::new(Policy::empty()));
-        let requirement = create_exec_approval_requirement_for_command(
-            &empty_policy,
-            &Features::with_defaults(),
-            &command,
-            AskForApproval::UnlessTrusted,
-            &SandboxPolicy::ReadOnly,
-            SandboxPermissions::UseDefault,
-        )
-        .await;
+        let manager = ExecPolicyManager::default();
+        let requirement = manager
+            .create_exec_approval_requirement_for_command(
+                &Features::with_defaults(),
+                &command,
+                AskForApproval::UnlessTrusted,
+                &SandboxPolicy::ReadOnly,
+                SandboxPermissions::UseDefault,
+            )
+            .await;
 
         assert_eq!(
             requirement,
@@ -644,15 +780,16 @@ prefix_rule(pattern=["rm"], decision="forbidden")
         let mut features = Features::with_defaults();
         features.disable(Feature::ExecPolicy);
 
-        let requirement = create_exec_approval_requirement_for_command(
-            &Arc::new(RwLock::new(Policy::empty())),
-            &features,
-            &command,
-            AskForApproval::UnlessTrusted,
-            &SandboxPolicy::ReadOnly,
-            SandboxPermissions::UseDefault,
-        )
-        .await;
+        let manager = ExecPolicyManager::default();
+        let requirement = manager
+            .create_exec_approval_requirement_for_command(
+                &features,
+                &command,
+                AskForApproval::UnlessTrusted,
+                &SandboxPolicy::ReadOnly,
+                SandboxPermissions::UseDefault,
+            )
+            .await;
 
         assert_eq!(
             requirement,
@@ -670,18 +807,19 @@ prefix_rule(pattern=["rm"], decision="forbidden")
         parser
             .parse("test.rules", policy_src)
             .expect("parse policy");
-        let policy = Arc::new(RwLock::new(parser.build()));
+        let policy = Arc::new(parser.build());
         let command = vec!["rm".to_string()];
 
-        let requirement = create_exec_approval_requirement_for_command(
-            &policy,
-            &Features::with_defaults(),
-            &command,
-            AskForApproval::OnRequest,
-            &SandboxPolicy::DangerFullAccess,
-            SandboxPermissions::UseDefault,
-        )
-        .await;
+        let manager = ExecPolicyManager::new(policy);
+        let requirement = manager
+            .create_exec_approval_requirement_for_command(
+                &Features::with_defaults(),
+                &command,
+                AskForApproval::OnRequest,
+                &SandboxPolicy::DangerFullAccess,
+                SandboxPermissions::UseDefault,
+            )
+            .await;
 
         assert_eq!(
             requirement,
@@ -699,15 +837,16 @@ prefix_rule(pattern=["rm"], decision="forbidden")
             "-lc".to_string(),
             "cargo build && echo ok".to_string(),
         ];
-        let requirement = create_exec_approval_requirement_for_command(
-            &Arc::new(RwLock::new(Policy::empty())),
-            &Features::with_defaults(),
-            &command,
-            AskForApproval::UnlessTrusted,
-            &SandboxPolicy::ReadOnly,
-            SandboxPermissions::UseDefault,
-        )
-        .await;
+        let manager = ExecPolicyManager::default();
+        let requirement = manager
+            .create_exec_approval_requirement_for_command(
+                &Features::with_defaults(),
+                &command,
+                AskForApproval::UnlessTrusted,
+                &SandboxPolicy::ReadOnly,
+                SandboxPermissions::UseDefault,
+            )
+            .await;
 
         assert_eq!(
             requirement,
@@ -728,7 +867,7 @@ prefix_rule(pattern=["rm"], decision="forbidden")
         parser
             .parse("test.rules", policy_src)
             .expect("parse policy");
-        let policy = Arc::new(RwLock::new(parser.build()));
+        let policy = Arc::new(parser.build());
 
         let command = vec![
             "bash".to_string(),
@@ -737,15 +876,15 @@ prefix_rule(pattern=["rm"], decision="forbidden")
         ];
 
         assert_eq!(
-            create_exec_approval_requirement_for_command(
-                &policy,
-                &Features::with_defaults(),
-                &command,
-                AskForApproval::UnlessTrusted,
-                &SandboxPolicy::ReadOnly,
-                SandboxPermissions::UseDefault,
-            )
-            .await,
+            ExecPolicyManager::new(policy)
+                .create_exec_approval_requirement_for_command(
+                    &Features::with_defaults(),
+                    &command,
+                    AskForApproval::UnlessTrusted,
+                    &SandboxPolicy::ReadOnly,
+                    SandboxPermissions::UseDefault,
+                )
+                .await,
             ExecApprovalRequirement::NeedsApproval {
                 reason: None,
                 proposed_execpolicy_amendment: Some(ExecPolicyAmendment::new(vec![
@@ -759,15 +898,16 @@ prefix_rule(pattern=["rm"], decision="forbidden")
     async fn proposed_execpolicy_amendment_is_present_when_heuristics_allow() {
         let command = vec!["echo".to_string(), "safe".to_string()];
 
-        let requirement = create_exec_approval_requirement_for_command(
-            &Arc::new(RwLock::new(Policy::empty())),
-            &Features::with_defaults(),
-            &command,
-            AskForApproval::OnRequest,
-            &SandboxPolicy::ReadOnly,
-            SandboxPermissions::UseDefault,
-        )
-        .await;
+        let manager = ExecPolicyManager::default();
+        let requirement = manager
+            .create_exec_approval_requirement_for_command(
+                &Features::with_defaults(),
+                &command,
+                AskForApproval::OnRequest,
+                &SandboxPolicy::ReadOnly,
+                SandboxPermissions::UseDefault,
+            )
+            .await;
 
         assert_eq!(
             requirement,
@@ -785,18 +925,19 @@ prefix_rule(pattern=["rm"], decision="forbidden")
         parser
             .parse("test.rules", policy_src)
             .expect("parse policy");
-        let policy = Arc::new(RwLock::new(parser.build()));
+        let policy = Arc::new(parser.build());
         let command = vec!["echo".to_string(), "safe".to_string()];
 
-        let requirement = create_exec_approval_requirement_for_command(
-            &policy,
-            &Features::with_defaults(),
-            &command,
-            AskForApproval::OnRequest,
-            &SandboxPolicy::ReadOnly,
-            SandboxPermissions::UseDefault,
-        )
-        .await;
+        let manager = ExecPolicyManager::new(policy);
+        let requirement = manager
+            .create_exec_approval_requirement_for_command(
+                &Features::with_defaults(),
+                &command,
+                AskForApproval::OnRequest,
+                &SandboxPolicy::ReadOnly,
+                SandboxPermissions::UseDefault,
+            )
+            .await;
 
         assert_eq!(
             requirement,

codex-rs/core/src/features.rs

@@ -8,6 +8,7 @@
 use crate::config::ConfigToml;
 use crate::config::profile::ConfigProfile;
 use serde::Deserialize;
+use serde::Serialize;
 use std::collections::BTreeMap;
 use std::collections::BTreeSet;
 
@@ -19,6 +20,7 @@ pub(crate) use legacy::LegacyFeatureToggles;
 pub enum Stage {
     Experimental,
     Beta {
+        name: &'static str,
         menu_description: &'static str,
         announcement: &'static str,
     },
@@ -28,6 +30,13 @@ pub enum Stage {
 }
 
 impl Stage {
+    pub fn beta_menu_name(self) -> Option<&'static str> {
+        match self {
+            Stage::Beta { name, .. } => Some(name),
+            _ => None,
+        }
+    }
+
     pub fn beta_menu_description(self) -> Option<&'static str> {
         match self {
             Stage::Beta {
@@ -61,8 +70,6 @@ pub enum Feature {
     // Experimental
     /// Use the single unified PTY-backed exec tool.
     UnifiedExec,
-    /// Enable experimental RMCP features such as OAuth login.
-    RmcpClient,
     /// Include the freeform apply_patch tool.
     ApplyPatchFreeform,
     /// Allow the model to request web searches.
@@ -79,12 +86,14 @@ pub enum Feature {
     RemoteModels,
     /// Allow model to call multiple tools in parallel (only for models supporting it).
     ParallelToolCalls,
-    /// Experimental skills injection (CLI flag-driven).
-    Skills,
     /// Experimental shell snapshotting.
     ShellSnapshot,
     /// Experimental TUI v2 (viewport) implementation.
     Tui2,
+    /// Enable discovery and injection of skills.
+    Skills,
+    /// Enforce UTF8 output in Powershell.
+    PowershellUtf8,
 }
 
 impl Feature {
@@ -218,7 +227,6 @@ impl Features {
         let base_legacy = LegacyFeatureToggles {
             experimental_use_freeform_apply_patch: cfg.experimental_use_freeform_apply_patch,
             experimental_use_unified_exec_tool: cfg.experimental_use_unified_exec_tool,
-            experimental_use_rmcp_client: cfg.experimental_use_rmcp_client,
             tools_web_search: cfg.tools.as_ref().and_then(|t| t.web_search),
             tools_view_image: cfg.tools.as_ref().and_then(|t| t.view_image),
             ..Default::default()
@@ -235,7 +243,6 @@ impl Features {
                 .experimental_use_freeform_apply_patch,
 
             experimental_use_unified_exec_tool: config_profile.experimental_use_unified_exec_tool,
-            experimental_use_rmcp_client: config_profile.experimental_use_rmcp_client,
             tools_web_search: config_profile.tools_web_search,
             tools_view_image: config_profile.tools_view_image,
         };
@@ -266,7 +273,7 @@ pub fn is_known_feature_key(key: &str) -> bool {
 }
 
 /// Deserializable features table for TOML.
-#[derive(Deserialize, Debug, Clone, Default, PartialEq)]
+#[derive(Serialize, Deserialize, Debug, Clone, Default, PartialEq)]
 pub struct FeaturesToml {
     #[serde(flatten)]
     pub entries: BTreeMap<String, bool>,
@@ -287,7 +294,7 @@ pub const FEATURES: &[FeatureSpec] = &[
         id: Feature::GhostCommit,
         key: "undo",
         stage: Stage::Stable,
-        default_enabled: true,
+        default_enabled: false,
     },
     FeatureSpec {
         id: Feature::ParallelToolCalls,
@@ -320,41 +327,24 @@ pub const FEATURES: &[FeatureSpec] = &[
         default_enabled: false,
     },
     // Beta program. Rendered in the `/experimental` menu for users.
-    FeatureSpec {
-        id: Feature::Skills,
-        key: "skills",
-        // stage: Stage::Beta {
-        //     menu_description: "Define new `skills` for the model",
-        //     announcement: "NEW! Try the new `skills` features. Enable in /experimental!",
-        // },
-        stage: Stage::Experimental,
-        default_enabled: false,
-    },
     FeatureSpec {
         id: Feature::UnifiedExec,
         key: "unified_exec",
-        // stage: Stage::Beta {
-        //     menu_description: "Run long-running terminal commands in the background.",
-        //     announcement: "NEW! Try Background terminals for long running processes. Enable in /experimental!",
-        // },
-        stage: Stage::Experimental,
+        stage: Stage::Beta {
+            name: "Background terminal",
+            menu_description: "Run long-running terminal commands in the background.",
+            announcement: "NEW! Try Background terminals for long running processes. Enable in /experimental!",
+        },
         default_enabled: false,
     },
     FeatureSpec {
         id: Feature::ShellSnapshot,
         key: "shell_snapshot",
-        // stage: Stage::Beta {
-        //     menu_description: "Snapshot your shell environment to avoid re-running login scripts for every command.",
-        //     announcement: "NEW! Try shell snapshotting to make your Codex faster. Enable in /experimental!",
-        // },
-        stage: Stage::Experimental,
-        default_enabled: false,
-    },
-    // Unstable features.
-    FeatureSpec {
-        id: Feature::RmcpClient,
-        key: "rmcp_client",
-        stage: Stage::Experimental,
+        stage: Stage::Beta {
+            name: "Shell snapshot",
+            menu_description: "Snapshot your shell environment to avoid re-running login scripts for every command.",
+            announcement: "NEW! Try shell snapshotting to make your Codex faster. Enable in /experimental!",
+        },
         default_enabled: false,
     },
     FeatureSpec {
@@ -394,8 +384,14 @@ pub const FEATURES: &[FeatureSpec] = &[
         default_enabled: false,
     },
     FeatureSpec {
-        id: Feature::ShellSnapshot,
-        key: "shell_snapshot",
+        id: Feature::Skills,
+        key: "skills",
+        stage: Stage::Experimental,
+        default_enabled: true,
+    },
+    FeatureSpec {
+        id: Feature::PowershellUtf8,
+        key: "powershell_utf8",
         stage: Stage::Experimental,
         default_enabled: false,
     },

codex-rs/core/src/features/legacy.rs

@@ -17,10 +17,6 @@ const ALIASES: &[Alias] = &[
         legacy_key: "experimental_use_unified_exec_tool",
         feature: Feature::UnifiedExec,
     },
-    Alias {
-        legacy_key: "experimental_use_rmcp_client",
-        feature: Feature::RmcpClient,
-    },
     Alias {
         legacy_key: "experimental_use_freeform_apply_patch",
         feature: Feature::ApplyPatchFreeform,
@@ -50,7 +46,6 @@ pub struct LegacyFeatureToggles {
     pub include_apply_patch_tool: Option<bool>,
     pub experimental_use_freeform_apply_patch: Option<bool>,
     pub experimental_use_unified_exec_tool: Option<bool>,
-    pub experimental_use_rmcp_client: Option<bool>,
     pub tools_web_search: Option<bool>,
     pub tools_view_image: Option<bool>,
 }
@@ -75,12 +70,6 @@ impl LegacyFeatureToggles {
             self.experimental_use_unified_exec_tool,
             "experimental_use_unified_exec_tool",
         );
-        set_if_some(
-            features,
-            Feature::RmcpClient,
-            self.experimental_use_rmcp_client,
-            "experimental_use_rmcp_client",
-        );
         set_if_some(
             features,
             Feature::WebSearchRequest,

codex-rs/core/src/lib.rs

@@ -33,9 +33,9 @@ pub mod git_info;
 pub mod landlock;
 pub mod mcp;
 mod mcp_connection_manager;
-pub mod openai_models;
+pub mod models_manager;
 pub use mcp_connection_manager::MCP_SANDBOX_STATE_CAPABILITY;
-pub use mcp_connection_manager::MCP_SANDBOX_STATE_NOTIFICATION;
+pub use mcp_connection_manager::MCP_SANDBOX_STATE_METHOD;
 pub use mcp_connection_manager::SandboxState;
 mod mcp_tool_call;
 mod message_history;

codex-rs/core/src/mcp_connection_manager.rs

@@ -184,17 +184,20 @@ struct ManagedClient {
 }
 
 impl ManagedClient {
+    /// Returns once the server has ack'd the sandbox state update.
     async fn notify_sandbox_state_change(&self, sandbox_state: &SandboxState) -> Result<()> {
         if !self.server_supports_sandbox_state_capability {
             return Ok(());
         }
 
-        self.client
-            .send_custom_notification(
-                MCP_SANDBOX_STATE_NOTIFICATION,
+        let _response = self
+            .client
+            .send_custom_request(
+                MCP_SANDBOX_STATE_METHOD,
                 Some(serde_json::to_value(sandbox_state)?),
             )
-            .await
+            .await?;
+        Ok(())
     }
 }
 
@@ -253,9 +256,9 @@ impl AsyncManagedClient {
 
 pub const MCP_SANDBOX_STATE_CAPABILITY: &str = "codex/sandbox-state";
 
-/// Custom MCP notification for sandbox state updates.
+/// Custom MCP request to push sandbox state updates.
 /// When used, the `params` field of the notification is [`SandboxState`].
-pub const MCP_SANDBOX_STATE_NOTIFICATION: &str = "codex/sandbox-state/update";
+pub const MCP_SANDBOX_STATE_METHOD: &str = "codex/sandbox-state/update";
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
 #[serde(rename_all = "camelCase")]

codex-rs/core/src/message_history.rs

@@ -401,9 +401,7 @@ fn history_log_id(_metadata: &std::fs::Metadata) -> Option<u64> {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use crate::config::Config;
-    use crate::config::ConfigOverrides;
-    use crate::config::ConfigToml;
+    use crate::config::ConfigBuilder;
     use codex_protocol::ConversationId;
     use pretty_assertions::assert_eq;
     use std::fs::File;
@@ -493,12 +491,11 @@ mod tests {
     async fn append_entry_trims_history_when_beyond_max_bytes() {
         let codex_home = TempDir::new().expect("create temp dir");
 
-        let mut config = Config::load_from_base_config_with_overrides(
-            ConfigToml::default(),
-            ConfigOverrides::default(),
-            codex_home.path().to_path_buf(),
-        )
-        .expect("load config");
+        let mut config = ConfigBuilder::default()
+            .codex_home(codex_home.path().to_path_buf())
+            .build()
+            .await
+            .expect("load config");
 
         let conversation_id = ConversationId::new();
 
@@ -541,12 +538,11 @@ mod tests {
     async fn append_entry_trims_history_to_soft_cap() {
         let codex_home = TempDir::new().expect("create temp dir");
 
-        let mut config = Config::load_from_base_config_with_overrides(
-            ConfigToml::default(),
-            ConfigOverrides::default(),
-            codex_home.path().to_path_buf(),
-        )
-        .expect("load config");
+        let mut config = ConfigBuilder::default()
+            .codex_home(codex_home.path().to_path_buf())
+            .build()
+            .await
+            .expect("load config");
 
         let conversation_id = ConversationId::new();
 

codex-rs/core/src/models_manager/manager.rs

@@ -24,12 +24,13 @@ use crate::default_client::build_reqwest_client;
 use crate::error::Result as CoreResult;
 use crate::features::Feature;
 use crate::model_provider_info::ModelProviderInfo;
-use crate::openai_models::model_family::ModelFamily;
-use crate::openai_models::model_presets::builtin_model_presets;
+use crate::models_manager::model_family::ModelFamily;
+use crate::models_manager::model_presets::builtin_model_presets;
 
 const MODEL_CACHE_FILE: &str = "models_cache.json";
 const DEFAULT_MODEL_CACHE_TTL: Duration = Duration::from_secs(300);
-const OPENAI_DEFAULT_MODEL: &str = "gpt-5.1-codex-max";
+const OPENAI_DEFAULT_API_MODEL: &str = "gpt-5.1-codex-max";
+const OPENAI_DEFAULT_CHATGPT_MODEL: &str = "gpt-5.2-codex";
 const CODEX_AUTO_BALANCED_MODEL: &str = "codex-auto-balanced";
 
 /// Coordinates remote model discovery plus cached metadata on disk.
@@ -76,7 +77,7 @@ impl ModelsManager {
     }
 
     /// Fetch the latest remote models, using the on-disk cache when still fresh.
-    pub async fn refresh_available_models(&self, config: &Config) -> CoreResult<()> {
+    pub async fn refresh_available_models_with_cache(&self, config: &Config) -> CoreResult<()> {
         if !config.features.enabled(Feature::RemoteModels)
             || self.auth_manager.get_auth_mode() == Some(AuthMode::ApiKey)
         {
@@ -85,7 +86,13 @@ impl ModelsManager {
         if self.try_load_cache().await {
             return Ok(());
         }
+        self.refresh_available_models_no_cache().await
+    }
 
+    pub(crate) async fn refresh_available_models_no_cache(&self) -> CoreResult<()> {
+        if self.auth_manager.get_auth_mode() == Some(AuthMode::ApiKey) {
+            return Ok(());
+        }
         let auth = self.auth_manager.auth();
         let api_provider = self.provider.to_api_provider(Some(AuthMode::ChatGPT))?;
         let api_auth = auth_provider_from_auth(auth.clone(), &self.provider).await?;
@@ -93,13 +100,11 @@ impl ModelsManager {
         let client = ModelsClient::new(transport, api_provider, api_auth);
 
         let client_version = format_client_version_to_whole();
-        let ModelsResponse { models, etag } = client
+        let (models, etag) = client
             .list_models(&client_version, HeaderMap::new())
             .await
             .map_err(map_api_error)?;
 
-        let etag = (!etag.is_empty()).then_some(etag);
-
         self.apply_remote_models(models.clone()).await;
         *self.etag.write().await = etag.clone();
         self.persist_cache(&models, etag).await;
@@ -107,15 +112,15 @@ impl ModelsManager {
     }
 
     pub async fn list_models(&self, config: &Config) -> Vec<ModelPreset> {
-        if let Err(err) = self.refresh_available_models(config).await {
+        if let Err(err) = self.refresh_available_models_with_cache(config).await {
             error!("failed to refresh available models: {err}");
         }
-        let remote_models = self.remote_models.read().await.clone();
+        let remote_models = self.remote_models(config).await;
         self.build_available_models(remote_models)
     }
 
-    pub fn try_list_models(&self) -> Result<Vec<ModelPreset>, TryLockError> {
-        let remote_models = self.remote_models.try_read()?.clone();
+    pub fn try_list_models(&self, config: &Config) -> Result<Vec<ModelPreset>, TryLockError> {
+        let remote_models = self.try_get_remote_models(config)?;
         Ok(self.build_available_models(remote_models))
     }
 
@@ -126,7 +131,7 @@ impl ModelsManager {
     /// Look up the requested model family while applying remote metadata overrides.
     pub async fn construct_model_family(&self, model: &str, config: &Config) -> ModelFamily {
         Self::find_family_for_model(model)
-            .with_remote_overrides(self.remote_models.read().await.clone())
+            .with_remote_overrides(self.remote_models(config).await)
             .with_config_overrides(config)
     }
 
@@ -134,12 +139,12 @@ impl ModelsManager {
         if let Some(model) = model.as_ref() {
             return model.to_string();
         }
-        if let Err(err) = self.refresh_available_models(config).await {
+        if let Err(err) = self.refresh_available_models_with_cache(config).await {
             error!("failed to refresh available models: {err}");
         }
         // if codex-auto-balanced exists & signed in with chatgpt mode, return it, otherwise return the default model
         let auth_mode = self.auth_manager.get_auth_mode();
-        let remote_models = self.remote_models.read().await.clone();
+        let remote_models = self.remote_models(config).await;
         if auth_mode == Some(AuthMode::ChatGPT)
             && self
                 .build_available_models(remote_models)
@@ -147,13 +152,24 @@ impl ModelsManager {
                 .any(|m| m.model == CODEX_AUTO_BALANCED_MODEL)
         {
             return CODEX_AUTO_BALANCED_MODEL.to_string();
+        } else if auth_mode == Some(AuthMode::ChatGPT) {
+            return OPENAI_DEFAULT_CHATGPT_MODEL.to_string();
+        }
+        OPENAI_DEFAULT_API_MODEL.to_string()
+    }
+    pub async fn refresh_if_new_etag(&self, etag: String) {
+        let current_etag = self.get_etag().await;
+        if current_etag.clone().is_some() && current_etag.as_deref() == Some(etag.as_str()) {
+            return;
+        }
+        if let Err(err) = self.refresh_available_models_no_cache().await {
+            error!("failed to refresh available models: {err}");
         }
-        OPENAI_DEFAULT_MODEL.to_string()
     }
 
     #[cfg(any(test, feature = "test-support"))]
     pub fn get_model_offline(model: Option<&str>) -> String {
-        model.unwrap_or(OPENAI_DEFAULT_MODEL).to_string()
+        model.unwrap_or(OPENAI_DEFAULT_CHATGPT_MODEL).to_string()
     }
 
     #[cfg(any(test, feature = "test-support"))]
@@ -162,6 +178,10 @@ impl ModelsManager {
         Self::find_family_for_model(model).with_config_overrides(config)
     }
 
+    async fn get_etag(&self) -> Option<String> {
+        self.etag.read().await.clone()
+    }
+
     /// Replace the cached remote models and rebuild the derived presets list.
     async fn apply_remote_models(&self, models: Vec<ModelInfo>) {
         *self.remote_models.write().await = models;
@@ -217,7 +237,7 @@ impl ModelsManager {
         let remote_presets: Vec<ModelPreset> = remote_models.into_iter().map(Into::into).collect();
         let existing_presets = self.local_models.clone();
         let mut merged_presets = Self::merge_presets(remote_presets, existing_presets);
-        merged_presets = Self::filter_visible_models(merged_presets);
+        merged_presets = self.filter_visible_models(merged_presets);
 
         let has_default = merged_presets.iter().any(|preset| preset.is_default);
         if let Some(default) = merged_presets.first_mut()
@@ -229,10 +249,11 @@ impl ModelsManager {
         merged_presets
     }
 
-    fn filter_visible_models(models: Vec<ModelPreset>) -> Vec<ModelPreset> {
+    fn filter_visible_models(&self, models: Vec<ModelPreset>) -> Vec<ModelPreset> {
+        let chatgpt_mode = self.auth_manager.get_auth_mode() == Some(AuthMode::ChatGPT);
         models
             .into_iter()
-            .filter(|model| model.show_in_picker)
+            .filter(|model| model.show_in_picker && (chatgpt_mode || model.supported_in_api))
             .collect()
     }
 
@@ -261,6 +282,22 @@ impl ModelsManager {
         merged_presets
     }
 
+    async fn remote_models(&self, config: &Config) -> Vec<ModelInfo> {
+        if config.features.enabled(Feature::RemoteModels) {
+            self.remote_models.read().await.clone()
+        } else {
+            Vec::new()
+        }
+    }
+
+    fn try_get_remote_models(&self, config: &Config) -> Result<Vec<ModelInfo>, TryLockError> {
+        if config.features.enabled(Feature::RemoteModels) {
+            Ok(self.remote_models.try_read()?.clone())
+        } else {
+            Ok(Vec::new())
+        }
+    }
+
     fn cache_path(&self) -> PathBuf {
         self.codex_home.join(MODEL_CACHE_FILE)
     }
@@ -268,35 +305,21 @@ impl ModelsManager {
 
 /// Convert a client version string to a whole version string (e.g. "1.2.3-alpha.4" -> "1.2.3")
 fn format_client_version_to_whole() -> String {
-    format_client_version_from_parts(
+    format!(
+        "{}.{}.{}",
         env!("CARGO_PKG_VERSION_MAJOR"),
         env!("CARGO_PKG_VERSION_MINOR"),
-        env!("CARGO_PKG_VERSION_PATCH"),
+        env!("CARGO_PKG_VERSION_PATCH")
     )
 }
 
-fn format_client_version_from_parts(major: &str, minor: &str, patch: &str) -> String {
-    const DEV_VERSION: &str = "0.0.0";
-    const FALLBACK_VERSION: &str = "99.99.99";
-
-    let normalized = format!("{major}.{minor}.{patch}");
-
-    if normalized == DEV_VERSION {
-        FALLBACK_VERSION.to_string()
-    } else {
-        normalized
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::cache::ModelsCache;
     use super::*;
     use crate::CodexAuth;
     use crate::auth::AuthCredentialsStoreMode;
-    use crate::config::Config;
-    use crate::config::ConfigOverrides;
-    use crate::config::ConfigToml;
+    use crate::config::ConfigBuilder;
     use crate::features::Feature;
     use crate::model_provider_info::WireApi;
     use codex_protocol::openai_models::ModelsResponse;
@@ -336,7 +359,6 @@ mod tests {
             "truncation_policy": {"mode": "bytes", "limit": 10_000},
             "supports_parallel_tool_calls": false,
             "context_window": null,
-            "reasoning_summary_format": "none",
             "experimental_supported_tools": [],
         }))
         .expect("valid model")
@@ -371,18 +393,16 @@ mod tests {
             &server,
             ModelsResponse {
                 models: remote_models.clone(),
-                etag: String::new(),
             },
         )
         .await;
 
         let codex_home = tempdir().expect("temp dir");
-        let mut config = Config::load_from_base_config_with_overrides(
-            ConfigToml::default(),
-            ConfigOverrides::default(),
-            codex_home.path().to_path_buf(),
-        )
-        .expect("load default test config");
+        let mut config = ConfigBuilder::default()
+            .codex_home(codex_home.path().to_path_buf())
+            .build()
+            .await
+            .expect("load default test config");
         config.features.enable(Feature::RemoteModels);
         let auth_manager =
             AuthManager::from_auth_for_testing(CodexAuth::create_dummy_chatgpt_auth_for_testing());
@@ -390,10 +410,10 @@ mod tests {
         let manager = ModelsManager::with_provider(auth_manager, provider);
 
         manager
-            .refresh_available_models(&config)
+            .refresh_available_models_with_cache(&config)
             .await
             .expect("refresh succeeds");
-        let cached_remote = manager.remote_models.read().await.clone();
+        let cached_remote = manager.remote_models(&config).await;
         assert_eq!(cached_remote, remote_models);
 
         let available = manager.list_models(&config).await;
@@ -429,18 +449,16 @@ mod tests {
             &server,
             ModelsResponse {
                 models: remote_models.clone(),
-                etag: String::new(),
             },
         )
         .await;
 
         let codex_home = tempdir().expect("temp dir");
-        let mut config = Config::load_from_base_config_with_overrides(
-            ConfigToml::default(),
-            ConfigOverrides::default(),
-            codex_home.path().to_path_buf(),
-        )
-        .expect("load default test config");
+        let mut config = ConfigBuilder::default()
+            .codex_home(codex_home.path().to_path_buf())
+            .build()
+            .await
+            .expect("load default test config");
         config.features.enable(Feature::RemoteModels);
         let auth_manager = Arc::new(AuthManager::new(
             codex_home.path().to_path_buf(),
@@ -451,22 +469,22 @@ mod tests {
         let manager = ModelsManager::with_provider(auth_manager, provider);
 
         manager
-            .refresh_available_models(&config)
+            .refresh_available_models_with_cache(&config)
             .await
             .expect("first refresh succeeds");
         assert_eq!(
-            *manager.remote_models.read().await,
+            manager.remote_models(&config).await,
             remote_models,
             "remote cache should store fetched models"
         );
 
         // Second call should read from cache and avoid the network.
         manager
-            .refresh_available_models(&config)
+            .refresh_available_models_with_cache(&config)
             .await
             .expect("cached refresh succeeds");
         assert_eq!(
-            *manager.remote_models.read().await,
+            manager.remote_models(&config).await,
             remote_models,
             "cache path should not mutate stored models"
         );
@@ -485,18 +503,16 @@ mod tests {
             &server,
             ModelsResponse {
                 models: initial_models.clone(),
-                etag: String::new(),
             },
         )
         .await;
 
         let codex_home = tempdir().expect("temp dir");
-        let mut config = Config::load_from_base_config_with_overrides(
-            ConfigToml::default(),
-            ConfigOverrides::default(),
-            codex_home.path().to_path_buf(),
-        )
-        .expect("load default test config");
+        let mut config = ConfigBuilder::default()
+            .codex_home(codex_home.path().to_path_buf())
+            .build()
+            .await
+            .expect("load default test config");
         config.features.enable(Feature::RemoteModels);
         let auth_manager = Arc::new(AuthManager::new(
             codex_home.path().to_path_buf(),
@@ -507,7 +523,7 @@ mod tests {
         let manager = ModelsManager::with_provider(auth_manager, provider);
 
         manager
-            .refresh_available_models(&config)
+            .refresh_available_models_with_cache(&config)
             .await
             .expect("initial refresh succeeds");
 
@@ -527,17 +543,16 @@ mod tests {
             &server,
             ModelsResponse {
                 models: updated_models.clone(),
-                etag: String::new(),
             },
         )
         .await;
 
         manager
-            .refresh_available_models(&config)
+            .refresh_available_models_with_cache(&config)
             .await
             .expect("second refresh succeeds");
         assert_eq!(
-            *manager.remote_models.read().await,
+            manager.remote_models(&config).await,
             updated_models,
             "stale cache should trigger refetch"
         );
@@ -561,18 +576,16 @@ mod tests {
             &server,
             ModelsResponse {
                 models: initial_models,
-                etag: String::new(),
             },
         )
         .await;
 
         let codex_home = tempdir().expect("temp dir");
-        let mut config = Config::load_from_base_config_with_overrides(
-            ConfigToml::default(),
-            ConfigOverrides::default(),
-            codex_home.path().to_path_buf(),
-        )
-        .expect("load default test config");
+        let mut config = ConfigBuilder::default()
+            .codex_home(codex_home.path().to_path_buf())
+            .build()
+            .await
+            .expect("load default test config");
         config.features.enable(Feature::RemoteModels);
         let auth_manager =
             AuthManager::from_auth_for_testing(CodexAuth::create_dummy_chatgpt_auth_for_testing());
@@ -581,7 +594,7 @@ mod tests {
         manager.cache_ttl = Duration::ZERO;
 
         manager
-            .refresh_available_models(&config)
+            .refresh_available_models_with_cache(&config)
             .await
             .expect("initial refresh succeeds");
 
@@ -591,18 +604,17 @@ mod tests {
             &server,
             ModelsResponse {
                 models: refreshed_models,
-                etag: String::new(),
             },
         )
         .await;
 
         manager
-            .refresh_available_models(&config)
+            .refresh_available_models_with_cache(&config)
             .await
             .expect("second refresh succeeds");
 
         let available = manager
-            .try_list_models()
+            .try_list_models(&config)
             .expect("models should be available");
         assert!(
             available.iter().any(|preset| preset.model == "remote-new"),

codex-rs/core/src/models_manager/mod.rs

@@ -1,4 +1,4 @@
-mod cache;
+pub mod cache;
+pub mod manager;
 pub mod model_family;
 pub mod model_presets;
-pub mod models_manager;

codex-rs/core/src/models_manager/model_family.rs

@@ -3,7 +3,6 @@ use codex_protocol::openai_models::ApplyPatchToolType;
 use codex_protocol::openai_models::ConfigShellToolType;
 use codex_protocol::openai_models::ModelInfo;
 use codex_protocol::openai_models::ReasoningEffort;
-use codex_protocol::openai_models::ReasoningSummaryFormat;
 
 use crate::config::Config;
 use crate::truncate::TruncationPolicy;
@@ -16,6 +15,7 @@ const GPT_5_CODEX_INSTRUCTIONS: &str = include_str!("../../gpt_5_codex_prompt.md
 const GPT_5_1_INSTRUCTIONS: &str = include_str!("../../gpt_5_1_prompt.md");
 const GPT_5_2_INSTRUCTIONS: &str = include_str!("../../gpt_5_2_prompt.md");
 const GPT_5_1_CODEX_MAX_INSTRUCTIONS: &str = include_str!("../../gpt-5.1-codex-max_prompt.md");
+const GPT_5_2_CODEX_INSTRUCTIONS: &str = include_str!("../../gpt-5.2-codex_prompt.md");
 pub(crate) const CONTEXT_WINDOW_272K: i64 = 272_000;
 
 /// A model family is a group of models that share certain characteristics.
@@ -47,9 +47,6 @@ pub struct ModelFamily {
     // The reasoning effort to use for this model family when none is explicitly chosen.
     pub default_reasoning_effort: Option<ReasoningEffort>,
 
-    // Define if we need a special handling of reasoning summary
-    pub reasoning_summary_format: ReasoningSummaryFormat,
-
     /// Whether this model supports parallel tool calls when using the
     /// Responses API.
     pub supports_parallel_tool_calls: bool,
@@ -87,9 +84,6 @@ impl ModelFamily {
         if let Some(supports_reasoning_summaries) = config.model_supports_reasoning_summaries {
             self.supports_reasoning_summaries = supports_reasoning_summaries;
         }
-        if let Some(reasoning_summary_format) = config.model_reasoning_summary_format.as_ref() {
-            self.reasoning_summary_format = reasoning_summary_format.clone();
-        }
         if let Some(context_window) = config.model_context_window {
             self.context_window = Some(context_window);
         }
@@ -116,7 +110,6 @@ impl ModelFamily {
             supported_reasoning_levels: _,
             shell_type,
             visibility: _,
-            minimal_client_version: _,
             supported_in_api: _,
             priority: _,
             upgrade: _,
@@ -128,7 +121,6 @@ impl ModelFamily {
             truncation_policy,
             supports_parallel_tool_calls,
             context_window,
-            reasoning_summary_format,
             experimental_supported_tools,
         } = model;
 
@@ -144,7 +136,6 @@ impl ModelFamily {
         self.truncation_policy = truncation_policy.into();
         self.supports_parallel_tool_calls = supports_parallel_tool_calls;
         self.context_window = context_window;
-        self.reasoning_summary_format = reasoning_summary_format;
         self.experimental_supported_tools = experimental_supported_tools;
     }
 
@@ -175,7 +166,6 @@ macro_rules! model_family {
             context_window: Some(CONTEXT_WINDOW_272K),
             auto_compact_token_limit: None,
             supports_reasoning_summaries: false,
-            reasoning_summary_format: ReasoningSummaryFormat::None,
             supports_parallel_tool_calls: false,
             apply_patch_tool_type: None,
             base_instructions: BASE_INSTRUCTIONS.to_string(),
@@ -198,6 +188,7 @@ macro_rules! model_family {
 
 /// Internal offline helper for `ModelsManager` that returns a `ModelFamily` for the given
 /// model slug.
+#[allow(clippy::if_same_then_else)]
 pub(super) fn find_family_for_model(slug: &str) -> ModelFamily {
     if slug.starts_with("o3") {
         model_family!(
@@ -249,7 +240,6 @@ pub(super) fn find_family_for_model(slug: &str) -> ModelFamily {
         model_family!(
             slug, slug,
             supports_reasoning_summaries: true,
-            reasoning_summary_format: ReasoningSummaryFormat::Experimental,
             base_instructions: GPT_5_CODEX_INSTRUCTIONS.to_string(),
             experimental_supported_tools: vec![
                 "grep_files".to_string(),
@@ -269,8 +259,7 @@ pub(super) fn find_family_for_model(slug: &str) -> ModelFamily {
         model_family!(
             slug, slug,
             supports_reasoning_summaries: true,
-            reasoning_summary_format: ReasoningSummaryFormat::Experimental,
-            base_instructions: GPT_5_1_CODEX_MAX_INSTRUCTIONS.to_string(),
+            base_instructions: GPT_5_2_CODEX_INSTRUCTIONS.to_string(),
             apply_patch_tool_type: Some(ApplyPatchToolType::Freeform),
             shell_type: ConfigShellToolType::ShellCommand,
             supports_parallel_tool_calls: true,
@@ -294,11 +283,34 @@ pub(super) fn find_family_for_model(slug: &str) -> ModelFamily {
         )
 
     // Production models.
+    } else if slug.starts_with("gpt-5.2-codex") {
+        model_family!(
+            slug, slug,
+            supports_reasoning_summaries: true,
+            base_instructions: GPT_5_2_CODEX_INSTRUCTIONS.to_string(),
+            apply_patch_tool_type: Some(ApplyPatchToolType::Freeform),
+            shell_type: ConfigShellToolType::ShellCommand,
+            supports_parallel_tool_calls: true,
+            support_verbosity: false,
+            truncation_policy: TruncationPolicy::Tokens(10_000),
+            context_window: Some(CONTEXT_WINDOW_272K),
+        )
+    } else if slug.starts_with("bengalfox") {
+        model_family!(
+            slug, slug,
+            supports_reasoning_summaries: true,
+            base_instructions: GPT_5_2_CODEX_INSTRUCTIONS.to_string(),
+            apply_patch_tool_type: Some(ApplyPatchToolType::Freeform),
+            shell_type: ConfigShellToolType::ShellCommand,
+            supports_parallel_tool_calls: true,
+            support_verbosity: false,
+            truncation_policy: TruncationPolicy::Tokens(10_000),
+            context_window: Some(CONTEXT_WINDOW_272K),
+        )
     } else if slug.starts_with("gpt-5.1-codex-max") {
         model_family!(
             slug, slug,
             supports_reasoning_summaries: true,
-            reasoning_summary_format: ReasoningSummaryFormat::Experimental,
             base_instructions: GPT_5_1_CODEX_MAX_INSTRUCTIONS.to_string(),
             apply_patch_tool_type: Some(ApplyPatchToolType::Freeform),
             shell_type: ConfigShellToolType::ShellCommand,
@@ -314,7 +326,6 @@ pub(super) fn find_family_for_model(slug: &str) -> ModelFamily {
         model_family!(
             slug, slug,
             supports_reasoning_summaries: true,
-            reasoning_summary_format: ReasoningSummaryFormat::Experimental,
             base_instructions: GPT_5_CODEX_INSTRUCTIONS.to_string(),
             apply_patch_tool_type: Some(ApplyPatchToolType::Freeform),
             shell_type: ConfigShellToolType::ShellCommand,
@@ -337,6 +348,20 @@ pub(super) fn find_family_for_model(slug: &str) -> ModelFamily {
             supports_parallel_tool_calls: true,
             context_window: Some(CONTEXT_WINDOW_272K),
         )
+    } else if slug.starts_with("boomslang") {
+        model_family!(
+            slug, slug,
+            supports_reasoning_summaries: true,
+            apply_patch_tool_type: Some(ApplyPatchToolType::Freeform),
+            support_verbosity: true,
+            default_verbosity: Some(Verbosity::Low),
+            base_instructions: GPT_5_2_INSTRUCTIONS.to_string(),
+            default_reasoning_effort: Some(ReasoningEffort::Medium),
+            truncation_policy: TruncationPolicy::Bytes(10_000),
+            shell_type: ConfigShellToolType::ShellCommand,
+            supports_parallel_tool_calls: true,
+            context_window: Some(CONTEXT_WINDOW_272K),
+        )
     } else if slug.starts_with("gpt-5.1") {
         model_family!(
             slug, "gpt-5.1",
@@ -375,7 +400,6 @@ fn derive_default_model_family(model: &str) -> ModelFamily {
         context_window: None,
         auto_compact_token_limit: None,
         supports_reasoning_summaries: false,
-        reasoning_summary_format: ReasoningSummaryFormat::None,
         supports_parallel_tool_calls: false,
         apply_patch_tool_type: None,
         base_instructions: BASE_INSTRUCTIONS.to_string(),
@@ -392,7 +416,6 @@ fn derive_default_model_family(model: &str) -> ModelFamily {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use codex_protocol::openai_models::ClientVersion;
     use codex_protocol::openai_models::ModelVisibility;
     use codex_protocol::openai_models::ReasoningEffortPreset;
     use codex_protocol::openai_models::TruncationPolicyConfig;
@@ -409,7 +432,6 @@ mod tests {
             }],
             shell_type: shell,
             visibility: ModelVisibility::List,
-            minimal_client_version: ClientVersion(0, 1, 0),
             supported_in_api: true,
             priority: 1,
             upgrade: None,
@@ -421,7 +443,6 @@ mod tests {
             truncation_policy: TruncationPolicyConfig::bytes(10_000),
             supports_parallel_tool_calls: false,
             context_window: None,
-            reasoning_summary_format: ReasoningSummaryFormat::None,
             experimental_supported_tools: Vec::new(),
         }
     }
@@ -485,7 +506,6 @@ mod tests {
             experimental_supported_tools: vec!["local".to_string()],
             truncation_policy: TruncationPolicy::Bytes(10_000),
             context_window: Some(100),
-            reasoning_summary_format: ReasoningSummaryFormat::None,
         );
 
         let updated = family.with_remote_overrides(vec![ModelInfo {
@@ -499,7 +519,6 @@ mod tests {
             }],
             shell_type: ConfigShellToolType::ShellCommand,
             visibility: ModelVisibility::List,
-            minimal_client_version: ClientVersion(0, 1, 0),
             supported_in_api: true,
             priority: 10,
             upgrade: None,
@@ -511,7 +530,6 @@ mod tests {
             truncation_policy: TruncationPolicyConfig::tokens(2_000),
             supports_parallel_tool_calls: true,
             context_window: Some(400_000),
-            reasoning_summary_format: ReasoningSummaryFormat::Experimental,
             experimental_supported_tools: vec!["alpha".to_string(), "beta".to_string()],
         }]);
 
@@ -530,10 +548,6 @@ mod tests {
         assert_eq!(updated.truncation_policy, TruncationPolicy::Tokens(2_000));
         assert!(updated.supports_parallel_tool_calls);
         assert_eq!(updated.context_window, Some(400_000));
-        assert_eq!(
-            updated.reasoning_summary_format,
-            ReasoningSummaryFormat::Experimental
-        );
         assert_eq!(
             updated.experimental_supported_tools,
             vec!["alpha".to_string(), "beta".to_string()]

codex-rs/core/src/models_manager/model_presets.rs

@@ -12,10 +12,10 @@ pub const HIDE_GPT_5_1_CODEX_MAX_MIGRATION_PROMPT_CONFIG: &str =
 static PRESETS: Lazy<Vec<ModelPreset>> = Lazy::new(|| {
     vec![
         ModelPreset {
-            id: "gpt-5.1-codex-max".to_string(),
-            model: "gpt-5.1-codex-max".to_string(),
-            display_name: "gpt-5.1-codex-max".to_string(),
-            description: "Latest Codex-optimized flagship for deep and fast reasoning.".to_string(),
+            id: "gpt-5.2-codex".to_string(),
+            model: "gpt-5.2-codex".to_string(),
+            display_name: "gpt-5.2-codex".to_string(),
+            description: "Latest frontier agentic coding model.".to_string(),
             default_reasoning_effort: ReasoningEffort::Medium,
             supported_reasoning_efforts: vec![
                 ReasoningEffortPreset {
@@ -38,35 +38,36 @@ static PRESETS: Lazy<Vec<ModelPreset>> = Lazy::new(|| {
             is_default: true,
             upgrade: None,
             show_in_picker: true,
+            supported_in_api: false,
         },
         ModelPreset {
-            id: "gpt-5.1-codex".to_string(),
-            model: "gpt-5.1-codex".to_string(),
-            display_name: "gpt-5.1-codex".to_string(),
-            description: "Optimized for codex.".to_string(),
+            id: "gpt-5.1-codex-max".to_string(),
+            model: "gpt-5.1-codex-max".to_string(),
+            display_name: "gpt-5.1-codex-max".to_string(),
+            description: "Codex-optimized flagship for deep and fast reasoning.".to_string(),
             default_reasoning_effort: ReasoningEffort::Medium,
             supported_reasoning_efforts: vec![
                 ReasoningEffortPreset {
                     effort: ReasoningEffort::Low,
-                    description: "Fastest responses with limited reasoning".to_string(),
+                    description: "Fast responses with lighter reasoning".to_string(),
                 },
                 ReasoningEffortPreset {
                     effort: ReasoningEffort::Medium,
-                    description: "Dynamically adjusts reasoning based on the task".to_string(),
+                    description: "Balances speed and reasoning depth for everyday tasks".to_string(),
                 },
                 ReasoningEffortPreset {
                     effort: ReasoningEffort::High,
-                    description: "Maximizes reasoning depth for complex or ambiguous problems"
-                        .to_string(),
+                    description: "Greater reasoning depth for complex problems".to_string(),
+                },
+                ReasoningEffortPreset {
+                    effort: ReasoningEffort::XHigh,
+                    description: "Extra high reasoning depth for complex problems".to_string(),
                 },
             ],
             is_default: false,
-            upgrade: Some(ModelUpgrade {
-                id: "gpt-5.1-codex-max".to_string(),
-                reasoning_effort_mapping: None,
-                migration_config_key: HIDE_GPT_5_1_CODEX_MAX_MIGRATION_PROMPT_CONFIG.to_string(),
-            }),
+            upgrade: Some(gpt_52_codex_upgrade()),
             show_in_picker: true,
+            supported_in_api: true,
         },
         ModelPreset {
             id: "gpt-5.1-codex-mini".to_string(),
@@ -86,12 +87,9 @@ static PRESETS: Lazy<Vec<ModelPreset>> = Lazy::new(|| {
                 },
             ],
             is_default: false,
-            upgrade: Some(ModelUpgrade {
-                id: "gpt-5.1-codex-max".to_string(),
-                reasoning_effort_mapping: None,
-                migration_config_key: HIDE_GPT_5_1_CODEX_MAX_MIGRATION_PROMPT_CONFIG.to_string(),
-            }),
+            upgrade: Some(gpt_52_codex_upgrade()),
             show_in_picker: true,
+            supported_in_api: true,
         },
         ModelPreset {
             id: "gpt-5.2".to_string(),
@@ -118,14 +116,44 @@ static PRESETS: Lazy<Vec<ModelPreset>> = Lazy::new(|| {
                 },
             ],
             is_default: false,
-            upgrade: None,
+            upgrade: Some(gpt_52_codex_upgrade()),
             show_in_picker: true,
+            supported_in_api: true,
         },
         ModelPreset {
-            id: "gpt-5.1".to_string(),
-            model: "gpt-5.1".to_string(),
-            display_name: "gpt-5.1".to_string(),
-            description: "Broad world knowledge with strong general reasoning.".to_string(),
+            id: "bengalfox".to_string(),
+            model: "bengalfox".to_string(),
+            display_name: "bengalfox".to_string(),
+            description: "bengalfox".to_string(),
+            default_reasoning_effort: ReasoningEffort::Medium,
+            supported_reasoning_efforts: vec![
+                ReasoningEffortPreset {
+                    effort: ReasoningEffort::Low,
+                    description: "Fast responses with lighter reasoning".to_string(),
+                },
+                ReasoningEffortPreset {
+                    effort: ReasoningEffort::Medium,
+                    description: "Balances speed and reasoning depth for everyday tasks".to_string(),
+                },
+                ReasoningEffortPreset {
+                    effort: ReasoningEffort::High,
+                    description: "Greater reasoning depth for complex problems".to_string(),
+                },
+                ReasoningEffortPreset {
+                    effort: ReasoningEffort::XHigh,
+                    description: "Extra high reasoning depth for complex problems".to_string(),
+                },
+            ],
+            is_default: false,
+            upgrade: None,
+            show_in_picker: false,
+            supported_in_api: true,
+        },
+        ModelPreset {
+            id: "boomslang".to_string(),
+            model: "boomslang".to_string(),
+            display_name: "boomslang".to_string(),
+            description: "boomslang".to_string(),
             default_reasoning_effort: ReasoningEffort::Medium,
             supported_reasoning_efforts: vec![
                 ReasoningEffortPreset {
@@ -140,14 +168,15 @@ static PRESETS: Lazy<Vec<ModelPreset>> = Lazy::new(|| {
                     effort: ReasoningEffort::High,
                     description: "Maximizes reasoning depth for complex or ambiguous problems".to_string(),
                 },
+                ReasoningEffortPreset {
+                    effort: ReasoningEffort::XHigh,
+                    description: "Extra high reasoning for complex problems".to_string(),
+                },
             ],
             is_default: false,
-            upgrade: Some(ModelUpgrade {
-                id: "gpt-5.1-codex-max".to_string(),
-                reasoning_effort_mapping: None,
-                migration_config_key: HIDE_GPT_5_1_CODEX_MAX_MIGRATION_PROMPT_CONFIG.to_string(),
-            }),
-            show_in_picker: true,
+            upgrade: None,
+            show_in_picker: false,
+            supported_in_api: true,
         },
         // Deprecated models.
         ModelPreset {
@@ -171,12 +200,9 @@ static PRESETS: Lazy<Vec<ModelPreset>> = Lazy::new(|| {
                 },
             ],
             is_default: false,
-            upgrade: Some(ModelUpgrade {
-                id: "gpt-5.1-codex-max".to_string(),
-                reasoning_effort_mapping: None,
-                migration_config_key: HIDE_GPT_5_1_CODEX_MAX_MIGRATION_PROMPT_CONFIG.to_string(),
-            }),
+            upgrade: Some(gpt_52_codex_upgrade()),
             show_in_picker: false,
+            supported_in_api: true,
         },
         ModelPreset {
             id: "gpt-5-codex-mini".to_string(),
@@ -195,12 +221,35 @@ static PRESETS: Lazy<Vec<ModelPreset>> = Lazy::new(|| {
                 },
             ],
             is_default: false,
-            upgrade: Some(ModelUpgrade {
-                id: "gpt-5.1-codex-mini".to_string(),
-                reasoning_effort_mapping: None,
-                migration_config_key: HIDE_GPT5_1_MIGRATION_PROMPT_CONFIG.to_string(),
-            }),
+            upgrade: Some(gpt_52_codex_upgrade()),
             show_in_picker: false,
+            supported_in_api: true,
+        },
+        ModelPreset {
+            id: "gpt-5.1-codex".to_string(),
+            model: "gpt-5.1-codex".to_string(),
+            display_name: "gpt-5.1-codex".to_string(),
+            description: "Optimized for codex.".to_string(),
+            default_reasoning_effort: ReasoningEffort::Medium,
+            supported_reasoning_efforts: vec![
+                ReasoningEffortPreset {
+                    effort: ReasoningEffort::Low,
+                    description: "Fastest responses with limited reasoning".to_string(),
+                },
+                ReasoningEffortPreset {
+                    effort: ReasoningEffort::Medium,
+                    description: "Dynamically adjusts reasoning based on the task".to_string(),
+                },
+                ReasoningEffortPreset {
+                    effort: ReasoningEffort::High,
+                    description: "Maximizes reasoning depth for complex or ambiguous problems"
+                        .to_string(),
+                },
+            ],
+            is_default: false,
+            upgrade: Some(gpt_52_codex_upgrade()),
+            show_in_picker: false,
+            supported_in_api: true,
         },
         ModelPreset {
             id: "gpt-5".to_string(),
@@ -227,16 +276,51 @@ static PRESETS: Lazy<Vec<ModelPreset>> = Lazy::new(|| {
                 },
             ],
             is_default: false,
-            upgrade: Some(ModelUpgrade {
-                id: "gpt-5.1-codex-max".to_string(),
-                reasoning_effort_mapping: None,
-                migration_config_key: HIDE_GPT_5_1_CODEX_MAX_MIGRATION_PROMPT_CONFIG.to_string(),
-            }),
+            upgrade: Some(gpt_52_codex_upgrade()),
             show_in_picker: false,
+            supported_in_api: true,
+        },
+        ModelPreset {
+            id: "gpt-5.1".to_string(),
+            model: "gpt-5.1".to_string(),
+            display_name: "gpt-5.1".to_string(),
+            description: "Broad world knowledge with strong general reasoning.".to_string(),
+            default_reasoning_effort: ReasoningEffort::Medium,
+            supported_reasoning_efforts: vec![
+                ReasoningEffortPreset {
+                    effort: ReasoningEffort::Low,
+                    description: "Balances speed with some reasoning; useful for straightforward queries and short explanations".to_string(),
+                },
+                ReasoningEffortPreset {
+                    effort: ReasoningEffort::Medium,
+                    description: "Provides a solid balance of reasoning depth and latency for general-purpose tasks".to_string(),
+                },
+                ReasoningEffortPreset {
+                    effort: ReasoningEffort::High,
+                    description: "Maximizes reasoning depth for complex or ambiguous problems".to_string(),
+                },
+            ],
+            is_default: false,
+            upgrade: Some(gpt_52_codex_upgrade()),
+            show_in_picker: false,
+            supported_in_api: true,
         },
     ]
 });
 
+fn gpt_52_codex_upgrade() -> ModelUpgrade {
+    ModelUpgrade {
+        id: "gpt-5.2-codex".to_string(),
+        reasoning_effort_mapping: None,
+        migration_config_key: "gpt-5.2-codex".to_string(),
+        model_link: Some("https://openai.com/index/introducing-gpt-5-2-codex".to_string()),
+        upgrade_copy: Some(
+            "Codex is now powered by gpt-5.2-codex, our latest frontier agentic coding model. It is smarter and faster than its predecessors and capable of long-running project-scale work."
+                .to_string(),
+        ),
+    }
+}
+
 pub(super) fn builtin_model_presets(_auth_mode: Option<AuthMode>) -> Vec<ModelPreset> {
     PRESETS
         .iter()

codex-rs/core/src/path_utils.rs

@@ -3,8 +3,8 @@ use std::path::PathBuf;
 
 use crate::env;
 
-pub fn normalize_for_path_comparison(path: &Path) -> std::io::Result<PathBuf> {
-    let canonical = path.canonicalize()?;
+pub fn normalize_for_path_comparison(path: impl AsRef<Path>) -> std::io::Result<PathBuf> {
+    let canonical = path.as_ref().canonicalize()?;
     Ok(normalize_for_wsl(canonical))
 }
 

codex-rs/core/src/powershell.rs

@@ -8,6 +8,30 @@ use crate::shell::detect_shell_type;
 
 const POWERSHELL_FLAGS: &[&str] = &["-nologo", "-noprofile", "-command", "-c"];
 
+/// Prefixed command for powershell shell calls to force UTF-8 console output.
+pub(crate) const UTF8_OUTPUT_PREFIX: &str =
+    "[Console]::OutputEncoding=[System.Text.Encoding]::UTF8;\n";
+
+pub(crate) fn prefix_powershell_script_with_utf8(command: &[String]) -> Vec<String> {
+    let Some((_, script)) = extract_powershell_command(command) else {
+        return command.to_vec();
+    };
+
+    let trimmed = script.trim_start();
+    let script = if trimmed.starts_with(UTF8_OUTPUT_PREFIX) {
+        script.to_string()
+    } else {
+        format!("{UTF8_OUTPUT_PREFIX}{script}")
+    };
+
+    let mut command: Vec<String> = command[..(command.len() - 1)]
+        .iter()
+        .map(std::string::ToString::to_string)
+        .collect();
+    command.push(script);
+    command
+}
+
 /// Extract the PowerShell script body from an invocation such as:
 ///
 /// - ["pwsh", "-NoProfile", "-Command", "Get-ChildItem -Recurse | Select-String foo"]
@@ -22,7 +46,10 @@ pub fn extract_powershell_command(command: &[String]) -> Option<(&str, &str)> {
     }
 
     let shell = &command[0];
-    if detect_shell_type(&PathBuf::from(shell)) != Some(ShellType::PowerShell) {
+    if !matches!(
+        detect_shell_type(&PathBuf::from(shell)),
+        Some(ShellType::PowerShell)
+    ) {
         return None;
     }
 
@@ -36,7 +63,7 @@ pub fn extract_powershell_command(command: &[String]) -> Option<(&str, &str)> {
         }
         if flag.eq_ignore_ascii_case("-Command") || flag.eq_ignore_ascii_case("-c") {
             let script = &command[i + 1];
-            return Some((shell, script.as_str()));
+            return Some((shell, script));
         }
         i += 1;
     }

codex-rs/core/src/project_doc.rs

@@ -14,7 +14,6 @@
 //! 3.  We do **not** walk past the Git root.
 
 use crate::config::Config;
-use crate::features::Feature;
 use crate::skills::SkillMetadata;
 use crate::skills::render_skills_section;
 use dunce::canonicalize as normalize_path;
@@ -37,11 +36,7 @@ pub(crate) async fn get_user_instructions(
     config: &Config,
     skills: Option<&[SkillMetadata]>,
 ) -> Option<String> {
-    let skills_section = if config.features.enabled(Feature::Skills) {
-        skills.and_then(render_skills_section)
-    } else {
-        None
-    };
+    let skills_section = skills.and_then(render_skills_section);
 
     let project_docs = match read_project_docs(config).await {
         Ok(docs) => docs,
@@ -237,8 +232,7 @@ fn merge_project_docs_with_skills(
 #[cfg(test)]
 mod tests {
     use super::*;
-    use crate::config::ConfigOverrides;
-    use crate::config::ConfigToml;
+    use crate::config::ConfigBuilder;
     use crate::skills::load_skills;
     use std::fs;
     use std::path::PathBuf;
@@ -249,30 +243,28 @@ mod tests {
     /// optionally specify a custom `instructions` string – when `None` the
     /// value is cleared to mimic a scenario where no system instructions have
     /// been configured.
-    fn make_config(root: &TempDir, limit: usize, instructions: Option<&str>) -> Config {
+    async fn make_config(root: &TempDir, limit: usize, instructions: Option<&str>) -> Config {
         let codex_home = TempDir::new().unwrap();
-        let mut config = Config::load_from_base_config_with_overrides(
-            ConfigToml::default(),
-            ConfigOverrides::default(),
-            codex_home.path().to_path_buf(),
-        )
-        .expect("defaults for test should always succeed");
+        let mut config = ConfigBuilder::default()
+            .codex_home(codex_home.path().to_path_buf())
+            .build()
+            .await
+            .expect("defaults for test should always succeed");
 
         config.cwd = root.path().to_path_buf();
         config.project_doc_max_bytes = limit;
-        config.features.enable(Feature::Skills);
 
         config.user_instructions = instructions.map(ToOwned::to_owned);
         config
     }
 
-    fn make_config_with_fallback(
+    async fn make_config_with_fallback(
         root: &TempDir,
         limit: usize,
         instructions: Option<&str>,
         fallbacks: &[&str],
     ) -> Config {
-        let mut config = make_config(root, limit, instructions);
+        let mut config = make_config(root, limit, instructions).await;
         config.project_doc_fallback_filenames = fallbacks
             .iter()
             .map(std::string::ToString::to_string)
@@ -285,7 +277,7 @@ mod tests {
     async fn no_doc_file_returns_none() {
         let tmp = tempfile::tempdir().expect("tempdir");
 
-        let res = get_user_instructions(&make_config(&tmp, 4096, None), None).await;
+        let res = get_user_instructions(&make_config(&tmp, 4096, None).await, None).await;
         assert!(
             res.is_none(),
             "Expected None when AGENTS.md is absent and no system instructions provided"
@@ -299,7 +291,7 @@ mod tests {
         let tmp = tempfile::tempdir().expect("tempdir");
         fs::write(tmp.path().join("AGENTS.md"), "hello world").unwrap();
 
-        let res = get_user_instructions(&make_config(&tmp, 4096, None), None)
+        let res = get_user_instructions(&make_config(&tmp, 4096, None).await, None)
             .await
             .expect("doc expected");
 
@@ -318,7 +310,7 @@ mod tests {
         let huge = "A".repeat(LIMIT * 2); // 2 KiB
         fs::write(tmp.path().join("AGENTS.md"), &huge).unwrap();
 
-        let res = get_user_instructions(&make_config(&tmp, LIMIT, None), None)
+        let res = get_user_instructions(&make_config(&tmp, LIMIT, None).await, None)
             .await
             .expect("doc expected");
 
@@ -347,7 +339,7 @@ mod tests {
         std::fs::create_dir_all(&nested).unwrap();
 
         // Build config pointing at the nested dir.
-        let mut cfg = make_config(&repo, 4096, None);
+        let mut cfg = make_config(&repo, 4096, None).await;
         cfg.cwd = nested;
 
         let res = get_user_instructions(&cfg, None)
@@ -362,7 +354,7 @@ mod tests {
         let tmp = tempfile::tempdir().expect("tempdir");
         fs::write(tmp.path().join("AGENTS.md"), "something").unwrap();
 
-        let res = get_user_instructions(&make_config(&tmp, 0, None), None).await;
+        let res = get_user_instructions(&make_config(&tmp, 0, None).await, None).await;
         assert!(
             res.is_none(),
             "With limit 0 the function should return None"
@@ -378,7 +370,7 @@ mod tests {
 
         const INSTRUCTIONS: &str = "base instructions";
 
-        let res = get_user_instructions(&make_config(&tmp, 4096, Some(INSTRUCTIONS)), None)
+        let res = get_user_instructions(&make_config(&tmp, 4096, Some(INSTRUCTIONS)).await, None)
             .await
             .expect("should produce a combined instruction string");
 
@@ -395,7 +387,8 @@ mod tests {
 
         const INSTRUCTIONS: &str = "some instructions";
 
-        let res = get_user_instructions(&make_config(&tmp, 4096, Some(INSTRUCTIONS)), None).await;
+        let res =
+            get_user_instructions(&make_config(&tmp, 4096, Some(INSTRUCTIONS)).await, None).await;
 
         assert_eq!(res, Some(INSTRUCTIONS.to_string()));
     }
@@ -421,7 +414,7 @@ mod tests {
         std::fs::create_dir_all(&nested).unwrap();
         fs::write(nested.join("AGENTS.md"), "crate doc").unwrap();
 
-        let mut cfg = make_config(&repo, 4096, None);
+        let mut cfg = make_config(&repo, 4096, None).await;
         cfg.cwd = nested;
 
         let res = get_user_instructions(&cfg, None)
@@ -437,7 +430,7 @@ mod tests {
         fs::write(tmp.path().join(DEFAULT_PROJECT_DOC_FILENAME), "versioned").unwrap();
         fs::write(tmp.path().join(LOCAL_PROJECT_DOC_FILENAME), "local").unwrap();
 
-        let cfg = make_config(&tmp, 4096, None);
+        let cfg = make_config(&tmp, 4096, None).await;
 
         let res = get_user_instructions(&cfg, None)
             .await
@@ -459,7 +452,7 @@ mod tests {
         let tmp = tempfile::tempdir().expect("tempdir");
         fs::write(tmp.path().join("EXAMPLE.md"), "example instructions").unwrap();
 
-        let cfg = make_config_with_fallback(&tmp, 4096, None, &["EXAMPLE.md"]);
+        let cfg = make_config_with_fallback(&tmp, 4096, None, &["EXAMPLE.md"]).await;
 
         let res = get_user_instructions(&cfg, None)
             .await
@@ -475,7 +468,7 @@ mod tests {
         fs::write(tmp.path().join("AGENTS.md"), "primary").unwrap();
         fs::write(tmp.path().join("EXAMPLE.md"), "secondary").unwrap();
 
-        let cfg = make_config_with_fallback(&tmp, 4096, None, &["EXAMPLE.md", ".example.md"]);
+        let cfg = make_config_with_fallback(&tmp, 4096, None, &["EXAMPLE.md", ".example.md"]).await;
 
         let res = get_user_instructions(&cfg, None)
             .await
@@ -499,7 +492,7 @@ mod tests {
         let tmp = tempfile::tempdir().expect("tempdir");
         fs::write(tmp.path().join("AGENTS.md"), "base doc").unwrap();
 
-        let cfg = make_config(&tmp, 4096, None);
+        let cfg = make_config(&tmp, 4096, None).await;
         create_skill(
             cfg.codex_home.clone(),
             "pdf-processing",
@@ -530,7 +523,7 @@ mod tests {
     #[tokio::test]
     async fn skills_render_without_project_doc() {
         let tmp = tempfile::tempdir().expect("tempdir");
-        let cfg = make_config(&tmp, 4096, None);
+        let cfg = make_config(&tmp, 4096, None).await;
         create_skill(cfg.codex_home.clone(), "linting", "run clippy");
 
         let skills = load_skills(&cfg);

codex-rs/core/src/safety.rs

@@ -91,7 +91,10 @@ pub fn assess_patch_safety(
     if is_write_patch_constrained_to_writable_paths(action, sandbox_policy, cwd)
         || policy == AskForApproval::OnFailure
     {
-        if matches!(sandbox_policy, SandboxPolicy::DangerFullAccess) {
+        if matches!(
+            sandbox_policy,
+            SandboxPolicy::DangerFullAccess | SandboxPolicy::ExternalSandbox { .. }
+        ) {
             // DangerFullAccess is intended to bypass sandboxing entirely.
             SafetyCheck::AutoApprove {
                 sandbox_type: SandboxType::None,
@@ -147,7 +150,7 @@ fn is_write_patch_constrained_to_writable_paths(
         SandboxPolicy::ReadOnly => {
             return false;
         }
-        SandboxPolicy::DangerFullAccess => {
+        SandboxPolicy::DangerFullAccess | SandboxPolicy::ExternalSandbox { .. } => {
             return true;
         }
         SandboxPolicy::WorkspaceWrite { .. } => sandbox_policy.get_writable_roots_with_cwd(cwd),
@@ -262,4 +265,23 @@ mod tests {
             &cwd,
         ));
     }
+
+    #[test]
+    fn external_sandbox_auto_approves_in_on_request() {
+        let tmp = TempDir::new().unwrap();
+        let cwd = tmp.path().to_path_buf();
+        let add_inside = ApplyPatchAction::new_add_for_test(&cwd.join("inner.txt"), "".to_string());
+
+        let policy = SandboxPolicy::ExternalSandbox {
+            network_access: codex_protocol::protocol::NetworkAccess::Enabled,
+        };
+
+        assert_eq!(
+            assess_patch_safety(&add_inside, AskForApproval::OnRequest, &policy, &cwd,),
+            SafetyCheck::AutoApprove {
+                sandbox_type: SandboxType::None,
+                user_explicitly_approved: false,
+            }
+        );
+    }
 }

codex-rs/core/src/sandboxing/mod.rs

@@ -85,7 +85,9 @@ impl SandboxManager {
                 crate::safety::get_platform_sandbox().unwrap_or(SandboxType::None)
             }
             SandboxablePreference::Auto => match policy {
-                SandboxPolicy::DangerFullAccess => SandboxType::None,
+                SandboxPolicy::DangerFullAccess | SandboxPolicy::ExternalSandbox { .. } => {
+                    SandboxType::None
+                }
                 _ => crate::safety::get_platform_sandbox().unwrap_or(SandboxType::None),
             },
         }

codex-rs/core/src/skills/assets/samples/skill-creator/SKILL.md

@@ -0,0 +1,373 @@
+---
+name: skill-creator
+description: Guide for creating effective skills. This skill should be used when users want to create a new skill (or update an existing skill) that extends Codex's capabilities with specialized knowledge, workflows, or tool integrations.
+metadata:
+  short-description: Create or update a skill
+---
+
+# Skill Creator
+
+This skill provides guidance for creating effective skills.
+
+## About Skills
+
+Skills are modular, self-contained packages that extend Codex's capabilities by providing
+specialized knowledge, workflows, and tools. Think of them as "onboarding guides" for specific
+domains or tasks—they transform Codex from a general-purpose agent into a specialized agent
+equipped with procedural knowledge that no model can fully possess.
+
+### What Skills Provide
+
+1. Specialized workflows - Multi-step procedures for specific domains
+2. Tool integrations - Instructions for working with specific file formats or APIs
+3. Domain expertise - Company-specific knowledge, schemas, business logic
+4. Bundled resources - Scripts, references, and assets for complex and repetitive tasks
+
+## Core Principles
+
+### Concise is Key
+
+The context window is a public good. Skills share the context window with everything else Codex needs: system prompt, conversation history, other Skills' metadata, and the actual user request.
+
+**Default assumption: Codex is already very smart.** Only add context Codex doesn't already have. Challenge each piece of information: "Does Codex really need this explanation?" and "Does this paragraph justify its token cost?"
+
+Prefer concise examples over verbose explanations.
+
+### Set Appropriate Degrees of Freedom
+
+Match the level of specificity to the task's fragility and variability:
+
+**High freedom (text-based instructions)**: Use when multiple approaches are valid, decisions depend on context, or heuristics guide the approach.
+
+**Medium freedom (pseudocode or scripts with parameters)**: Use when a preferred pattern exists, some variation is acceptable, or configuration affects behavior.
+
+**Low freedom (specific scripts, few parameters)**: Use when operations are fragile and error-prone, consistency is critical, or a specific sequence must be followed.
+
+Think of Codex as exploring a path: a narrow bridge with cliffs needs specific guardrails (low freedom), while an open field allows many routes (high freedom).
+
+### Anatomy of a Skill
+
+Every skill consists of a required SKILL.md file and optional bundled resources:
+
+```
+skill-name/
+├── SKILL.md (required)
+│   ├── YAML frontmatter metadata (required)
+│   │   ├── name: (required)
+│   │   └── description: (required)
+│   └── Markdown instructions (required)
+└── Bundled Resources (optional)
+    ├── scripts/          - Executable code (Python/Bash/etc.)
+    ├── references/       - Documentation intended to be loaded into context as needed
+    └── assets/           - Files used in output (templates, icons, fonts, etc.)
+```
+
+#### SKILL.md (required)
+
+Every SKILL.md consists of:
+
+- **Frontmatter** (YAML): Contains `name` and `description` fields. These are the only fields that Codex reads to determine when the skill gets used, thus it is very important to be clear and comprehensive in describing what the skill is, and when it should be used.
+- **Body** (Markdown): Instructions and guidance for using the skill. Only loaded AFTER the skill triggers (if at all).
+
+#### Bundled Resources (optional)
+
+##### Scripts (`scripts/`)
+
+Executable code (Python/Bash/etc.) for tasks that require deterministic reliability or are repeatedly rewritten.
+
+- **When to include**: When the same code is being rewritten repeatedly or deterministic reliability is needed
+- **Example**: `scripts/rotate_pdf.py` for PDF rotation tasks
+- **Benefits**: Token efficient, deterministic, may be executed without loading into context
+- **Note**: Scripts may still need to be read by Codex for patching or environment-specific adjustments
+
+##### References (`references/`)
+
+Documentation and reference material intended to be loaded as needed into context to inform Codex's process and thinking.
+
+- **When to include**: For documentation that Codex should reference while working
+- **Examples**: `references/finance.md` for financial schemas, `references/mnda.md` for company NDA template, `references/policies.md` for company policies, `references/api_docs.md` for API specifications
+- **Use cases**: Database schemas, API documentation, domain knowledge, company policies, detailed workflow guides
+- **Benefits**: Keeps SKILL.md lean, loaded only when Codex determines it's needed
+- **Best practice**: If files are large (>10k words), include grep search patterns in SKILL.md
+- **Avoid duplication**: Information should live in either SKILL.md or references files, not both. Prefer references files for detailed information unless it's truly core to the skill—this keeps SKILL.md lean while making information discoverable without hogging the context window. Keep only essential procedural instructions and workflow guidance in SKILL.md; move detailed reference material, schemas, and examples to references files.
+
+##### Assets (`assets/`)
+
+Files not intended to be loaded into context, but rather used within the output Codex produces.
+
+- **When to include**: When the skill needs files that will be used in the final output
+- **Examples**: `assets/logo.png` for brand assets, `assets/slides.pptx` for PowerPoint templates, `assets/frontend-template/` for HTML/React boilerplate, `assets/font.ttf` for typography
+- **Use cases**: Templates, images, icons, boilerplate code, fonts, sample documents that get copied or modified
+- **Benefits**: Separates output resources from documentation, enables Codex to use files without loading them into context
+
+#### What to Not Include in a Skill
+
+A skill should only contain essential files that directly support its functionality. Do NOT create extraneous documentation or auxiliary files, including:
+
+- README.md
+- INSTALLATION_GUIDE.md
+- QUICK_REFERENCE.md
+- CHANGELOG.md
+- etc.
+
+The skill should only contain the information needed for an AI agent to do the job at hand. It should not contain auxiliary context about the process that went into creating it, setup and testing procedures, user-facing documentation, etc. Creating additional documentation files just adds clutter and confusion.
+
+### Progressive Disclosure Design Principle
+
+Skills use a three-level loading system to manage context efficiently:
+
+1. **Metadata (name + description)** - Always in context (~100 words)
+2. **SKILL.md body** - When skill triggers (<5k words)
+3. **Bundled resources** - As needed by Codex (Unlimited because scripts can be executed without reading into context window)
+
+#### Progressive Disclosure Patterns
+
+Keep SKILL.md body to the essentials and under 500 lines to minimize context bloat. Split content into separate files when approaching this limit. When splitting out content into other files, it is very important to reference them from SKILL.md and describe clearly when to read them, to ensure the reader of the skill knows they exist and when to use them.
+
+**Key principle:** When a skill supports multiple variations, frameworks, or options, keep only the core workflow and selection guidance in SKILL.md. Move variant-specific details (patterns, examples, configuration) into separate reference files.
+
+**Pattern 1: High-level guide with references**
+
+```markdown
+# PDF Processing
+
+## Quick start
+
+Extract text with pdfplumber:
+[code example]
+
+## Advanced features
+
+- **Form filling**: See [FORMS.md](FORMS.md) for complete guide
+- **API reference**: See [REFERENCE.md](REFERENCE.md) for all methods
+- **Examples**: See [EXAMPLES.md](EXAMPLES.md) for common patterns
+```
+
+Codex loads FORMS.md, REFERENCE.md, or EXAMPLES.md only when needed.
+
+**Pattern 2: Domain-specific organization**
+
+For Skills with multiple domains, organize content by domain to avoid loading irrelevant context:
+
+```
+bigquery-skill/
+├── SKILL.md (overview and navigation)
+└── reference/
+    ├── finance.md (revenue, billing metrics)
+    ├── sales.md (opportunities, pipeline)
+    ├── product.md (API usage, features)
+    └── marketing.md (campaigns, attribution)
+```
+
+When a user asks about sales metrics, Codex only reads sales.md.
+
+Similarly, for skills supporting multiple frameworks or variants, organize by variant:
+
+```
+cloud-deploy/
+├── SKILL.md (workflow + provider selection)
+└── references/
+    ├── aws.md (AWS deployment patterns)
+    ├── gcp.md (GCP deployment patterns)
+    └── azure.md (Azure deployment patterns)
+```
+
+When the user chooses AWS, Codex only reads aws.md.
+
+**Pattern 3: Conditional details**
+
+Show basic content, link to advanced content:
+
+```markdown
+# DOCX Processing
+
+## Creating documents
+
+Use docx-js for new documents. See [DOCX-JS.md](DOCX-JS.md).
+
+## Editing documents
+
+For simple edits, modify the XML directly.
+
+**For tracked changes**: See [REDLINING.md](REDLINING.md)
+**For OOXML details**: See [OOXML.md](OOXML.md)
+```
+
+Codex reads REDLINING.md or OOXML.md only when the user needs those features.
+
+**Important guidelines:**
+
+- **Avoid deeply nested references** - Keep references one level deep from SKILL.md. All reference files should link directly from SKILL.md.
+- **Structure longer reference files** - For files longer than 100 lines, include a table of contents at the top so Codex can see the full scope when previewing.
+
+## Skill Creation Process
+
+Skill creation involves these steps:
+
+1. Understand the skill with concrete examples
+2. Plan reusable skill contents (scripts, references, assets)
+3. Initialize the skill (run init_skill.py)
+4. Edit the skill (implement resources and write SKILL.md)
+5. Package the skill (run package_skill.py)
+6. Iterate based on real usage
+
+Follow these steps in order, skipping only if there is a clear reason why they are not applicable.
+
+### Skill Naming
+
+- Use lowercase letters, digits, and hyphens only; normalize user-provided titles to hyphen-case (e.g., "Plan Mode" -> `plan-mode`).
+- When generating names, generate a name under 64 characters (letters, digits, hyphens).
+- Prefer short, verb-led phrases that describe the action.
+- Namespace by tool when it improves clarity or triggering (e.g., `gh-address-comments`, `linear-address-issue`).
+- Name the skill folder exactly after the skill name.
+
+### Step 1: Understanding the Skill with Concrete Examples
+
+Skip this step only when the skill's usage patterns are already clearly understood. It remains valuable even when working with an existing skill.
+
+To create an effective skill, clearly understand concrete examples of how the skill will be used. This understanding can come from either direct user examples or generated examples that are validated with user feedback.
+
+For example, when building an image-editor skill, relevant questions include:
+
+- "What functionality should the image-editor skill support? Editing, rotating, anything else?"
+- "Can you give some examples of how this skill would be used?"
+- "I can imagine users asking for things like 'Remove the red-eye from this image' or 'Rotate this image'. Are there other ways you imagine this skill being used?"
+- "What would a user say that should trigger this skill?"
+
+To avoid overwhelming users, avoid asking too many questions in a single message. Start with the most important questions and follow up as needed for better effectiveness.
+
+Conclude this step when there is a clear sense of the functionality the skill should support.
+
+### Step 2: Planning the Reusable Skill Contents
+
+To turn concrete examples into an effective skill, analyze each example by:
+
+1. Considering how to execute on the example from scratch
+2. Identifying what scripts, references, and assets would be helpful when executing these workflows repeatedly
+
+Example: When building a `pdf-editor` skill to handle queries like "Help me rotate this PDF," the analysis shows:
+
+1. Rotating a PDF requires re-writing the same code each time
+2. A `scripts/rotate_pdf.py` script would be helpful to store in the skill
+
+Example: When designing a `frontend-webapp-builder` skill for queries like "Build me a todo app" or "Build me a dashboard to track my steps," the analysis shows:
+
+1. Writing a frontend webapp requires the same boilerplate HTML/React each time
+2. An `assets/hello-world/` template containing the boilerplate HTML/React project files would be helpful to store in the skill
+
+Example: When building a `big-query` skill to handle queries like "How many users have logged in today?" the analysis shows:
+
+1. Querying BigQuery requires re-discovering the table schemas and relationships each time
+2. A `references/schema.md` file documenting the table schemas would be helpful to store in the skill
+
+To establish the skill's contents, analyze each concrete example to create a list of the reusable resources to include: scripts, references, and assets.
+
+### Step 3: Initializing the Skill
+
+At this point, it is time to actually create the skill.
+
+Skip this step only if the skill being developed already exists, and iteration or packaging is needed. In this case, continue to the next step.
+
+When creating a new skill from scratch, always run the `init_skill.py` script. The script conveniently generates a new template skill directory that automatically includes everything a skill requires, making the skill creation process much more efficient and reliable.
+
+Usage:
+
+```bash
+scripts/init_skill.py <skill-name> --path <output-directory> [--resources scripts,references,assets] [--examples]
+```
+
+Examples:
+
+```bash
+scripts/init_skill.py my-skill --path skills/public
+scripts/init_skill.py my-skill --path skills/public --resources scripts,references
+scripts/init_skill.py my-skill --path skills/public --resources scripts --examples
+```
+
+The script:
+
+- Creates the skill directory at the specified path
+- Generates a SKILL.md template with proper frontmatter and TODO placeholders
+- Optionally creates resource directories based on `--resources`
+- Optionally adds example files when `--examples` is set
+
+After initialization, customize the SKILL.md and add resources as needed. If you used `--examples`, replace or delete placeholder files.
+
+### Step 4: Edit the Skill
+
+When editing the (newly-generated or existing) skill, remember that the skill is being created for another instance of Codex to use. Include information that would be beneficial and non-obvious to Codex. Consider what procedural knowledge, domain-specific details, or reusable assets would help another Codex instance execute these tasks more effectively.
+
+#### Learn Proven Design Patterns
+
+Consult these helpful guides based on your skill's needs:
+
+- **Multi-step processes**: See references/workflows.md for sequential workflows and conditional logic
+- **Specific output formats or quality standards**: See references/output-patterns.md for template and example patterns
+
+These files contain established best practices for effective skill design.
+
+#### Start with Reusable Skill Contents
+
+To begin implementation, start with the reusable resources identified above: `scripts/`, `references/`, and `assets/` files. Note that this step may require user input. For example, when implementing a `brand-guidelines` skill, the user may need to provide brand assets or templates to store in `assets/`, or documentation to store in `references/`.
+
+Added scripts must be tested by actually running them to ensure there are no bugs and that the output matches what is expected. If there are many similar scripts, only a representative sample needs to be tested to ensure confidence that they all work while balancing time to completion.
+
+If you used `--examples`, delete any placeholder files that are not needed for the skill. Only create resource directories that are actually required.
+
+#### Update SKILL.md
+
+**Writing Guidelines:** Always use imperative/infinitive form.
+
+##### Frontmatter
+
+Write the YAML frontmatter with `name` and `description`:
+
+- `name`: The skill name
+- `description`: This is the primary triggering mechanism for your skill, and helps Codex understand when to use the skill.
+  - Include both what the Skill does and specific triggers/contexts for when to use it.
+  - Include all "when to use" information here - Not in the body. The body is only loaded after triggering, so "When to Use This Skill" sections in the body are not helpful to Codex.
+  - Example description for a `docx` skill: "Comprehensive document creation, editing, and analysis with support for tracked changes, comments, formatting preservation, and text extraction. Use when Codex needs to work with professional documents (.docx files) for: (1) Creating new documents, (2) Modifying or editing content, (3) Working with tracked changes, (4) Adding comments, or any other document tasks"
+
+Do not include any other fields in YAML frontmatter.
+
+##### Body
+
+Write instructions for using the skill and its bundled resources.
+
+### Step 5: Packaging a Skill
+
+Once development of the skill is complete, it must be packaged into a distributable .skill file that gets shared with the user. The packaging process automatically validates the skill first to ensure it meets all requirements:
+
+```bash
+scripts/package_skill.py <path/to/skill-folder>
+```
+
+Optional output directory specification:
+
+```bash
+scripts/package_skill.py <path/to/skill-folder> ./dist
+```
+
+The packaging script will:
+
+1. **Validate** the skill automatically, checking:
+
+   - YAML frontmatter format and required fields
+   - Skill naming conventions and directory structure
+   - Description completeness and quality
+   - File organization and resource references
+
+2. **Package** the skill if validation passes, creating a .skill file named after the skill (e.g., `my-skill.skill`) that includes all files and maintains the proper directory structure for distribution. The .skill file is a zip file with a .skill extension.
+
+If validation fails, the script will report the errors and exit without creating a package. Fix any validation errors and run the packaging command again.
+
+### Step 6: Iterate
+
+After testing the skill, users may request improvements. Often this happens right after using the skill, with fresh context of how the skill performed.
+
+**Iteration workflow:**
+
+1. Use the skill on real tasks
+2. Notice struggles or inefficiencies
+3. Identify how SKILL.md or bundled resources should be updated
+4. Implement changes and test again

codex-rs/core/src/skills/assets/samples/skill-creator/license.txt

@@ -0,0 +1,202 @@
+
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+
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codex-rs/core/src/skills/assets/samples/skill-creator/scripts/init_skill.py

@@ -0,0 +1,378 @@
+#!/usr/bin/env python3
+"""
+Skill Initializer - Creates a new skill from template
+
+Usage:
+    init_skill.py <skill-name> --path <path> [--resources scripts,references,assets] [--examples]
+
+Examples:
+    init_skill.py my-new-skill --path skills/public
+    init_skill.py my-new-skill --path skills/public --resources scripts,references
+    init_skill.py my-api-helper --path skills/private --resources scripts --examples
+    init_skill.py custom-skill --path /custom/location
+"""
+
+import argparse
+import re
+import sys
+from pathlib import Path
+
+MAX_SKILL_NAME_LENGTH = 64
+ALLOWED_RESOURCES = {"scripts", "references", "assets"}
+
+SKILL_TEMPLATE = """---
+name: {skill_name}
+description: [TODO: Complete and informative explanation of what the skill does and when to use it. Include WHEN to use this skill - specific scenarios, file types, or tasks that trigger it.]
+---
+
+# {skill_title}
+
+## Overview
+
+[TODO: 1-2 sentences explaining what this skill enables]
+
+## Structuring This Skill
+
+[TODO: Choose the structure that best fits this skill's purpose. Common patterns:
+
+**1. Workflow-Based** (best for sequential processes)
+- Works well when there are clear step-by-step procedures
+- Example: DOCX skill with "Workflow Decision Tree" -> "Reading" -> "Creating" -> "Editing"
+- Structure: ## Overview -> ## Workflow Decision Tree -> ## Step 1 -> ## Step 2...
+
+**2. Task-Based** (best for tool collections)
+- Works well when the skill offers different operations/capabilities
+- Example: PDF skill with "Quick Start" -> "Merge PDFs" -> "Split PDFs" -> "Extract Text"
+- Structure: ## Overview -> ## Quick Start -> ## Task Category 1 -> ## Task Category 2...
+
+**3. Reference/Guidelines** (best for standards or specifications)
+- Works well for brand guidelines, coding standards, or requirements
+- Example: Brand styling with "Brand Guidelines" -> "Colors" -> "Typography" -> "Features"
+- Structure: ## Overview -> ## Guidelines -> ## Specifications -> ## Usage...
+
+**4. Capabilities-Based** (best for integrated systems)
+- Works well when the skill provides multiple interrelated features
+- Example: Product Management with "Core Capabilities" -> numbered capability list
+- Structure: ## Overview -> ## Core Capabilities -> ### 1. Feature -> ### 2. Feature...
+
+Patterns can be mixed and matched as needed. Most skills combine patterns (e.g., start with task-based, add workflow for complex operations).
+
+Delete this entire "Structuring This Skill" section when done - it's just guidance.]
+
+## [TODO: Replace with the first main section based on chosen structure]
+
+[TODO: Add content here. See examples in existing skills:
+- Code samples for technical skills
+- Decision trees for complex workflows
+- Concrete examples with realistic user requests
+- References to scripts/templates/references as needed]
+
+## Resources (optional)
+
+Create only the resource directories this skill actually needs. Delete this section if no resources are required.
+
+### scripts/
+Executable code (Python/Bash/etc.) that can be run directly to perform specific operations.
+
+**Examples from other skills:**
+- PDF skill: `fill_fillable_fields.py`, `extract_form_field_info.py` - utilities for PDF manipulation
+- DOCX skill: `document.py`, `utilities.py` - Python modules for document processing
+
+**Appropriate for:** Python scripts, shell scripts, or any executable code that performs automation, data processing, or specific operations.
+
+**Note:** Scripts may be executed without loading into context, but can still be read by Codex for patching or environment adjustments.
+
+### references/
+Documentation and reference material intended to be loaded into context to inform Codex's process and thinking.
+
+**Examples from other skills:**
+- Product management: `communication.md`, `context_building.md` - detailed workflow guides
+- BigQuery: API reference documentation and query examples
+- Finance: Schema documentation, company policies
+
+**Appropriate for:** In-depth documentation, API references, database schemas, comprehensive guides, or any detailed information that Codex should reference while working.
+
+### assets/
+Files not intended to be loaded into context, but rather used within the output Codex produces.
+
+**Examples from other skills:**
+- Brand styling: PowerPoint template files (.pptx), logo files
+- Frontend builder: HTML/React boilerplate project directories
+- Typography: Font files (.ttf, .woff2)
+
+**Appropriate for:** Templates, boilerplate code, document templates, images, icons, fonts, or any files meant to be copied or used in the final output.
+
+---
+
+**Not every skill requires all three types of resources.**
+"""
+
+EXAMPLE_SCRIPT = '''#!/usr/bin/env python3
+"""
+Example helper script for {skill_name}
+
+This is a placeholder script that can be executed directly.
+Replace with actual implementation or delete if not needed.
+
+Example real scripts from other skills:
+- pdf/scripts/fill_fillable_fields.py - Fills PDF form fields
+- pdf/scripts/convert_pdf_to_images.py - Converts PDF pages to images
+"""
+
+def main():
+    print("This is an example script for {skill_name}")
+    # TODO: Add actual script logic here
+    # This could be data processing, file conversion, API calls, etc.
+
+if __name__ == "__main__":
+    main()
+'''
+
+EXAMPLE_REFERENCE = """# Reference Documentation for {skill_title}
+
+This is a placeholder for detailed reference documentation.
+Replace with actual reference content or delete if not needed.
+
+Example real reference docs from other skills:
+- product-management/references/communication.md - Comprehensive guide for status updates
+- product-management/references/context_building.md - Deep-dive on gathering context
+- bigquery/references/ - API references and query examples
+
+## When Reference Docs Are Useful
+
+Reference docs are ideal for:
+- Comprehensive API documentation
+- Detailed workflow guides
+- Complex multi-step processes
+- Information too lengthy for main SKILL.md
+- Content that's only needed for specific use cases
+
+## Structure Suggestions
+
+### API Reference Example
+- Overview
+- Authentication
+- Endpoints with examples
+- Error codes
+- Rate limits
+
+### Workflow Guide Example
+- Prerequisites
+- Step-by-step instructions
+- Common patterns
+- Troubleshooting
+- Best practices
+"""
+
+EXAMPLE_ASSET = """# Example Asset File
+
+This placeholder represents where asset files would be stored.
+Replace with actual asset files (templates, images, fonts, etc.) or delete if not needed.
+
+Asset files are NOT intended to be loaded into context, but rather used within
+the output Codex produces.
+
+Example asset files from other skills:
+- Brand guidelines: logo.png, slides_template.pptx
+- Frontend builder: hello-world/ directory with HTML/React boilerplate
+- Typography: custom-font.ttf, font-family.woff2
+- Data: sample_data.csv, test_dataset.json
+
+## Common Asset Types
+
+- Templates: .pptx, .docx, boilerplate directories
+- Images: .png, .jpg, .svg, .gif
+- Fonts: .ttf, .otf, .woff, .woff2
+- Boilerplate code: Project directories, starter files
+- Icons: .ico, .svg
+- Data files: .csv, .json, .xml, .yaml
+
+Note: This is a text placeholder. Actual assets can be any file type.
+"""
+
+
+def normalize_skill_name(skill_name):
+    """Normalize a skill name to lowercase hyphen-case."""
+    normalized = skill_name.strip().lower()
+    normalized = re.sub(r"[^a-z0-9]+", "-", normalized)
+    normalized = normalized.strip("-")
+    normalized = re.sub(r"-{2,}", "-", normalized)
+    return normalized
+
+
+def title_case_skill_name(skill_name):
+    """Convert hyphenated skill name to Title Case for display."""
+    return " ".join(word.capitalize() for word in skill_name.split("-"))
+
+
+def parse_resources(raw_resources):
+    if not raw_resources:
+        return []
+    resources = [item.strip() for item in raw_resources.split(",") if item.strip()]
+    invalid = sorted({item for item in resources if item not in ALLOWED_RESOURCES})
+    if invalid:
+        allowed = ", ".join(sorted(ALLOWED_RESOURCES))
+        print(f"[ERROR] Unknown resource type(s): {', '.join(invalid)}")
+        print(f"   Allowed: {allowed}")
+        sys.exit(1)
+    deduped = []
+    seen = set()
+    for resource in resources:
+        if resource not in seen:
+            deduped.append(resource)
+            seen.add(resource)
+    return deduped
+
+
+def create_resource_dirs(skill_dir, skill_name, skill_title, resources, include_examples):
+    for resource in resources:
+        resource_dir = skill_dir / resource
+        resource_dir.mkdir(exist_ok=True)
+        if resource == "scripts":
+            if include_examples:
+                example_script = resource_dir / "example.py"
+                example_script.write_text(EXAMPLE_SCRIPT.format(skill_name=skill_name))
+                example_script.chmod(0o755)
+                print("[OK] Created scripts/example.py")
+            else:
+                print("[OK] Created scripts/")
+        elif resource == "references":
+            if include_examples:
+                example_reference = resource_dir / "api_reference.md"
+                example_reference.write_text(EXAMPLE_REFERENCE.format(skill_title=skill_title))
+                print("[OK] Created references/api_reference.md")
+            else:
+                print("[OK] Created references/")
+        elif resource == "assets":
+            if include_examples:
+                example_asset = resource_dir / "example_asset.txt"
+                example_asset.write_text(EXAMPLE_ASSET)
+                print("[OK] Created assets/example_asset.txt")
+            else:
+                print("[OK] Created assets/")
+
+
+def init_skill(skill_name, path, resources, include_examples):
+    """
+    Initialize a new skill directory with template SKILL.md.
+
+    Args:
+        skill_name: Name of the skill
+        path: Path where the skill directory should be created
+        resources: Resource directories to create
+        include_examples: Whether to create example files in resource directories
+
+    Returns:
+        Path to created skill directory, or None if error
+    """
+    # Determine skill directory path
+    skill_dir = Path(path).resolve() / skill_name
+
+    # Check if directory already exists
+    if skill_dir.exists():
+        print(f"[ERROR] Skill directory already exists: {skill_dir}")
+        return None
+
+    # Create skill directory
+    try:
+        skill_dir.mkdir(parents=True, exist_ok=False)
+        print(f"[OK] Created skill directory: {skill_dir}")
+    except Exception as e:
+        print(f"[ERROR] Error creating directory: {e}")
+        return None
+
+    # Create SKILL.md from template
+    skill_title = title_case_skill_name(skill_name)
+    skill_content = SKILL_TEMPLATE.format(skill_name=skill_name, skill_title=skill_title)
+
+    skill_md_path = skill_dir / "SKILL.md"
+    try:
+        skill_md_path.write_text(skill_content)
+        print("[OK] Created SKILL.md")
+    except Exception as e:
+        print(f"[ERROR] Error creating SKILL.md: {e}")
+        return None
+
+    # Create resource directories if requested
+    if resources:
+        try:
+            create_resource_dirs(skill_dir, skill_name, skill_title, resources, include_examples)
+        except Exception as e:
+            print(f"[ERROR] Error creating resource directories: {e}")
+            return None
+
+    # Print next steps
+    print(f"\n[OK] Skill '{skill_name}' initialized successfully at {skill_dir}")
+    print("\nNext steps:")
+    print("1. Edit SKILL.md to complete the TODO items and update the description")
+    if resources:
+        if include_examples:
+            print("2. Customize or delete the example files in scripts/, references/, and assets/")
+        else:
+            print("2. Add resources to scripts/, references/, and assets/ as needed")
+    else:
+        print("2. Create resource directories only if needed (scripts/, references/, assets/)")
+    print("3. Run the validator when ready to check the skill structure")
+
+    return skill_dir
+
+
+def main():
+    parser = argparse.ArgumentParser(
+        description="Create a new skill directory with a SKILL.md template.",
+    )
+    parser.add_argument("skill_name", help="Skill name (normalized to hyphen-case)")
+    parser.add_argument("--path", required=True, help="Output directory for the skill")
+    parser.add_argument(
+        "--resources",
+        default="",
+        help="Comma-separated list: scripts,references,assets",
+    )
+    parser.add_argument(
+        "--examples",
+        action="store_true",
+        help="Create example files inside the selected resource directories",
+    )
+    args = parser.parse_args()
+
+    raw_skill_name = args.skill_name
+    skill_name = normalize_skill_name(raw_skill_name)
+    if not skill_name:
+        print("[ERROR] Skill name must include at least one letter or digit.")
+        sys.exit(1)
+    if len(skill_name) > MAX_SKILL_NAME_LENGTH:
+        print(
+            f"[ERROR] Skill name '{skill_name}' is too long ({len(skill_name)} characters). "
+            f"Maximum is {MAX_SKILL_NAME_LENGTH} characters."
+        )
+        sys.exit(1)
+    if skill_name != raw_skill_name:
+        print(f"Note: Normalized skill name from '{raw_skill_name}' to '{skill_name}'.")
+
+    resources = parse_resources(args.resources)
+    if args.examples and not resources:
+        print("[ERROR] --examples requires --resources to be set.")
+        sys.exit(1)
+
+    path = args.path
+
+    print(f"Initializing skill: {skill_name}")
+    print(f"   Location: {path}")
+    if resources:
+        print(f"   Resources: {', '.join(resources)}")
+        if args.examples:
+            print("   Examples: enabled")
+    else:
+        print("   Resources: none (create as needed)")
+    print()
+
+    result = init_skill(skill_name, path, resources, args.examples)
+
+    if result:
+        sys.exit(0)
+    else:
+        sys.exit(1)
+
+
+if __name__ == "__main__":
+    main()

codex-rs/core/src/skills/assets/samples/skill-creator/scripts/package_skill.py

@@ -0,0 +1,111 @@
+#!/usr/bin/env python3
+"""
+Skill Packager - Creates a distributable .skill file of a skill folder
+
+Usage:
+    python utils/package_skill.py <path/to/skill-folder> [output-directory]
+
+Example:
+    python utils/package_skill.py skills/public/my-skill
+    python utils/package_skill.py skills/public/my-skill ./dist
+"""
+
+import sys
+import zipfile
+from pathlib import Path
+
+from quick_validate import validate_skill
+
+
+def package_skill(skill_path, output_dir=None):
+    """
+    Package a skill folder into a .skill file.
+
+    Args:
+        skill_path: Path to the skill folder
+        output_dir: Optional output directory for the .skill file (defaults to current directory)
+
+    Returns:
+        Path to the created .skill file, or None if error
+    """
+    skill_path = Path(skill_path).resolve()
+
+    # Validate skill folder exists
+    if not skill_path.exists():
+        print(f"[ERROR] Skill folder not found: {skill_path}")
+        return None
+
+    if not skill_path.is_dir():
+        print(f"[ERROR] Path is not a directory: {skill_path}")
+        return None
+
+    # Validate SKILL.md exists
+    skill_md = skill_path / "SKILL.md"
+    if not skill_md.exists():
+        print(f"[ERROR] SKILL.md not found in {skill_path}")
+        return None
+
+    # Run validation before packaging
+    print("Validating skill...")
+    valid, message = validate_skill(skill_path)
+    if not valid:
+        print(f"[ERROR] Validation failed: {message}")
+        print("   Please fix the validation errors before packaging.")
+        return None
+    print(f"[OK] {message}\n")
+
+    # Determine output location
+    skill_name = skill_path.name
+    if output_dir:
+        output_path = Path(output_dir).resolve()
+        output_path.mkdir(parents=True, exist_ok=True)
+    else:
+        output_path = Path.cwd()
+
+    skill_filename = output_path / f"{skill_name}.skill"
+
+    # Create the .skill file (zip format)
+    try:
+        with zipfile.ZipFile(skill_filename, "w", zipfile.ZIP_DEFLATED) as zipf:
+            # Walk through the skill directory
+            for file_path in skill_path.rglob("*"):
+                if file_path.is_file():
+                    # Calculate the relative path within the zip
+                    arcname = file_path.relative_to(skill_path.parent)
+                    zipf.write(file_path, arcname)
+                    print(f"  Added: {arcname}")
+
+        print(f"\n[OK] Successfully packaged skill to: {skill_filename}")
+        return skill_filename
+
+    except Exception as e:
+        print(f"[ERROR] Error creating .skill file: {e}")
+        return None
+
+
+def main():
+    if len(sys.argv) < 2:
+        print("Usage: python utils/package_skill.py <path/to/skill-folder> [output-directory]")
+        print("\nExample:")
+        print("  python utils/package_skill.py skills/public/my-skill")
+        print("  python utils/package_skill.py skills/public/my-skill ./dist")
+        sys.exit(1)
+
+    skill_path = sys.argv[1]
+    output_dir = sys.argv[2] if len(sys.argv) > 2 else None
+
+    print(f"Packaging skill: {skill_path}")
+    if output_dir:
+        print(f"   Output directory: {output_dir}")
+    print()
+
+    result = package_skill(skill_path, output_dir)
+
+    if result:
+        sys.exit(0)
+    else:
+        sys.exit(1)
+
+
+if __name__ == "__main__":
+    main()