Add tokio test-util for tui tests

fix oc
simplifying types
2026-05-12 23:32:44 +00:00 · 2025-12-02 23:45:24 -05:00 · 2025-12-02 23:18:21 -05:00 · 2025-12-02 23:18:21 -05:00 · 2025-12-02 23:18:21 -05:00 · 2025-12-02 23:18:21 -05:00
300 changed files with 16294 additions and 15908 deletions
--- a/.github/workflows/cargo-deny.yml
+++ b/.github/workflows/cargo-deny.yml
@@ -0,0 +1,26 @@
+name: cargo-deny
+
+on:
+  pull_request:
+  push:
+    branches:
+      - main
+
+jobs:
+  cargo-deny:
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: ./codex-rs
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Install Rust toolchain
+        uses: dtolnay/rust-toolchain@stable
+
+      - name: Run cargo-deny
+        uses: EmbarkStudios/cargo-deny-action@v1
+        with:
+          rust-version: stable
+          manifest-path: ./codex-rs/Cargo.toml
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -12,7 +12,7 @@ jobs:
      NODE_OPTIONS: --max-old-space-size=4096
    steps:
      - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6

      - name: Setup pnpm
        uses: pnpm/action-setup@v4
--- a/.github/workflows/cla.yml
+++ b/.github/workflows/cla.yml
@@ -46,6 +46,4 @@ jobs:
          path-to-document: https://github.com/openai/codex/blob/main/docs/CLA.md
          path-to-signatures: signatures/cla.json
          branch: cla-signatures
-          allowlist: |
-            codex
-            dependabot[bot]
+          allowlist: codex,dependabot,dependabot[bot],github-actions[bot]
--- a/.github/workflows/codespell.yml
+++ b/.github/workflows/codespell.yml
@@ -18,7 +18,7 @@ jobs:

    steps:
      - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
      - name: Annotate locations with typos
        uses: codespell-project/codespell-problem-matcher@b80729f885d32f78a716c2f107b4db1025001c42 # v1
      - name: Codespell
--- a/.github/workflows/issue-deduplicator.yml
+++ b/.github/workflows/issue-deduplicator.yml
@@ -16,7 +16,7 @@ jobs:
    outputs:
      codex_output: ${{ steps.codex.outputs.final-message }}
    steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6

      - name: Prepare Codex inputs
        env:
--- a/.github/workflows/issue-labeler.yml
+++ b/.github/workflows/issue-labeler.yml
@@ -16,7 +16,7 @@ jobs:
    outputs:
      codex_output: ${{ steps.codex.outputs.final-message }}
    steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6

      - id: codex
        uses: openai/codex-action@main
--- a/.github/workflows/rust-ci.yml
+++ b/.github/workflows/rust-ci.yml
@@ -17,7 +17,7 @@ jobs:
      codex: ${{ steps.detect.outputs.codex }}
      workflows: ${{ steps.detect.outputs.workflows }}
    steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
        with:
          fetch-depth: 0
      - name: Detect changed paths (no external action)
@@ -56,7 +56,7 @@ jobs:
      run:
        working-directory: codex-rs
    steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
      - uses: dtolnay/rust-toolchain@1.90
        with:
          components: rustfmt
@@ -74,7 +74,7 @@ jobs:
      run:
        working-directory: codex-rs
    steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
      - uses: dtolnay/rust-toolchain@1.90
      - uses: taiki-e/install-action@44c6d64aa62cd779e873306675c7a58e86d6d532 # v2
        with:
@@ -147,12 +147,21 @@ jobs:
            profile: release

    steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
      - uses: dtolnay/rust-toolchain@1.90
        with:
          targets: ${{ matrix.target }}
          components: clippy

+      - name: Compute lockfile hash
+        id: lockhash
+        working-directory: codex-rs
+        shell: bash
+        run: |
+          set -euo pipefail
+          echo "hash=$(sha256sum Cargo.lock | cut -d' ' -f1)" >> "$GITHUB_OUTPUT"
+          echo "toolchain_hash=$(sha256sum rust-toolchain.toml | cut -d' ' -f1)" >> "$GITHUB_OUTPUT"
+
      # Explicit cache restore: split cargo home vs target, so we can
      # avoid caching the large target dir on the gnu-dev job.
      - name: Restore cargo home cache
@@ -164,7 +173,7 @@ jobs:
            ~/.cargo/registry/index/
            ~/.cargo/registry/cache/
            ~/.cargo/git/db/
-          key: cargo-home-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-${{ hashFiles('**/Cargo.lock') }}-${{ hashFiles('codex-rs/rust-toolchain.toml') }}
+          key: cargo-home-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-${{ steps.lockhash.outputs.hash }}-${{ steps.lockhash.outputs.toolchain_hash }}
          restore-keys: |
            cargo-home-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-

@@ -201,9 +210,9 @@ jobs:
        uses: actions/cache/restore@v4
        with:
          path: ${{ github.workspace }}/.sccache/
-          key: sccache-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-${{ hashFiles('**/Cargo.lock') }}-${{ github.run_id }}
+          key: sccache-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-${{ steps.lockhash.outputs.hash }}-${{ github.run_id }}
          restore-keys: |
-            sccache-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-${{ hashFiles('**/Cargo.lock') }}-
+            sccache-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-${{ steps.lockhash.outputs.hash }}-
            sccache-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-

      - if: ${{ matrix.target == 'x86_64-unknown-linux-musl' || matrix.target == 'aarch64-unknown-linux-musl'}}
@@ -278,7 +287,7 @@ jobs:
            ~/.cargo/registry/index/
            ~/.cargo/registry/cache/
            ~/.cargo/git/db/
-          key: cargo-home-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-${{ hashFiles('**/Cargo.lock') }}-${{ hashFiles('codex-rs/rust-toolchain.toml') }}
+          key: cargo-home-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-${{ steps.lockhash.outputs.hash }}-${{ steps.lockhash.outputs.toolchain_hash }}

      - name: Save sccache cache (fallback)
        if: always() && !cancelled() && env.USE_SCCACHE == 'true' && env.SCCACHE_GHA_ENABLED != 'true'
@@ -286,7 +295,7 @@ jobs:
        uses: actions/cache/save@v4
        with:
          path: ${{ github.workspace }}/.sccache/
-          key: sccache-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-${{ hashFiles('**/Cargo.lock') }}-${{ github.run_id }}
+          key: sccache-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-${{ steps.lockhash.outputs.hash }}-${{ github.run_id }}

      - name: sccache stats
        if: always() && env.USE_SCCACHE == 'true'
@@ -359,11 +368,20 @@ jobs:
            profile: dev

    steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
      - uses: dtolnay/rust-toolchain@1.90
        with:
          targets: ${{ matrix.target }}

+      - name: Compute lockfile hash
+        id: lockhash
+        working-directory: codex-rs
+        shell: bash
+        run: |
+          set -euo pipefail
+          echo "hash=$(sha256sum Cargo.lock | cut -d' ' -f1)" >> "$GITHUB_OUTPUT"
+          echo "toolchain_hash=$(sha256sum rust-toolchain.toml | cut -d' ' -f1)" >> "$GITHUB_OUTPUT"
+
      - name: Restore cargo home cache
        id: cache_cargo_home_restore
        uses: actions/cache/restore@v4
@@ -373,7 +391,7 @@ jobs:
            ~/.cargo/registry/index/
            ~/.cargo/registry/cache/
            ~/.cargo/git/db/
-          key: cargo-home-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-${{ hashFiles('**/Cargo.lock') }}-${{ hashFiles('codex-rs/rust-toolchain.toml') }}
+          key: cargo-home-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-${{ steps.lockhash.outputs.hash }}-${{ steps.lockhash.outputs.toolchain_hash }}
          restore-keys: |
            cargo-home-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-

@@ -409,9 +427,9 @@ jobs:
        uses: actions/cache/restore@v4
        with:
          path: ${{ github.workspace }}/.sccache/
-          key: sccache-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-${{ hashFiles('**/Cargo.lock') }}-${{ github.run_id }}
+          key: sccache-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-${{ steps.lockhash.outputs.hash }}-${{ github.run_id }}
          restore-keys: |
-            sccache-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-${{ hashFiles('**/Cargo.lock') }}-
+            sccache-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-${{ steps.lockhash.outputs.hash }}-
            sccache-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-

      - uses: taiki-e/install-action@44c6d64aa62cd779e873306675c7a58e86d6d532 # v2
@@ -436,7 +454,7 @@ jobs:
            ~/.cargo/registry/index/
            ~/.cargo/registry/cache/
            ~/.cargo/git/db/
-          key: cargo-home-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-${{ hashFiles('**/Cargo.lock') }}-${{ hashFiles('codex-rs/rust-toolchain.toml') }}
+          key: cargo-home-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-${{ steps.lockhash.outputs.hash }}-${{ steps.lockhash.outputs.toolchain_hash }}

      - name: Save sccache cache (fallback)
        if: always() && !cancelled() && env.USE_SCCACHE == 'true' && env.SCCACHE_GHA_ENABLED != 'true'
@@ -444,7 +462,7 @@ jobs:
        uses: actions/cache/save@v4
        with:
          path: ${{ github.workspace }}/.sccache/
-          key: sccache-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-${{ hashFiles('**/Cargo.lock') }}-${{ github.run_id }}
+          key: sccache-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-${{ steps.lockhash.outputs.hash }}-${{ github.run_id }}

      - name: sccache stats
        if: always() && env.USE_SCCACHE == 'true'
--- a/.github/workflows/rust-release.yml
+++ b/.github/workflows/rust-release.yml
@@ -19,7 +19,7 @@ jobs:
  tag-check:
    runs-on: ubuntu-latest
    steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6

      - name: Validate tag matches Cargo.toml version
        shell: bash
@@ -76,7 +76,7 @@ jobs:
            target: aarch64-pc-windows-msvc

    steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
      - uses: dtolnay/rust-toolchain@1.90
        with:
          targets: ${{ matrix.target }}
@@ -377,8 +377,7 @@ jobs:
    uses: ./.github/workflows/shell-tool-mcp.yml
    with:
      release-tag: ${{ github.ref_name }}
-      # We are not ready to publish yet.
-      publish: false
+      publish: true
    secrets: inherit

  release:
@@ -398,7 +397,7 @@ jobs:

    steps:
      - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6

      - uses: actions/download-artifact@v4
        with:
--- a/.github/workflows/sdk.yml
+++ b/.github/workflows/sdk.yml
@@ -11,7 +11,7 @@ jobs:
    timeout-minutes: 10
    steps:
      - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6

      - name: Setup pnpm
        uses: pnpm/action-setup@v4
--- a/.github/workflows/shell-tool-mcp-ci.yml
+++ b/.github/workflows/shell-tool-mcp-ci.yml
@@ -22,7 +22,7 @@ jobs:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6

      - name: Setup pnpm
        uses: pnpm/action-setup@v4
--- a/.github/workflows/shell-tool-mcp.yml
+++ b/.github/workflows/shell-tool-mcp.yml
@@ -91,7 +91,7 @@ jobs:
            install_musl: true
    steps:
      - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6

      - uses: dtolnay/rust-toolchain@1.90
        with:
@@ -113,7 +113,7 @@ jobs:
          cp "target/${{ matrix.target }}/release/codex-exec-mcp-server" "$dest/"
          cp "target/${{ matrix.target }}/release/codex-execve-wrapper" "$dest/"

-      - uses: actions/upload-artifact@v4
+      - uses: actions/upload-artifact@v5
        with:
          name: shell-tool-mcp-rust-${{ matrix.target }}
          path: artifacts/**
@@ -138,10 +138,6 @@ jobs:
            target: x86_64-unknown-linux-musl
            variant: ubuntu-22.04
            image: ubuntu:22.04
-          - runner: ubuntu-24.04
-            target: x86_64-unknown-linux-musl
-            variant: ubuntu-20.04
-            image: ubuntu:20.04
          - runner: ubuntu-24.04
            target: x86_64-unknown-linux-musl
            variant: debian-12
@@ -196,7 +192,7 @@ jobs:
          fi

      - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6

      - name: Build patched Bash
        shell: bash
@@ -215,7 +211,7 @@ jobs:
          mkdir -p "$dest"
          cp bash "$dest/bash"

-      - uses: actions/upload-artifact@v4
+      - uses: actions/upload-artifact@v5
        with:
          name: shell-tool-mcp-bash-${{ matrix.target }}-${{ matrix.variant }}
          path: artifacts/**
@@ -236,12 +232,9 @@ jobs:
          - runner: macos-14
            target: aarch64-apple-darwin
            variant: macos-14
-          - runner: macos-13
-            target: x86_64-apple-darwin
-            variant: macos-13
    steps:
      - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6

      - name: Build patched Bash
        shell: bash
@@ -260,7 +253,7 @@ jobs:
          mkdir -p "$dest"
          cp bash "$dest/bash"

-      - uses: actions/upload-artifact@v4
+      - uses: actions/upload-artifact@v5
        with:
          name: shell-tool-mcp-bash-${{ matrix.target }}-${{ matrix.variant }}
          path: artifacts/**
@@ -278,7 +271,7 @@ jobs:
      PACKAGE_VERSION: ${{ needs.metadata.outputs.version }}
    steps:
      - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6

      - name: Setup pnpm
        uses: pnpm/action-setup@v4
@@ -359,7 +352,7 @@ jobs:
          filename=$(PACK_INFO="$pack_info" node -e 'const data = JSON.parse(process.env.PACK_INFO); console.log(data[0].filename);')
          mv "dist/npm/${filename}" "dist/npm/codex-shell-tool-mcp-npm-${PACKAGE_VERSION}.tgz"

-      - uses: actions/upload-artifact@v4
+      - uses: actions/upload-artifact@v5
        with:
          name: codex-shell-tool-mcp-npm
          path: dist/npm/codex-shell-tool-mcp-npm-${{ env.PACKAGE_VERSION }}.tgz
--- a/.gitignore
+++ b/.gitignore
@@ -85,5 +85,3 @@ CHANGELOG.ignore.md
 # nix related
 .direnv
 .envrc
-
-plans/
--- a/README.md
+++ b/README.md
@@ -69,38 +69,9 @@ Codex can access MCP servers. To configure them, refer to the [config docs](./do

 Codex CLI supports a rich set of configuration options, with preferences stored in `~/.codex/config.toml`. For full configuration options, see [Configuration](./docs/config.md).

-### Execpolicy Quickstart
+### Execpolicy

-Codex can enforce your own rules-based execution policy before it runs shell commands.
-
-1. Create a policy directory: `mkdir -p ~/.codex/policy`.
-2. Create one or more `.codexpolicy` files in that folder. Codex automatically loads every `.codexpolicy` file in there on startup.
-3. Write `prefix_rule` entries to describe the commands you want to allow, prompt, or block:
-
-```starlark
-prefix_rule(
-    pattern = ["git", ["push", "fetch"]],
-    decision = "prompt",  # allow | prompt | forbidden
-    match = [["git", "push", "origin", "main"]],  # examples that must match
-    not_match = [["git", "status"]],              # examples that must not match
-)
-```
-
- `pattern` is a list of shell tokens, evaluated from left to right; wrap tokens in a nested list to express alternatives (e.g., match both `push` and `fetch`).
- `decision` sets the severity; Codex picks the strictest decision when multiple rules match (forbidden > prompt > allow).
- `match` and `not_match` act as (optional) unit tests. Codex validates them when it loads your policy, so you get feedback if an example has unexpected behavior.
-
-In this example rule, if Codex wants to run commands with the prefix `git push` or `git fetch`, it will first ask for user approval.
-
-Use the `codex execpolicy check` subcommand to preview decisions before you save a rule (see the [`codex-execpolicy` README](./codex-rs/execpolicy/README.md) for syntax details):
-
-```shell
-codex execpolicy check --policy ~/.codex/policy/default.codexpolicy git push origin main
-```
-
-Pass multiple `--policy` flags to test how several files combine, and use `--pretty` for formatted JSON output. See the [`codex-rs/execpolicy` README](./codex-rs/execpolicy/README.md) for a more detailed walkthrough of the available syntax.
-
-## Note: `execpolicy` commands are still in preview. The API may have breaking changes in the future.
+See the [Execpolicy quickstart](./docs/execpolicy.md) to set up rules that govern what commands Codex can execute.

 ### Docs & FAQ

@@ -114,6 +85,7 @@ Pass multiple `--policy` flags to test how several files combine, and use `--pre
 - [**Configuration**](./docs/config.md)
  - [Example config](./docs/example-config.md)
 - [**Sandbox & approvals**](./docs/sandbox.md)
+- [**Execpolicy quickstart**](./docs/execpolicy.md)
 - [**Authentication**](./docs/authentication.md)
  - [Auth methods](./docs/authentication.md#forcing-a-specific-auth-method-advanced)
  - [Login on a "Headless" machine](./docs/authentication.md#connecting-on-a-headless-machine)
--- a/codex-rs/.cargo/audit.toml
+++ b/codex-rs/.cargo/audit.toml
@@ -0,0 +1,6 @@
+[advisories]
+ignore = [
+    "RUSTSEC-2024-0388", # derivative 2.2.0 via starlark; upstream crate is unmaintained
+    "RUSTSEC-2025-0057", # fxhash 0.2.1 via starlark_map; upstream crate is unmaintained
+    "RUSTSEC-2024-0436", # paste 1.0.15 via starlark/ratatui; upstream crate is unmaintained
+]
--- a/codex-rs/.github/workflows/cargo-audit.yml
+++ b/codex-rs/.github/workflows/cargo-audit.yml
@@ -0,0 +1,26 @@
+name: Cargo audit
+
+on:
+  pull_request:
+  push:
+    branches:
+      - main
+
+permissions:
+  contents: read
+
+jobs:
+  audit:
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: codex-rs
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@stable
+      - name: Install cargo-audit
+        uses: taiki-e/install-action@v2
+        with:
+          tool: cargo-audit
+      - name: Run cargo audit
+        run: cargo audit --deny warnings
--- a/codex-rs/Cargo.lock
+++ b/codex-rs/Cargo.lock
@@ -198,9 +198,9 @@ dependencies = [

 [[package]]
 name = "arboard"
-version = "3.6.0"
+version = "3.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "55f533f8e0af236ffe5eb979b99381df3258853f00ba2e44b6e1955292c75227"
+checksum = "0348a1c054491f4bfe6ab86a7b6ab1e44e45d899005de92f58b3df180b36ddaf"
 dependencies = [
 "clipboard-win",
 "image",
@@ -212,7 +212,7 @@ dependencies = [
 "objc2-foundation",
 "parking_lot",
 "percent-encoding",
- "windows-sys 0.59.0",
+ "windows-sys 0.60.2",
 "wl-clipboard-rs",
 "x11rb",
 ]
@@ -843,6 +843,30 @@ dependencies = [
 "tracing",
 ]

+[[package]]
+name = "codex-api"
+version = "0.0.0"
+dependencies = [
+ "anyhow",
+ "assert_matches",
+ "async-trait",
+ "bytes",
+ "codex-client",
+ "codex-protocol",
+ "eventsource-stream",
+ "futures",
+ "http",
+ "pretty_assertions",
+ "regex-lite",
+ "serde",
+ "serde_json",
+ "thiserror 2.0.17",
+ "tokio",
+ "tokio-test",
+ "tokio-util",
+ "tracing",
+]
+
 [[package]]
 name = "codex-app-server"
 version = "0.0.0"
@@ -870,6 +894,7 @@ dependencies = [
 "serde",
 "serde_json",
 "serial_test",
+ "sha2",
 "shlex",
 "tempfile",
 "tokio",
@@ -1028,6 +1053,24 @@ dependencies = [
 "tracing",
 ]

+[[package]]
+name = "codex-client"
+version = "0.0.0"
+dependencies = [
+ "async-trait",
+ "bytes",
+ "eventsource-stream",
+ "futures",
+ "http",
+ "rand 0.9.2",
+ "reqwest",
+ "serde",
+ "serde_json",
+ "thiserror 2.0.17",
+ "tokio",
+ "tracing",
+]
+
 [[package]]
 name = "codex-cloud-tasks"
 version = "0.0.0"
@@ -1095,13 +1138,14 @@ dependencies = [
 "async-channel",
 "async-trait",
 "base64",
- "bytes",
 "chardetng",
 "chrono",
+ "codex-api",
 "codex-app-server-protocol",
 "codex-apply-patch",
 "codex-arg0",
 "codex-async-utils",
+ "codex-core",
 "codex-execpolicy",
 "codex-file-search",
 "codex-git",
@@ -1126,7 +1170,6 @@ dependencies = [
 "http",
 "image",
 "indexmap 2.12.0",
- "insta",
 "keyring",
 "landlock",
 "libc",
@@ -1144,6 +1187,7 @@ dependencies = [
 "seccompiler",
 "serde",
 "serde_json",
+ "serde_yaml",
 "serial_test",
 "sha1",
 "sha2",
@@ -1239,6 +1283,7 @@ dependencies = [
 "serde_json",
 "shlex",
 "starlark",
+ "tempfile",
 "thiserror 2.0.17",
 ]

@@ -1570,6 +1615,7 @@ dependencies = [
 "textwrap 0.16.2",
 "tokio",
 "tokio-stream",
+ "tokio-util",
 "toml",
 "tracing",
 "tracing-appender",
@@ -1638,7 +1684,7 @@ version = "0.0.0"

 [[package]]
 name = "codex-windows-sandbox"
-version = "0.1.0"
+version = "0.0.0"
 dependencies = [
 "anyhow",
 "codex-protocol",
@@ -1647,6 +1693,7 @@ dependencies = [
 "rand 0.8.5",
 "serde",
 "serde_json",
+ "tempfile",
 "windows-sys 0.52.0",
 ]

@@ -1778,6 +1825,7 @@ version = "0.0.0"
 dependencies = [
 "anyhow",
 "assert_cmd",
+ "base64",
 "codex-core",
 "codex-protocol",
 "notify",
@@ -3249,9 +3297,9 @@ dependencies = [

 [[package]]
 name = "image"
-version = "0.25.8"
+version = "0.25.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "529feb3e6769d234375c4cf1ee2ce713682b8e76538cb13f9fc23e1400a591e7"
+checksum = "e6506c6c10786659413faa717ceebcb8f70731c0a60cbae39795fdf114519c1a"
 dependencies = [
 "bytemuck",
 "byteorder-lite",
@@ -3259,8 +3307,8 @@ dependencies = [
 "num-traits",
 "png",
 "tiff",
- "zune-core",
- "zune-jpeg",
+ "zune-core 0.5.0",
+ "zune-jpeg 0.5.5",
 ]

 [[package]]
@@ -3336,7 +3384,6 @@ checksum = "46fdb647ebde000f43b5b53f773c30cf9b0cb4300453208713fa38b2c70935a0"
 dependencies = [
 "console",
 "once_cell",
- "serde",
 "similar",
 ]

@@ -3589,9 +3636,9 @@ checksum = "bbd2bcb4c963f2ddae06a2efc7e9f3591312473c50c6685e1f298068316e66fe"

 [[package]]
 name = "libc"
-version = "0.2.175"
+version = "0.2.177"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6a82ae493e598baaea5209805c49bbf2ea7de956d50d7da0da1164f9c6d28543"
+checksum = "2874a2af47a2325c2001a6e6fad9b16a53b802102b528163885171cf92b15976"

 [[package]]
 name = "libdbus-sys"
@@ -4421,6 +4468,12 @@ version = "1.0.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "57c0d7b74b563b49d38dae00a0c37d4d6de9b432382b2892f0574ddcae73fd0a"

+[[package]]
+name = "pastey"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "57d6c094ee800037dff99e02cab0eaf3142826586742a270ab3d7a62656bd27a"
+
 [[package]]
 name = "path-absolutize"
 version = "3.1.1"
@@ -4995,9 +5048,9 @@ dependencies = [

 [[package]]
 name = "regex"
-version = "1.11.1"
+version = "1.12.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b544ef1b4eac5dc2db33ea63606ae9ffcfac26c1416a2806ae0bf5f56b201191"
+checksum = "843bc0191f75f3e22651ae5f1e72939ab2f72a4bc30fa80a066bd66edefc24d4"
 dependencies = [
 "aho-corasick",
 "memchr",
@@ -5007,9 +5060,9 @@ dependencies = [

 [[package]]
 name = "regex-automata"
-version = "0.4.9"
+version = "0.4.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "809e8dc61f6de73b46c85f4c96486310fe304c434cfa43669d7b40f711150908"
+checksum = "5276caf25ac86c8d810222b3dbb938e512c55c6831a10f3e6ed1c93b84041f1c"
 dependencies = [
 "aho-corasick",
 "memchr",
@@ -5036,9 +5089,9 @@ checksum = "2b15c43186be67a4fd63bee50d0303afffcef381492ebe2c5d87f324e1b8815c"

 [[package]]
 name = "reqwest"
-version = "0.12.23"
+version = "0.12.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d429f34c8092b2d42c7c93cec323bb4adeb7c67698f70839adec842ec10c7ceb"
+checksum = "9d0946410b9f7b082a427e4ef5c8ff541a88b357bc6c637c40db3a68ac70a36f"
 dependencies = [
 "base64",
 "bytes",
@@ -5099,10 +5152,11 @@ dependencies = [

 [[package]]
 name = "rmcp"
-version = "0.8.5"
+version = "0.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e5947688160b56fb6c827e3c20a72c90392a1d7e9dec74749197aa1780ac42ca"
+checksum = "38b18323edc657390a6ed4d7a9110b0dec2dc3ed128eb2a123edfbafabdbddc5"
 dependencies = [
+ "async-trait",
 "base64",
 "bytes",
 "chrono",
@@ -5111,7 +5165,7 @@ dependencies = [
 "http-body",
 "http-body-util",
 "oauth2",
- "paste",
+ "pastey",
 "pin-project-lite",
 "process-wrap",
 "rand 0.9.2",
@@ -5133,9 +5187,9 @@ dependencies = [

 [[package]]
 name = "rmcp-macros"
-version = "0.8.5"
+version = "0.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "01263441d3f8635c628e33856c468b96ebbce1af2d3699ea712ca71432d4ee7a"
+checksum = "c75d0a62676bf8c8003c4e3c348e2ceb6a7b3e48323681aaf177fdccdac2ce50"
 dependencies = [
 "darling 0.21.3",
 "proc-macro2",
@@ -5694,9 +5748,9 @@ dependencies = [

 [[package]]
 name = "serde_with"
-version = "3.14.0"
+version = "3.16.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f2c45cd61fefa9db6f254525d46e392b852e0e61d9a1fd36e5bd183450a556d5"
+checksum = "4fa237f2807440d238e0364a218270b98f767a00d3dada77b1c53ae88940e2e7"
 dependencies = [
 "base64",
 "chrono",
@@ -5705,8 +5759,7 @@ dependencies = [
 "indexmap 2.12.0",
 "schemars 0.9.0",
 "schemars 1.0.4",
- "serde",
- "serde_derive",
+ "serde_core",
 "serde_json",
 "serde_with_macros",
 "time",
@@ -5714,16 +5767,29 @@ dependencies = [

 [[package]]
 name = "serde_with_macros"
-version = "3.14.0"
+version = "3.16.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "de90945e6565ce0d9a25098082ed4ee4002e047cb59892c318d66821e14bb30f"
+checksum = "52a8e3ca0ca629121f70ab50f95249e5a6f925cc0f6ffe8256c45b728875706c"
 dependencies = [
- "darling 0.20.11",
+ "darling 0.21.3",
 "proc-macro2",
 "quote",
 "syn 2.0.104",
 ]

+[[package]]
+name = "serde_yaml"
+version = "0.9.34+deprecated"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6a8b1a1a2ebf674015cc02edccce75287f1a0130d394307b36743c2f5d504b47"
+dependencies = [
+ "indexmap 2.12.0",
+ "itoa",
+ "ryu",
+ "serde",
+ "unsafe-libyaml",
+]
+
 [[package]]
 name = "serial2"
 version = "0.2.31"
@@ -6367,7 +6433,7 @@ dependencies = [
 "half",
 "quick-error",
 "weezl",
- "zune-jpeg",
+ "zune-jpeg 0.4.19",
 ]

 [[package]]
@@ -6535,6 +6601,7 @@ dependencies = [
 "futures-sink",
 "futures-util",
 "pin-project-lite",
+ "slab",
 "tokio",
 ]

@@ -6555,18 +6622,18 @@ dependencies = [

 [[package]]
 name = "toml_datetime"
-version = "0.7.0"
+version = "0.7.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bade1c3e902f58d73d3f294cd7f20391c1cb2fbcb643b73566bc773971df91e3"
+checksum = "f2cdb639ebbc97961c51720f858597f7f24c4fc295327923af55b74c3c724533"
 dependencies = [
- "serde",
+ "serde_core",
 ]

 [[package]]
 name = "toml_edit"
-version = "0.23.4"
+version = "0.23.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7211ff1b8f0d3adae1663b7da9ffe396eabe1ca25f0b0bee42b0da29a9ddce93"
+checksum = "6485ef6d0d9b5d0ec17244ff7eb05310113c3f316f2d14200d4de56b3cb98f8d"
 dependencies = [
 "indexmap 2.12.0",
 "toml_datetime",
@@ -6577,18 +6644,18 @@ dependencies = [

 [[package]]
 name = "toml_parser"
-version = "1.0.2"
+version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b551886f449aa90d4fe2bdaa9f4a2577ad2dde302c61ecf262d80b116db95c10"
+checksum = "c0cbe268d35bdb4bb5a56a2de88d0ad0eb70af5384a99d648cd4b3d04039800e"
 dependencies = [
 "winnow",
 ]

 [[package]]
 name = "toml_writer"
-version = "1.0.2"
+version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fcc842091f2def52017664b53082ecbbeb5c7731092bad69d2c63050401dfd64"
+checksum = "df8b2b54733674ad286d16267dcfc7a71ed5c776e4ac7aa3c3e2561f7c637bf2"

 [[package]]
 name = "tonic"
@@ -6672,9 +6739,9 @@ checksum = "8df9b6e13f2d32c91b9bd719c00d1958837bc7dec474d94952798cc8e69eeec3"

 [[package]]
 name = "tracing"
-version = "0.1.41"
+version = "0.1.43"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "784e0ac535deb450455cbfa28a6f0df145ea1bb7ae51b821cf5e7927fdcfbdd0"
+checksum = "2d15d90a0b5c19378952d479dc858407149d7bb45a14de0142f6c534b16fc647"
 dependencies = [
 "log",
 "pin-project-lite",
@@ -6696,9 +6763,9 @@ dependencies = [

 [[package]]
 name = "tracing-attributes"
-version = "0.1.30"
+version = "0.1.31"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "81383ab64e72a7a8b8e13130c49e3dab29def6d0c7d76a03087b3cf71c5c6903"
+checksum = "7490cfa5ec963746568740651ac6781f701c9c5ea257c58e057f3ba8cf69e8da"
 dependencies = [
 "proc-macro2",
 "quote",
@@ -6707,9 +6774,9 @@ dependencies = [

 [[package]]
 name = "tracing-core"
-version = "0.1.34"
+version = "0.1.35"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b9d12581f227e93f094d3af2ae690a574abb8a2b9b7a96e7cfe9647b2b617678"
+checksum = "7a04e24fab5c89c6a36eb8558c9656f30d81de51dfa4d3b45f26b21d61fa0a6c"
 dependencies = [
 "once_cell",
 "valuable",
@@ -6938,6 +7005,12 @@ version = "0.2.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ebc1c04c71510c7f702b52b7c350734c9ff1295c464a03335b00bb84fc54f853"

+[[package]]
+name = "unsafe-libyaml"
+version = "0.2.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "673aac59facbab8a9007c7f6108d11f63b603f7cabff99fabf650fea5c32b861"
+
 [[package]]
 name = "untrusted"
 version = "0.9.0"
@@ -7258,9 +7331,9 @@ dependencies = [

 [[package]]
 name = "webbrowser"
-version = "1.0.5"
+version = "1.0.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "aaf4f3c0ba838e82b4e5ccc4157003fb8c324ee24c058470ffb82820becbde98"
+checksum = "00f1243ef785213e3a32fa0396093424a3a6ea566f9948497e5a2309261a4c97"
 dependencies = [
 "core-foundation 0.10.1",
 "jni",
@@ -7753,9 +7826,9 @@ checksum = "271414315aff87387382ec3d271b52d7ae78726f5d44ac98b4f4030c91880486"

 [[package]]
 name = "winnow"
-version = "0.7.12"
+version = "0.7.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f3edebf492c8125044983378ecb5766203ad3b4c2f7a922bd7dd207f6d443e95"
+checksum = "21a0236b59786fed61e2a80582dd500fe61f18b5dca67a4a067d0bc9039339cf"
 dependencies = [
 "memchr",
 ]
@@ -8052,13 +8125,28 @@ version = "0.4.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3f423a2c17029964870cfaabb1f13dfab7d092a62a29a89264f4d36990ca414a"

+[[package]]
+name = "zune-core"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "111f7d9820f05fd715df3144e254d6fc02ee4088b0644c0ffd0efc9e6d9d2773"
+
 [[package]]
 name = "zune-jpeg"
 version = "0.4.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2c9e525af0a6a658e031e95f14b7f889976b74a11ba0eca5a5fc9ac8a1c43a6a"
 dependencies = [
- "zune-core",
+ "zune-core 0.4.12",
+]
+
+[[package]]
+name = "zune-jpeg"
+version = "0.5.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dc6fb7703e32e9a07fb3f757360338b3a567a5054f21b5f52a666752e333d58e"
+dependencies = [
+ "zune-core 0.5.0",
 ]

 [[package]]
--- a/codex-rs/Cargo.toml
+++ b/codex-rs/Cargo.toml
@@ -41,6 +41,8 @@ members = [
    "utils/pty",
    "utils/readiness",
    "utils/string",
+    "codex-client",
+    "codex-api",
 ]
 resolver = "2"

@@ -51,11 +53,13 @@ version = "0.0.0"
 # crates created with `cargo new -w ...` automatically inherit the 2024
 # edition.
 edition = "2024"
+license = "Apache-2.0"

 [workspace.dependencies]
 # Internal
 app_test_support = { path = "app-server/tests/common" }
 codex-ansi-escape = { path = "ansi-escape" }
+codex-api = { path = "codex-api" }
 codex-app-server = { path = "app-server" }
 codex-app-server-protocol = { path = "app-server-protocol" }
 codex-apply-patch = { path = "apply-patch" }
@@ -63,6 +67,7 @@ codex-arg0 = { path = "arg0" }
 codex-async-utils = { path = "async-utils" }
 codex-backend-client = { path = "backend-client" }
 codex-chatgpt = { path = "chatgpt" }
+codex-client = { path = "codex-client" }
 codex-common = { path = "common" }
 codex-core = { path = "core" }
 codex-exec = { path = "exec" }
@@ -108,8 +113,8 @@ async-trait = "0.1.89"
 axum = { version = "0.8", default-features = false }
 base64 = "0.22.1"
 bytes = "1.10.1"
-chrono = "0.4.42"
 chardetng = "0.1.17"
+chrono = "0.4.42"
 clap = "4"
 clap_complete = "4"
 color-eyre = "0.6.3"
@@ -120,9 +125,9 @@ diffy = "0.4.2"
 dirs = "6"
 dotenvy = "0.15.7"
 dunce = "1.0.4"
+encoding_rs = "0.8.35"
 env-flags = "0.1.1"
 env_logger = "0.11.5"
-encoding_rs = "0.8.35"
 escargot = "0.5"
 eventsource-stream = "0.2.3"
 futures = { version = "0.3", default-features = false }
@@ -131,14 +136,14 @@ icu_decimal = "2.1"
 icu_locale_core = "2.1"
 icu_provider = { version = "2.1", features = ["sync"] }
 ignore = "0.4.23"
-image = { version = "^0.25.8", default-features = false }
+image = { version = "^0.25.9", default-features = false }
 indexmap = "2.12.0"
 insta = "1.43.2"
 itertools = "0.14.0"
 keyring = { version = "3.6", default-features = false }
 landlock = "0.4.1"
 lazy_static = "1"
-libc = "0.2.175"
+libc = "0.2.177"
 log = "0.4"
 lru = "0.12.5"
 maplit = "1.0.2"
@@ -164,15 +169,17 @@ pulldown-cmark = "0.10"
 rand = "0.9"
 ratatui = "0.29.0"
 ratatui-macros = "0.6.0"
+regex = "1.12.2"
 regex-lite = "0.1.7"
-regex = "1.11.1"
 reqwest = "0.12"
-rmcp = { version = "0.8.5", default-features = false }
+rmcp = { version = "0.10.0", default-features = false }
 schemars = "0.8.22"
 seccompiler = "0.5.0"
+sentry = "0.34.0"
 serde = "1"
 serde_json = "1"
-serde_with = "3.14"
+serde_yaml = "0.9"
+serde_with = "3.16"
 serial_test = "3.2.0"
 sha1 = "0.10.6"
 sha2 = "0.10"
@@ -195,9 +202,9 @@ tokio-stream = "0.1.17"
 tokio-test = "0.4"
 tokio-util = "0.7.16"
 toml = "0.9.5"
-toml_edit = "0.23.4"
+toml_edit = "0.23.5"
 tonic = "0.13.1"
-tracing = "0.1.41"
+tracing = "0.1.43"
 tracing-appender = "0.2.3"
 tracing-subscriber = "0.3.20"
 tracing-test = "0.2.5"
@@ -261,15 +268,10 @@ unwrap_used = "deny"
 # cargo-shear cannot see the platform-specific openssl-sys usage, so we
 # silence the false positive here instead of deleting a real dependency.
 [workspace.metadata.cargo-shear]
-ignored = [
-    "icu_provider",
-    "openssl-sys",
-    "codex-utils-readiness",
-]
+ignored = ["icu_provider", "openssl-sys", "codex-utils-readiness"]

 [profile.release]
-opt-level = "z"        # or "s" (z is smaller)
-lto = "thin"           # "fat" can be smaller sometimes; test both
+lto = "fat"
 # Because we bundle some of these executables with the TypeScript CLI, we
 # remove everything to make the binary as small as possible.
 strip = "symbols"
--- a/codex-rs/ansi-escape/Cargo.toml
+++ b/codex-rs/ansi-escape/Cargo.toml
@@ -1,7 +1,8 @@
 [package]
-edition = "2024"
 name = "codex-ansi-escape"
-version = { workspace = true }
+version.workspace = true
+edition.workspace = true
+license.workspace = true

 [lib]
 name = "codex_ansi_escape"
--- a/codex-rs/app-server-protocol/Cargo.toml
+++ b/codex-rs/app-server-protocol/Cargo.toml
@@ -1,7 +1,8 @@
 [package]
-edition = "2024"
 name = "codex-app-server-protocol"
-version = { workspace = true }
+version.workspace = true
+edition.workspace = true
+license.workspace = true

 [lib]
 name = "codex_app_server_protocol"
--- a/codex-rs/app-server-protocol/src/protocol/common.rs
+++ b/codex-rs/app-server-protocol/src/protocol/common.rs
@@ -131,7 +131,7 @@ client_request_definitions! {
    },
    ReviewStart => "review/start" {
        params: v2::ReviewStartParams,
-        response: v2::TurnStartResponse,
+        response: v2::ReviewStartResponse,
    },

    ModelList => "model/list" {
@@ -164,6 +164,25 @@ client_request_definitions! {
        response: v2::FeedbackUploadResponse,
    },

+    /// Execute a command (argv vector) under the server's sandbox.
+    OneOffCommandExec => "command/exec" {
+        params: v2::CommandExecParams,
+        response: v2::CommandExecResponse,
+    },
+
+    ConfigRead => "config/read" {
+        params: v2::ConfigReadParams,
+        response: v2::ConfigReadResponse,
+    },
+    ConfigValueWrite => "config/value/write" {
+        params: v2::ConfigValueWriteParams,
+        response: v2::ConfigWriteResponse,
+    },
+    ConfigBatchWrite => "config/batchWrite" {
+        params: v2::ConfigBatchWriteParams,
+        response: v2::ConfigWriteResponse,
+    },
+
    GetAccount => "account/read" {
        params: v2::GetAccountParams,
        response: v2::GetAccountResponse,
@@ -489,18 +508,23 @@ server_notification_definitions! {
    /// NEW NOTIFICATIONS
    Error => "error" (v2::ErrorNotification),
    ThreadStarted => "thread/started" (v2::ThreadStartedNotification),
+    ThreadTokenUsageUpdated => "thread/tokenUsage/updated" (v2::ThreadTokenUsageUpdatedNotification),
    TurnStarted => "turn/started" (v2::TurnStartedNotification),
    TurnCompleted => "turn/completed" (v2::TurnCompletedNotification),
+    TurnDiffUpdated => "turn/diff/updated" (v2::TurnDiffUpdatedNotification),
+    TurnPlanUpdated => "turn/plan/updated" (v2::TurnPlanUpdatedNotification),
    ItemStarted => "item/started" (v2::ItemStartedNotification),
    ItemCompleted => "item/completed" (v2::ItemCompletedNotification),
    AgentMessageDelta => "item/agentMessage/delta" (v2::AgentMessageDeltaNotification),
    CommandExecutionOutputDelta => "item/commandExecution/outputDelta" (v2::CommandExecutionOutputDeltaNotification),
+    FileChangeOutputDelta => "item/fileChange/outputDelta" (v2::FileChangeOutputDeltaNotification),
    McpToolCallProgress => "item/mcpToolCall/progress" (v2::McpToolCallProgressNotification),
    AccountUpdated => "account/updated" (v2::AccountUpdatedNotification),
    AccountRateLimitsUpdated => "account/rateLimits/updated" (v2::AccountRateLimitsUpdatedNotification),
    ReasoningSummaryTextDelta => "item/reasoning/summaryTextDelta" (v2::ReasoningSummaryTextDeltaNotification),
    ReasoningSummaryPartAdded => "item/reasoning/summaryPartAdded" (v2::ReasoningSummaryPartAddedNotification),
    ReasoningTextDelta => "item/reasoning/textDelta" (v2::ReasoningTextDeltaNotification),
+    ContextCompacted => "thread/compacted" (v2::ContextCompactedNotification),

    /// Notifies the user of world-writable directories on Windows, which cannot be protected by the sandbox.
    WindowsWorldWritableWarning => "windows/worldWritableWarning" (v2::WindowsWorldWritableWarningNotification),
--- a/codex-rs/app-server-protocol/src/protocol/mappers.rs
+++ b/codex-rs/app-server-protocol/src/protocol/mappers.rs
@@ -0,0 +1,15 @@
+use crate::protocol::v1;
+use crate::protocol::v2;
+
+impl From<v1::ExecOneOffCommandParams> for v2::CommandExecParams {
+    fn from(value: v1::ExecOneOffCommandParams) -> Self {
+        Self {
+            command: value.command,
+            timeout_ms: value
+                .timeout_ms
+                .map(|timeout| i64::try_from(timeout).unwrap_or(60_000)),
+            cwd: value.cwd,
+            sandbox_policy: value.sandbox_policy.map(std::convert::Into::into),
+        }
+    }
+}
--- a/codex-rs/app-server-protocol/src/protocol/mod.rs
+++ b/codex-rs/app-server-protocol/src/protocol/mod.rs
@@ -2,6 +2,7 @@
 // Exposes protocol pieces used by `lib.rs` via `pub use protocol::common::*;`.

 pub mod common;
+mod mappers;
 pub mod thread_history;
 pub mod v1;
 pub mod v2;
--- a/codex-rs/app-server-protocol/src/protocol/thread_history.rs
+++ b/codex-rs/app-server-protocol/src/protocol/thread_history.rs
@@ -1,5 +1,6 @@
 use crate::protocol::v2::ThreadItem;
 use crate::protocol::v2::Turn;
+use crate::protocol::v2::TurnError;
 use crate::protocol::v2::TurnStatus;
 use crate::protocol::v2::UserInput;
 use codex_protocol::protocol::AgentReasoningEvent;
@@ -142,6 +143,7 @@ impl ThreadHistoryBuilder {
        PendingTurn {
            id: self.next_turn_id(),
            items: Vec::new(),
+            error: None,
            status: TurnStatus::Completed,
        }
    }
@@ -190,6 +192,7 @@ impl ThreadHistoryBuilder {
 struct PendingTurn {
    id: String,
    items: Vec<ThreadItem>,
+    error: Option<TurnError>,
    status: TurnStatus,
 }

@@ -198,6 +201,7 @@ impl From<PendingTurn> for Turn {
        Self {
            id: value.id,
            items: value.items,
+            error: value.error,
            status: value.status,
        }
    }
--- a/codex-rs/app-server-protocol/src/protocol/v2.rs
+++ b/codex-rs/app-server-protocol/src/protocol/v2.rs
@@ -11,11 +11,15 @@ use codex_protocol::items::AgentMessageContent as CoreAgentMessageContent;
 use codex_protocol::items::TurnItem as CoreTurnItem;
 use codex_protocol::models::ResponseItem;
 use codex_protocol::parse_command::ParsedCommand as CoreParsedCommand;
+use codex_protocol::plan_tool::PlanItemArg as CorePlanItemArg;
+use codex_protocol::plan_tool::StepStatus as CorePlanStepStatus;
 use codex_protocol::protocol::CodexErrorInfo as CoreCodexErrorInfo;
 use codex_protocol::protocol::CreditsSnapshot as CoreCreditsSnapshot;
 use codex_protocol::protocol::RateLimitSnapshot as CoreRateLimitSnapshot;
 use codex_protocol::protocol::RateLimitWindow as CoreRateLimitWindow;
 use codex_protocol::protocol::SessionSource as CoreSessionSource;
+use codex_protocol::protocol::TokenUsage as CoreTokenUsage;
+use codex_protocol::protocol::TokenUsageInfo as CoreTokenUsageInfo;
 use codex_protocol::user_input::UserInput as CoreUserInput;
 use mcp_types::ContentBlock as McpContentBlock;
 use schemars::JsonSchema;
@@ -128,6 +132,133 @@ v2_enum_from_core!(
    }
 );

+v2_enum_from_core!(
+    pub enum ReviewDelivery from codex_protocol::protocol::ReviewDelivery {
+        Inline, Detached
+    }
+);
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
+pub enum ConfigLayerName {
+    Mdm,
+    System,
+    SessionFlags,
+    User,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
+pub struct ConfigLayerMetadata {
+    pub name: ConfigLayerName,
+    pub source: String,
+    pub version: String,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
+pub struct ConfigLayer {
+    pub name: ConfigLayerName,
+    pub source: String,
+    pub version: String,
+    pub config: JsonValue,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
+pub enum MergeStrategy {
+    Replace,
+    Upsert,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
+pub enum WriteStatus {
+    Ok,
+    OkOverridden,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
+pub struct OverriddenMetadata {
+    pub message: String,
+    pub overriding_layer: ConfigLayerMetadata,
+    pub effective_value: JsonValue,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
+pub struct ConfigWriteResponse {
+    pub status: WriteStatus,
+    pub version: String,
+    pub overridden_metadata: Option<OverriddenMetadata>,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
+pub enum ConfigWriteErrorCode {
+    ConfigLayerReadonly,
+    ConfigVersionConflict,
+    ConfigValidationError,
+    ConfigPathNotFound,
+    ConfigSchemaUnknownKey,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
+pub struct ConfigReadParams {
+    #[serde(default)]
+    pub include_layers: bool,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
+pub struct ConfigReadResponse {
+    pub config: JsonValue,
+    pub origins: HashMap<String, ConfigLayerMetadata>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub layers: Option<Vec<ConfigLayer>>,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
+pub struct ConfigValueWriteParams {
+    pub file_path: String,
+    pub key_path: String,
+    pub value: JsonValue,
+    pub merge_strategy: MergeStrategy,
+    pub expected_version: Option<String>,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
+pub struct ConfigBatchWriteParams {
+    pub file_path: String,
+    pub edits: Vec<ConfigEdit>,
+    pub expected_version: Option<String>,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
+pub struct ConfigEdit {
+    pub key_path: String,
+    pub value: JsonValue,
+    pub merge_strategy: MergeStrategy,
+}
+
 v2_enum_from_core!(
    pub enum CommandRiskLevel from codex_protocol::approvals::SandboxRiskLevel {
        Low,
@@ -501,6 +632,26 @@ pub struct FeedbackUploadResponse {
    pub thread_id: String,
 }

+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
+pub struct CommandExecParams {
+    pub command: Vec<String>,
+    #[ts(type = "number | null")]
+    pub timeout_ms: Option<i64>,
+    pub cwd: Option<PathBuf>,
+    pub sandbox_policy: Option<SandboxPolicy>,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
+pub struct CommandExecResponse {
+    pub exit_code: i32,
+    pub stdout: String,
+    pub stderr: String,
+}
+
 // === Threads, Turns, and Items ===
 // Thread APIs
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Default, JsonSchema, TS)]
@@ -635,6 +786,7 @@ pub struct Thread {
    /// Model provider used for this thread (for example, 'openai').
    pub model_provider: String,
    /// Unix timestamp (in seconds) when the thread was created.
+    #[ts(type = "number")]
    pub created_at: i64,
    /// [UNSTABLE] Path to the thread on disk.
    pub path: PathBuf,
@@ -659,6 +811,63 @@ pub struct AccountUpdatedNotification {
    pub auth_mode: Option<AuthMode>,
 }

+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
+pub struct ThreadTokenUsageUpdatedNotification {
+    pub thread_id: String,
+    pub turn_id: String,
+    pub token_usage: ThreadTokenUsage,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
+pub struct ThreadTokenUsage {
+    pub total: TokenUsageBreakdown,
+    pub last: TokenUsageBreakdown,
+    #[ts(type = "number | null")]
+    pub model_context_window: Option<i64>,
+}
+
+impl From<CoreTokenUsageInfo> for ThreadTokenUsage {
+    fn from(value: CoreTokenUsageInfo) -> Self {
+        Self {
+            total: value.total_token_usage.into(),
+            last: value.last_token_usage.into(),
+            model_context_window: value.model_context_window,
+        }
+    }
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
+pub struct TokenUsageBreakdown {
+    #[ts(type = "number")]
+    pub total_tokens: i64,
+    #[ts(type = "number")]
+    pub input_tokens: i64,
+    #[ts(type = "number")]
+    pub cached_input_tokens: i64,
+    #[ts(type = "number")]
+    pub output_tokens: i64,
+    #[ts(type = "number")]
+    pub reasoning_output_tokens: i64,
+}
+
+impl From<CoreTokenUsage> for TokenUsageBreakdown {
+    fn from(value: CoreTokenUsage) -> Self {
+        Self {
+            total_tokens: value.total_tokens,
+            input_tokens: value.input_tokens,
+            cached_input_tokens: value.cached_input_tokens,
+            output_tokens: value.output_tokens,
+            reasoning_output_tokens: value.reasoning_output_tokens,
+        }
+    }
+}
+
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
 #[serde(rename_all = "camelCase")]
 #[ts(export_to = "v2/")]
@@ -668,8 +877,9 @@ pub struct Turn {
    /// For all other responses and notifications returning a Turn,
    /// the items field will be an empty list.
    pub items: Vec<ThreadItem>,
-    #[serde(flatten)]
    pub status: TurnStatus,
+    /// Only populated when the Turn's status is failed.
+    pub error: Option<TurnError>,
 }

 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS, Error)]
@@ -686,15 +896,17 @@ pub struct TurnError {
 #[ts(export_to = "v2/")]
 pub struct ErrorNotification {
    pub error: TurnError,
+    pub thread_id: String,
+    pub turn_id: String,
 }

 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
-#[serde(tag = "status", rename_all = "camelCase")]
-#[ts(tag = "status", export_to = "v2/")]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
 pub enum TurnStatus {
    Completed,
    Interrupted,
-    Failed { error: TurnError },
+    Failed,
    InProgress,
 }

@@ -726,9 +938,22 @@ pub struct ReviewStartParams {
    pub thread_id: String,
    pub target: ReviewTarget,

-    /// When true, also append the final review message to the original thread.
+    /// Where to run the review: inline (default) on the current thread or
+    /// detached on a new thread (returned in `reviewThreadId`).
    #[serde(default)]
-    pub append_to_original_thread: bool,
+    pub delivery: Option<ReviewDelivery>,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
+pub struct ReviewStartResponse {
+    pub turn: Turn,
+    /// Identifies the thread where the review runs.
+    ///
+    /// For inline reviews, this is the original thread id.
+    /// For detached reviews, this is the id of the new review thread.
+    pub review_thread_id: String,
 }

 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
@@ -838,6 +1063,8 @@ pub enum ThreadItem {
        command: String,
        /// The command's working directory.
        cwd: PathBuf,
+        /// Identifier for the underlying PTY process (when available).
+        process_id: Option<String>,
        status: CommandExecutionStatus,
        /// A best-effort parsing of the command to understand the action(s) it will perform.
        /// This returns a list of CommandAction objects because a single shell command may
@@ -848,6 +1075,7 @@ pub enum ThreadItem {
        /// The command's exit code.
        exit_code: Option<i32>,
        /// The duration of the command execution in milliseconds.
+        #[ts(type = "number | null")]
        duration_ms: Option<i64>,
    },
    #[serde(rename_all = "camelCase")]
@@ -879,7 +1107,10 @@ pub enum ThreadItem {
    ImageView { id: String, path: String },
    #[serde(rename_all = "camelCase")]
    #[ts(rename_all = "camelCase")]
-    CodeReview { id: String, review: String },
+    EnteredReviewMode { id: String, review: String },
+    #[serde(rename_all = "camelCase")]
+    #[ts(rename_all = "camelCase")]
+    ExitedReviewMode { id: String, review: String },
 }

 impl From<CoreTurnItem> for ThreadItem {
@@ -997,6 +1228,7 @@ pub struct ThreadStartedNotification {
 #[serde(rename_all = "camelCase")]
 #[ts(export_to = "v2/")]
 pub struct TurnStartedNotification {
+    pub thread_id: String,
    pub turn: Turn,
 }

@@ -1013,14 +1245,73 @@ pub struct Usage {
 #[serde(rename_all = "camelCase")]
 #[ts(export_to = "v2/")]
 pub struct TurnCompletedNotification {
+    pub thread_id: String,
    pub turn: Turn,
 }

+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
+/// Notification that the turn-level unified diff has changed.
+/// Contains the latest aggregated diff across all file changes in the turn.
+pub struct TurnDiffUpdatedNotification {
+    pub thread_id: String,
+    pub turn_id: String,
+    pub diff: String,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
+pub struct TurnPlanUpdatedNotification {
+    pub turn_id: String,
+    pub explanation: Option<String>,
+    pub plan: Vec<TurnPlanStep>,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
+pub struct TurnPlanStep {
+    pub step: String,
+    pub status: TurnPlanStepStatus,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, Copy, PartialEq, Eq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
+pub enum TurnPlanStepStatus {
+    Pending,
+    InProgress,
+    Completed,
+}
+
+impl From<CorePlanItemArg> for TurnPlanStep {
+    fn from(value: CorePlanItemArg) -> Self {
+        Self {
+            step: value.step,
+            status: value.status.into(),
+        }
+    }
+}
+
+impl From<CorePlanStepStatus> for TurnPlanStepStatus {
+    fn from(value: CorePlanStepStatus) -> Self {
+        match value {
+            CorePlanStepStatus::Pending => Self::Pending,
+            CorePlanStepStatus::InProgress => Self::InProgress,
+            CorePlanStepStatus::Completed => Self::Completed,
+        }
+    }
+}
+
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
 #[serde(rename_all = "camelCase")]
 #[ts(export_to = "v2/")]
 pub struct ItemStartedNotification {
    pub item: ThreadItem,
+    pub thread_id: String,
+    pub turn_id: String,
 }

 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
@@ -1028,6 +1319,8 @@ pub struct ItemStartedNotification {
 #[ts(export_to = "v2/")]
 pub struct ItemCompletedNotification {
    pub item: ThreadItem,
+    pub thread_id: String,
+    pub turn_id: String,
 }

 // Item-specific progress notifications
@@ -1035,6 +1328,8 @@ pub struct ItemCompletedNotification {
 #[serde(rename_all = "camelCase")]
 #[ts(export_to = "v2/")]
 pub struct AgentMessageDeltaNotification {
+    pub thread_id: String,
+    pub turn_id: String,
    pub item_id: String,
    pub delta: String,
 }
@@ -1043,8 +1338,11 @@ pub struct AgentMessageDeltaNotification {
 #[serde(rename_all = "camelCase")]
 #[ts(export_to = "v2/")]
 pub struct ReasoningSummaryTextDeltaNotification {
+    pub thread_id: String,
+    pub turn_id: String,
    pub item_id: String,
    pub delta: String,
+    #[ts(type = "number")]
    pub summary_index: i64,
 }

@@ -1052,7 +1350,10 @@ pub struct ReasoningSummaryTextDeltaNotification {
 #[serde(rename_all = "camelCase")]
 #[ts(export_to = "v2/")]
 pub struct ReasoningSummaryPartAddedNotification {
+    pub thread_id: String,
+    pub turn_id: String,
    pub item_id: String,
+    #[ts(type = "number")]
    pub summary_index: i64,
 }

@@ -1060,8 +1361,11 @@ pub struct ReasoningSummaryPartAddedNotification {
 #[serde(rename_all = "camelCase")]
 #[ts(export_to = "v2/")]
 pub struct ReasoningTextDeltaNotification {
+    pub thread_id: String,
+    pub turn_id: String,
    pub item_id: String,
    pub delta: String,
+    #[ts(type = "number")]
    pub content_index: i64,
 }

@@ -1069,6 +1373,18 @@ pub struct ReasoningTextDeltaNotification {
 #[serde(rename_all = "camelCase")]
 #[ts(export_to = "v2/")]
 pub struct CommandExecutionOutputDeltaNotification {
+    pub thread_id: String,
+    pub turn_id: String,
+    pub item_id: String,
+    pub delta: String,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
+pub struct FileChangeOutputDeltaNotification {
+    pub thread_id: String,
+    pub turn_id: String,
    pub item_id: String,
    pub delta: String,
 }
@@ -1077,6 +1393,8 @@ pub struct CommandExecutionOutputDeltaNotification {
 #[serde(rename_all = "camelCase")]
 #[ts(export_to = "v2/")]
 pub struct McpToolCallProgressNotification {
+    pub thread_id: String,
+    pub turn_id: String,
    pub item_id: String,
    pub message: String,
 }
@@ -1090,6 +1408,14 @@ pub struct WindowsWorldWritableWarningNotification {
    pub failed_scan: bool,
 }

+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
+pub struct ContextCompactedNotification {
+    pub thread_id: String,
+    pub turn_id: String,
+}
+
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
 #[serde(rename_all = "camelCase")]
 #[ts(export_to = "v2/")]
@@ -1174,7 +1500,9 @@ impl From<CoreRateLimitSnapshot> for RateLimitSnapshot {
 #[ts(export_to = "v2/")]
 pub struct RateLimitWindow {
    pub used_percent: i32,
+    #[ts(type = "number | null")]
    pub window_duration_mins: Option<i64>,
+    #[ts(type = "number | null")]
    pub resets_at: Option<i64>,
 }

--- a/codex-rs/app-server-test-client/Cargo.toml
+++ b/codex-rs/app-server-test-client/Cargo.toml
@@ -1,7 +1,8 @@
 [package]
 name = "codex-app-server-test-client"
-version = { workspace = true }
-edition = "2024"
+version.workspace = true
+edition.workspace = true
+license.workspace = true

 [lints]
 workspace = true
--- a/codex-rs/app-server-test-client/src/main.rs
+++ b/codex-rs/app-server-test-client/src/main.rs
@@ -101,6 +101,15 @@ enum CliCommand {
    /// Start a V2 turn that should not elicit an ExecCommand approval.
    #[command(name = "no-trigger-cmd-approval")]
    NoTriggerCmdApproval,
+    /// Send two sequential V2 turns in the same thread to test follow-up behavior.
+    SendFollowUpV2 {
+        /// Initial user message for the first turn.
+        #[arg()]
+        first_message: String,
+        /// Follow-up user message for the second turn.
+        #[arg()]
+        follow_up_message: String,
+    },
    /// Trigger the ChatGPT login flow and wait for completion.
    TestLogin,
    /// Fetch the current account rate limits from the Codex app-server.
@@ -120,6 +129,10 @@ fn main() -> Result<()> {
            trigger_patch_approval(codex_bin, user_message)
        }
        CliCommand::NoTriggerCmdApproval => no_trigger_cmd_approval(codex_bin),
+        CliCommand::SendFollowUpV2 {
+            first_message,
+            follow_up_message,
+        } => send_follow_up_v2(codex_bin, first_message, follow_up_message),
        CliCommand::TestLogin => test_login(codex_bin),
        CliCommand::GetAccountRateLimits => get_account_rate_limits(codex_bin),
    }
@@ -209,6 +222,44 @@ fn send_message_v2_with_policies(
    Ok(())
 }

+fn send_follow_up_v2(
+    codex_bin: String,
+    first_message: String,
+    follow_up_message: String,
+) -> Result<()> {
+    let mut client = CodexClient::spawn(codex_bin)?;
+
+    let initialize = client.initialize()?;
+    println!("< initialize response: {initialize:?}");
+
+    let thread_response = client.thread_start(ThreadStartParams::default())?;
+    println!("< thread/start response: {thread_response:?}");
+
+    let first_turn_params = TurnStartParams {
+        thread_id: thread_response.thread.id.clone(),
+        input: vec![V2UserInput::Text {
+            text: first_message,
+        }],
+        ..Default::default()
+    };
+    let first_turn_response = client.turn_start(first_turn_params)?;
+    println!("< turn/start response (initial): {first_turn_response:?}");
+    client.stream_turn(&thread_response.thread.id, &first_turn_response.turn.id)?;
+
+    let follow_up_params = TurnStartParams {
+        thread_id: thread_response.thread.id.clone(),
+        input: vec![V2UserInput::Text {
+            text: follow_up_message,
+        }],
+        ..Default::default()
+    };
+    let follow_up_response = client.turn_start(follow_up_params)?;
+    println!("< turn/start response (follow-up): {follow_up_response:?}");
+    client.stream_turn(&thread_response.thread.id, &follow_up_response.turn.id)?;
+
+    Ok(())
+}
+
 fn test_login(codex_bin: String) -> Result<()> {
    let mut client = CodexClient::spawn(codex_bin)?;

@@ -512,7 +563,9 @@ impl CodexClient {
                ServerNotification::TurnCompleted(payload) => {
                    if payload.turn.id == turn_id {
                        println!("\n< turn/completed notification: {:?}", payload.turn.status);
-                        if let TurnStatus::Failed { error } = &payload.turn.status {
+                        if payload.turn.status == TurnStatus::Failed
+                            && let Some(error) = payload.turn.error
+                        {
                            println!("[turn error] {}", error.message);
                        }
                        break;
--- a/codex-rs/app-server/Cargo.toml
+++ b/codex-rs/app-server/Cargo.toml
@@ -1,7 +1,8 @@
 [package]
-edition = "2024"
 name = "codex-app-server"
-version = { workspace = true }
+version.workspace = true
+edition.workspace = true
+license.workspace = true

 [[bin]]
 name = "codex-app-server"
@@ -29,6 +30,9 @@ codex-utils-json-to-toml = { workspace = true }
 chrono = { workspace = true }
 serde = { workspace = true, features = ["derive"] }
 serde_json = { workspace = true }
+sha2 = { workspace = true }
+tempfile = { workspace = true }
+toml = { workspace = true }
 tokio = { workspace = true, features = [
    "io-std",
    "macros",
@@ -50,7 +54,5 @@ mcp-types = { workspace = true }
 os_info = { workspace = true }
 pretty_assertions = { workspace = true }
 serial_test = { workspace = true }
-tempfile = { workspace = true }
-toml = { workspace = true }
 wiremock = { workspace = true }
 shlex = { workspace = true }
--- a/codex-rs/app-server/README.md
+++ b/codex-rs/app-server/README.md
@@ -1,6 +1,6 @@
 # codex-app-server

-`codex app-server` is the interface Codex uses to power rich interfaces such as the [Codex VS Code extension](https://marketplace.visualstudio.com/items?itemName=openai.chatgpt). The message schema is currently unstable, but those who wish to build experimental UIs on top of Codex may find it valuable.
+`codex app-server` is the interface Codex uses to power rich interfaces such as the [Codex VS Code extension](https://marketplace.visualstudio.com/items?itemName=openai.chatgpt).

 ## Table of Contents
 - [Protocol](#protocol)
@@ -65,7 +65,8 @@ The JSON-RPC API exposes dedicated methods for managing Codex conversations. Thr
 - `thread/archive` — move a thread’s rollout file into the archived directory; returns `{}` on success.
 - `turn/start` — add user input to a thread and begin Codex generation; responds with the initial `turn` object and streams `turn/started`, `item/*`, and `turn/completed` notifications.
 - `turn/interrupt` — request cancellation of an in-flight turn by `(thread_id, turn_id)`; success is an empty `{}` response and the turn finishes with `status: "interrupted"`.
- `review/start` — kick off Codex’s automated reviewer for a thread; responds like `turn/start` and emits a `item/completed` notification with a `codeReview` item when results are ready.
+- `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).

 ### 1) Start or resume a thread

@@ -190,49 +191,75 @@ Use `review/start` to run Codex’s reviewer on the currently checked-out projec
 - `{"type":"baseBranch","branch":"main"}` — diff against the provided branch’s upstream (see prompt for the exact `git merge-base`/`git diff` instructions Codex will run).
 - `{"type":"commit","sha":"abc1234","title":"Optional subject"}` — review a specific commit.
 - `{"type":"custom","instructions":"Free-form reviewer instructions"}` — fallback prompt equivalent to the legacy manual review request.
- `appendToOriginalThread` (bool, default `false`) — when `true`, Codex also records a final assistant-style message with the review summary in the original thread. When `false`, only the `codeReview` item is emitted for the review run and no extra message is added to the original thread.
+- `delivery` (`"inline"` or `"detached"`, default `"inline"`) — where the review runs:
+  - `"inline"`: run the review as a new turn on the existing thread. The response’s `reviewThreadId` equals the original `threadId`, and no new `thread/started` notification is emitted.
+  - `"detached"`: fork a new review thread from the parent conversation and run the review there. The response’s `reviewThreadId` is the id of this new review thread, and the server emits a `thread/started` notification for it before streaming review items.

 Example request/response:

 ```json
 { "method": "review/start", "id": 40, "params": {
    "threadId": "thr_123",
-    "appendToOriginalThread": true,
+    "delivery": "inline",
    "target": { "type": "commit", "sha": "1234567deadbeef", "title": "Polish tui colors" }
 } }
-{ "id": 40, "result": { "turn": {
-    "id": "turn_900",
-    "status": "inProgress",
-    "items": [
-        { "type": "userMessage", "id": "turn_900", "content": [ { "type": "text", "text": "Review commit 1234567: Polish tui colors" } ] }
-    ],
-    "error": null
-} } }
+{ "id": 40, "result": {
+    "turn": {
+        "id": "turn_900",
+        "status": "inProgress",
+        "items": [
+            { "type": "userMessage", "id": "turn_900", "content": [ { "type": "text", "text": "Review commit 1234567: Polish tui colors" } ] }
+        ],
+        "error": null
+    },
+    "reviewThreadId": "thr_123"
+} }
 ```

+For a detached review, use `"delivery": "detached"`. The response is the same shape, but `reviewThreadId` will be the id of the new review thread (different from the original `threadId`). The server also emits a `thread/started` notification for that new thread before streaming the review turn.
+
 Codex streams the usual `turn/started` notification followed by an `item/started`
-with the same `codeReview` item id so clients can show progress:
+with an `enteredReviewMode` item so clients can show progress:

 ```json
 { "method": "item/started", "params": { "item": {
-    "type": "codeReview",
+    "type": "enteredReviewMode",
    "id": "turn_900",
    "review": "current changes"
 } } }
 ```

-When the reviewer finishes, the server emits `item/completed` containing the same
-`codeReview` item with the final review text:
+When the reviewer finishes, the server emits `item/started` and `item/completed`
+containing an `exitedReviewMode` item with the final review text:

 ```json
 { "method": "item/completed", "params": { "item": {
-    "type": "codeReview",
+    "type": "exitedReviewMode",
    "id": "turn_900",
    "review": "Looks solid overall...\n\n- Prefer Stylize helpers — app.rs:10-20\n  ..."
 } } }
 ```

-The `review` string is plain text that already bundles the overall explanation plus a bullet list for each structured finding (matching `ThreadItem::CodeReview` in the generated schema). Use this notification to render the reviewer output in your client.
+The `review` string is plain text that already bundles the overall explanation plus a bullet list for each structured finding (matching `ThreadItem::ExitedReviewMode` in the generated schema). Use this notification to render the reviewer output in your client.
+
+### 7) One-off command execution
+
+Run a standalone command (argv vector) in the server’s sandbox without creating a thread or turn:
+
+```json
+{ "method": "command/exec", "id": 32, "params": {
+    "command": ["ls", "-la"],
+    "cwd": "/Users/me/project",                    // optional; defaults to server cwd
+    "sandboxPolicy": { "type": "workspaceWrite" }, // optional; defaults to user config
+    "timeoutMs": 10000                             // optional; ms timeout; defaults to server timeout
+} }
+{ "id": 32, "result": { "exitCode": 0, "stdout": "...", "stderr": "" } }
+```
+
+Notes:
+- Empty `command` arrays are rejected.
+- `sandboxPolicy` accepts the same shape used by `turn/start` (e.g., `dangerFullAccess`, `readOnly`, `workspaceWrite` with flags).
+- When omitted, `timeoutMs` falls back to the server default.

 ## Events (work-in-progress)

@@ -240,10 +267,11 @@ Event notifications are the server-initiated event stream for thread lifecycles,

 ### Turn events

-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` plus token `usage`), and 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`.
+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/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`.

 Today both notifications carry an empty `items` array even when item events were streamed; rely on `item/*` notifications for the canonical item list until this is fixed.

@@ -257,6 +285,7 @@ Today both notifications carry an empty `items` array even when item events were
 - `fileChange` — `{id, changes, status}` describing proposed edits; `changes` list `{path, kind, diff}` and `status` is `inProgress`, `completed`, `failed`, or `declined`.
 - `mcpToolCall` — `{id, server, tool, status, arguments, result?, error?}` describing MCP calls; `status` is `inProgress`, `completed`, or `failed`.
 - `webSearch` — `{id, query}` for a web search request issued by the agent.
+- `compacted` - `{threadId, turnId}` when codex compacts the conversation history. This can happen automatically.

 All items emit two shared lifecycle events:
 - `item/started` — emits the full `item` when a new unit of work begins so the UI can render it immediately; the `item.id` in this payload matches the `itemId` used by deltas.
--- a/codex-rs/app-server/src/bespoke_event_handling.rs
+++ b/codex-rs/app-server/src/bespoke_event_handling.rs
--- a/codex-rs/app-server/src/codex_message_processor.rs
+++ b/codex-rs/app-server/src/codex_message_processor.rs
@@ -21,9 +21,9 @@ use codex_app_server_protocol::CancelLoginAccountParams;
 use codex_app_server_protocol::CancelLoginAccountResponse;
 use codex_app_server_protocol::CancelLoginChatGptResponse;
 use codex_app_server_protocol::ClientRequest;
+use codex_app_server_protocol::CommandExecParams;
 use codex_app_server_protocol::ConversationGitInfo;
 use codex_app_server_protocol::ConversationSummary;
-use codex_app_server_protocol::ExecOneOffCommandParams;
 use codex_app_server_protocol::ExecOneOffCommandResponse;
 use codex_app_server_protocol::FeedbackUploadParams;
 use codex_app_server_protocol::FeedbackUploadResponse;
@@ -61,8 +61,10 @@ use codex_app_server_protocol::RemoveConversationSubscriptionResponse;
 use codex_app_server_protocol::RequestId;
 use codex_app_server_protocol::ResumeConversationParams;
 use codex_app_server_protocol::ResumeConversationResponse;
+use codex_app_server_protocol::ReviewDelivery as ApiReviewDelivery;
 use codex_app_server_protocol::ReviewStartParams;
-use codex_app_server_protocol::ReviewTarget;
+use codex_app_server_protocol::ReviewStartResponse;
+use codex_app_server_protocol::ReviewTarget as ApiReviewTarget;
 use codex_app_server_protocol::SandboxMode;
 use codex_app_server_protocol::SendUserMessageParams;
 use codex_app_server_protocol::SendUserMessageResponse;
@@ -116,12 +118,13 @@ use codex_core::exec::ExecParams;
 use codex_core::exec_env::create_env;
 use codex_core::features::Feature;
 use codex_core::find_conversation_path_by_id_str;
-use codex_core::get_platform_sandbox;
 use codex_core::git_info::git_diff_to_remote;
 use codex_core::parse_cursor;
 use codex_core::protocol::EventMsg;
 use codex_core::protocol::Op;
+use codex_core::protocol::ReviewDelivery as CoreReviewDelivery;
 use codex_core::protocol::ReviewRequest;
+use codex_core::protocol::ReviewTarget as CoreReviewTarget;
 use codex_core::protocol::SessionConfiguredEvent;
 use codex_core::read_head_for_summary;
 use codex_feedback::CodexFeedback;
@@ -253,8 +256,7 @@ impl CodexMessageProcessor {
    }

    fn review_request_from_target(
-        target: ReviewTarget,
-        append_to_original_thread: bool,
+        target: ApiReviewTarget,
    ) -> Result<(ReviewRequest, String), JSONRPCErrorError> {
        fn invalid_request(message: String) -> JSONRPCErrorError {
            JSONRPCErrorError {
@@ -264,77 +266,52 @@ impl CodexMessageProcessor {
            }
        }

-        match target {
-            // TODO(jif) those messages will be extracted in a follow-up PR.
-            ReviewTarget::UncommittedChanges => Ok((
-                ReviewRequest {
-                    prompt: "Review the current code changes (staged, unstaged, and untracked files) and provide prioritized findings.".to_string(),
-                    user_facing_hint: "current changes".to_string(),
-                    append_to_original_thread,
-                },
-                "Review uncommitted changes".to_string(),
-            )),
-            ReviewTarget::BaseBranch { branch } => {
+        let cleaned_target = match target {
+            ApiReviewTarget::UncommittedChanges => ApiReviewTarget::UncommittedChanges,
+            ApiReviewTarget::BaseBranch { branch } => {
                let branch = branch.trim().to_string();
                if branch.is_empty() {
                    return Err(invalid_request("branch must not be empty".to_string()));
                }
-                let prompt = format!("Review the code changes against the base branch '{branch}'. Start by finding the merge diff between the current branch and {branch}'s upstream e.g. (`git merge-base HEAD \"$(git rev-parse --abbrev-ref \"{branch}@{{upstream}}\")\"`), then run `git diff` against that SHA to see what changes we would merge into the {branch} branch. Provide prioritized, actionable findings.");
-                let hint = format!("changes against '{branch}'");
-                let display = format!("Review changes against base branch '{branch}'");
-                Ok((
-                    ReviewRequest {
-                        prompt,
-                        user_facing_hint: hint,
-                        append_to_original_thread,
-                    },
-                    display,
-                ))
+                ApiReviewTarget::BaseBranch { branch }
            }
-            ReviewTarget::Commit { sha, title } => {
+            ApiReviewTarget::Commit { sha, title } => {
                let sha = sha.trim().to_string();
                if sha.is_empty() {
                    return Err(invalid_request("sha must not be empty".to_string()));
                }
-                let brief_title = title
+                let title = title
                    .map(|t| t.trim().to_string())
                    .filter(|t| !t.is_empty());
-                let prompt = if let Some(title) = brief_title.clone() {
-                    format!("Review the code changes introduced by commit {sha} (\"{title}\"). Provide prioritized, actionable findings.")
-                } else {
-                    format!("Review the code changes introduced by commit {sha}. Provide prioritized, actionable findings.")
-                };
-                let short_sha = sha.chars().take(7).collect::<String>();
-                let hint = format!("commit {short_sha}");
-                let display = if let Some(title) = brief_title {
-                    format!("Review commit {short_sha}: {title}")
-                } else {
-                    format!("Review commit {short_sha}")
-                };
-                Ok((
-                    ReviewRequest {
-                        prompt,
-                        user_facing_hint: hint,
-                        append_to_original_thread,
-                    },
-                    display,
-                ))
+                ApiReviewTarget::Commit { sha, title }
            }
-            ReviewTarget::Custom { instructions } => {
+            ApiReviewTarget::Custom { instructions } => {
                let trimmed = instructions.trim().to_string();
                if trimmed.is_empty() {
-                    return Err(invalid_request("instructions must not be empty".to_string()));
+                    return Err(invalid_request(
+                        "instructions must not be empty".to_string(),
+                    ));
+                }
+                ApiReviewTarget::Custom {
+                    instructions: trimmed,
                }
-                Ok((
-                    ReviewRequest {
-                        prompt: trimmed.clone(),
-                        user_facing_hint: trimmed.clone(),
-                        append_to_original_thread,
-                    },
-                    trimmed,
-                ))
            }
-        }
+        };
+
+        let core_target = match cleaned_target {
+            ApiReviewTarget::UncommittedChanges => CoreReviewTarget::UncommittedChanges,
+            ApiReviewTarget::BaseBranch { branch } => CoreReviewTarget::BaseBranch { branch },
+            ApiReviewTarget::Commit { sha, title } => CoreReviewTarget::Commit { sha, title },
+            ApiReviewTarget::Custom { instructions } => CoreReviewTarget::Custom { instructions },
+        };
+
+        let hint = codex_core::review_prompts::user_facing_hint(&core_target);
+        let review_request = ReviewRequest {
+            target: core_target,
+            user_facing_hint: Some(hint.clone()),
+        };
+
+        Ok((review_request, hint))
    }

    pub async fn process_request(&mut self, request: ClientRequest) {
@@ -470,9 +447,17 @@ impl CodexMessageProcessor {
            ClientRequest::FuzzyFileSearch { request_id, params } => {
                self.fuzzy_file_search(request_id, params).await;
            }
-            ClientRequest::ExecOneOffCommand { request_id, params } => {
+            ClientRequest::OneOffCommandExec { request_id, params } => {
                self.exec_one_off_command(request_id, params).await;
            }
+            ClientRequest::ExecOneOffCommand { request_id, params } => {
+                self.exec_one_off_command(request_id, params.into()).await;
+            }
+            ClientRequest::ConfigRead { .. }
+            | ClientRequest::ConfigValueWrite { .. }
+            | ClientRequest::ConfigBatchWrite { .. } => {
+                warn!("Config request reached CodexMessageProcessor unexpectedly");
+            }
            ClientRequest::GetAccountRateLimits {
                request_id,
                params: _,
@@ -1152,7 +1137,7 @@ impl CodexMessageProcessor {
        }
    }

-    async fn exec_one_off_command(&self, request_id: RequestId, params: ExecOneOffCommandParams) {
+    async fn exec_one_off_command(&self, request_id: RequestId, params: CommandExecParams) {
        tracing::debug!("ExecOneOffCommand params: {params:?}");

        if params.command.is_empty() {
@@ -1167,7 +1152,9 @@ impl CodexMessageProcessor {

        let cwd = params.cwd.unwrap_or_else(|| self.config.cwd.clone());
        let env = create_env(&self.config.shell_environment_policy);
-        let timeout_ms = params.timeout_ms;
+        let timeout_ms = params
+            .timeout_ms
+            .and_then(|timeout_ms| u64::try_from(timeout_ms).ok());
        let exec_params = ExecParams {
            command: params.command,
            cwd,
@@ -1180,15 +1167,9 @@ impl CodexMessageProcessor {

        let effective_policy = params
            .sandbox_policy
+            .map(|policy| policy.to_core())
            .unwrap_or_else(|| self.config.sandbox_policy.clone());

-        let sandbox_type = match &effective_policy {
-            codex_core::protocol::SandboxPolicy::DangerFullAccess => {
-                codex_core::exec::SandboxType::None
-            }
-            _ => get_platform_sandbox().unwrap_or(codex_core::exec::SandboxType::None),
-        };
-        tracing::debug!("Sandbox type: {sandbox_type:?}");
        let codex_linux_sandbox_exe = self.config.codex_linux_sandbox_exe.clone();
        let outgoing = self.outgoing.clone();
        let req_id = request_id;
@@ -1197,7 +1178,6 @@ impl CodexMessageProcessor {
        tokio::spawn(async move {
            match codex_core::exec::process_exec_tool_call(
                exec_params,
-                sandbox_type,
                &effective_policy,
                sandbox_cwd.as_path(),
                &codex_linux_sandbox_exe,
@@ -2475,6 +2455,7 @@ impl CodexMessageProcessor {
                let turn = Turn {
                    id: turn_id.clone(),
                    items: vec![],
+                    error: None,
                    status: TurnStatus::InProgress,
                };

@@ -2482,7 +2463,10 @@ impl CodexMessageProcessor {
                self.outgoing.send_response(request_id, response).await;

                // Emit v2 turn/started notification.
-                let notif = TurnStartedNotification { turn };
+                let notif = TurnStartedNotification {
+                    thread_id: params.thread_id,
+                    turn,
+                };
                self.outgoing
                    .send_server_notification(ServerNotification::TurnStarted(notif))
                    .await;
@@ -2498,60 +2482,221 @@ impl CodexMessageProcessor {
        }
    }

-    async fn review_start(&self, request_id: RequestId, params: ReviewStartParams) {
+    fn build_review_turn(turn_id: String, display_text: &str) -> Turn {
+        let items = if display_text.is_empty() {
+            Vec::new()
+        } else {
+            vec![ThreadItem::UserMessage {
+                id: turn_id.clone(),
+                content: vec![V2UserInput::Text {
+                    text: display_text.to_string(),
+                }],
+            }]
+        };
+
+        Turn {
+            id: turn_id,
+            items,
+            error: None,
+            status: TurnStatus::InProgress,
+        }
+    }
+
+    async fn emit_review_started(
+        &self,
+        request_id: &RequestId,
+        turn: Turn,
+        parent_thread_id: String,
+        review_thread_id: String,
+    ) {
+        let response = ReviewStartResponse {
+            turn: turn.clone(),
+            review_thread_id,
+        };
+        self.outgoing
+            .send_response(request_id.clone(), response)
+            .await;
+
+        let notif = TurnStartedNotification {
+            thread_id: parent_thread_id,
+            turn,
+        };
+        self.outgoing
+            .send_server_notification(ServerNotification::TurnStarted(notif))
+            .await;
+    }
+
+    async fn start_inline_review(
+        &self,
+        request_id: &RequestId,
+        parent_conversation: Arc<CodexConversation>,
+        review_request: ReviewRequest,
+        display_text: &str,
+        parent_thread_id: String,
+    ) -> std::result::Result<(), JSONRPCErrorError> {
+        let turn_id = parent_conversation
+            .submit(Op::Review { review_request })
+            .await;
+
+        match turn_id {
+            Ok(turn_id) => {
+                let turn = Self::build_review_turn(turn_id, display_text);
+                self.emit_review_started(
+                    request_id,
+                    turn,
+                    parent_thread_id.clone(),
+                    parent_thread_id,
+                )
+                .await;
+                Ok(())
+            }
+            Err(err) => Err(JSONRPCErrorError {
+                code: INTERNAL_ERROR_CODE,
+                message: format!("failed to start review: {err}"),
+                data: None,
+            }),
+        }
+    }
+
+    async fn start_detached_review(
+        &mut self,
+        request_id: &RequestId,
+        parent_conversation_id: ConversationId,
+        review_request: ReviewRequest,
+        display_text: &str,
+    ) -> std::result::Result<(), JSONRPCErrorError> {
+        let rollout_path = find_conversation_path_by_id_str(
+            &self.config.codex_home,
+            &parent_conversation_id.to_string(),
+        )
+        .await
+        .map_err(|err| JSONRPCErrorError {
+            code: INTERNAL_ERROR_CODE,
+            message: format!("failed to locate conversation id {parent_conversation_id}: {err}"),
+            data: None,
+        })?
+        .ok_or_else(|| JSONRPCErrorError {
+            code: INVALID_REQUEST_ERROR_CODE,
+            message: format!("no rollout found for conversation id {parent_conversation_id}"),
+            data: None,
+        })?;
+
+        let mut config = self.config.as_ref().clone();
+        config.model = self.config.review_model.clone();
+
+        let NewConversation {
+            conversation_id,
+            conversation,
+            session_configured,
+            ..
+        } = self
+            .conversation_manager
+            .fork_conversation(usize::MAX, config, rollout_path)
+            .await
+            .map_err(|err| JSONRPCErrorError {
+                code: INTERNAL_ERROR_CODE,
+                message: format!("error creating detached review conversation: {err}"),
+                data: None,
+            })?;
+
+        if let Err(err) = self
+            .attach_conversation_listener(conversation_id, false, ApiVersion::V2)
+            .await
+        {
+            tracing::warn!(
+                "failed to attach listener for review conversation {}: {}",
+                conversation_id,
+                err.message
+            );
+        }
+
+        let rollout_path = conversation.rollout_path();
+        let fallback_provider = self.config.model_provider_id.as_str();
+        match read_summary_from_rollout(rollout_path.as_path(), fallback_provider).await {
+            Ok(summary) => {
+                let thread = summary_to_thread(summary);
+                let notif = ThreadStartedNotification { thread };
+                self.outgoing
+                    .send_server_notification(ServerNotification::ThreadStarted(notif))
+                    .await;
+            }
+            Err(err) => {
+                tracing::warn!(
+                    "failed to load summary for review conversation {}: {}",
+                    session_configured.session_id,
+                    err
+                );
+            }
+        }
+
+        let turn_id = conversation
+            .submit(Op::Review { review_request })
+            .await
+            .map_err(|err| JSONRPCErrorError {
+                code: INTERNAL_ERROR_CODE,
+                message: format!("failed to start detached review turn: {err}"),
+                data: None,
+            })?;
+
+        let turn = Self::build_review_turn(turn_id, display_text);
+        let review_thread_id = conversation_id.to_string();
+        self.emit_review_started(request_id, turn, review_thread_id.clone(), review_thread_id)
+            .await;
+
+        Ok(())
+    }
+
+    async fn review_start(&mut self, request_id: RequestId, params: ReviewStartParams) {
        let ReviewStartParams {
            thread_id,
            target,
-            append_to_original_thread,
+            delivery,
        } = params;
-        let (_, conversation) = match self.conversation_from_thread_id(&thread_id).await {
-            Ok(v) => v,
-            Err(error) => {
-                self.outgoing.send_error(request_id, error).await;
-                return;
-            }
-        };
-
-        let (review_request, display_text) =
-            match Self::review_request_from_target(target, append_to_original_thread) {
-                Ok(value) => value,
-                Err(err) => {
-                    self.outgoing.send_error(request_id, err).await;
+        let (parent_conversation_id, parent_conversation) =
+            match self.conversation_from_thread_id(&thread_id).await {
+                Ok(v) => v,
+                Err(error) => {
+                    self.outgoing.send_error(request_id, error).await;
                    return;
                }
            };

-        let turn_id = conversation.submit(Op::Review { review_request }).await;
-
-        match turn_id {
-            Ok(turn_id) => {
-                let mut items = Vec::new();
-                if !display_text.is_empty() {
-                    items.push(ThreadItem::UserMessage {
-                        id: turn_id.clone(),
-                        content: vec![V2UserInput::Text { text: display_text }],
-                    });
-                }
-                let turn = Turn {
-                    id: turn_id.clone(),
-                    items,
-                    status: TurnStatus::InProgress,
-                };
-                let response = TurnStartResponse { turn: turn.clone() };
-                self.outgoing.send_response(request_id, response).await;
-
-                let notif = TurnStartedNotification { turn };
-                self.outgoing
-                    .send_server_notification(ServerNotification::TurnStarted(notif))
-                    .await;
-            }
+        let (review_request, display_text) = match Self::review_request_from_target(target) {
+            Ok(value) => value,
            Err(err) => {
-                let error = JSONRPCErrorError {
-                    code: INTERNAL_ERROR_CODE,
-                    message: format!("failed to start review: {err}"),
-                    data: None,
-                };
-                self.outgoing.send_error(request_id, error).await;
+                self.outgoing.send_error(request_id, err).await;
+                return;
+            }
+        };
+
+        let delivery = delivery.unwrap_or(ApiReviewDelivery::Inline).to_core();
+        match delivery {
+            CoreReviewDelivery::Inline => {
+                if let Err(err) = self
+                    .start_inline_review(
+                        &request_id,
+                        parent_conversation,
+                        review_request,
+                        display_text.as_str(),
+                        thread_id.clone(),
+                    )
+                    .await
+                {
+                    self.outgoing.send_error(request_id, err).await;
+                }
+            }
+            CoreReviewDelivery::Detached => {
+                if let Err(err) = self
+                    .start_detached_review(
+                        &request_id,
+                        parent_conversation_id,
+                        review_request,
+                        display_text.as_str(),
+                    )
+                    .await
+                {
+                    self.outgoing.send_error(request_id, err).await;
+                }
            }
        }
    }
@@ -2803,6 +2948,7 @@ impl CodexMessageProcessor {
        } else {
            None
        };
+        let session_source = self.conversation_manager.session_source();

        let upload_result = tokio::task::spawn_blocking(move || {
            let rollout_path_ref = validated_rollout_path.as_deref();
@@ -2811,6 +2957,7 @@ impl CodexMessageProcessor {
                reason.as_deref(),
                include_logs,
                rollout_path_ref,
+                Some(session_source),
            )
        })
        .await;
--- a/codex-rs/app-server/src/config_api.rs
+++ b/codex-rs/app-server/src/config_api.rs
@@ -0,0 +1,974 @@
+use crate::error_code::INTERNAL_ERROR_CODE;
+use crate::error_code::INVALID_REQUEST_ERROR_CODE;
+use anyhow::anyhow;
+use codex_app_server_protocol::ConfigBatchWriteParams;
+use codex_app_server_protocol::ConfigLayer;
+use codex_app_server_protocol::ConfigLayerMetadata;
+use codex_app_server_protocol::ConfigLayerName;
+use codex_app_server_protocol::ConfigReadParams;
+use codex_app_server_protocol::ConfigReadResponse;
+use codex_app_server_protocol::ConfigValueWriteParams;
+use codex_app_server_protocol::ConfigWriteErrorCode;
+use codex_app_server_protocol::ConfigWriteResponse;
+use codex_app_server_protocol::JSONRPCErrorError;
+use codex_app_server_protocol::MergeStrategy;
+use codex_app_server_protocol::OverriddenMetadata;
+use codex_app_server_protocol::WriteStatus;
+use codex_core::config::ConfigToml;
+use codex_core::config_loader::LoadedConfigLayers;
+use codex_core::config_loader::LoaderOverrides;
+use codex_core::config_loader::load_config_layers_with_overrides;
+use codex_core::config_loader::merge_toml_values;
+use serde_json::Value as JsonValue;
+use serde_json::json;
+use sha2::Digest;
+use sha2::Sha256;
+use std::collections::HashMap;
+use std::path::Path;
+use std::path::PathBuf;
+use tempfile::NamedTempFile;
+use tokio::task;
+use toml::Value as TomlValue;
+
+const SESSION_FLAGS_SOURCE: &str = "--config";
+const MDM_SOURCE: &str = "com.openai.codex/config_toml_base64";
+const CONFIG_FILE_NAME: &str = "config.toml";
+
+#[derive(Clone)]
+pub(crate) struct ConfigApi {
+    codex_home: PathBuf,
+    cli_overrides: Vec<(String, TomlValue)>,
+    loader_overrides: LoaderOverrides,
+}
+
+impl ConfigApi {
+    pub(crate) fn new(codex_home: PathBuf, cli_overrides: Vec<(String, TomlValue)>) -> Self {
+        Self {
+            codex_home,
+            cli_overrides,
+            loader_overrides: LoaderOverrides::default(),
+        }
+    }
+
+    #[cfg(test)]
+    fn with_overrides(
+        codex_home: PathBuf,
+        cli_overrides: Vec<(String, TomlValue)>,
+        loader_overrides: LoaderOverrides,
+    ) -> Self {
+        Self {
+            codex_home,
+            cli_overrides,
+            loader_overrides,
+        }
+    }
+
+    pub(crate) async fn read(
+        &self,
+        params: ConfigReadParams,
+    ) -> Result<ConfigReadResponse, JSONRPCErrorError> {
+        let layers = self
+            .load_layers_state()
+            .await
+            .map_err(|err| internal_error("failed to read configuration layers", err))?;
+
+        let effective = layers.effective_config();
+        validate_config(&effective).map_err(|err| internal_error("invalid configuration", err))?;
+
+        let response = ConfigReadResponse {
+            config: to_json_value(&effective),
+            origins: layers.origins(),
+            layers: params.include_layers.then(|| layers.layers_high_to_low()),
+        };
+
+        Ok(response)
+    }
+
+    pub(crate) async fn write_value(
+        &self,
+        params: ConfigValueWriteParams,
+    ) -> Result<ConfigWriteResponse, JSONRPCErrorError> {
+        let edits = vec![(params.key_path, params.value, params.merge_strategy)];
+        self.apply_edits(params.file_path, params.expected_version, edits)
+            .await
+    }
+
+    pub(crate) async fn batch_write(
+        &self,
+        params: ConfigBatchWriteParams,
+    ) -> Result<ConfigWriteResponse, JSONRPCErrorError> {
+        let edits = params
+            .edits
+            .into_iter()
+            .map(|edit| (edit.key_path, edit.value, edit.merge_strategy))
+            .collect();
+
+        self.apply_edits(params.file_path, params.expected_version, edits)
+            .await
+    }
+
+    async fn apply_edits(
+        &self,
+        file_path: String,
+        expected_version: Option<String>,
+        edits: Vec<(String, JsonValue, MergeStrategy)>,
+    ) -> Result<ConfigWriteResponse, JSONRPCErrorError> {
+        let allowed_path = self.codex_home.join(CONFIG_FILE_NAME);
+        if !paths_match(&allowed_path, &file_path) {
+            return Err(config_write_error(
+                ConfigWriteErrorCode::ConfigLayerReadonly,
+                "Only writes to the user config are allowed",
+            ));
+        }
+
+        let layers = self
+            .load_layers_state()
+            .await
+            .map_err(|err| internal_error("failed to load configuration", err))?;
+
+        if let Some(expected) = expected_version.as_deref()
+            && expected != layers.user.version
+        {
+            return Err(config_write_error(
+                ConfigWriteErrorCode::ConfigVersionConflict,
+                "Configuration was modified since last read. Fetch latest version and retry.",
+            ));
+        }
+
+        let mut user_config = layers.user.config.clone();
+        let mut mutated = false;
+        let mut parsed_segments = Vec::new();
+
+        for (key_path, value, strategy) in edits.into_iter() {
+            let segments = parse_key_path(&key_path).map_err(|message| {
+                config_write_error(ConfigWriteErrorCode::ConfigValidationError, message)
+            })?;
+            let parsed_value = parse_value(value).map_err(|message| {
+                config_write_error(ConfigWriteErrorCode::ConfigValidationError, message)
+            })?;
+
+            let changed = apply_merge(&mut user_config, &segments, parsed_value.as_ref(), strategy)
+                .map_err(|err| match err {
+                    MergeError::PathNotFound => config_write_error(
+                        ConfigWriteErrorCode::ConfigPathNotFound,
+                        "Path not found",
+                    ),
+                    MergeError::Validation(message) => {
+                        config_write_error(ConfigWriteErrorCode::ConfigValidationError, message)
+                    }
+                })?;
+
+            mutated |= changed;
+            parsed_segments.push(segments);
+        }
+
+        validate_config(&user_config).map_err(|err| {
+            config_write_error(
+                ConfigWriteErrorCode::ConfigValidationError,
+                format!("Invalid configuration: {err}"),
+            )
+        })?;
+
+        let updated_layers = layers.with_user_config(user_config.clone());
+        let effective = updated_layers.effective_config();
+        validate_config(&effective).map_err(|err| {
+            config_write_error(
+                ConfigWriteErrorCode::ConfigValidationError,
+                format!("Invalid configuration: {err}"),
+            )
+        })?;
+
+        if mutated {
+            self.persist_user_config(&user_config)
+                .await
+                .map_err(|err| internal_error("failed to persist config.toml", err))?;
+        }
+
+        let overridden = first_overridden_edit(&updated_layers, &effective, &parsed_segments);
+        let status = overridden
+            .as_ref()
+            .map(|_| WriteStatus::OkOverridden)
+            .unwrap_or(WriteStatus::Ok);
+
+        Ok(ConfigWriteResponse {
+            status,
+            version: updated_layers.user.version.clone(),
+            overridden_metadata: overridden,
+        })
+    }
+
+    async fn load_layers_state(&self) -> std::io::Result<LayersState> {
+        let LoadedConfigLayers {
+            base,
+            managed_config,
+            managed_preferences,
+        } = load_config_layers_with_overrides(&self.codex_home, self.loader_overrides.clone())
+            .await?;
+
+        let user = LayerState::new(
+            ConfigLayerName::User,
+            self.codex_home.join(CONFIG_FILE_NAME),
+            base,
+        );
+
+        let session_flags = LayerState::new(
+            ConfigLayerName::SessionFlags,
+            PathBuf::from(SESSION_FLAGS_SOURCE),
+            {
+                let mut root = TomlValue::Table(toml::map::Map::new());
+                for (path, value) in self.cli_overrides.iter() {
+                    apply_override(&mut root, path, value.clone());
+                }
+                root
+            },
+        );
+
+        let system = managed_config.map(|cfg| {
+            LayerState::new(
+                ConfigLayerName::System,
+                system_config_path(&self.codex_home),
+                cfg,
+            )
+        });
+
+        let mdm = managed_preferences
+            .map(|cfg| LayerState::new(ConfigLayerName::Mdm, PathBuf::from(MDM_SOURCE), cfg));
+
+        Ok(LayersState {
+            user,
+            session_flags,
+            system,
+            mdm,
+        })
+    }
+
+    async fn persist_user_config(&self, user_config: &TomlValue) -> anyhow::Result<()> {
+        let codex_home = self.codex_home.clone();
+        let serialized = toml::to_string_pretty(user_config)?;
+
+        task::spawn_blocking(move || -> anyhow::Result<()> {
+            std::fs::create_dir_all(&codex_home)?;
+
+            let target = codex_home.join(CONFIG_FILE_NAME);
+            let tmp = NamedTempFile::new_in(&codex_home)?;
+            std::fs::write(tmp.path(), serialized.as_bytes())?;
+            tmp.persist(&target)?;
+            Ok(())
+        })
+        .await
+        .map_err(|err| anyhow!("config persistence task panicked: {err}"))??;
+
+        Ok(())
+    }
+}
+
+fn parse_value(value: JsonValue) -> Result<Option<TomlValue>, String> {
+    if value.is_null() {
+        return Ok(None);
+    }
+
+    serde_json::from_value::<TomlValue>(value)
+        .map(Some)
+        .map_err(|err| format!("invalid value: {err}"))
+}
+
+fn parse_key_path(path: &str) -> Result<Vec<String>, String> {
+    if path.trim().is_empty() {
+        return Err("keyPath must not be empty".to_string());
+    }
+    Ok(path
+        .split('.')
+        .map(std::string::ToString::to_string)
+        .collect())
+}
+
+fn apply_override(target: &mut TomlValue, path: &str, value: TomlValue) {
+    use toml::value::Table;
+
+    let segments: Vec<&str> = path.split('.').collect();
+    let mut current = target;
+
+    for (idx, segment) in segments.iter().enumerate() {
+        let is_last = idx == segments.len() - 1;
+
+        if is_last {
+            match current {
+                TomlValue::Table(table) => {
+                    table.insert(segment.to_string(), value);
+                }
+                _ => {
+                    let mut table = Table::new();
+                    table.insert(segment.to_string(), value);
+                    *current = TomlValue::Table(table);
+                }
+            }
+            return;
+        }
+
+        match current {
+            TomlValue::Table(table) => {
+                current = table
+                    .entry((*segment).to_string())
+                    .or_insert_with(|| TomlValue::Table(Table::new()));
+            }
+            _ => {
+                *current = TomlValue::Table(Table::new());
+                if let TomlValue::Table(tbl) = current {
+                    current = tbl
+                        .entry((*segment).to_string())
+                        .or_insert_with(|| TomlValue::Table(Table::new()));
+                }
+            }
+        }
+    }
+}
+
+#[derive(Debug)]
+enum MergeError {
+    PathNotFound,
+    Validation(String),
+}
+
+fn apply_merge(
+    root: &mut TomlValue,
+    segments: &[String],
+    value: Option<&TomlValue>,
+    strategy: MergeStrategy,
+) -> Result<bool, MergeError> {
+    let Some(value) = value else {
+        return clear_path(root, segments);
+    };
+
+    let Some((last, parents)) = segments.split_last() else {
+        return Err(MergeError::Validation(
+            "keyPath must not be empty".to_string(),
+        ));
+    };
+
+    let mut current = root;
+
+    for segment in parents {
+        match current {
+            TomlValue::Table(table) => {
+                current = table
+                    .entry(segment.clone())
+                    .or_insert_with(|| TomlValue::Table(toml::map::Map::new()));
+            }
+            _ => {
+                *current = TomlValue::Table(toml::map::Map::new());
+                if let TomlValue::Table(table) = current {
+                    current = table
+                        .entry(segment.clone())
+                        .or_insert_with(|| TomlValue::Table(toml::map::Map::new()));
+                }
+            }
+        }
+    }
+
+    let table = current.as_table_mut().ok_or_else(|| {
+        MergeError::Validation("cannot set value on non-table parent".to_string())
+    })?;
+
+    if matches!(strategy, MergeStrategy::Upsert)
+        && let Some(existing) = table.get_mut(last)
+        && matches!(existing, TomlValue::Table(_))
+        && matches!(value, TomlValue::Table(_))
+    {
+        merge_toml_values(existing, value);
+        return Ok(true);
+    }
+
+    let changed = table
+        .get(last)
+        .map(|existing| Some(existing) != Some(value))
+        .unwrap_or(true);
+    table.insert(last.clone(), value.clone());
+    Ok(changed)
+}
+
+fn clear_path(root: &mut TomlValue, segments: &[String]) -> Result<bool, MergeError> {
+    let Some((last, parents)) = segments.split_last() else {
+        return Err(MergeError::Validation(
+            "keyPath must not be empty".to_string(),
+        ));
+    };
+
+    let mut current = root;
+    for segment in parents {
+        match current {
+            TomlValue::Table(table) => {
+                current = table.get_mut(segment).ok_or(MergeError::PathNotFound)?;
+            }
+            _ => return Err(MergeError::PathNotFound),
+        }
+    }
+
+    let Some(parent) = current.as_table_mut() else {
+        return Err(MergeError::PathNotFound);
+    };
+
+    Ok(parent.remove(last).is_some())
+}
+
+#[derive(Clone)]
+struct LayerState {
+    name: ConfigLayerName,
+    source: PathBuf,
+    config: TomlValue,
+    version: String,
+}
+
+impl LayerState {
+    fn new(name: ConfigLayerName, source: PathBuf, config: TomlValue) -> Self {
+        let version = version_for_toml(&config);
+        Self {
+            name,
+            source,
+            config,
+            version,
+        }
+    }
+
+    fn metadata(&self) -> ConfigLayerMetadata {
+        ConfigLayerMetadata {
+            name: self.name.clone(),
+            source: self.source.display().to_string(),
+            version: self.version.clone(),
+        }
+    }
+
+    fn as_layer(&self) -> ConfigLayer {
+        ConfigLayer {
+            name: self.name.clone(),
+            source: self.source.display().to_string(),
+            version: self.version.clone(),
+            config: to_json_value(&self.config),
+        }
+    }
+}
+
+#[derive(Clone)]
+struct LayersState {
+    user: LayerState,
+    session_flags: LayerState,
+    system: Option<LayerState>,
+    mdm: Option<LayerState>,
+}
+
+impl LayersState {
+    fn with_user_config(self, user_config: TomlValue) -> Self {
+        Self {
+            user: LayerState::new(self.user.name, self.user.source, user_config),
+            session_flags: self.session_flags,
+            system: self.system,
+            mdm: self.mdm,
+        }
+    }
+
+    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);
+        }
+        merged
+    }
+
+    fn origins(&self) -> HashMap<String, ConfigLayerMetadata> {
+        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);
+        }
+
+        origins
+    }
+
+    fn layers_high_to_low(&self) -> Vec<ConfigLayer> {
+        let mut layers = Vec::new();
+        if let Some(mdm) = &self.mdm {
+            layers.push(mdm.as_layer());
+        }
+        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
+    }
+}
+
+fn record_origins(
+    value: &TomlValue,
+    meta: &ConfigLayerMetadata,
+    path: &mut Vec<String>,
+    origins: &mut HashMap<String, ConfigLayerMetadata>,
+) {
+    match value {
+        TomlValue::Table(table) => {
+            for (key, val) in table {
+                path.push(key.clone());
+                record_origins(val, meta, path, origins);
+                path.pop();
+            }
+        }
+        TomlValue::Array(items) => {
+            for (idx, item) in items.iter().enumerate() {
+                path.push(idx.to_string());
+                record_origins(item, meta, path, origins);
+                path.pop();
+            }
+        }
+        _ => {
+            if !path.is_empty() {
+                origins.insert(path.join("."), meta.clone());
+            }
+        }
+    }
+}
+
+fn to_json_value(value: &TomlValue) -> JsonValue {
+    serde_json::to_value(value).unwrap_or(JsonValue::Null)
+}
+
+fn validate_config(value: &TomlValue) -> Result<(), toml::de::Error> {
+    let _: ConfigToml = value.clone().try_into()?;
+    Ok(())
+}
+
+fn version_for_toml(value: &TomlValue) -> String {
+    let json = to_json_value(value);
+    let canonical = canonical_json(&json);
+    let serialized = serde_json::to_vec(&canonical).unwrap_or_default();
+    let mut hasher = Sha256::new();
+    hasher.update(serialized);
+    let hash = hasher.finalize();
+    let hex = hash
+        .iter()
+        .map(|byte| format!("{byte:02x}"))
+        .collect::<String>();
+    format!("sha256:{hex}")
+}
+
+fn canonical_json(value: &JsonValue) -> JsonValue {
+    match value {
+        JsonValue::Object(map) => {
+            let mut sorted = serde_json::Map::new();
+            let mut keys = map.keys().cloned().collect::<Vec<_>>();
+            keys.sort();
+            for key in keys {
+                if let Some(val) = map.get(&key) {
+                    sorted.insert(key, canonical_json(val));
+                }
+            }
+            JsonValue::Object(sorted)
+        }
+        JsonValue::Array(items) => JsonValue::Array(items.iter().map(canonical_json).collect()),
+        other => other.clone(),
+    }
+}
+
+fn paths_match(expected: &Path, provided: &str) -> bool {
+    let provided_path = PathBuf::from(provided);
+    if let (Ok(expanded_expected), Ok(expanded_provided)) =
+        (expected.canonicalize(), provided_path.canonicalize())
+    {
+        return expanded_expected == expanded_provided;
+    }
+
+    expected == provided_path
+}
+
+fn value_at_path<'a>(root: &'a TomlValue, segments: &[String]) -> Option<&'a TomlValue> {
+    let mut current = root;
+    for segment in segments {
+        match current {
+            TomlValue::Table(table) => {
+                current = table.get(segment)?;
+            }
+            TomlValue::Array(items) => {
+                let idx: usize = segment.parse().ok()?;
+                current = items.get(idx)?;
+            }
+            _ => return None,
+        }
+    }
+    Some(current)
+}
+
+fn override_message(layer: &ConfigLayerName) -> String {
+    match layer {
+        ConfigLayerName::Mdm => "Overridden by managed policy (mdm)".to_string(),
+        ConfigLayerName::System => "Overridden by managed config (system)".to_string(),
+        ConfigLayerName::SessionFlags => "Overridden by session flags".to_string(),
+        ConfigLayerName::User => "Overridden by user config".to_string(),
+    }
+}
+
+fn compute_override_metadata(
+    layers: &LayersState,
+    effective: &TomlValue,
+    segments: &[String],
+) -> Option<OverriddenMetadata> {
+    let user_value = value_at_path(&layers.user.config, segments);
+    let effective_value = value_at_path(effective, segments);
+
+    if user_value.is_some() && user_value == effective_value {
+        return None;
+    }
+
+    if user_value.is_none() && effective_value.is_none() {
+        return None;
+    }
+
+    let effective_layer = find_effective_layer(layers, segments);
+    let overriding_layer = effective_layer.unwrap_or_else(|| layers.user.metadata());
+    let message = override_message(&overriding_layer.name);
+
+    Some(OverriddenMetadata {
+        message,
+        overriding_layer,
+        effective_value: effective_value
+            .map(to_json_value)
+            .unwrap_or(JsonValue::Null),
+    })
+}
+
+fn first_overridden_edit(
+    layers: &LayersState,
+    effective: &TomlValue,
+    edits: &[Vec<String>],
+) -> Option<OverriddenMetadata> {
+    for segments in edits {
+        if let Some(meta) = compute_override_metadata(layers, effective, segments) {
+            return Some(meta);
+        }
+    }
+    None
+}
+
+fn find_effective_layer(layers: &LayersState, segments: &[String]) -> Option<ConfigLayerMetadata> {
+    let check =
+        |state: &LayerState| value_at_path(&state.config, segments).map(|_| state.metadata());
+
+    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)
+}
+
+fn system_config_path(codex_home: &Path) -> PathBuf {
+    if let Ok(path) = std::env::var("CODEX_MANAGED_CONFIG_PATH") {
+        return PathBuf::from(path);
+    }
+
+    #[cfg(unix)]
+    {
+        let _ = codex_home;
+        PathBuf::from("/etc/codex/managed_config.toml")
+    }
+
+    #[cfg(not(unix))]
+    {
+        codex_home.join("managed_config.toml")
+    }
+}
+
+fn internal_error<E: std::fmt::Display>(context: &str, err: E) -> JSONRPCErrorError {
+    JSONRPCErrorError {
+        code: INTERNAL_ERROR_CODE,
+        message: format!("{context}: {err}"),
+        data: None,
+    }
+}
+
+fn config_write_error(code: ConfigWriteErrorCode, message: impl Into<String>) -> JSONRPCErrorError {
+    JSONRPCErrorError {
+        code: INVALID_REQUEST_ERROR_CODE,
+        message: message.into(),
+        data: Some(json!({
+            "config_write_error_code": code,
+        })),
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use pretty_assertions::assert_eq;
+    use tempfile::tempdir;
+
+    #[tokio::test]
+    async fn read_includes_origins_and_layers() {
+        let tmp = tempdir().expect("tempdir");
+        std::fs::write(tmp.path().join(CONFIG_FILE_NAME), "model = \"user\"").unwrap();
+
+        let managed_path = tmp.path().join("managed_config.toml");
+        std::fs::write(&managed_path, "approval_policy = \"never\"").unwrap();
+
+        let api = ConfigApi::with_overrides(
+            tmp.path().to_path_buf(),
+            vec![],
+            LoaderOverrides {
+                managed_config_path: Some(managed_path),
+                #[cfg(target_os = "macos")]
+                managed_preferences_base64: None,
+            },
+        );
+
+        let response = api
+            .read(ConfigReadParams {
+                include_layers: true,
+            })
+            .await
+            .expect("response");
+
+        assert_eq!(
+            response.config.get("approval_policy"),
+            Some(&json!("never"))
+        );
+
+        assert_eq!(
+            response
+                .origins
+                .get("approval_policy")
+                .expect("origin")
+                .name,
+            ConfigLayerName::System
+        );
+        let layers = response.layers.expect("layers present");
+        assert_eq!(layers.first().unwrap().name, ConfigLayerName::System);
+        assert_eq!(layers.get(1).unwrap().name, ConfigLayerName::SessionFlags);
+        assert_eq!(layers.last().unwrap().name, ConfigLayerName::User);
+    }
+
+    #[tokio::test]
+    async fn write_value_reports_override() {
+        let tmp = tempdir().expect("tempdir");
+        std::fs::write(
+            tmp.path().join(CONFIG_FILE_NAME),
+            "approval_policy = \"on-request\"",
+        )
+        .unwrap();
+
+        let managed_path = tmp.path().join("managed_config.toml");
+        std::fs::write(&managed_path, "approval_policy = \"never\"").unwrap();
+
+        let api = ConfigApi::with_overrides(
+            tmp.path().to_path_buf(),
+            vec![],
+            LoaderOverrides {
+                managed_config_path: Some(managed_path),
+                #[cfg(target_os = "macos")]
+                managed_preferences_base64: None,
+            },
+        );
+
+        let result = api
+            .write_value(ConfigValueWriteParams {
+                file_path: tmp.path().join(CONFIG_FILE_NAME).display().to_string(),
+                key_path: "approval_policy".to_string(),
+                value: json!("never"),
+                merge_strategy: MergeStrategy::Replace,
+                expected_version: None,
+            })
+            .await
+            .expect("result");
+
+        let read_after = api
+            .read(ConfigReadParams {
+                include_layers: true,
+            })
+            .await
+            .expect("read");
+        let config_object = read_after.config.as_object().expect("object");
+        assert_eq!(config_object.get("approval_policy"), Some(&json!("never")));
+        assert_eq!(
+            read_after
+                .origins
+                .get("approval_policy")
+                .expect("origin")
+                .name,
+            ConfigLayerName::System
+        );
+        assert_eq!(result.status, WriteStatus::Ok);
+        assert!(result.overridden_metadata.is_none());
+    }
+
+    #[tokio::test]
+    async fn version_conflict_rejected() {
+        let tmp = tempdir().expect("tempdir");
+        std::fs::write(tmp.path().join(CONFIG_FILE_NAME), "model = \"user\"").unwrap();
+
+        let api = ConfigApi::new(tmp.path().to_path_buf(), vec![]);
+        let error = api
+            .write_value(ConfigValueWriteParams {
+                file_path: tmp.path().join(CONFIG_FILE_NAME).display().to_string(),
+                key_path: "model".to_string(),
+                value: json!("gpt-5"),
+                merge_strategy: MergeStrategy::Replace,
+                expected_version: Some("sha256:bogus".to_string()),
+            })
+            .await
+            .expect_err("should fail");
+
+        assert_eq!(error.code, INVALID_REQUEST_ERROR_CODE);
+        assert_eq!(
+            error
+                .data
+                .as_ref()
+                .and_then(|d| d.get("config_write_error_code"))
+                .and_then(serde_json::Value::as_str),
+            Some("configVersionConflict")
+        );
+    }
+
+    #[tokio::test]
+    async fn invalid_user_value_rejected_even_if_overridden_by_managed() {
+        let tmp = tempdir().expect("tempdir");
+        std::fs::write(tmp.path().join(CONFIG_FILE_NAME), "model = \"user\"").unwrap();
+
+        let managed_path = tmp.path().join("managed_config.toml");
+        std::fs::write(&managed_path, "approval_policy = \"never\"").unwrap();
+
+        let api = ConfigApi::with_overrides(
+            tmp.path().to_path_buf(),
+            vec![],
+            LoaderOverrides {
+                managed_config_path: Some(managed_path),
+                #[cfg(target_os = "macos")]
+                managed_preferences_base64: None,
+            },
+        );
+
+        let error = api
+            .write_value(ConfigValueWriteParams {
+                file_path: tmp.path().join(CONFIG_FILE_NAME).display().to_string(),
+                key_path: "approval_policy".to_string(),
+                value: json!("bogus"),
+                merge_strategy: MergeStrategy::Replace,
+                expected_version: None,
+            })
+            .await
+            .expect_err("should fail validation");
+
+        assert_eq!(error.code, INVALID_REQUEST_ERROR_CODE);
+        assert_eq!(
+            error
+                .data
+                .as_ref()
+                .and_then(|d| d.get("config_write_error_code"))
+                .and_then(serde_json::Value::as_str),
+            Some("configValidationError")
+        );
+
+        let contents =
+            std::fs::read_to_string(tmp.path().join(CONFIG_FILE_NAME)).expect("read config");
+        assert_eq!(contents.trim(), "model = \"user\"");
+    }
+
+    #[tokio::test]
+    async fn read_reports_managed_overrides_user_and_session_flags() {
+        let tmp = tempdir().expect("tempdir");
+        std::fs::write(tmp.path().join(CONFIG_FILE_NAME), "model = \"user\"").unwrap();
+
+        let managed_path = tmp.path().join("managed_config.toml");
+        std::fs::write(&managed_path, "model = \"system\"").unwrap();
+
+        let cli_overrides = vec![(
+            "model".to_string(),
+            TomlValue::String("session".to_string()),
+        )];
+
+        let api = ConfigApi::with_overrides(
+            tmp.path().to_path_buf(),
+            cli_overrides,
+            LoaderOverrides {
+                managed_config_path: Some(managed_path),
+                #[cfg(target_os = "macos")]
+                managed_preferences_base64: None,
+            },
+        );
+
+        let response = api
+            .read(ConfigReadParams {
+                include_layers: true,
+            })
+            .await
+            .expect("response");
+
+        assert_eq!(response.config.get("model"), Some(&json!("system")));
+        assert_eq!(
+            response.origins.get("model").expect("origin").name,
+            ConfigLayerName::System
+        );
+        let layers = response.layers.expect("layers");
+        assert_eq!(layers.first().unwrap().name, ConfigLayerName::System);
+        assert_eq!(layers.get(1).unwrap().name, ConfigLayerName::SessionFlags);
+        assert_eq!(layers.get(2).unwrap().name, ConfigLayerName::User);
+    }
+
+    #[tokio::test]
+    async fn write_value_reports_managed_override() {
+        let tmp = tempdir().expect("tempdir");
+        std::fs::write(tmp.path().join(CONFIG_FILE_NAME), "").unwrap();
+
+        let managed_path = tmp.path().join("managed_config.toml");
+        std::fs::write(&managed_path, "approval_policy = \"never\"").unwrap();
+
+        let api = ConfigApi::with_overrides(
+            tmp.path().to_path_buf(),
+            vec![],
+            LoaderOverrides {
+                managed_config_path: Some(managed_path),
+                #[cfg(target_os = "macos")]
+                managed_preferences_base64: None,
+            },
+        );
+
+        let result = api
+            .write_value(ConfigValueWriteParams {
+                file_path: tmp.path().join(CONFIG_FILE_NAME).display().to_string(),
+                key_path: "approval_policy".to_string(),
+                value: json!("on-request"),
+                merge_strategy: MergeStrategy::Replace,
+                expected_version: None,
+            })
+            .await
+            .expect("result");
+
+        assert_eq!(result.status, WriteStatus::OkOverridden);
+        let overridden = result.overridden_metadata.expect("overridden metadata");
+        assert_eq!(overridden.overriding_layer.name, ConfigLayerName::System);
+        assert_eq!(overridden.effective_value, json!("never"));
+    }
+}
--- a/codex-rs/app-server/src/lib.rs
+++ b/codex-rs/app-server/src/lib.rs
@@ -18,6 +18,7 @@ use tokio::io::AsyncWriteExt;
 use tokio::io::BufReader;
 use tokio::io::{self};
 use tokio::sync::mpsc;
+use toml::Value as TomlValue;
 use tracing::Level;
 use tracing::debug;
 use tracing::error;
@@ -30,6 +31,7 @@ use tracing_subscriber::util::SubscriberInitExt;

 mod bespoke_event_handling;
 mod codex_message_processor;
+mod config_api;
 mod error_code;
 mod fuzzy_file_search;
 mod message_processor;
@@ -80,11 +82,12 @@ pub async fn run_main(
            format!("error parsing -c overrides: {e}"),
        )
    })?;
-    let config = Config::load_with_cli_overrides(cli_kv_overrides, 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(), ConfigOverrides::default())
+            .await
+            .map_err(|e| {
+                std::io::Error::new(ErrorKind::InvalidData, format!("error loading config: {e}"))
+            })?;

    let feedback = CodexFeedback::new();

@@ -121,10 +124,12 @@ pub async fn run_main(
    // Task: process incoming messages.
    let processor_handle = tokio::spawn({
        let outgoing_message_sender = OutgoingMessageSender::new(outgoing_tx);
+        let cli_overrides: Vec<(String, TomlValue)> = cli_kv_overrides.clone();
        let mut processor = MessageProcessor::new(
            outgoing_message_sender,
            codex_linux_sandbox_exe,
            std::sync::Arc::new(config),
+            cli_overrides,
            feedback.clone(),
        );
        async move {
--- a/codex-rs/app-server/src/message_processor.rs
+++ b/codex-rs/app-server/src/message_processor.rs
@@ -1,16 +1,22 @@
 use std::path::PathBuf;
+use std::sync::Arc;

 use crate::codex_message_processor::CodexMessageProcessor;
+use crate::config_api::ConfigApi;
 use crate::error_code::INVALID_REQUEST_ERROR_CODE;
 use crate::outgoing_message::OutgoingMessageSender;
 use codex_app_server_protocol::ClientInfo;
 use codex_app_server_protocol::ClientRequest;
+use codex_app_server_protocol::ConfigBatchWriteParams;
+use codex_app_server_protocol::ConfigReadParams;
+use codex_app_server_protocol::ConfigValueWriteParams;
 use codex_app_server_protocol::InitializeResponse;
 use codex_app_server_protocol::JSONRPCError;
 use codex_app_server_protocol::JSONRPCErrorError;
 use codex_app_server_protocol::JSONRPCNotification;
 use codex_app_server_protocol::JSONRPCRequest;
 use codex_app_server_protocol::JSONRPCResponse;
+use codex_app_server_protocol::RequestId;
 use codex_core::AuthManager;
 use codex_core::ConversationManager;
 use codex_core::config::Config;
@@ -18,11 +24,12 @@ use codex_core::default_client::USER_AGENT_SUFFIX;
 use codex_core::default_client::get_codex_user_agent;
 use codex_feedback::CodexFeedback;
 use codex_protocol::protocol::SessionSource;
-use std::sync::Arc;
+use toml::Value as TomlValue;

 pub(crate) struct MessageProcessor {
    outgoing: Arc<OutgoingMessageSender>,
    codex_message_processor: CodexMessageProcessor,
+    config_api: ConfigApi,
    initialized: bool,
 }

@@ -33,6 +40,7 @@ impl MessageProcessor {
        outgoing: OutgoingMessageSender,
        codex_linux_sandbox_exe: Option<PathBuf>,
        config: Arc<Config>,
+        cli_overrides: Vec<(String, TomlValue)>,
        feedback: CodexFeedback,
    ) -> Self {
        let outgoing = Arc::new(outgoing);
@@ -50,13 +58,15 @@ impl MessageProcessor {
            conversation_manager,
            outgoing.clone(),
            codex_linux_sandbox_exe,
-            config,
+            Arc::clone(&config),
            feedback,
        );
+        let config_api = ConfigApi::new(config.codex_home.clone(), cli_overrides);

        Self {
            outgoing,
            codex_message_processor,
+            config_api,
            initialized: false,
        }
    }
@@ -134,9 +144,20 @@ impl MessageProcessor {
            }
        }

-        self.codex_message_processor
-            .process_request(codex_request)
-            .await;
+        match codex_request {
+            ClientRequest::ConfigRead { request_id, params } => {
+                self.handle_config_read(request_id, params).await;
+            }
+            ClientRequest::ConfigValueWrite { request_id, params } => {
+                self.handle_config_value_write(request_id, params).await;
+            }
+            ClientRequest::ConfigBatchWrite { request_id, params } => {
+                self.handle_config_batch_write(request_id, params).await;
+            }
+            other => {
+                self.codex_message_processor.process_request(other).await;
+            }
+        }
    }

    pub(crate) async fn process_notification(&self, notification: JSONRPCNotification) {
@@ -156,4 +177,33 @@ impl MessageProcessor {
    pub(crate) fn process_error(&mut self, err: JSONRPCError) {
        tracing::error!("<- error: {:?}", err);
    }
+
+    async fn handle_config_read(&self, request_id: RequestId, params: ConfigReadParams) {
+        match self.config_api.read(params).await {
+            Ok(response) => self.outgoing.send_response(request_id, response).await,
+            Err(error) => self.outgoing.send_error(request_id, error).await,
+        }
+    }
+
+    async fn handle_config_value_write(
+        &self,
+        request_id: RequestId,
+        params: ConfigValueWriteParams,
+    ) {
+        match self.config_api.write_value(params).await {
+            Ok(response) => self.outgoing.send_response(request_id, response).await,
+            Err(error) => self.outgoing.send_error(request_id, error).await,
+        }
+    }
+
+    async fn handle_config_batch_write(
+        &self,
+        request_id: RequestId,
+        params: ConfigBatchWriteParams,
+    ) {
+        match self.config_api.batch_write(params).await {
+            Ok(response) => self.outgoing.send_response(request_id, response).await,
+            Err(error) => self.outgoing.send_error(request_id, error).await,
+        }
+    }
 }
--- a/codex-rs/app-server/tests/common/Cargo.toml
+++ b/codex-rs/app-server/tests/common/Cargo.toml
@@ -1,7 +1,8 @@
 [package]
-edition = "2024"
 name = "app_test_support"
-version = { workspace = true }
+version.workspace = true
+edition.workspace = true
+license.workspace = true

 [lib]
 path = "lib.rs"
--- a/codex-rs/app-server/tests/common/lib.rs
+++ b/codex-rs/app-server/tests/common/lib.rs
@@ -15,6 +15,7 @@ pub use mcp_process::McpProcess;
 pub use mock_model_server::create_mock_chat_completions_server;
 pub use mock_model_server::create_mock_chat_completions_server_unchecked;
 pub use responses::create_apply_patch_sse_response;
+pub use responses::create_exec_command_sse_response;
 pub use responses::create_final_assistant_message_sse_response;
 pub use responses::create_shell_command_sse_response;
 pub use rollout::create_fake_rollout;
--- a/codex-rs/app-server/tests/common/mcp_process.rs
+++ b/codex-rs/app-server/tests/common/mcp_process.rs
@@ -18,6 +18,9 @@ use codex_app_server_protocol::CancelLoginAccountParams;
 use codex_app_server_protocol::CancelLoginChatGptParams;
 use codex_app_server_protocol::ClientInfo;
 use codex_app_server_protocol::ClientNotification;
+use codex_app_server_protocol::ConfigBatchWriteParams;
+use codex_app_server_protocol::ConfigReadParams;
+use codex_app_server_protocol::ConfigValueWriteParams;
 use codex_app_server_protocol::FeedbackUploadParams;
 use codex_app_server_protocol::GetAccountParams;
 use codex_app_server_protocol::GetAuthStatusParams;
@@ -401,6 +404,30 @@ impl McpProcess {
        self.send_request("logoutChatGpt", None).await
    }

+    pub async fn send_config_read_request(
+        &mut self,
+        params: ConfigReadParams,
+    ) -> anyhow::Result<i64> {
+        let params = Some(serde_json::to_value(params)?);
+        self.send_request("config/read", params).await
+    }
+
+    pub async fn send_config_value_write_request(
+        &mut self,
+        params: ConfigValueWriteParams,
+    ) -> anyhow::Result<i64> {
+        let params = Some(serde_json::to_value(params)?);
+        self.send_request("config/value/write", params).await
+    }
+
+    pub async fn send_config_batch_write_request(
+        &mut self,
+        params: ConfigBatchWriteParams,
+    ) -> anyhow::Result<i64> {
+        let params = Some(serde_json::to_value(params)?);
+        self.send_request("config/batchWrite", params).await
+    }
+
    /// Send an `account/logout` JSON-RPC request.
    pub async fn send_logout_account_request(&mut self) -> anyhow::Result<i64> {
        self.send_request("account/logout", None).await
--- a/codex-rs/app-server/tests/common/responses.rs
+++ b/codex-rs/app-server/tests/common/responses.rs
@@ -94,3 +94,42 @@ pub fn create_apply_patch_sse_response(
    );
    Ok(sse)
 }
+
+pub fn create_exec_command_sse_response(call_id: &str) -> anyhow::Result<String> {
+    let (cmd, args) = if cfg!(windows) {
+        ("cmd.exe", vec!["/d", "/c", "echo hi"])
+    } else {
+        ("/bin/sh", vec!["-c", "echo hi"])
+    };
+    let command = std::iter::once(cmd.to_string())
+        .chain(args.into_iter().map(str::to_string))
+        .collect::<Vec<_>>();
+    let tool_call_arguments = serde_json::to_string(&json!({
+        "cmd": command.join(" "),
+        "yield_time_ms": 500
+    }))?;
+    let tool_call = json!({
+        "choices": [
+            {
+                "delta": {
+                    "tool_calls": [
+                        {
+                            "id": call_id,
+                            "function": {
+                                "name": "exec_command",
+                                "arguments": tool_call_arguments
+                            }
+                        }
+                    ]
+                },
+                "finish_reason": "tool_calls"
+            }
+        ]
+    });
+
+    let sse = format!(
+        "data: {}\n\ndata: DONE\n\n",
+        serde_json::to_string(&tool_call)?
+    );
+    Ok(sse)
+}
--- a/codex-rs/app-server/tests/suite/send_message.rs
+++ b/codex-rs/app-server/tests/suite/send_message.rs
@@ -272,40 +272,45 @@ async fn read_raw_response_item(
    mcp: &mut McpProcess,
    conversation_id: ConversationId,
 ) -> ResponseItem {
-    let raw_notification: JSONRPCNotification = timeout(
-        DEFAULT_READ_TIMEOUT,
-        mcp.read_stream_until_notification_message("codex/event/raw_response_item"),
-    )
-    .await
-    .expect("codex/event/raw_response_item notification timeout")
-    .expect("codex/event/raw_response_item notification resp");
+    loop {
+        let raw_notification: JSONRPCNotification = timeout(
+            DEFAULT_READ_TIMEOUT,
+            mcp.read_stream_until_notification_message("codex/event/raw_response_item"),
+        )
+        .await
+        .expect("codex/event/raw_response_item notification timeout")
+        .expect("codex/event/raw_response_item notification resp");

-    let serde_json::Value::Object(params) = raw_notification
-        .params
-        .expect("codex/event/raw_response_item should have params")
-    else {
-        panic!("codex/event/raw_response_item should have params");
-    };
+        let serde_json::Value::Object(params) = raw_notification
+            .params
+            .expect("codex/event/raw_response_item should have params")
+        else {
+            panic!("codex/event/raw_response_item should have params");
+        };

-    let conversation_id_value = params
-        .get("conversationId")
-        .and_then(|value| value.as_str())
-        .expect("raw response item should include conversationId");
+        let conversation_id_value = params
+            .get("conversationId")
+            .and_then(|value| value.as_str())
+            .expect("raw response item should include conversationId");

-    assert_eq!(
-        conversation_id_value,
-        conversation_id.to_string(),
-        "raw response item conversation mismatch"
-    );
+        assert_eq!(
+            conversation_id_value,
+            conversation_id.to_string(),
+            "raw response item conversation mismatch"
+        );

-    let msg_value = params
-        .get("msg")
-        .cloned()
-        .expect("raw response item should include msg payload");
+        let msg_value = params
+            .get("msg")
+            .cloned()
+            .expect("raw response item should include msg payload");

-    let event: RawResponseItemEvent =
-        serde_json::from_value(msg_value).expect("deserialize raw response item");
-    event.item
+        // Ghost snapshots are produced concurrently and may arrive before the model reply.
+        let event: RawResponseItemEvent =
+            serde_json::from_value(msg_value).expect("deserialize raw response item");
+        if !matches!(event.item, ResponseItem::GhostSnapshot { .. }) {
+            return event.item;
+        }
+    }
 }

 fn assert_instructions_message(item: &ResponseItem) {
--- a/codex-rs/app-server/tests/suite/v2/config_rpc.rs
+++ b/codex-rs/app-server/tests/suite/v2/config_rpc.rs
@@ -0,0 +1,347 @@
+use anyhow::Result;
+use app_test_support::McpProcess;
+use app_test_support::to_response;
+use codex_app_server_protocol::ConfigBatchWriteParams;
+use codex_app_server_protocol::ConfigEdit;
+use codex_app_server_protocol::ConfigLayerName;
+use codex_app_server_protocol::ConfigReadParams;
+use codex_app_server_protocol::ConfigReadResponse;
+use codex_app_server_protocol::ConfigValueWriteParams;
+use codex_app_server_protocol::ConfigWriteResponse;
+use codex_app_server_protocol::JSONRPCError;
+use codex_app_server_protocol::JSONRPCResponse;
+use codex_app_server_protocol::MergeStrategy;
+use codex_app_server_protocol::RequestId;
+use codex_app_server_protocol::WriteStatus;
+use pretty_assertions::assert_eq;
+use serde_json::json;
+use tempfile::TempDir;
+use tokio::time::timeout;
+
+const DEFAULT_READ_TIMEOUT: std::time::Duration = std::time::Duration::from_secs(10);
+
+fn write_config(codex_home: &TempDir, contents: &str) -> Result<()> {
+    Ok(std::fs::write(
+        codex_home.path().join("config.toml"),
+        contents,
+    )?)
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn config_read_returns_effective_and_layers() -> Result<()> {
+    let codex_home = TempDir::new()?;
+    write_config(
+        &codex_home,
+        r#"
+model = "gpt-user"
+sandbox_mode = "workspace-write"
+"#,
+    )?;
+
+    let mut mcp = McpProcess::new(codex_home.path()).await?;
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize()).await??;
+
+    let request_id = mcp
+        .send_config_read_request(ConfigReadParams {
+            include_layers: true,
+        })
+        .await?;
+    let resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(request_id)),
+    )
+    .await??;
+    let ConfigReadResponse {
+        config,
+        origins,
+        layers,
+    } = to_response(resp)?;
+
+    assert_eq!(config.get("model"), Some(&json!("gpt-user")));
+    assert_eq!(
+        origins.get("model").expect("origin").name,
+        ConfigLayerName::User
+    );
+    let layers = layers.expect("layers present");
+    assert_eq!(layers.len(), 2);
+    assert_eq!(layers[0].name, ConfigLayerName::SessionFlags);
+    assert_eq!(layers[1].name, ConfigLayerName::User);
+
+    Ok(())
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn config_read_includes_system_layer_and_overrides() -> Result<()> {
+    let codex_home = TempDir::new()?;
+    write_config(
+        &codex_home,
+        r#"
+model = "gpt-user"
+approval_policy = "on-request"
+sandbox_mode = "workspace-write"
+
+[sandbox_workspace_write]
+writable_roots = ["/user"]
+network_access = true
+"#,
+    )?;
+
+    let managed_path = codex_home.path().join("managed_config.toml");
+    std::fs::write(
+        &managed_path,
+        r#"
+model = "gpt-system"
+approval_policy = "never"
+
+[sandbox_workspace_write]
+writable_roots = ["/system"]
+"#,
+    )?;
+
+    let managed_path_str = managed_path.display().to_string();
+
+    let mut mcp = McpProcess::new_with_env(
+        codex_home.path(),
+        &[("CODEX_MANAGED_CONFIG_PATH", Some(&managed_path_str))],
+    )
+    .await?;
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize()).await??;
+
+    let request_id = mcp
+        .send_config_read_request(ConfigReadParams {
+            include_layers: true,
+        })
+        .await?;
+    let resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(request_id)),
+    )
+    .await??;
+    let ConfigReadResponse {
+        config,
+        origins,
+        layers,
+    } = to_response(resp)?;
+
+    assert_eq!(config.get("model"), Some(&json!("gpt-system")));
+    assert_eq!(
+        origins.get("model").expect("origin").name,
+        ConfigLayerName::System
+    );
+
+    assert_eq!(config.get("approval_policy"), Some(&json!("never")));
+    assert_eq!(
+        origins.get("approval_policy").expect("origin").name,
+        ConfigLayerName::System
+    );
+
+    assert_eq!(config.get("sandbox_mode"), Some(&json!("workspace-write")));
+    assert_eq!(
+        origins.get("sandbox_mode").expect("origin").name,
+        ConfigLayerName::User
+    );
+
+    assert_eq!(
+        config
+            .get("sandbox_workspace_write")
+            .and_then(|v| v.get("writable_roots")),
+        Some(&json!(["/system"]))
+    );
+    assert_eq!(
+        origins
+            .get("sandbox_workspace_write.writable_roots.0")
+            .expect("origin")
+            .name,
+        ConfigLayerName::System
+    );
+
+    assert_eq!(
+        config
+            .get("sandbox_workspace_write")
+            .and_then(|v| v.get("network_access")),
+        Some(&json!(true))
+    );
+    assert_eq!(
+        origins
+            .get("sandbox_workspace_write.network_access")
+            .expect("origin")
+            .name,
+        ConfigLayerName::User
+    );
+
+    let layers = layers.expect("layers present");
+    assert_eq!(layers.len(), 3);
+    assert_eq!(layers[0].name, ConfigLayerName::System);
+    assert_eq!(layers[1].name, ConfigLayerName::SessionFlags);
+    assert_eq!(layers[2].name, ConfigLayerName::User);
+
+    Ok(())
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn config_value_write_replaces_value() -> Result<()> {
+    let codex_home = TempDir::new()?;
+    write_config(
+        &codex_home,
+        r#"
+model = "gpt-old"
+"#,
+    )?;
+
+    let mut mcp = McpProcess::new(codex_home.path()).await?;
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize()).await??;
+
+    let read_id = mcp
+        .send_config_read_request(ConfigReadParams {
+            include_layers: false,
+        })
+        .await?;
+    let read_resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(read_id)),
+    )
+    .await??;
+    let read: ConfigReadResponse = to_response(read_resp)?;
+    let expected_version = read.origins.get("model").map(|m| m.version.clone());
+
+    let write_id = mcp
+        .send_config_value_write_request(ConfigValueWriteParams {
+            file_path: codex_home.path().join("config.toml").display().to_string(),
+            key_path: "model".to_string(),
+            value: json!("gpt-new"),
+            merge_strategy: MergeStrategy::Replace,
+            expected_version,
+        })
+        .await?;
+    let write_resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(write_id)),
+    )
+    .await??;
+    let write: ConfigWriteResponse = to_response(write_resp)?;
+
+    assert_eq!(write.status, WriteStatus::Ok);
+    assert!(write.overridden_metadata.is_none());
+
+    let verify_id = mcp
+        .send_config_read_request(ConfigReadParams {
+            include_layers: false,
+        })
+        .await?;
+    let verify_resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(verify_id)),
+    )
+    .await??;
+    let verify: ConfigReadResponse = to_response(verify_resp)?;
+    assert_eq!(verify.config.get("model"), Some(&json!("gpt-new")));
+
+    Ok(())
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn config_value_write_rejects_version_conflict() -> Result<()> {
+    let codex_home = TempDir::new()?;
+    write_config(
+        &codex_home,
+        r#"
+model = "gpt-old"
+"#,
+    )?;
+
+    let mut mcp = McpProcess::new(codex_home.path()).await?;
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize()).await??;
+
+    let write_id = mcp
+        .send_config_value_write_request(ConfigValueWriteParams {
+            file_path: codex_home.path().join("config.toml").display().to_string(),
+            key_path: "model".to_string(),
+            value: json!("gpt-new"),
+            merge_strategy: MergeStrategy::Replace,
+            expected_version: Some("sha256:stale".to_string()),
+        })
+        .await?;
+
+    let err: JSONRPCError = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_error_message(RequestId::Integer(write_id)),
+    )
+    .await??;
+    let code = err
+        .error
+        .data
+        .as_ref()
+        .and_then(|d| d.get("config_write_error_code"))
+        .and_then(|v| v.as_str());
+    assert_eq!(code, Some("configVersionConflict"));
+
+    Ok(())
+}
+
+#[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 mut mcp = McpProcess::new(codex_home.path()).await?;
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize()).await??;
+
+    let batch_id = mcp
+        .send_config_batch_write_request(ConfigBatchWriteParams {
+            file_path: codex_home.path().join("config.toml").display().to_string(),
+            edits: vec![
+                ConfigEdit {
+                    key_path: "sandbox_mode".to_string(),
+                    value: json!("workspace-write"),
+                    merge_strategy: MergeStrategy::Replace,
+                },
+                ConfigEdit {
+                    key_path: "sandbox_workspace_write".to_string(),
+                    value: json!({
+                        "writable_roots": ["/tmp"],
+                        "network_access": false
+                    }),
+                    merge_strategy: MergeStrategy::Replace,
+                },
+            ],
+            expected_version: None,
+        })
+        .await?;
+    let batch_resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(batch_id)),
+    )
+    .await??;
+    let batch_write: ConfigWriteResponse = to_response(batch_resp)?;
+    assert_eq!(batch_write.status, WriteStatus::Ok);
+
+    let read_id = mcp
+        .send_config_read_request(ConfigReadParams {
+            include_layers: false,
+        })
+        .await?;
+    let read_resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(read_id)),
+    )
+    .await??;
+    let read: ConfigReadResponse = to_response(read_resp)?;
+    assert_eq!(
+        read.config.get("sandbox_mode"),
+        Some(&json!("workspace-write"))
+    );
+    assert_eq!(
+        read.config
+            .get("sandbox_workspace_write")
+            .and_then(|v| v.get("writable_roots")),
+        Some(&json!(["/tmp"]))
+    );
+    assert_eq!(
+        read.config
+            .get("sandbox_workspace_write")
+            .and_then(|v| v.get("network_access")),
+        Some(&json!(false))
+    );
+
+    Ok(())
+}
--- a/codex-rs/app-server/tests/suite/v2/mod.rs
+++ b/codex-rs/app-server/tests/suite/v2/mod.rs
@@ -1,4 +1,5 @@
 mod account;
+mod config_rpc;
 mod model_list;
 mod rate_limits;
 mod review;
--- a/codex-rs/app-server/tests/suite/v2/review.rs
+++ b/codex-rs/app-server/tests/suite/v2/review.rs
@@ -9,12 +9,13 @@ use codex_app_server_protocol::JSONRPCError;
 use codex_app_server_protocol::JSONRPCNotification;
 use codex_app_server_protocol::JSONRPCResponse;
 use codex_app_server_protocol::RequestId;
+use codex_app_server_protocol::ReviewDelivery;
 use codex_app_server_protocol::ReviewStartParams;
+use codex_app_server_protocol::ReviewStartResponse;
 use codex_app_server_protocol::ReviewTarget;
 use codex_app_server_protocol::ThreadItem;
 use codex_app_server_protocol::ThreadStartParams;
 use codex_app_server_protocol::ThreadStartResponse;
-use codex_app_server_protocol::TurnStartResponse;
 use codex_app_server_protocol::TurnStatus;
 use serde_json::json;
 use tempfile::TempDir;
@@ -59,7 +60,7 @@ async fn review_start_runs_review_turn_and_emits_code_review_item() -> Result<()
    let review_req = mcp
        .send_review_start_request(ReviewStartParams {
            thread_id: thread_id.clone(),
-            append_to_original_thread: true,
+            delivery: Some(ReviewDelivery::Inline),
            target: ReviewTarget::Commit {
                sha: "1234567deadbeef".to_string(),
                title: Some("Tidy UI colors".to_string()),
@@ -71,43 +72,43 @@ async fn review_start_runs_review_turn_and_emits_code_review_item() -> Result<()
        mcp.read_stream_until_response_message(RequestId::Integer(review_req)),
    )
    .await??;
-    let TurnStartResponse { turn } = to_response::<TurnStartResponse>(review_resp)?;
+    let ReviewStartResponse {
+        turn,
+        review_thread_id,
+    } = to_response::<ReviewStartResponse>(review_resp)?;
+    assert_eq!(review_thread_id, thread_id.clone());
    let turn_id = turn.id.clone();
    assert_eq!(turn.status, TurnStatus::InProgress);
-    assert_eq!(turn.items.len(), 1);
-    match &turn.items[0] {
-        ThreadItem::UserMessage { content, .. } => {
-            assert_eq!(content.len(), 1);
-            assert!(matches!(
-                &content[0],
-                codex_app_server_protocol::UserInput::Text { .. }
-            ));
-        }
-        other => panic!("expected user message, got {other:?}"),
-    }

-    let _started: JSONRPCNotification = timeout(
-        DEFAULT_READ_TIMEOUT,
-        mcp.read_stream_until_notification_message("turn/started"),
-    )
-    .await??;
-    let item_started: JSONRPCNotification = timeout(
-        DEFAULT_READ_TIMEOUT,
-        mcp.read_stream_until_notification_message("item/started"),
-    )
-    .await??;
-    let started: ItemStartedNotification =
-        serde_json::from_value(item_started.params.expect("params must be present"))?;
-    match started.item {
-        ThreadItem::CodeReview { id, review } => {
-            assert_eq!(id, turn_id);
-            assert_eq!(review, "commit 1234567");
+    // Confirm we see the EnteredReviewMode marker on the main thread.
+    let mut saw_entered_review_mode = false;
+    for _ in 0..10 {
+        let item_started: JSONRPCNotification = timeout(
+            DEFAULT_READ_TIMEOUT,
+            mcp.read_stream_until_notification_message("item/started"),
+        )
+        .await??;
+        let started: ItemStartedNotification =
+            serde_json::from_value(item_started.params.expect("params must be present"))?;
+        match started.item {
+            ThreadItem::EnteredReviewMode { id, review } => {
+                assert_eq!(id, turn_id);
+                assert_eq!(review, "commit 1234567: Tidy UI colors");
+                saw_entered_review_mode = true;
+                break;
+            }
+            _ => continue,
        }
-        other => panic!("expected code review item, got {other:?}"),
    }
+    assert!(
+        saw_entered_review_mode,
+        "did not observe enteredReviewMode item"
+    );

+    // Confirm we see the ExitedReviewMode marker (with review text)
+    // on the same turn. Ignore any other items the stream surfaces.
    let mut review_body: Option<String> = None;
-    for _ in 0..5 {
+    for _ in 0..10 {
        let review_notif: JSONRPCNotification = timeout(
            DEFAULT_READ_TIMEOUT,
            mcp.read_stream_until_notification_message("item/completed"),
@@ -116,13 +117,12 @@ async fn review_start_runs_review_turn_and_emits_code_review_item() -> Result<()
        let completed: ItemCompletedNotification =
            serde_json::from_value(review_notif.params.expect("params must be present"))?;
        match completed.item {
-            ThreadItem::CodeReview { id, review } => {
+            ThreadItem::ExitedReviewMode { id, review } => {
                assert_eq!(id, turn_id);
                review_body = Some(review);
                break;
            }
-            ThreadItem::UserMessage { .. } => continue,
-            other => panic!("unexpected item/completed payload: {other:?}"),
+            _ => continue,
        }
    }

@@ -146,7 +146,7 @@ async fn review_start_rejects_empty_base_branch() -> Result<()> {
    let request_id = mcp
        .send_review_start_request(ReviewStartParams {
            thread_id,
-            append_to_original_thread: true,
+            delivery: Some(ReviewDelivery::Inline),
            target: ReviewTarget::BaseBranch {
                branch: "   ".to_string(),
            },
@@ -167,6 +167,56 @@ async fn review_start_rejects_empty_base_branch() -> Result<()> {
    Ok(())
 }

+#[tokio::test]
+async fn review_start_with_detached_delivery_returns_new_thread_id() -> Result<()> {
+    let review_payload = json!({
+        "findings": [],
+        "overall_correctness": "ok",
+        "overall_explanation": "detached review",
+        "overall_confidence_score": 0.5
+    })
+    .to_string();
+    let responses = vec![create_final_assistant_message_sse_response(
+        &review_payload,
+    )?];
+    let server = create_mock_chat_completions_server_unchecked(responses).await;
+
+    let codex_home = TempDir::new()?;
+    create_config_toml(codex_home.path(), &server.uri())?;
+
+    let mut mcp = McpProcess::new(codex_home.path()).await?;
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize()).await??;
+
+    let thread_id = start_default_thread(&mut mcp).await?;
+
+    let review_req = mcp
+        .send_review_start_request(ReviewStartParams {
+            thread_id: thread_id.clone(),
+            delivery: Some(ReviewDelivery::Detached),
+            target: ReviewTarget::Custom {
+                instructions: "detached review".to_string(),
+            },
+        })
+        .await?;
+    let review_resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(review_req)),
+    )
+    .await??;
+    let ReviewStartResponse {
+        turn,
+        review_thread_id,
+    } = to_response::<ReviewStartResponse>(review_resp)?;
+
+    assert_eq!(turn.status, TurnStatus::InProgress);
+    assert_ne!(
+        review_thread_id, thread_id,
+        "detached review should run on a different thread"
+    );
+
+    Ok(())
+}
+
 #[tokio::test]
 async fn review_start_rejects_empty_commit_sha() -> Result<()> {
    let server = create_mock_chat_completions_server_unchecked(vec![]).await;
@@ -180,7 +230,7 @@ async fn review_start_rejects_empty_commit_sha() -> Result<()> {
    let request_id = mcp
        .send_review_start_request(ReviewStartParams {
            thread_id,
-            append_to_original_thread: true,
+            delivery: Some(ReviewDelivery::Inline),
            target: ReviewTarget::Commit {
                sha: "\t".to_string(),
                title: None,
@@ -215,7 +265,7 @@ async fn review_start_rejects_empty_custom_instructions() -> Result<()> {
    let request_id = mcp
        .send_review_start_request(ReviewStartParams {
            thread_id,
-            append_to_original_thread: true,
+            delivery: Some(ReviewDelivery::Inline),
            target: ReviewTarget::Custom {
                instructions: "\n\n".to_string(),
            },
--- a/codex-rs/app-server/tests/suite/v2/turn_interrupt.rs
+++ b/codex-rs/app-server/tests/suite/v2/turn_interrupt.rs
@@ -88,10 +88,11 @@ async fn turn_interrupt_aborts_running_turn() -> Result<()> {
    // Give the command a brief moment to start.
    tokio::time::sleep(std::time::Duration::from_secs(1)).await;

+    let thread_id = thread.id.clone();
    // Interrupt the in-progress turn by id (v2 API).
    let interrupt_id = mcp
        .send_turn_interrupt_request(TurnInterruptParams {
-            thread_id: thread.id,
+            thread_id: thread_id.clone(),
            turn_id: turn.id,
        })
        .await?;
@@ -112,6 +113,7 @@ async fn turn_interrupt_aborts_running_turn() -> Result<()> {
            .params
            .expect("turn/completed params must be present"),
    )?;
+    assert_eq!(completed.thread_id, thread_id);
    assert_eq!(completed.turn.status, TurnStatus::Interrupted);

    Ok(())
--- a/codex-rs/app-server/tests/suite/v2/turn_start.rs
+++ b/codex-rs/app-server/tests/suite/v2/turn_start.rs
@@ -1,6 +1,7 @@
 use anyhow::Result;
 use app_test_support::McpProcess;
 use app_test_support::create_apply_patch_sse_response;
+use app_test_support::create_exec_command_sse_response;
 use app_test_support::create_final_assistant_message_sse_response;
 use app_test_support::create_mock_chat_completions_server;
 use app_test_support::create_mock_chat_completions_server_unchecked;
@@ -10,6 +11,7 @@ use app_test_support::to_response;
 use codex_app_server_protocol::ApprovalDecision;
 use codex_app_server_protocol::CommandExecutionRequestApprovalResponse;
 use codex_app_server_protocol::CommandExecutionStatus;
+use codex_app_server_protocol::FileChangeOutputDeltaNotification;
 use codex_app_server_protocol::FileChangeRequestApprovalResponse;
 use codex_app_server_protocol::ItemCompletedNotification;
 use codex_app_server_protocol::ItemStartedNotification;
@@ -95,6 +97,7 @@ async fn turn_start_emits_notifications_and_accepts_model_override() -> Result<(
    .await??;
    let started: TurnStartedNotification =
        serde_json::from_value(notif.params.expect("params must be present"))?;
+    assert_eq!(started.thread_id, thread.id);
    assert_eq!(
        started.turn.status,
        codex_app_server_protocol::TurnStatus::InProgress
@@ -138,6 +141,7 @@ async fn turn_start_emits_notifications_and_accepts_model_override() -> Result<(
            .params
            .expect("turn/completed params must be present"),
    )?;
+    assert_eq!(completed.thread_id, thread.id);
    assert_eq!(completed.turn.status, TurnStatus::Completed);

    Ok(())
@@ -614,10 +618,6 @@ async fn turn_start_updates_sandbox_and_cwd_between_turns_v2() -> Result<()> {
 #[tokio::test]
 async fn turn_start_file_change_approval_v2() -> Result<()> {
    skip_if_no_network!(Ok(()));
-    if cfg!(windows) {
-        // TODO apply_patch approvals are not parsed from powershell commands yet
-        return Ok(());
-    }

    let tmp = TempDir::new()?;
    let codex_home = tmp.path().join("codex_home");
@@ -726,6 +726,26 @@ async fn turn_start_file_change_approval_v2() -> Result<()> {
    )
    .await?;

+    let output_delta_notif = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_notification_message("item/fileChange/outputDelta"),
+    )
+    .await??;
+    let output_delta: FileChangeOutputDeltaNotification = serde_json::from_value(
+        output_delta_notif
+            .params
+            .clone()
+            .expect("item/fileChange/outputDelta params"),
+    )?;
+    assert_eq!(output_delta.thread_id, thread.id);
+    assert_eq!(output_delta.turn_id, turn.id);
+    assert_eq!(output_delta.item_id, "patch-call");
+    assert!(
+        !output_delta.delta.is_empty(),
+        "expected delta to be non-empty, got: {}",
+        output_delta.delta
+    );
+
    let completed_file_change = timeout(DEFAULT_READ_TIMEOUT, async {
        loop {
            let completed_notif = mcp
@@ -764,10 +784,6 @@ async fn turn_start_file_change_approval_v2() -> Result<()> {
 #[tokio::test]
 async fn turn_start_file_change_approval_decline_v2() -> Result<()> {
    skip_if_no_network!(Ok(()));
-    if cfg!(windows) {
-        // TODO apply_patch approvals are not parsed from powershell commands yet
-        return Ok(());
-    }

    let tmp = TempDir::new()?;
    let codex_home = tmp.path().join("codex_home");
@@ -913,6 +929,134 @@ async fn turn_start_file_change_approval_decline_v2() -> Result<()> {
    Ok(())
 }

+#[tokio::test]
+#[cfg_attr(windows, ignore = "process id reporting differs on Windows")]
+async fn command_execution_notifications_include_process_id() -> Result<()> {
+    skip_if_no_network!(Ok(()));
+
+    let responses = vec![
+        create_exec_command_sse_response("uexec-1")?,
+        create_final_assistant_message_sse_response("done")?,
+    ];
+    let server = create_mock_chat_completions_server(responses).await;
+    let codex_home = TempDir::new()?;
+    create_config_toml(codex_home.path(), &server.uri(), "never")?;
+    let config_toml = codex_home.path().join("config.toml");
+    let mut config_contents = std::fs::read_to_string(&config_toml)?;
+    config_contents.push_str(
+        r#"
+[features]
+unified_exec = true
+"#,
+    );
+    std::fs::write(&config_toml, config_contents)?;
+
+    let mut mcp = McpProcess::new(codex_home.path()).await?;
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize()).await??;
+
+    let start_id = mcp
+        .send_thread_start_request(ThreadStartParams {
+            model: Some("mock-model".to_string()),
+            ..Default::default()
+        })
+        .await?;
+    let start_resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(start_id)),
+    )
+    .await??;
+    let ThreadStartResponse { thread, .. } = to_response::<ThreadStartResponse>(start_resp)?;
+
+    let turn_id = mcp
+        .send_turn_start_request(TurnStartParams {
+            thread_id: thread.id.clone(),
+            input: vec![V2UserInput::Text {
+                text: "run a command".to_string(),
+            }],
+            ..Default::default()
+        })
+        .await?;
+    let turn_resp: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(turn_id)),
+    )
+    .await??;
+    let TurnStartResponse { turn: _turn } = to_response::<TurnStartResponse>(turn_resp)?;
+
+    let started_command = timeout(DEFAULT_READ_TIMEOUT, async {
+        loop {
+            let notif = mcp
+                .read_stream_until_notification_message("item/started")
+                .await?;
+            let started: ItemStartedNotification = serde_json::from_value(
+                notif
+                    .params
+                    .clone()
+                    .expect("item/started should include params"),
+            )?;
+            if let ThreadItem::CommandExecution { .. } = started.item {
+                return Ok::<ThreadItem, anyhow::Error>(started.item);
+            }
+        }
+    })
+    .await??;
+    let ThreadItem::CommandExecution {
+        id,
+        process_id: started_process_id,
+        status,
+        ..
+    } = started_command
+    else {
+        unreachable!("loop ensures we break on command execution items");
+    };
+    assert_eq!(id, "uexec-1");
+    assert_eq!(status, CommandExecutionStatus::InProgress);
+    let started_process_id = started_process_id.expect("process id should be present");
+
+    let completed_command = timeout(DEFAULT_READ_TIMEOUT, async {
+        loop {
+            let notif = mcp
+                .read_stream_until_notification_message("item/completed")
+                .await?;
+            let completed: ItemCompletedNotification = serde_json::from_value(
+                notif
+                    .params
+                    .clone()
+                    .expect("item/completed should include params"),
+            )?;
+            if let ThreadItem::CommandExecution { .. } = completed.item {
+                return Ok::<ThreadItem, anyhow::Error>(completed.item);
+            }
+        }
+    })
+    .await??;
+    let ThreadItem::CommandExecution {
+        id: completed_id,
+        process_id: completed_process_id,
+        status: completed_status,
+        exit_code,
+        ..
+    } = completed_command
+    else {
+        unreachable!("loop ensures we break on command execution items");
+    };
+    assert_eq!(completed_id, "uexec-1");
+    assert_eq!(completed_status, CommandExecutionStatus::Completed);
+    assert_eq!(exit_code, Some(0));
+    assert_eq!(
+        completed_process_id.as_deref(),
+        Some(started_process_id.as_str())
+    );
+
+    timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_notification_message("turn/completed"),
+    )
+    .await??;
+
+    Ok(())
+}
+
 // Helper to create a config.toml pointing at the mock model server.
 fn create_config_toml(
    codex_home: &Path,
--- a/codex-rs/apply-patch/Cargo.toml
+++ b/codex-rs/apply-patch/Cargo.toml
@@ -1,7 +1,8 @@
 [package]
-edition = "2024"
 name = "codex-apply-patch"
-version = { workspace = true }
+version.workspace = true
+edition.workspace = true
+license.workspace = true

 [lib]
 name = "codex_apply_patch"
--- a/codex-rs/apply-patch/src/lib.rs
+++ b/codex-rs/apply-patch/src/lib.rs
@@ -30,7 +30,13 @@ pub use standalone_executable::main;
 pub const APPLY_PATCH_TOOL_INSTRUCTIONS: &str = include_str!("../apply_patch_tool_instructions.md");

 const APPLY_PATCH_COMMANDS: [&str; 2] = ["apply_patch", "applypatch"];
-const APPLY_PATCH_SHELLS: [&str; 3] = ["bash", "zsh", "sh"];
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+enum ApplyPatchShell {
+    Unix,
+    PowerShell,
+    Cmd,
+}

 #[derive(Debug, Error, PartialEq)]
 pub enum ApplyPatchError {
@@ -97,11 +103,55 @@ pub struct ApplyPatchArgs {
    pub workdir: Option<String>,
 }

-fn shell_supports_apply_patch(shell: &str) -> bool {
+fn classify_shell_name(shell: &str) -> Option<String> {
    std::path::Path::new(shell)
-        .file_name()
+        .file_stem()
        .and_then(|name| name.to_str())
-        .is_some_and(|name| APPLY_PATCH_SHELLS.contains(&name))
+        .map(str::to_ascii_lowercase)
+}
+
+fn classify_shell(shell: &str, flag: &str) -> Option<ApplyPatchShell> {
+    classify_shell_name(shell).and_then(|name| match name.as_str() {
+        "bash" | "zsh" | "sh" if flag == "-lc" => Some(ApplyPatchShell::Unix),
+        "pwsh" | "powershell" if flag.eq_ignore_ascii_case("-command") => {
+            Some(ApplyPatchShell::PowerShell)
+        }
+        "cmd" if flag.eq_ignore_ascii_case("/c") => Some(ApplyPatchShell::Cmd),
+        _ => None,
+    })
+}
+
+fn can_skip_flag(shell: &str, flag: &str) -> bool {
+    classify_shell_name(shell).is_some_and(|name| {
+        matches!(name.as_str(), "pwsh" | "powershell") && flag.eq_ignore_ascii_case("-noprofile")
+    })
+}
+
+fn parse_shell_script(argv: &[String]) -> Option<(ApplyPatchShell, &str)> {
+    match argv {
+        [shell, flag, script] => classify_shell(shell, flag).map(|shell_type| {
+            let script = script.as_str();
+            (shell_type, script)
+        }),
+        [shell, skip_flag, flag, script] if can_skip_flag(shell, skip_flag) => {
+            classify_shell(shell, flag).map(|shell_type| {
+                let script = script.as_str();
+                (shell_type, script)
+            })
+        }
+        _ => None,
+    }
+}
+
+fn extract_apply_patch_from_shell(
+    shell: ApplyPatchShell,
+    script: &str,
+) -> std::result::Result<(String, Option<String>), ExtractHeredocError> {
+    match shell {
+        ApplyPatchShell::Unix | ApplyPatchShell::PowerShell | ApplyPatchShell::Cmd => {
+            extract_apply_patch_from_bash(script)
+        }
+    }
 }

 pub fn maybe_parse_apply_patch(argv: &[String]) -> MaybeApplyPatch {
@@ -111,9 +161,9 @@ pub fn maybe_parse_apply_patch(argv: &[String]) -> MaybeApplyPatch {
            Ok(source) => MaybeApplyPatch::Body(source),
            Err(e) => MaybeApplyPatch::PatchParseError(e),
        },
-        // Bash heredoc form: (optional `cd <path> &&`) apply_patch <<'EOF' ...
-        [shell, flag, script] if shell_supports_apply_patch(shell) && flag == "-lc" => {
-            match extract_apply_patch_from_bash(script) {
+        // Shell heredoc form: (optional `cd <path> &&`) apply_patch <<'EOF' ...
+        _ => match parse_shell_script(argv) {
+            Some((shell, script)) => match extract_apply_patch_from_shell(shell, script) {
                Ok((body, workdir)) => match parse_patch(&body) {
                    Ok(mut source) => {
                        source.workdir = workdir;
@@ -125,9 +175,9 @@ pub fn maybe_parse_apply_patch(argv: &[String]) -> MaybeApplyPatch {
                    MaybeApplyPatch::NotApplyPatch
                }
                Err(e) => MaybeApplyPatch::ShellParseError(e),
-            }
-        }
-        _ => MaybeApplyPatch::NotApplyPatch,
+            },
+            None => MaybeApplyPatch::NotApplyPatch,
+        },
    }
 }

@@ -222,24 +272,17 @@ impl ApplyPatchAction {
 /// cwd must be an absolute path so that we can resolve relative paths in the
 /// patch.
 pub fn maybe_parse_apply_patch_verified(argv: &[String], cwd: &Path) -> MaybeApplyPatchVerified {
-    // Detect a raw patch body passed directly as the command or as the body of a bash -lc
+    // Detect a raw patch body passed directly as the command or as the body of a shell
    // script. In these cases, report an explicit error rather than applying the patch.
-    match argv {
-        [body] => {
-            if parse_patch(body).is_ok() {
-                return MaybeApplyPatchVerified::CorrectnessError(
-                    ApplyPatchError::ImplicitInvocation,
-                );
-            }
-        }
-        [shell, flag, script]
-            if shell_supports_apply_patch(shell)
-                && flag == "-lc"
-                && parse_patch(script).is_ok() =>
-        {
-            return MaybeApplyPatchVerified::CorrectnessError(ApplyPatchError::ImplicitInvocation);
-        }
-        _ => {}
+    if let [body] = argv
+        && parse_patch(body).is_ok()
+    {
+        return MaybeApplyPatchVerified::CorrectnessError(ApplyPatchError::ImplicitInvocation);
+    }
+    if let Some((_, script)) = parse_shell_script(argv)
+        && parse_patch(script).is_ok()
+    {
+        return MaybeApplyPatchVerified::CorrectnessError(ApplyPatchError::ImplicitInvocation);
    }

    match maybe_parse_apply_patch(argv) {
@@ -871,6 +914,22 @@ mod tests {
        strs_to_strings(&["bash", "-lc", script])
    }

+    fn args_powershell(script: &str) -> Vec<String> {
+        strs_to_strings(&["powershell.exe", "-Command", script])
+    }
+
+    fn args_powershell_no_profile(script: &str) -> Vec<String> {
+        strs_to_strings(&["powershell.exe", "-NoProfile", "-Command", script])
+    }
+
+    fn args_pwsh(script: &str) -> Vec<String> {
+        strs_to_strings(&["pwsh", "-NoProfile", "-Command", script])
+    }
+
+    fn args_cmd(script: &str) -> Vec<String> {
+        strs_to_strings(&["cmd.exe", "/c", script])
+    }
+
    fn heredoc_script(prefix: &str) -> String {
        format!(
            "{prefix}apply_patch <<'PATCH'\n*** Begin Patch\n*** Add File: foo\n+hi\n*** End Patch\nPATCH"
@@ -890,8 +949,7 @@ mod tests {
        }]
    }

-    fn assert_match(script: &str, expected_workdir: Option<&str>) {
-        let args = args_bash(script);
+    fn assert_match_args(args: Vec<String>, expected_workdir: Option<&str>) {
        match maybe_parse_apply_patch(&args) {
            MaybeApplyPatch::Body(ApplyPatchArgs { hunks, workdir, .. }) => {
                assert_eq!(workdir.as_deref(), expected_workdir);
@@ -901,6 +959,11 @@ mod tests {
        }
    }

+    fn assert_match(script: &str, expected_workdir: Option<&str>) {
+        let args = args_bash(script);
+        assert_match_args(args, expected_workdir);
+    }
+
    fn assert_not_match(script: &str) {
        let args = args_bash(script);
        assert_matches!(
@@ -1014,6 +1077,28 @@ PATCH"#,
        }
    }

+    #[test]
+    fn test_powershell_heredoc() {
+        let script = heredoc_script("");
+        assert_match_args(args_powershell(&script), None);
+    }
+    #[test]
+    fn test_powershell_heredoc_no_profile() {
+        let script = heredoc_script("");
+        assert_match_args(args_powershell_no_profile(&script), None);
+    }
+    #[test]
+    fn test_pwsh_heredoc() {
+        let script = heredoc_script("");
+        assert_match_args(args_pwsh(&script), None);
+    }
+
+    #[test]
+    fn test_cmd_heredoc_with_cd() {
+        let script = heredoc_script("cd foo && ");
+        assert_match_args(args_cmd(&script), Some("foo"));
+    }
+
    #[test]
    fn test_heredoc_with_leading_cd() {
        assert_match(&heredoc_script("cd foo && "), Some("foo"));
--- a/codex-rs/arg0/Cargo.toml
+++ b/codex-rs/arg0/Cargo.toml
@@ -1,7 +1,8 @@
 [package]
-edition = "2024"
 name = "codex-arg0"
-version = { workspace = true }
+version.workspace = true
+edition.workspace = true
+license.workspace = true

 [lib]
 name = "codex_arg0"
--- a/codex-rs/async-utils/Cargo.toml
+++ b/codex-rs/async-utils/Cargo.toml
@@ -1,7 +1,8 @@
 [package]
-edition.workspace = true
 name = "codex-async-utils"
 version.workspace = true
+edition.workspace = true
+license.workspace = true

 [lints]
 workspace = true
--- a/codex-rs/backend-client/Cargo.toml
+++ b/codex-rs/backend-client/Cargo.toml
@@ -1,7 +1,8 @@
 [package]
 name = "codex-backend-client"
-version = "0.0.0"
-edition = "2024"
+version.workspace = true
+edition.workspace = true
+license.workspace = true
 publish = false

 [lib]
--- a/codex-rs/chatgpt/Cargo.toml
+++ b/codex-rs/chatgpt/Cargo.toml
@@ -1,7 +1,8 @@
 [package]
-edition = "2024"
 name = "codex-chatgpt"
-version = { workspace = true }
+version.workspace = true
+edition.workspace = true
+license.workspace = true

 [lints]
 workspace = true
--- a/codex-rs/cli/Cargo.toml
+++ b/codex-rs/cli/Cargo.toml
@@ -1,7 +1,8 @@
 [package]
-edition = "2024"
 name = "codex-cli"
-version = { workspace = true }
+version.workspace = true
+edition.workspace = true
+license.workspace = true

 [[bin]]
 name = "codex"
--- a/codex-rs/cli/src/main.rs
+++ b/codex-rs/cli/src/main.rs
@@ -18,6 +18,8 @@ use codex_cli::login::run_logout;
 use codex_cloud_tasks::Cli as CloudTasksCli;
 use codex_common::CliConfigOverrides;
 use codex_exec::Cli as ExecCli;
+use codex_exec::Command as ExecCommand;
+use codex_exec::ReviewArgs;
 use codex_execpolicy::ExecPolicyCheckCommand;
 use codex_responses_api_proxy::Args as ResponsesApiProxyArgs;
 use codex_tui::AppExitInfo;
@@ -72,6 +74,9 @@ enum Subcommand {
    #[clap(visible_alias = "e")]
    Exec(ExecCli),

+    /// Run a code review non-interactively.
+    Review(ReviewArgs),
+
    /// Manage login.
    Login(LoginCommand),

@@ -449,6 +454,15 @@ async fn cli_main(codex_linux_sandbox_exe: Option<PathBuf>) -> anyhow::Result<()
            );
            codex_exec::run_main(exec_cli, codex_linux_sandbox_exe).await?;
        }
+        Some(Subcommand::Review(review_args)) => {
+            let mut exec_cli = ExecCli::try_parse_from(["codex", "exec"])?;
+            exec_cli.command = Some(ExecCommand::Review(review_args));
+            prepend_config_flags(
+                &mut exec_cli.config_overrides,
+                root_config_overrides.clone(),
+            );
+            codex_exec::run_main(exec_cli, codex_linux_sandbox_exe).await?;
+        }
        Some(Subcommand::McpServer) => {
            codex_mcp_server::run_main(codex_linux_sandbox_exe, root_config_overrides).await?;
        }
--- a/codex-rs/cli/tests/execpolicy.rs
+++ b/codex-rs/cli/tests/execpolicy.rs
@@ -40,17 +40,15 @@ prefix_rule(
    assert_eq!(
        result,
        json!({
-            "match": {
-                "decision": "forbidden",
-                "matchedRules": [
-                    {
-                        "prefixRuleMatch": {
-                            "matchedPrefix": ["git", "push"],
-                            "decision": "forbidden"
-                        }
+            "decision": "forbidden",
+            "matchedRules": [
+                {
+                    "prefixRuleMatch": {
+                        "matchedPrefix": ["git", "push"],
+                        "decision": "forbidden"
                    }
-                ]
-            }
+                }
+            ]
        })
    );

--- a/codex-rs/cloud-tasks-client/Cargo.toml
+++ b/codex-rs/cloud-tasks-client/Cargo.toml
@@ -1,7 +1,8 @@
 [package]
 name = "codex-cloud-tasks-client"
-version = { workspace = true }
-edition = "2024"
+version.workspace = true
+edition.workspace = true
+license.workspace = true

 [lib]
 name = "codex_cloud_tasks_client"
--- a/codex-rs/cloud-tasks/Cargo.toml
+++ b/codex-rs/cloud-tasks/Cargo.toml
@@ -1,7 +1,8 @@
 [package]
-edition = "2024"
 name = "codex-cloud-tasks"
-version = { workspace = true }
+version.workspace = true
+edition.workspace = true
+license.workspace = true

 [lib]
 name = "codex_cloud_tasks"
--- a/codex-rs/codex-api/Cargo.toml
+++ b/codex-rs/codex-api/Cargo.toml
@@ -0,0 +1,30 @@
+[package]
+name = "codex-api"
+version.workspace = true
+edition.workspace = true
+license.workspace = true
+
+[dependencies]
+async-trait = { workspace = true }
+bytes = { workspace = true }
+codex-client = { workspace = true }
+codex-protocol = { workspace = true }
+futures = { workspace = true }
+http = { workspace = true }
+serde = { workspace = true, features = ["derive"] }
+serde_json = { workspace = true }
+thiserror = { workspace = true }
+tokio = { workspace = true, features = ["macros", "rt", "sync", "time"] }
+tracing = { workspace = true }
+eventsource-stream = { workspace = true }
+regex-lite = { workspace = true }
+tokio-util = { workspace = true, features = ["codec"] }
+
+[dev-dependencies]
+anyhow = { workspace = true }
+assert_matches = { workspace = true }
+pretty_assertions = { workspace = true }
+tokio-test = { workspace = true }
+
+[lints]
+workspace = true
--- a/codex-rs/codex-api/README.md
+++ b/codex-rs/codex-api/README.md
@@ -0,0 +1,32 @@
+# codex-api
+
+Typed clients for Codex/OpenAI APIs built on top of the generic transport in `codex-client`.
+
+- Hosts the request/response models and prompt helpers for Responses, Chat Completions, and Compact APIs.
+- Owns provider configuration (base URLs, headers, query params), auth header injection, retry tuning, and stream idle settings.
+- Parses SSE streams into `ResponseEvent`/`ResponseStream`, including rate-limit snapshots and API-specific error mapping.
+- Serves as the wire-level layer consumed by `codex-core`; higher layers handle auth refresh and business logic.
+
+## Core interface
+
+The public interface of this crate is intentionally small and uniform:
+
+- **Prompted endpoints (Chat + Responses)**
+  - Input: a single `Prompt` plus endpoint-specific options.
+    - `Prompt` (re-exported as `codex_api::Prompt`) carries:
+      - `instructions: String` – the fully-resolved system prompt for this turn.
+      - `input: Vec<ResponseItem>` – conversation history and user/tool messages.
+      - `tools: Vec<serde_json::Value>` – JSON tools compatible with the target API.
+      - `parallel_tool_calls: bool`.
+      - `output_schema: Option<Value>` – used to build `text.format` when present.
+  - Output: a `ResponseStream` of `ResponseEvent` (both re-exported from `common`).
+
+- **Compaction endpoint**
+  - Input: `CompactionInput<'a>` (re-exported as `codex_api::CompactionInput`):
+    - `model: &str`.
+    - `input: &[ResponseItem]` – history to compact.
+    - `instructions: &str` – fully-resolved compaction instructions.
+  - Output: `Vec<ResponseItem>`.
+  - `CompactClient::compact_input(&CompactionInput, extra_headers)` wraps the JSON encoding and retry/telemetry wiring.
+
+All HTTP details (URLs, headers, retry/backoff policies, SSE framing) are encapsulated in `codex-api` and `codex-client`. Callers construct prompts/inputs using protocol types and work with typed streams of `ResponseEvent` or compacted `ResponseItem` values.
--- a/codex-rs/codex-api/src/auth.rs
+++ b/codex-rs/codex-api/src/auth.rs
@@ -0,0 +1,27 @@
+use codex_client::Request;
+
+/// Provides bearer and account identity information for API requests.
+///
+/// Implementations should be cheap and non-blocking; any asynchronous
+/// refresh or I/O should be handled by higher layers before requests
+/// reach this interface.
+pub trait AuthProvider: Send + Sync {
+    fn bearer_token(&self) -> Option<String>;
+    fn account_id(&self) -> Option<String> {
+        None
+    }
+}
+
+pub(crate) fn add_auth_headers<A: AuthProvider>(auth: &A, mut req: Request) -> Request {
+    if let Some(token) = auth.bearer_token()
+        && let Ok(header) = format!("Bearer {token}").parse()
+    {
+        let _ = req.headers.insert(http::header::AUTHORIZATION, header);
+    }
+    if let Some(account_id) = auth.account_id()
+        && let Ok(header) = account_id.parse()
+    {
+        let _ = req.headers.insert("ChatGPT-Account-ID", header);
+    }
+    req
+}
--- a/codex-rs/codex-api/src/common.rs
+++ b/codex-rs/codex-api/src/common.rs
@@ -0,0 +1,167 @@
+use crate::error::ApiError;
+use codex_protocol::config_types::ReasoningEffort as ReasoningEffortConfig;
+use codex_protocol::config_types::ReasoningSummary as ReasoningSummaryConfig;
+use codex_protocol::config_types::Verbosity as VerbosityConfig;
+use codex_protocol::models::ResponseItem;
+use codex_protocol::protocol::RateLimitSnapshot;
+use codex_protocol::protocol::TokenUsage;
+use futures::Stream;
+use serde::Serialize;
+use serde_json::Value;
+use std::pin::Pin;
+use std::task::Context;
+use std::task::Poll;
+use tokio::sync::mpsc;
+
+/// Canonical prompt input for Chat and Responses endpoints.
+#[derive(Debug, Clone)]
+pub struct Prompt {
+    /// Fully-resolved system instructions for this turn.
+    pub instructions: String,
+    /// Conversation history and user/tool messages.
+    pub input: Vec<ResponseItem>,
+    /// JSON-encoded tool definitions compatible with the target API.
+    // TODO(jif) have a proper type here
+    pub tools: Vec<Value>,
+    /// Whether parallel tool calls are permitted.
+    pub parallel_tool_calls: bool,
+    /// Optional output schema used to build the `text.format` controls.
+    pub output_schema: Option<Value>,
+}
+
+/// Canonical input payload for the compaction endpoint.
+#[derive(Debug, Clone, Serialize)]
+pub struct CompactionInput<'a> {
+    pub model: &'a str,
+    pub input: &'a [ResponseItem],
+    pub instructions: &'a str,
+}
+
+#[derive(Debug)]
+pub enum ResponseEvent {
+    Created,
+    OutputItemDone(ResponseItem),
+    OutputItemAdded(ResponseItem),
+    Completed {
+        response_id: String,
+        token_usage: Option<TokenUsage>,
+    },
+    OutputTextDelta(String),
+    ReasoningSummaryDelta {
+        delta: String,
+        summary_index: i64,
+    },
+    ReasoningContentDelta {
+        delta: String,
+        content_index: i64,
+    },
+    ReasoningSummaryPartAdded {
+        summary_index: i64,
+    },
+    RateLimits(RateLimitSnapshot),
+}
+
+#[derive(Debug, Serialize, Clone)]
+pub struct Reasoning {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub effort: Option<ReasoningEffortConfig>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub summary: Option<ReasoningSummaryConfig>,
+}
+
+#[derive(Debug, Serialize, Default, Clone)]
+#[serde(rename_all = "snake_case")]
+pub enum TextFormatType {
+    #[default]
+    JsonSchema,
+}
+
+#[derive(Debug, Serialize, Default, Clone)]
+pub struct TextFormat {
+    /// Format type used by the OpenAI text controls.
+    pub r#type: TextFormatType,
+    /// When true, the server is expected to strictly validate responses.
+    pub strict: bool,
+    /// JSON schema for the desired output.
+    pub schema: Value,
+    /// Friendly name for the format, used in telemetry/debugging.
+    pub name: String,
+}
+
+/// Controls the `text` field for the Responses API, combining verbosity and
+/// optional JSON schema output formatting.
+#[derive(Debug, Serialize, Default, Clone)]
+pub struct TextControls {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub verbosity: Option<OpenAiVerbosity>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub format: Option<TextFormat>,
+}
+
+#[derive(Debug, Serialize, Default, Clone)]
+#[serde(rename_all = "lowercase")]
+pub enum OpenAiVerbosity {
+    Low,
+    #[default]
+    Medium,
+    High,
+}
+
+impl From<VerbosityConfig> for OpenAiVerbosity {
+    fn from(v: VerbosityConfig) -> Self {
+        match v {
+            VerbosityConfig::Low => OpenAiVerbosity::Low,
+            VerbosityConfig::Medium => OpenAiVerbosity::Medium,
+            VerbosityConfig::High => OpenAiVerbosity::High,
+        }
+    }
+}
+
+#[derive(Debug, Serialize)]
+pub struct ResponsesApiRequest<'a> {
+    pub model: &'a str,
+    pub instructions: &'a str,
+    pub input: &'a [ResponseItem],
+    pub tools: &'a [serde_json::Value],
+    pub tool_choice: &'static str,
+    pub parallel_tool_calls: bool,
+    pub reasoning: Option<Reasoning>,
+    pub store: bool,
+    pub stream: bool,
+    pub include: Vec<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub prompt_cache_key: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub text: Option<TextControls>,
+}
+
+pub fn create_text_param_for_request(
+    verbosity: Option<VerbosityConfig>,
+    output_schema: &Option<Value>,
+) -> Option<TextControls> {
+    if verbosity.is_none() && output_schema.is_none() {
+        return None;
+    }
+
+    Some(TextControls {
+        verbosity: verbosity.map(std::convert::Into::into),
+        format: output_schema.as_ref().map(|schema| TextFormat {
+            r#type: TextFormatType::JsonSchema,
+            strict: true,
+            schema: schema.clone(),
+            name: "codex_output_schema".to_string(),
+        }),
+    })
+}
+
+pub struct ResponseStream {
+    pub rx_event: mpsc::Receiver<Result<ResponseEvent, ApiError>>,
+}
+
+impl Stream for ResponseStream {
+    type Item = Result<ResponseEvent, ApiError>;
+
+    fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
+        self.rx_event.poll_recv(cx)
+    }
+}
--- a/codex-rs/codex-api/src/endpoint/chat.rs
+++ b/codex-rs/codex-api/src/endpoint/chat.rs
@@ -0,0 +1,266 @@
+use crate::ChatRequest;
+use crate::auth::AuthProvider;
+use crate::common::Prompt as ApiPrompt;
+use crate::common::ResponseEvent;
+use crate::common::ResponseStream;
+use crate::endpoint::streaming::StreamingClient;
+use crate::error::ApiError;
+use crate::provider::Provider;
+use crate::provider::WireApi;
+use crate::sse::chat::spawn_chat_stream;
+use crate::telemetry::SseTelemetry;
+use codex_client::HttpTransport;
+use codex_client::RequestTelemetry;
+use codex_protocol::models::ContentItem;
+use codex_protocol::models::ReasoningItemContent;
+use codex_protocol::models::ResponseItem;
+use codex_protocol::protocol::SessionSource;
+use futures::Stream;
+use http::HeaderMap;
+use serde_json::Value;
+use std::collections::VecDeque;
+use std::pin::Pin;
+use std::sync::Arc;
+use std::task::Context;
+use std::task::Poll;
+
+pub struct ChatClient<T: HttpTransport, A: AuthProvider> {
+    streaming: StreamingClient<T, A>,
+}
+
+impl<T: HttpTransport, A: AuthProvider> ChatClient<T, A> {
+    pub fn new(transport: T, provider: Provider, auth: A) -> Self {
+        Self {
+            streaming: StreamingClient::new(transport, provider, auth),
+        }
+    }
+
+    pub fn with_telemetry(
+        self,
+        request: Option<Arc<dyn RequestTelemetry>>,
+        sse: Option<Arc<dyn SseTelemetry>>,
+    ) -> Self {
+        Self {
+            streaming: self.streaming.with_telemetry(request, sse),
+        }
+    }
+
+    pub async fn stream_request(&self, request: ChatRequest) -> Result<ResponseStream, ApiError> {
+        self.stream(request.body, request.headers).await
+    }
+
+    pub async fn stream_prompt(
+        &self,
+        model: &str,
+        prompt: &ApiPrompt,
+        conversation_id: Option<String>,
+        session_source: Option<SessionSource>,
+    ) -> Result<ResponseStream, ApiError> {
+        use crate::requests::ChatRequestBuilder;
+
+        let request =
+            ChatRequestBuilder::new(model, &prompt.instructions, &prompt.input, &prompt.tools)
+                .conversation_id(conversation_id)
+                .session_source(session_source)
+                .build(self.streaming.provider())?;
+
+        self.stream_request(request).await
+    }
+
+    fn path(&self) -> &'static str {
+        match self.streaming.provider().wire {
+            WireApi::Chat => "chat/completions",
+            _ => "responses",
+        }
+    }
+
+    pub async fn stream(
+        &self,
+        body: Value,
+        extra_headers: HeaderMap,
+    ) -> Result<ResponseStream, ApiError> {
+        self.streaming
+            .stream(self.path(), body, extra_headers, spawn_chat_stream)
+            .await
+    }
+}
+
+#[derive(Copy, Clone, Eq, PartialEq)]
+pub enum AggregateMode {
+    AggregatedOnly,
+    Streaming,
+}
+
+/// Stream adapter that merges token deltas into a single assistant message per turn.
+pub struct AggregatedStream {
+    inner: ResponseStream,
+    cumulative: String,
+    cumulative_reasoning: String,
+    pending: VecDeque<ResponseEvent>,
+    mode: AggregateMode,
+}
+
+impl Stream for AggregatedStream {
+    type Item = Result<ResponseEvent, ApiError>;
+
+    fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
+        let this = self.get_mut();
+
+        if let Some(ev) = this.pending.pop_front() {
+            return Poll::Ready(Some(Ok(ev)));
+        }
+
+        loop {
+            match Pin::new(&mut this.inner).poll_next(cx) {
+                Poll::Pending => return Poll::Pending,
+                Poll::Ready(None) => return Poll::Ready(None),
+                Poll::Ready(Some(Err(e))) => return Poll::Ready(Some(Err(e))),
+                Poll::Ready(Some(Ok(ResponseEvent::OutputItemDone(item)))) => {
+                    let is_assistant_message = matches!(
+                        &item,
+                        ResponseItem::Message { role, .. } if role == "assistant"
+                    );
+
+                    if is_assistant_message {
+                        match this.mode {
+                            AggregateMode::AggregatedOnly => {
+                                if this.cumulative.is_empty()
+                                    && let ResponseItem::Message { content, .. } = &item
+                                    && let Some(text) = content.iter().find_map(|c| match c {
+                                        ContentItem::OutputText { text } => Some(text),
+                                        _ => None,
+                                    })
+                                {
+                                    this.cumulative.push_str(text);
+                                }
+                                continue;
+                            }
+                            AggregateMode::Streaming => {
+                                if this.cumulative.is_empty() {
+                                    return Poll::Ready(Some(Ok(ResponseEvent::OutputItemDone(
+                                        item,
+                                    ))));
+                                } else {
+                                    continue;
+                                }
+                            }
+                        }
+                    }
+
+                    return Poll::Ready(Some(Ok(ResponseEvent::OutputItemDone(item))));
+                }
+                Poll::Ready(Some(Ok(ResponseEvent::RateLimits(snapshot)))) => {
+                    return Poll::Ready(Some(Ok(ResponseEvent::RateLimits(snapshot))));
+                }
+                Poll::Ready(Some(Ok(ResponseEvent::Completed {
+                    response_id,
+                    token_usage,
+                }))) => {
+                    let mut emitted_any = false;
+
+                    if !this.cumulative_reasoning.is_empty() {
+                        let aggregated_reasoning = ResponseItem::Reasoning {
+                            id: String::new(),
+                            summary: Vec::new(),
+                            content: Some(vec![ReasoningItemContent::ReasoningText {
+                                text: std::mem::take(&mut this.cumulative_reasoning),
+                            }]),
+                            encrypted_content: None,
+                        };
+                        this.pending
+                            .push_back(ResponseEvent::OutputItemDone(aggregated_reasoning));
+                        emitted_any = true;
+                    }
+
+                    if !this.cumulative.is_empty() {
+                        let aggregated_message = ResponseItem::Message {
+                            id: None,
+                            role: "assistant".to_string(),
+                            content: vec![ContentItem::OutputText {
+                                text: std::mem::take(&mut this.cumulative),
+                            }],
+                        };
+                        this.pending
+                            .push_back(ResponseEvent::OutputItemDone(aggregated_message));
+                        emitted_any = true;
+                    }
+
+                    if emitted_any {
+                        this.pending.push_back(ResponseEvent::Completed {
+                            response_id: response_id.clone(),
+                            token_usage: token_usage.clone(),
+                        });
+                        if let Some(ev) = this.pending.pop_front() {
+                            return Poll::Ready(Some(Ok(ev)));
+                        }
+                    }
+
+                    return Poll::Ready(Some(Ok(ResponseEvent::Completed {
+                        response_id,
+                        token_usage,
+                    })));
+                }
+                Poll::Ready(Some(Ok(ResponseEvent::Created))) => {
+                    continue;
+                }
+                Poll::Ready(Some(Ok(ResponseEvent::OutputTextDelta(delta)))) => {
+                    this.cumulative.push_str(&delta);
+                    if matches!(this.mode, AggregateMode::Streaming) {
+                        return Poll::Ready(Some(Ok(ResponseEvent::OutputTextDelta(delta))));
+                    } else {
+                        continue;
+                    }
+                }
+                Poll::Ready(Some(Ok(ResponseEvent::ReasoningContentDelta {
+                    delta,
+                    content_index,
+                }))) => {
+                    this.cumulative_reasoning.push_str(&delta);
+                    if matches!(this.mode, AggregateMode::Streaming) {
+                        return Poll::Ready(Some(Ok(ResponseEvent::ReasoningContentDelta {
+                            delta,
+                            content_index,
+                        })));
+                    } else {
+                        continue;
+                    }
+                }
+                Poll::Ready(Some(Ok(ResponseEvent::ReasoningSummaryDelta { .. }))) => continue,
+                Poll::Ready(Some(Ok(ResponseEvent::ReasoningSummaryPartAdded { .. }))) => {
+                    continue;
+                }
+                Poll::Ready(Some(Ok(ResponseEvent::OutputItemAdded(item)))) => {
+                    return Poll::Ready(Some(Ok(ResponseEvent::OutputItemAdded(item))));
+                }
+            }
+        }
+    }
+}
+
+pub trait AggregateStreamExt {
+    fn aggregate(self) -> AggregatedStream;
+
+    fn streaming_mode(self) -> ResponseStream;
+}
+
+impl AggregateStreamExt for ResponseStream {
+    fn aggregate(self) -> AggregatedStream {
+        AggregatedStream::new(self, AggregateMode::AggregatedOnly)
+    }
+
+    fn streaming_mode(self) -> ResponseStream {
+        self
+    }
+}
+
+impl AggregatedStream {
+    fn new(inner: ResponseStream, mode: AggregateMode) -> Self {
+        AggregatedStream {
+            inner,
+            cumulative: String::new(),
+            cumulative_reasoning: String::new(),
+            pending: VecDeque::new(),
+            mode,
+        }
+    }
+}
--- a/codex-rs/codex-api/src/endpoint/compact.rs
+++ b/codex-rs/codex-api/src/endpoint/compact.rs
@@ -0,0 +1,162 @@
+use crate::auth::AuthProvider;
+use crate::auth::add_auth_headers;
+use crate::common::CompactionInput;
+use crate::error::ApiError;
+use crate::provider::Provider;
+use crate::provider::WireApi;
+use crate::telemetry::run_with_request_telemetry;
+use codex_client::HttpTransport;
+use codex_client::RequestTelemetry;
+use codex_protocol::models::ResponseItem;
+use http::HeaderMap;
+use http::Method;
+use serde::Deserialize;
+use serde_json::to_value;
+use std::sync::Arc;
+
+pub struct CompactClient<T: HttpTransport, A: AuthProvider> {
+    transport: T,
+    provider: Provider,
+    auth: A,
+    request_telemetry: Option<Arc<dyn RequestTelemetry>>,
+}
+
+impl<T: HttpTransport, A: AuthProvider> CompactClient<T, A> {
+    pub fn new(transport: T, provider: Provider, auth: A) -> Self {
+        Self {
+            transport,
+            provider,
+            auth,
+            request_telemetry: None,
+        }
+    }
+
+    pub fn with_telemetry(mut self, request: Option<Arc<dyn RequestTelemetry>>) -> Self {
+        self.request_telemetry = request;
+        self
+    }
+
+    fn path(&self) -> Result<&'static str, ApiError> {
+        match self.provider.wire {
+            WireApi::Compact | WireApi::Responses => Ok("responses/compact"),
+            WireApi::Chat => Err(ApiError::Stream(
+                "compact endpoint requires responses wire api".to_string(),
+            )),
+        }
+    }
+
+    pub async fn compact(
+        &self,
+        body: serde_json::Value,
+        extra_headers: HeaderMap,
+    ) -> Result<Vec<ResponseItem>, ApiError> {
+        let path = self.path()?;
+        let builder = || {
+            let mut req = self.provider.build_request(Method::POST, path);
+            req.headers.extend(extra_headers.clone());
+            req.body = Some(body.clone());
+            add_auth_headers(&self.auth, req)
+        };
+
+        let resp = run_with_request_telemetry(
+            self.provider.retry.to_policy(),
+            self.request_telemetry.clone(),
+            builder,
+            |req| self.transport.execute(req),
+        )
+        .await?;
+        let parsed: CompactHistoryResponse =
+            serde_json::from_slice(&resp.body).map_err(|e| ApiError::Stream(e.to_string()))?;
+        Ok(parsed.output)
+    }
+
+    pub async fn compact_input(
+        &self,
+        input: &CompactionInput<'_>,
+        extra_headers: HeaderMap,
+    ) -> Result<Vec<ResponseItem>, ApiError> {
+        let body = to_value(input)
+            .map_err(|e| ApiError::Stream(format!("failed to encode compaction input: {e}")))?;
+        self.compact(body, extra_headers).await
+    }
+}
+
+#[derive(Debug, Deserialize)]
+struct CompactHistoryResponse {
+    output: Vec<ResponseItem>,
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::provider::RetryConfig;
+    use async_trait::async_trait;
+    use codex_client::Request;
+    use codex_client::Response;
+    use codex_client::StreamResponse;
+    use codex_client::TransportError;
+    use http::HeaderMap;
+    use std::time::Duration;
+
+    #[derive(Clone, Default)]
+    struct DummyTransport;
+
+    #[async_trait]
+    impl HttpTransport for DummyTransport {
+        async fn execute(&self, _req: Request) -> Result<Response, TransportError> {
+            Err(TransportError::Build("execute should not run".to_string()))
+        }
+
+        async fn stream(&self, _req: Request) -> Result<StreamResponse, TransportError> {
+            Err(TransportError::Build("stream should not run".to_string()))
+        }
+    }
+
+    #[derive(Clone, Default)]
+    struct DummyAuth;
+
+    impl AuthProvider for DummyAuth {
+        fn bearer_token(&self) -> Option<String> {
+            None
+        }
+    }
+
+    fn provider(wire: WireApi) -> Provider {
+        Provider {
+            name: "test".to_string(),
+            base_url: "https://example.com/v1".to_string(),
+            query_params: None,
+            wire,
+            headers: HeaderMap::new(),
+            retry: RetryConfig {
+                max_attempts: 1,
+                base_delay: Duration::from_millis(1),
+                retry_429: false,
+                retry_5xx: true,
+                retry_transport: true,
+            },
+            stream_idle_timeout: Duration::from_secs(1),
+        }
+    }
+
+    #[tokio::test]
+    async fn errors_when_wire_is_chat() {
+        let client = CompactClient::new(DummyTransport, provider(WireApi::Chat), DummyAuth);
+        let input = CompactionInput {
+            model: "gpt-test",
+            input: &[],
+            instructions: "inst",
+        };
+        let err = client
+            .compact_input(&input, HeaderMap::new())
+            .await
+            .expect_err("expected wire mismatch to fail");
+
+        match err {
+            ApiError::Stream(msg) => {
+                assert_eq!(msg, "compact endpoint requires responses wire api");
+            }
+            other => panic!("unexpected error: {other:?}"),
+        }
+    }
+}
--- a/codex-rs/codex-api/src/endpoint/mod.rs
+++ b/codex-rs/codex-api/src/endpoint/mod.rs
@@ -0,0 +1,4 @@
+pub mod chat;
+pub mod compact;
+pub mod responses;
+mod streaming;
--- a/codex-rs/codex-api/src/endpoint/responses.rs
+++ b/codex-rs/codex-api/src/endpoint/responses.rs
@@ -0,0 +1,107 @@
+use crate::auth::AuthProvider;
+use crate::common::Prompt as ApiPrompt;
+use crate::common::Reasoning;
+use crate::common::ResponseStream;
+use crate::common::TextControls;
+use crate::endpoint::streaming::StreamingClient;
+use crate::error::ApiError;
+use crate::provider::Provider;
+use crate::provider::WireApi;
+use crate::requests::ResponsesRequest;
+use crate::requests::ResponsesRequestBuilder;
+use crate::sse::spawn_response_stream;
+use crate::telemetry::SseTelemetry;
+use codex_client::HttpTransport;
+use codex_client::RequestTelemetry;
+use codex_protocol::protocol::SessionSource;
+use http::HeaderMap;
+use serde_json::Value;
+use std::sync::Arc;
+
+pub struct ResponsesClient<T: HttpTransport, A: AuthProvider> {
+    streaming: StreamingClient<T, A>,
+}
+
+#[derive(Default)]
+pub struct ResponsesOptions {
+    pub reasoning: Option<Reasoning>,
+    pub include: Vec<String>,
+    pub prompt_cache_key: Option<String>,
+    pub text: Option<TextControls>,
+    pub store_override: Option<bool>,
+    pub conversation_id: Option<String>,
+    pub session_source: Option<SessionSource>,
+}
+
+impl<T: HttpTransport, A: AuthProvider> ResponsesClient<T, A> {
+    pub fn new(transport: T, provider: Provider, auth: A) -> Self {
+        Self {
+            streaming: StreamingClient::new(transport, provider, auth),
+        }
+    }
+
+    pub fn with_telemetry(
+        self,
+        request: Option<Arc<dyn RequestTelemetry>>,
+        sse: Option<Arc<dyn SseTelemetry>>,
+    ) -> Self {
+        Self {
+            streaming: self.streaming.with_telemetry(request, sse),
+        }
+    }
+
+    pub async fn stream_request(
+        &self,
+        request: ResponsesRequest,
+    ) -> Result<ResponseStream, ApiError> {
+        self.stream(request.body, request.headers).await
+    }
+
+    pub async fn stream_prompt(
+        &self,
+        model: &str,
+        prompt: &ApiPrompt,
+        options: ResponsesOptions,
+    ) -> Result<ResponseStream, ApiError> {
+        let ResponsesOptions {
+            reasoning,
+            include,
+            prompt_cache_key,
+            text,
+            store_override,
+            conversation_id,
+            session_source,
+        } = options;
+
+        let request = ResponsesRequestBuilder::new(model, &prompt.instructions, &prompt.input)
+            .tools(&prompt.tools)
+            .parallel_tool_calls(prompt.parallel_tool_calls)
+            .reasoning(reasoning)
+            .include(include)
+            .prompt_cache_key(prompt_cache_key)
+            .text(text)
+            .conversation(conversation_id)
+            .session_source(session_source)
+            .store_override(store_override)
+            .build(self.streaming.provider())?;
+
+        self.stream_request(request).await
+    }
+
+    fn path(&self) -> &'static str {
+        match self.streaming.provider().wire {
+            WireApi::Responses | WireApi::Compact => "responses",
+            WireApi::Chat => "chat/completions",
+        }
+    }
+
+    pub async fn stream(
+        &self,
+        body: Value,
+        extra_headers: HeaderMap,
+    ) -> Result<ResponseStream, ApiError> {
+        self.streaming
+            .stream(self.path(), body, extra_headers, spawn_response_stream)
+            .await
+    }
+}
--- a/codex-rs/codex-api/src/endpoint/streaming.rs
+++ b/codex-rs/codex-api/src/endpoint/streaming.rs
@@ -0,0 +1,82 @@
+use crate::auth::AuthProvider;
+use crate::auth::add_auth_headers;
+use crate::common::ResponseStream;
+use crate::error::ApiError;
+use crate::provider::Provider;
+use crate::telemetry::SseTelemetry;
+use crate::telemetry::run_with_request_telemetry;
+use codex_client::HttpTransport;
+use codex_client::RequestTelemetry;
+use codex_client::StreamResponse;
+use http::HeaderMap;
+use http::Method;
+use serde_json::Value;
+use std::sync::Arc;
+use std::time::Duration;
+
+pub(crate) struct StreamingClient<T: HttpTransport, A: AuthProvider> {
+    transport: T,
+    provider: Provider,
+    auth: A,
+    request_telemetry: Option<Arc<dyn RequestTelemetry>>,
+    sse_telemetry: Option<Arc<dyn SseTelemetry>>,
+}
+
+impl<T: HttpTransport, A: AuthProvider> StreamingClient<T, A> {
+    pub(crate) fn new(transport: T, provider: Provider, auth: A) -> Self {
+        Self {
+            transport,
+            provider,
+            auth,
+            request_telemetry: None,
+            sse_telemetry: None,
+        }
+    }
+
+    pub(crate) fn with_telemetry(
+        mut self,
+        request: Option<Arc<dyn RequestTelemetry>>,
+        sse: Option<Arc<dyn SseTelemetry>>,
+    ) -> Self {
+        self.request_telemetry = request;
+        self.sse_telemetry = sse;
+        self
+    }
+
+    pub(crate) fn provider(&self) -> &Provider {
+        &self.provider
+    }
+
+    pub(crate) async fn stream(
+        &self,
+        path: &str,
+        body: Value,
+        extra_headers: HeaderMap,
+        spawner: fn(StreamResponse, Duration, Option<Arc<dyn SseTelemetry>>) -> ResponseStream,
+    ) -> Result<ResponseStream, ApiError> {
+        let builder = || {
+            let mut req = self.provider.build_request(Method::POST, path);
+            req.headers.extend(extra_headers.clone());
+            req.headers.insert(
+                http::header::ACCEPT,
+                http::HeaderValue::from_static("text/event-stream"),
+            );
+            req.body = Some(body.clone());
+            add_auth_headers(&self.auth, req)
+        };
+
+        let stream_response = run_with_request_telemetry(
+            self.provider.retry.to_policy(),
+            self.request_telemetry.clone(),
+            builder,
+            |req| self.transport.stream(req),
+        )
+        .await?;
+
+        Ok(spawner(
+            stream_response,
+            self.provider.stream_idle_timeout,
+            self.sse_telemetry.clone(),
+        ))
+    }
+}
--- a/codex-rs/codex-api/src/error.rs
+++ b/codex-rs/codex-api/src/error.rs
@@ -0,0 +1,34 @@
+use crate::rate_limits::RateLimitError;
+use codex_client::TransportError;
+use http::StatusCode;
+use std::time::Duration;
+use thiserror::Error;
+
+#[derive(Debug, Error)]
+pub enum ApiError {
+    #[error(transparent)]
+    Transport(#[from] TransportError),
+    #[error("api error {status}: {message}")]
+    Api { status: StatusCode, message: String },
+    #[error("stream error: {0}")]
+    Stream(String),
+    #[error("context window exceeded")]
+    ContextWindowExceeded,
+    #[error("quota exceeded")]
+    QuotaExceeded,
+    #[error("usage not included")]
+    UsageNotIncluded,
+    #[error("retryable error: {message}")]
+    Retryable {
+        message: String,
+        delay: Option<Duration>,
+    },
+    #[error("rate limit: {0}")]
+    RateLimit(String),
+}
+
+impl From<RateLimitError> for ApiError {
+    fn from(err: RateLimitError) -> Self {
+        Self::RateLimit(err.to_string())
+    }
+}
--- a/codex-rs/codex-api/src/lib.rs
+++ b/codex-rs/codex-api/src/lib.rs
@@ -0,0 +1,35 @@
+pub mod auth;
+pub mod common;
+pub mod endpoint;
+pub mod error;
+pub mod provider;
+pub mod rate_limits;
+pub mod requests;
+pub mod sse;
+pub mod telemetry;
+
+pub use codex_client::RequestTelemetry;
+pub use codex_client::ReqwestTransport;
+pub use codex_client::TransportError;
+
+pub use crate::auth::AuthProvider;
+pub use crate::common::CompactionInput;
+pub use crate::common::Prompt;
+pub use crate::common::ResponseEvent;
+pub use crate::common::ResponseStream;
+pub use crate::common::ResponsesApiRequest;
+pub use crate::common::create_text_param_for_request;
+pub use crate::endpoint::chat::AggregateStreamExt;
+pub use crate::endpoint::chat::ChatClient;
+pub use crate::endpoint::compact::CompactClient;
+pub use crate::endpoint::responses::ResponsesClient;
+pub use crate::endpoint::responses::ResponsesOptions;
+pub use crate::error::ApiError;
+pub use crate::provider::Provider;
+pub use crate::provider::WireApi;
+pub use crate::requests::ChatRequest;
+pub use crate::requests::ChatRequestBuilder;
+pub use crate::requests::ResponsesRequest;
+pub use crate::requests::ResponsesRequestBuilder;
+pub use crate::sse::stream_from_fixture;
+pub use crate::telemetry::SseTelemetry;
--- a/codex-rs/codex-api/src/provider.rs
+++ b/codex-rs/codex-api/src/provider.rs
@@ -0,0 +1,118 @@
+use codex_client::Request;
+use codex_client::RetryOn;
+use codex_client::RetryPolicy;
+use http::Method;
+use http::header::HeaderMap;
+use std::collections::HashMap;
+use std::time::Duration;
+
+/// Wire-level APIs supported by a `Provider`.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum WireApi {
+    Responses,
+    Chat,
+    Compact,
+}
+
+/// High-level retry configuration for a provider.
+///
+/// This is converted into a `RetryPolicy` used by `codex-client` to drive
+/// transport-level retries for both unary and streaming calls.
+#[derive(Debug, Clone)]
+pub struct RetryConfig {
+    pub max_attempts: u64,
+    pub base_delay: Duration,
+    pub retry_429: bool,
+    pub retry_5xx: bool,
+    pub retry_transport: bool,
+}
+
+impl RetryConfig {
+    pub fn to_policy(&self) -> RetryPolicy {
+        RetryPolicy {
+            max_attempts: self.max_attempts,
+            base_delay: self.base_delay,
+            retry_on: RetryOn {
+                retry_429: self.retry_429,
+                retry_5xx: self.retry_5xx,
+                retry_transport: self.retry_transport,
+            },
+        }
+    }
+}
+
+/// HTTP endpoint configuration used to talk to a concrete API deployment.
+///
+/// Encapsulates base URL, default headers, query params, retry policy, and
+/// stream idle timeout, plus helper methods for building requests.
+#[derive(Debug, Clone)]
+pub struct Provider {
+    pub name: String,
+    pub base_url: String,
+    pub query_params: Option<HashMap<String, String>>,
+    pub wire: WireApi,
+    pub headers: HeaderMap,
+    pub retry: RetryConfig,
+    pub stream_idle_timeout: Duration,
+}
+
+impl Provider {
+    pub fn url_for_path(&self, path: &str) -> String {
+        let base = self.base_url.trim_end_matches('/');
+        let path = path.trim_start_matches('/');
+        let mut url = if path.is_empty() {
+            base.to_string()
+        } else {
+            format!("{base}/{path}")
+        };
+
+        if let Some(params) = &self.query_params
+            && !params.is_empty()
+        {
+            let qs = params
+                .iter()
+                .map(|(k, v)| format!("{k}={v}"))
+                .collect::<Vec<_>>()
+                .join("&");
+            url.push('?');
+            url.push_str(&qs);
+        }
+
+        url
+    }
+
+    pub fn build_request(&self, method: Method, path: &str) -> Request {
+        Request {
+            method,
+            url: self.url_for_path(path),
+            headers: self.headers.clone(),
+            body: None,
+            timeout: None,
+        }
+    }
+
+    pub fn is_azure_responses_endpoint(&self) -> bool {
+        if self.wire != WireApi::Responses {
+            return false;
+        }
+
+        if self.name.eq_ignore_ascii_case("azure") {
+            return true;
+        }
+
+        self.base_url.to_ascii_lowercase().contains("openai.azure.")
+            || matches_azure_responses_base_url(&self.base_url)
+    }
+}
+
+fn matches_azure_responses_base_url(base_url: &str) -> bool {
+    const AZURE_MARKERS: [&str; 5] = [
+        "cognitiveservices.azure.",
+        "aoai.azure.",
+        "azure-api.",
+        "azurefd.",
+        "windows.net/openai",
+    ];
+    let base = base_url.to_ascii_lowercase();
+    AZURE_MARKERS.iter().any(|marker| base.contains(marker))
+}
--- a/codex-rs/codex-api/src/rate_limits.rs
+++ b/codex-rs/codex-api/src/rate_limits.rs
@@ -0,0 +1,105 @@
+use codex_protocol::protocol::CreditsSnapshot;
+use codex_protocol::protocol::RateLimitSnapshot;
+use codex_protocol::protocol::RateLimitWindow;
+use http::HeaderMap;
+use std::fmt::Display;
+
+#[derive(Debug)]
+pub struct RateLimitError {
+    pub message: String,
+}
+
+impl Display for RateLimitError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.message)
+    }
+}
+
+/// Parses the bespoke Codex rate-limit headers into a `RateLimitSnapshot`.
+pub fn parse_rate_limit(headers: &HeaderMap) -> Option<RateLimitSnapshot> {
+    let primary = parse_rate_limit_window(
+        headers,
+        "x-codex-primary-used-percent",
+        "x-codex-primary-window-minutes",
+        "x-codex-primary-reset-at",
+    );
+
+    let secondary = parse_rate_limit_window(
+        headers,
+        "x-codex-secondary-used-percent",
+        "x-codex-secondary-window-minutes",
+        "x-codex-secondary-reset-at",
+    );
+
+    let credits = parse_credits_snapshot(headers);
+
+    Some(RateLimitSnapshot {
+        primary,
+        secondary,
+        credits,
+    })
+}
+
+fn parse_rate_limit_window(
+    headers: &HeaderMap,
+    used_percent_header: &str,
+    window_minutes_header: &str,
+    resets_at_header: &str,
+) -> Option<RateLimitWindow> {
+    let used_percent: Option<f64> = parse_header_f64(headers, used_percent_header);
+
+    used_percent.and_then(|used_percent| {
+        let window_minutes = parse_header_i64(headers, window_minutes_header);
+        let resets_at = parse_header_i64(headers, resets_at_header);
+
+        let has_data = used_percent != 0.0
+            || window_minutes.is_some_and(|minutes| minutes != 0)
+            || resets_at.is_some();
+
+        has_data.then_some(RateLimitWindow {
+            used_percent,
+            window_minutes,
+            resets_at,
+        })
+    })
+}
+
+fn parse_credits_snapshot(headers: &HeaderMap) -> Option<CreditsSnapshot> {
+    let has_credits = parse_header_bool(headers, "x-codex-credits-has-credits")?;
+    let unlimited = parse_header_bool(headers, "x-codex-credits-unlimited")?;
+    let balance = parse_header_str(headers, "x-codex-credits-balance")
+        .map(str::trim)
+        .filter(|value| !value.is_empty())
+        .map(std::string::ToString::to_string);
+    Some(CreditsSnapshot {
+        has_credits,
+        unlimited,
+        balance,
+    })
+}
+
+fn parse_header_f64(headers: &HeaderMap, name: &str) -> Option<f64> {
+    parse_header_str(headers, name)?
+        .parse::<f64>()
+        .ok()
+        .filter(|v| v.is_finite())
+}
+
+fn parse_header_i64(headers: &HeaderMap, name: &str) -> Option<i64> {
+    parse_header_str(headers, name)?.parse::<i64>().ok()
+}
+
+fn parse_header_bool(headers: &HeaderMap, name: &str) -> Option<bool> {
+    let raw = parse_header_str(headers, name)?;
+    if raw.eq_ignore_ascii_case("true") || raw == "1" {
+        Some(true)
+    } else if raw.eq_ignore_ascii_case("false") || raw == "0" {
+        Some(false)
+    } else {
+        None
+    }
+}
+
+fn parse_header_str<'a>(headers: &'a HeaderMap, name: &str) -> Option<&'a str> {
+    headers.get(name)?.to_str().ok()
+}
--- a/codex-rs/codex-api/src/requests/chat.rs
+++ b/codex-rs/codex-api/src/requests/chat.rs
@@ -0,0 +1,388 @@
+use crate::error::ApiError;
+use crate::provider::Provider;
+use crate::requests::headers::build_conversation_headers;
+use crate::requests::headers::insert_header;
+use crate::requests::headers::subagent_header;
+use codex_protocol::models::ContentItem;
+use codex_protocol::models::FunctionCallOutputContentItem;
+use codex_protocol::models::ReasoningItemContent;
+use codex_protocol::models::ResponseItem;
+use codex_protocol::protocol::SessionSource;
+use http::HeaderMap;
+use serde_json::Value;
+use serde_json::json;
+use std::collections::HashMap;
+
+/// Assembled request body plus headers for Chat Completions streaming calls.
+pub struct ChatRequest {
+    pub body: Value,
+    pub headers: HeaderMap,
+}
+
+pub struct ChatRequestBuilder<'a> {
+    model: &'a str,
+    instructions: &'a str,
+    input: &'a [ResponseItem],
+    tools: &'a [Value],
+    conversation_id: Option<String>,
+    session_source: Option<SessionSource>,
+}
+
+impl<'a> ChatRequestBuilder<'a> {
+    pub fn new(
+        model: &'a str,
+        instructions: &'a str,
+        input: &'a [ResponseItem],
+        tools: &'a [Value],
+    ) -> Self {
+        Self {
+            model,
+            instructions,
+            input,
+            tools,
+            conversation_id: None,
+            session_source: None,
+        }
+    }
+
+    pub fn conversation_id(mut self, id: Option<String>) -> Self {
+        self.conversation_id = id;
+        self
+    }
+
+    pub fn session_source(mut self, source: Option<SessionSource>) -> Self {
+        self.session_source = source;
+        self
+    }
+
+    pub fn build(self, _provider: &Provider) -> Result<ChatRequest, ApiError> {
+        let mut messages = Vec::<Value>::new();
+        messages.push(json!({"role": "system", "content": self.instructions}));
+
+        let input = self.input;
+        let mut reasoning_by_anchor_index: HashMap<usize, String> = HashMap::new();
+        let mut last_emitted_role: Option<&str> = None;
+        for item in input {
+            match item {
+                ResponseItem::Message { role, .. } => last_emitted_role = Some(role.as_str()),
+                ResponseItem::FunctionCall { .. } | ResponseItem::LocalShellCall { .. } => {
+                    last_emitted_role = Some("assistant")
+                }
+                ResponseItem::FunctionCallOutput { .. } => last_emitted_role = Some("tool"),
+                ResponseItem::Reasoning { .. } | ResponseItem::Other => {}
+                ResponseItem::CustomToolCall { .. } => {}
+                ResponseItem::CustomToolCallOutput { .. } => {}
+                ResponseItem::WebSearchCall { .. } => {}
+                ResponseItem::GhostSnapshot { .. } => {}
+                ResponseItem::CompactionSummary { .. } => {}
+            }
+        }
+
+        let mut last_user_index: Option<usize> = None;
+        for (idx, item) in input.iter().enumerate() {
+            if let ResponseItem::Message { role, .. } = item
+                && role == "user"
+            {
+                last_user_index = Some(idx);
+            }
+        }
+
+        if !matches!(last_emitted_role, Some("user")) {
+            for (idx, item) in input.iter().enumerate() {
+                if let Some(u_idx) = last_user_index
+                    && idx <= u_idx
+                {
+                    continue;
+                }
+
+                if let ResponseItem::Reasoning {
+                    content: Some(items),
+                    ..
+                } = item
+                {
+                    let mut text = String::new();
+                    for entry in items {
+                        match entry {
+                            ReasoningItemContent::ReasoningText { text: segment }
+                            | ReasoningItemContent::Text { text: segment } => {
+                                text.push_str(segment)
+                            }
+                        }
+                    }
+                    if text.trim().is_empty() {
+                        continue;
+                    }
+
+                    let mut attached = false;
+                    if idx > 0
+                        && let ResponseItem::Message { role, .. } = &input[idx - 1]
+                        && role == "assistant"
+                    {
+                        reasoning_by_anchor_index
+                            .entry(idx - 1)
+                            .and_modify(|v| v.push_str(&text))
+                            .or_insert(text.clone());
+                        attached = true;
+                    }
+
+                    if !attached && idx + 1 < input.len() {
+                        match &input[idx + 1] {
+                            ResponseItem::FunctionCall { .. }
+                            | ResponseItem::LocalShellCall { .. } => {
+                                reasoning_by_anchor_index
+                                    .entry(idx + 1)
+                                    .and_modify(|v| v.push_str(&text))
+                                    .or_insert(text.clone());
+                            }
+                            ResponseItem::Message { role, .. } if role == "assistant" => {
+                                reasoning_by_anchor_index
+                                    .entry(idx + 1)
+                                    .and_modify(|v| v.push_str(&text))
+                                    .or_insert(text.clone());
+                            }
+                            _ => {}
+                        }
+                    }
+                }
+            }
+        }
+
+        let mut last_assistant_text: Option<String> = None;
+
+        for (idx, item) in input.iter().enumerate() {
+            match item {
+                ResponseItem::Message { role, content, .. } => {
+                    let mut text = String::new();
+                    let mut items: Vec<Value> = Vec::new();
+                    let mut saw_image = false;
+
+                    for c in content {
+                        match c {
+                            ContentItem::InputText { text: t }
+                            | ContentItem::OutputText { text: t } => {
+                                text.push_str(t);
+                                items.push(json!({"type":"text","text": t}));
+                            }
+                            ContentItem::InputImage { image_url } => {
+                                saw_image = true;
+                                items.push(
+                                    json!({"type":"image_url","image_url": {"url": image_url}}),
+                                );
+                            }
+                        }
+                    }
+
+                    if role == "assistant" {
+                        if let Some(prev) = &last_assistant_text
+                            && prev == &text
+                        {
+                            continue;
+                        }
+                        last_assistant_text = Some(text.clone());
+                    }
+
+                    let content_value = if role == "assistant" {
+                        json!(text)
+                    } else if saw_image {
+                        json!(items)
+                    } else {
+                        json!(text)
+                    };
+
+                    let mut msg = json!({"role": role, "content": content_value});
+                    if role == "assistant"
+                        && let Some(reasoning) = reasoning_by_anchor_index.get(&idx)
+                        && let Some(obj) = msg.as_object_mut()
+                    {
+                        obj.insert("reasoning".to_string(), json!(reasoning));
+                    }
+                    messages.push(msg);
+                }
+                ResponseItem::FunctionCall {
+                    name,
+                    arguments,
+                    call_id,
+                    ..
+                } => {
+                    let mut msg = json!({
+                        "role": "assistant",
+                        "content": null,
+                        "tool_calls": [{
+                            "id": call_id,
+                            "type": "function",
+                            "function": {
+                                "name": name,
+                                "arguments": arguments,
+                            }
+                        }]
+                    });
+                    if let Some(reasoning) = reasoning_by_anchor_index.get(&idx)
+                        && let Some(obj) = msg.as_object_mut()
+                    {
+                        obj.insert("reasoning".to_string(), json!(reasoning));
+                    }
+                    messages.push(msg);
+                }
+                ResponseItem::LocalShellCall {
+                    id,
+                    call_id: _,
+                    status,
+                    action,
+                } => {
+                    let mut msg = json!({
+                        "role": "assistant",
+                        "content": null,
+                        "tool_calls": [{
+                            "id": id.clone().unwrap_or_default(),
+                            "type": "local_shell_call",
+                            "status": status,
+                            "action": action,
+                        }]
+                    });
+                    if let Some(reasoning) = reasoning_by_anchor_index.get(&idx)
+                        && let Some(obj) = msg.as_object_mut()
+                    {
+                        obj.insert("reasoning".to_string(), json!(reasoning));
+                    }
+                    messages.push(msg);
+                }
+                ResponseItem::FunctionCallOutput { call_id, output } => {
+                    let content_value = if let Some(items) = &output.content_items {
+                        let mapped: Vec<Value> = items
+                            .iter()
+                            .map(|it| match it {
+                                FunctionCallOutputContentItem::InputText { text } => {
+                                    json!({"type":"text","text": text})
+                                }
+                                FunctionCallOutputContentItem::InputImage { image_url } => {
+                                    json!({"type":"image_url","image_url": {"url": image_url}})
+                                }
+                            })
+                            .collect();
+                        json!(mapped)
+                    } else {
+                        json!(output.content)
+                    };
+
+                    messages.push(json!({
+                        "role": "tool",
+                        "tool_call_id": call_id,
+                        "content": content_value,
+                    }));
+                }
+                ResponseItem::CustomToolCall {
+                    id,
+                    call_id: _,
+                    name,
+                    input,
+                    status: _,
+                } => {
+                    messages.push(json!({
+                        "role": "assistant",
+                        "content": null,
+                        "tool_calls": [{
+                            "id": id,
+                            "type": "custom",
+                            "custom": {
+                                "name": name,
+                                "input": input,
+                            }
+                        }]
+                    }));
+                }
+                ResponseItem::CustomToolCallOutput { call_id, output } => {
+                    messages.push(json!({
+                        "role": "tool",
+                        "tool_call_id": call_id,
+                        "content": output,
+                    }));
+                }
+                ResponseItem::GhostSnapshot { .. } => {
+                    continue;
+                }
+                ResponseItem::Reasoning { .. }
+                | ResponseItem::WebSearchCall { .. }
+                | ResponseItem::Other
+                | ResponseItem::CompactionSummary { .. } => {
+                    continue;
+                }
+            }
+        }
+
+        let payload = json!({
+            "model": self.model,
+            "messages": messages,
+            "stream": true,
+            "tools": self.tools,
+        });
+
+        let mut headers = build_conversation_headers(self.conversation_id);
+        if let Some(subagent) = subagent_header(&self.session_source) {
+            insert_header(&mut headers, "x-openai-subagent", &subagent);
+        }
+
+        Ok(ChatRequest {
+            body: payload,
+            headers,
+        })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::provider::RetryConfig;
+    use crate::provider::WireApi;
+    use codex_protocol::protocol::SessionSource;
+    use codex_protocol::protocol::SubAgentSource;
+    use http::HeaderValue;
+    use pretty_assertions::assert_eq;
+    use std::time::Duration;
+
+    fn provider() -> Provider {
+        Provider {
+            name: "openai".to_string(),
+            base_url: "https://api.openai.com/v1".to_string(),
+            query_params: None,
+            wire: WireApi::Chat,
+            headers: HeaderMap::new(),
+            retry: RetryConfig {
+                max_attempts: 1,
+                base_delay: Duration::from_millis(10),
+                retry_429: false,
+                retry_5xx: true,
+                retry_transport: true,
+            },
+            stream_idle_timeout: Duration::from_secs(1),
+        }
+    }
+
+    #[test]
+    fn attaches_conversation_and_subagent_headers() {
+        let prompt_input = vec![ResponseItem::Message {
+            id: None,
+            role: "user".to_string(),
+            content: vec![ContentItem::InputText {
+                text: "hi".to_string(),
+            }],
+        }];
+        let req = ChatRequestBuilder::new("gpt-test", "inst", &prompt_input, &[])
+            .conversation_id(Some("conv-1".into()))
+            .session_source(Some(SessionSource::SubAgent(SubAgentSource::Review)))
+            .build(&provider())
+            .expect("request");
+
+        assert_eq!(
+            req.headers.get("conversation_id"),
+            Some(&HeaderValue::from_static("conv-1"))
+        );
+        assert_eq!(
+            req.headers.get("session_id"),
+            Some(&HeaderValue::from_static("conv-1"))
+        );
+        assert_eq!(
+            req.headers.get("x-openai-subagent"),
+            Some(&HeaderValue::from_static("review"))
+        );
+    }
+}
--- a/codex-rs/codex-api/src/requests/headers.rs
+++ b/codex-rs/codex-api/src/requests/headers.rs
@@ -0,0 +1,36 @@
+use codex_protocol::protocol::SessionSource;
+use http::HeaderMap;
+use http::HeaderValue;
+
+pub(crate) fn build_conversation_headers(conversation_id: Option<String>) -> HeaderMap {
+    let mut headers = HeaderMap::new();
+    if let Some(id) = conversation_id {
+        insert_header(&mut headers, "conversation_id", &id);
+        insert_header(&mut headers, "session_id", &id);
+    }
+    headers
+}
+
+pub(crate) fn subagent_header(source: &Option<SessionSource>) -> Option<String> {
+    let SessionSource::SubAgent(sub) = source.as_ref()? else {
+        return None;
+    };
+    match sub {
+        codex_protocol::protocol::SubAgentSource::Other(label) => Some(label.clone()),
+        other => Some(
+            serde_json::to_value(other)
+                .ok()
+                .and_then(|v| v.as_str().map(std::string::ToString::to_string))
+                .unwrap_or_else(|| "other".to_string()),
+        ),
+    }
+}
+
+pub(crate) fn insert_header(headers: &mut HeaderMap, name: &str, value: &str) {
+    if let (Ok(header_name), Ok(header_value)) = (
+        name.parse::<http::HeaderName>(),
+        HeaderValue::from_str(value),
+    ) {
+        headers.insert(header_name, header_value);
+    }
+}
--- a/codex-rs/codex-api/src/requests/mod.rs
+++ b/codex-rs/codex-api/src/requests/mod.rs
@@ -0,0 +1,8 @@
+pub mod chat;
+pub(crate) mod headers;
+pub mod responses;
+
+pub use chat::ChatRequest;
+pub use chat::ChatRequestBuilder;
+pub use responses::ResponsesRequest;
+pub use responses::ResponsesRequestBuilder;
--- a/codex-rs/codex-api/src/requests/responses.rs
+++ b/codex-rs/codex-api/src/requests/responses.rs
@@ -0,0 +1,247 @@
+use crate::common::Reasoning;
+use crate::common::ResponsesApiRequest;
+use crate::common::TextControls;
+use crate::error::ApiError;
+use crate::provider::Provider;
+use crate::requests::headers::build_conversation_headers;
+use crate::requests::headers::insert_header;
+use crate::requests::headers::subagent_header;
+use codex_protocol::models::ResponseItem;
+use codex_protocol::protocol::SessionSource;
+use http::HeaderMap;
+use serde_json::Value;
+
+/// Assembled request body plus headers for a Responses stream request.
+pub struct ResponsesRequest {
+    pub body: Value,
+    pub headers: HeaderMap,
+}
+
+#[derive(Default)]
+pub struct ResponsesRequestBuilder<'a> {
+    model: Option<&'a str>,
+    instructions: Option<&'a str>,
+    input: Option<&'a [ResponseItem]>,
+    tools: Option<&'a [Value]>,
+    parallel_tool_calls: bool,
+    reasoning: Option<Reasoning>,
+    include: Vec<String>,
+    prompt_cache_key: Option<String>,
+    text: Option<TextControls>,
+    conversation_id: Option<String>,
+    session_source: Option<SessionSource>,
+    store_override: Option<bool>,
+    headers: HeaderMap,
+}
+
+impl<'a> ResponsesRequestBuilder<'a> {
+    pub fn new(model: &'a str, instructions: &'a str, input: &'a [ResponseItem]) -> Self {
+        Self {
+            model: Some(model),
+            instructions: Some(instructions),
+            input: Some(input),
+            ..Default::default()
+        }
+    }
+
+    pub fn tools(mut self, tools: &'a [Value]) -> Self {
+        self.tools = Some(tools);
+        self
+    }
+
+    pub fn parallel_tool_calls(mut self, enabled: bool) -> Self {
+        self.parallel_tool_calls = enabled;
+        self
+    }
+
+    pub fn reasoning(mut self, reasoning: Option<Reasoning>) -> Self {
+        self.reasoning = reasoning;
+        self
+    }
+
+    pub fn include(mut self, include: Vec<String>) -> Self {
+        self.include = include;
+        self
+    }
+
+    pub fn prompt_cache_key(mut self, key: Option<String>) -> Self {
+        self.prompt_cache_key = key;
+        self
+    }
+
+    pub fn text(mut self, text: Option<TextControls>) -> Self {
+        self.text = text;
+        self
+    }
+
+    pub fn conversation(mut self, conversation_id: Option<String>) -> Self {
+        self.conversation_id = conversation_id;
+        self
+    }
+
+    pub fn session_source(mut self, source: Option<SessionSource>) -> Self {
+        self.session_source = source;
+        self
+    }
+
+    pub fn store_override(mut self, store: Option<bool>) -> Self {
+        self.store_override = store;
+        self
+    }
+
+    pub fn extra_headers(mut self, headers: HeaderMap) -> Self {
+        self.headers = headers;
+        self
+    }
+
+    pub fn build(self, provider: &Provider) -> Result<ResponsesRequest, ApiError> {
+        let model = self
+            .model
+            .ok_or_else(|| ApiError::Stream("missing model for responses request".into()))?;
+        let instructions = self
+            .instructions
+            .ok_or_else(|| ApiError::Stream("missing instructions for responses request".into()))?;
+        let input = self
+            .input
+            .ok_or_else(|| ApiError::Stream("missing input for responses request".into()))?;
+        let tools = self.tools.unwrap_or_default();
+
+        let store = self
+            .store_override
+            .unwrap_or_else(|| provider.is_azure_responses_endpoint());
+
+        let req = ResponsesApiRequest {
+            model,
+            instructions,
+            input,
+            tools,
+            tool_choice: "auto",
+            parallel_tool_calls: self.parallel_tool_calls,
+            reasoning: self.reasoning,
+            store,
+            stream: true,
+            include: self.include,
+            prompt_cache_key: self.prompt_cache_key,
+            text: self.text,
+        };
+
+        let mut body = serde_json::to_value(&req)
+            .map_err(|e| ApiError::Stream(format!("failed to encode responses request: {e}")))?;
+
+        if store && provider.is_azure_responses_endpoint() {
+            attach_item_ids(&mut body, input);
+        }
+
+        let mut headers = self.headers;
+        headers.extend(build_conversation_headers(self.conversation_id));
+        if let Some(subagent) = subagent_header(&self.session_source) {
+            insert_header(&mut headers, "x-openai-subagent", &subagent);
+        }
+
+        Ok(ResponsesRequest { body, headers })
+    }
+}
+
+fn attach_item_ids(payload_json: &mut Value, original_items: &[ResponseItem]) {
+    let Some(input_value) = payload_json.get_mut("input") else {
+        return;
+    };
+    let Value::Array(items) = input_value else {
+        return;
+    };
+
+    for (value, item) in items.iter_mut().zip(original_items.iter()) {
+        if let ResponseItem::Reasoning { id, .. }
+        | ResponseItem::Message { id: Some(id), .. }
+        | ResponseItem::WebSearchCall { id: Some(id), .. }
+        | ResponseItem::FunctionCall { id: Some(id), .. }
+        | ResponseItem::LocalShellCall { id: Some(id), .. }
+        | ResponseItem::CustomToolCall { id: Some(id), .. } = item
+        {
+            if id.is_empty() {
+                continue;
+            }
+
+            if let Some(obj) = value.as_object_mut() {
+                obj.insert("id".to_string(), Value::String(id.clone()));
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::provider::RetryConfig;
+    use crate::provider::WireApi;
+    use codex_protocol::protocol::SubAgentSource;
+    use http::HeaderValue;
+    use pretty_assertions::assert_eq;
+    use std::time::Duration;
+
+    fn provider(name: &str, base_url: &str) -> Provider {
+        Provider {
+            name: name.to_string(),
+            base_url: base_url.to_string(),
+            query_params: None,
+            wire: WireApi::Responses,
+            headers: HeaderMap::new(),
+            retry: RetryConfig {
+                max_attempts: 1,
+                base_delay: Duration::from_millis(50),
+                retry_429: false,
+                retry_5xx: true,
+                retry_transport: true,
+            },
+            stream_idle_timeout: Duration::from_secs(5),
+        }
+    }
+
+    #[test]
+    fn azure_default_store_attaches_ids_and_headers() {
+        let provider = provider("azure", "https://example.openai.azure.com/v1");
+        let input = vec![
+            ResponseItem::Message {
+                id: Some("m1".into()),
+                role: "assistant".into(),
+                content: Vec::new(),
+            },
+            ResponseItem::Message {
+                id: None,
+                role: "assistant".into(),
+                content: Vec::new(),
+            },
+        ];
+
+        let request = ResponsesRequestBuilder::new("gpt-test", "inst", &input)
+            .conversation(Some("conv-1".into()))
+            .session_source(Some(SessionSource::SubAgent(SubAgentSource::Review)))
+            .build(&provider)
+            .expect("request");
+
+        assert_eq!(request.body.get("store"), Some(&Value::Bool(true)));
+
+        let ids: Vec<Option<String>> = request
+            .body
+            .get("input")
+            .and_then(|v| v.as_array())
+            .into_iter()
+            .flatten()
+            .map(|item| item.get("id").and_then(|v| v.as_str().map(str::to_string)))
+            .collect();
+        assert_eq!(ids, vec![Some("m1".to_string()), None]);
+
+        assert_eq!(
+            request.headers.get("conversation_id"),
+            Some(&HeaderValue::from_static("conv-1"))
+        );
+        assert_eq!(
+            request.headers.get("session_id"),
+            Some(&HeaderValue::from_static("conv-1"))
+        );
+        assert_eq!(
+            request.headers.get("x-openai-subagent"),
+            Some(&HeaderValue::from_static("review"))
+        );
+    }
+}
--- a/codex-rs/codex-api/src/sse/chat.rs
+++ b/codex-rs/codex-api/src/sse/chat.rs
@@ -0,0 +1,504 @@
+use crate::common::ResponseEvent;
+use crate::common::ResponseStream;
+use crate::error::ApiError;
+use crate::telemetry::SseTelemetry;
+use codex_client::StreamResponse;
+use codex_protocol::models::ContentItem;
+use codex_protocol::models::ReasoningItemContent;
+use codex_protocol::models::ResponseItem;
+use eventsource_stream::Eventsource;
+use futures::Stream;
+use futures::StreamExt;
+use std::collections::HashMap;
+use std::time::Duration;
+use tokio::sync::mpsc;
+use tokio::time::Instant;
+use tokio::time::timeout;
+use tracing::debug;
+use tracing::trace;
+
+pub(crate) fn spawn_chat_stream(
+    stream_response: StreamResponse,
+    idle_timeout: Duration,
+    telemetry: Option<std::sync::Arc<dyn SseTelemetry>>,
+) -> ResponseStream {
+    let (tx_event, rx_event) = mpsc::channel::<Result<ResponseEvent, ApiError>>(1600);
+    tokio::spawn(async move {
+        process_chat_sse(stream_response.bytes, tx_event, idle_timeout, telemetry).await;
+    });
+    ResponseStream { rx_event }
+}
+
+pub async fn process_chat_sse<S>(
+    stream: S,
+    tx_event: mpsc::Sender<Result<ResponseEvent, ApiError>>,
+    idle_timeout: Duration,
+    telemetry: Option<std::sync::Arc<dyn SseTelemetry>>,
+) where
+    S: Stream<Item = Result<bytes::Bytes, codex_client::TransportError>> + Unpin,
+{
+    let mut stream = stream.eventsource();
+
+    #[derive(Default, Debug)]
+    struct ToolCallState {
+        name: Option<String>,
+        arguments: String,
+    }
+
+    let mut tool_calls: HashMap<String, ToolCallState> = HashMap::new();
+    let mut tool_call_order: Vec<String> = Vec::new();
+    let mut assistant_item: Option<ResponseItem> = None;
+    let mut reasoning_item: Option<ResponseItem> = None;
+    let mut completed_sent = false;
+
+    loop {
+        let start = Instant::now();
+        let response = timeout(idle_timeout, stream.next()).await;
+        if let Some(t) = telemetry.as_ref() {
+            t.on_sse_poll(&response, start.elapsed());
+        }
+        let sse = match response {
+            Ok(Some(Ok(sse))) => sse,
+            Ok(Some(Err(e))) => {
+                let _ = tx_event.send(Err(ApiError::Stream(e.to_string()))).await;
+                return;
+            }
+            Ok(None) => {
+                if let Some(reasoning) = reasoning_item {
+                    let _ = tx_event
+                        .send(Ok(ResponseEvent::OutputItemDone(reasoning)))
+                        .await;
+                }
+
+                if let Some(assistant) = assistant_item {
+                    let _ = tx_event
+                        .send(Ok(ResponseEvent::OutputItemDone(assistant)))
+                        .await;
+                }
+                if !completed_sent {
+                    let _ = tx_event
+                        .send(Ok(ResponseEvent::Completed {
+                            response_id: String::new(),
+                            token_usage: None,
+                        }))
+                        .await;
+                }
+                return;
+            }
+            Err(_) => {
+                let _ = tx_event
+                    .send(Err(ApiError::Stream("idle timeout waiting for SSE".into())))
+                    .await;
+                return;
+            }
+        };
+
+        trace!("SSE event: {}", sse.data);
+
+        if sse.data.trim().is_empty() {
+            continue;
+        }
+
+        let value: serde_json::Value = match serde_json::from_str(&sse.data) {
+            Ok(val) => val,
+            Err(err) => {
+                debug!(
+                    "Failed to parse ChatCompletions SSE event: {err}, data: {}",
+                    &sse.data
+                );
+                continue;
+            }
+        };
+
+        let Some(choices) = value.get("choices").and_then(|c| c.as_array()) else {
+            continue;
+        };
+
+        for choice in choices {
+            if let Some(delta) = choice.get("delta") {
+                if let Some(reasoning) = delta.get("reasoning") {
+                    if let Some(text) = reasoning.as_str() {
+                        append_reasoning_text(&tx_event, &mut reasoning_item, text.to_string())
+                            .await;
+                    } else if let Some(text) = reasoning.get("text").and_then(|v| v.as_str()) {
+                        append_reasoning_text(&tx_event, &mut reasoning_item, text.to_string())
+                            .await;
+                    } else if let Some(text) = reasoning.get("content").and_then(|v| v.as_str()) {
+                        append_reasoning_text(&tx_event, &mut reasoning_item, text.to_string())
+                            .await;
+                    }
+                }
+
+                if let Some(content) = delta.get("content") {
+                    if content.is_array() {
+                        for item in content.as_array().unwrap_or(&vec![]) {
+                            if let Some(text) = item.get("text").and_then(|t| t.as_str()) {
+                                append_assistant_text(
+                                    &tx_event,
+                                    &mut assistant_item,
+                                    text.to_string(),
+                                )
+                                .await;
+                            }
+                        }
+                    } else if let Some(text) = content.as_str() {
+                        append_assistant_text(&tx_event, &mut assistant_item, text.to_string())
+                            .await;
+                    }
+                }
+
+                if let Some(tool_call_values) = delta.get("tool_calls").and_then(|c| c.as_array()) {
+                    for tool_call in tool_call_values {
+                        let id = tool_call
+                            .get("id")
+                            .and_then(|i| i.as_str())
+                            .map(str::to_string)
+                            .unwrap_or_else(|| format!("tool-call-{}", tool_call_order.len()));
+
+                        let call_state = tool_calls.entry(id.clone()).or_default();
+                        if !tool_call_order.contains(&id) {
+                            tool_call_order.push(id.clone());
+                        }
+
+                        if let Some(func) = tool_call.get("function") {
+                            if let Some(fname) = func.get("name").and_then(|n| n.as_str()) {
+                                call_state.name = Some(fname.to_string());
+                            }
+                            if let Some(arguments) = func.get("arguments").and_then(|a| a.as_str())
+                            {
+                                call_state.arguments.push_str(arguments);
+                            }
+                        }
+                    }
+                }
+            }
+
+            if let Some(message) = choice.get("message")
+                && let Some(reasoning) = message.get("reasoning")
+            {
+                if let Some(text) = reasoning.as_str() {
+                    append_reasoning_text(&tx_event, &mut reasoning_item, text.to_string()).await;
+                } else if let Some(text) = reasoning.get("text").and_then(|v| v.as_str()) {
+                    append_reasoning_text(&tx_event, &mut reasoning_item, text.to_string()).await;
+                } else if let Some(text) = reasoning.get("content").and_then(|v| v.as_str()) {
+                    append_reasoning_text(&tx_event, &mut reasoning_item, text.to_string()).await;
+                }
+            }
+
+            let finish_reason = choice.get("finish_reason").and_then(|r| r.as_str());
+            if finish_reason == Some("stop") {
+                if let Some(reasoning) = reasoning_item.take() {
+                    let _ = tx_event
+                        .send(Ok(ResponseEvent::OutputItemDone(reasoning)))
+                        .await;
+                }
+
+                if let Some(assistant) = assistant_item.take() {
+                    let _ = tx_event
+                        .send(Ok(ResponseEvent::OutputItemDone(assistant)))
+                        .await;
+                }
+                if !completed_sent {
+                    let _ = tx_event
+                        .send(Ok(ResponseEvent::Completed {
+                            response_id: String::new(),
+                            token_usage: None,
+                        }))
+                        .await;
+                    completed_sent = true;
+                }
+                continue;
+            }
+
+            if finish_reason == Some("length") {
+                let _ = tx_event.send(Err(ApiError::ContextWindowExceeded)).await;
+                return;
+            }
+
+            if finish_reason == Some("tool_calls") {
+                if let Some(reasoning) = reasoning_item.take() {
+                    let _ = tx_event
+                        .send(Ok(ResponseEvent::OutputItemDone(reasoning)))
+                        .await;
+                }
+
+                for call_id in tool_call_order.drain(..) {
+                    let state = tool_calls.remove(&call_id).unwrap_or_default();
+                    let item = ResponseItem::FunctionCall {
+                        id: None,
+                        name: state.name.unwrap_or_default(),
+                        arguments: state.arguments,
+                        call_id: call_id.clone(),
+                    };
+                    let _ = tx_event.send(Ok(ResponseEvent::OutputItemDone(item))).await;
+                }
+            }
+        }
+    }
+}
+
+async fn append_assistant_text(
+    tx_event: &mpsc::Sender<Result<ResponseEvent, ApiError>>,
+    assistant_item: &mut Option<ResponseItem>,
+    text: String,
+) {
+    if assistant_item.is_none() {
+        let item = ResponseItem::Message {
+            id: None,
+            role: "assistant".to_string(),
+            content: vec![],
+        };
+        *assistant_item = Some(item.clone());
+        let _ = tx_event
+            .send(Ok(ResponseEvent::OutputItemAdded(item)))
+            .await;
+    }
+
+    if let Some(ResponseItem::Message { content, .. }) = assistant_item {
+        content.push(ContentItem::OutputText { text: text.clone() });
+        let _ = tx_event
+            .send(Ok(ResponseEvent::OutputTextDelta(text.clone())))
+            .await;
+    }
+}
+
+async fn append_reasoning_text(
+    tx_event: &mpsc::Sender<Result<ResponseEvent, ApiError>>,
+    reasoning_item: &mut Option<ResponseItem>,
+    text: String,
+) {
+    if reasoning_item.is_none() {
+        let item = ResponseItem::Reasoning {
+            id: String::new(),
+            summary: Vec::new(),
+            content: Some(vec![]),
+            encrypted_content: None,
+        };
+        *reasoning_item = Some(item.clone());
+        let _ = tx_event
+            .send(Ok(ResponseEvent::OutputItemAdded(item)))
+            .await;
+    }
+
+    if let Some(ResponseItem::Reasoning {
+        content: Some(content),
+        ..
+    }) = reasoning_item
+    {
+        let content_index = content.len() as i64;
+        content.push(ReasoningItemContent::ReasoningText { text: text.clone() });
+
+        let _ = tx_event
+            .send(Ok(ResponseEvent::ReasoningContentDelta {
+                delta: text.clone(),
+                content_index,
+            }))
+            .await;
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use assert_matches::assert_matches;
+    use codex_protocol::models::ResponseItem;
+    use futures::TryStreamExt;
+    use serde_json::json;
+    use tokio::sync::mpsc;
+    use tokio_util::io::ReaderStream;
+
+    fn build_body(events: &[serde_json::Value]) -> String {
+        let mut body = String::new();
+        for e in events {
+            body.push_str(&format!("event: message\ndata: {e}\n\n"));
+        }
+        body
+    }
+
+    async fn collect_events(body: &str) -> Vec<ResponseEvent> {
+        let reader = ReaderStream::new(std::io::Cursor::new(body.to_string()))
+            .map_err(|err| codex_client::TransportError::Network(err.to_string()));
+        let (tx, mut rx) = mpsc::channel::<Result<ResponseEvent, ApiError>>(16);
+        tokio::spawn(process_chat_sse(
+            reader,
+            tx,
+            Duration::from_millis(1000),
+            None,
+        ));
+
+        let mut out = Vec::new();
+        while let Some(ev) = rx.recv().await {
+            out.push(ev.expect("stream error"));
+        }
+        out
+    }
+
+    #[tokio::test]
+    async fn emits_multiple_tool_calls() {
+        let delta_a = json!({
+            "choices": [{
+                "delta": {
+                    "tool_calls": [{
+                        "id": "call_a",
+                        "function": { "name": "do_a", "arguments": "{\"foo\":1}" }
+                    }]
+                }
+            }]
+        });
+
+        let delta_b = json!({
+            "choices": [{
+                "delta": {
+                    "tool_calls": [{
+                        "id": "call_b",
+                        "function": { "name": "do_b", "arguments": "{\"bar\":2}" }
+                    }]
+                }
+            }]
+        });
+
+        let finish = json!({
+            "choices": [{
+                "finish_reason": "tool_calls"
+            }]
+        });
+
+        let body = build_body(&[delta_a, delta_b, finish]);
+        let events = collect_events(&body).await;
+        assert_eq!(events.len(), 3);
+
+        assert_matches!(
+            &events[0],
+            ResponseEvent::OutputItemDone(ResponseItem::FunctionCall { call_id, name, arguments, .. })
+            if call_id == "call_a" && name == "do_a" && arguments == "{\"foo\":1}"
+        );
+        assert_matches!(
+            &events[1],
+            ResponseEvent::OutputItemDone(ResponseItem::FunctionCall { call_id, name, arguments, .. })
+            if call_id == "call_b" && name == "do_b" && arguments == "{\"bar\":2}"
+        );
+        assert_matches!(events[2], ResponseEvent::Completed { .. });
+    }
+
+    #[tokio::test]
+    async fn concatenates_tool_call_arguments_across_deltas() {
+        let delta_name = json!({
+            "choices": [{
+                "delta": {
+                    "tool_calls": [{
+                        "id": "call_a",
+                        "function": { "name": "do_a" }
+                    }]
+                }
+            }]
+        });
+
+        let delta_args_1 = json!({
+            "choices": [{
+                "delta": {
+                    "tool_calls": [{
+                        "id": "call_a",
+                        "function": { "arguments": "{ \"foo\":" }
+                    }]
+                }
+            }]
+        });
+
+        let delta_args_2 = json!({
+            "choices": [{
+                "delta": {
+                    "tool_calls": [{
+                        "id": "call_a",
+                        "function": { "arguments": "1}" }
+                    }]
+                }
+            }]
+        });
+
+        let finish = json!({
+            "choices": [{
+                "finish_reason": "tool_calls"
+            }]
+        });
+
+        let body = build_body(&[delta_name, delta_args_1, delta_args_2, finish]);
+        let events = collect_events(&body).await;
+        assert_matches!(
+            &events[..],
+            [
+                ResponseEvent::OutputItemDone(ResponseItem::FunctionCall { call_id, name, arguments, .. }),
+                ResponseEvent::Completed { .. }
+            ] if call_id == "call_a" && name == "do_a" && arguments == "{ \"foo\":1}"
+        );
+    }
+
+    #[tokio::test]
+    async fn emits_tool_calls_even_when_content_and_reasoning_present() {
+        let delta_content_and_tools = json!({
+            "choices": [{
+                "delta": {
+                    "content": [{"text": "hi"}],
+                    "reasoning": "because",
+                    "tool_calls": [{
+                        "id": "call_a",
+                        "function": { "name": "do_a", "arguments": "{}" }
+                    }]
+                }
+            }]
+        });
+
+        let finish = json!({
+            "choices": [{
+                "finish_reason": "tool_calls"
+            }]
+        });
+
+        let body = build_body(&[delta_content_and_tools, finish]);
+        let events = collect_events(&body).await;
+
+        assert_matches!(
+            &events[..],
+            [
+                ResponseEvent::OutputItemAdded(ResponseItem::Reasoning { .. }),
+                ResponseEvent::ReasoningContentDelta { .. },
+                ResponseEvent::OutputItemAdded(ResponseItem::Message { .. }),
+                ResponseEvent::OutputTextDelta(delta),
+                ResponseEvent::OutputItemDone(ResponseItem::Reasoning { .. }),
+                ResponseEvent::OutputItemDone(ResponseItem::FunctionCall { call_id, name, .. }),
+                ResponseEvent::OutputItemDone(ResponseItem::Message { .. }),
+                ResponseEvent::Completed { .. }
+            ] if delta == "hi" && call_id == "call_a" && name == "do_a"
+        );
+    }
+
+    #[tokio::test]
+    async fn drops_partial_tool_calls_on_stop_finish_reason() {
+        let delta_tool = json!({
+            "choices": [{
+                "delta": {
+                    "tool_calls": [{
+                        "id": "call_a",
+                        "function": { "name": "do_a", "arguments": "{}" }
+                    }]
+                }
+            }]
+        });
+
+        let finish_stop = json!({
+            "choices": [{
+                "finish_reason": "stop"
+            }]
+        });
+
+        let body = build_body(&[delta_tool, finish_stop]);
+        let events = collect_events(&body).await;
+
+        assert!(!events.iter().any(|ev| {
+            matches!(
+                ev,
+                ResponseEvent::OutputItemDone(ResponseItem::FunctionCall { .. })
+            )
+        }));
+        assert_matches!(events.last(), Some(ResponseEvent::Completed { .. }));
+    }
+}
--- a/codex-rs/codex-api/src/sse/mod.rs
+++ b/codex-rs/codex-api/src/sse/mod.rs
@@ -0,0 +1,6 @@
+pub mod chat;
+pub mod responses;
+
+pub use responses::process_sse;
+pub use responses::spawn_response_stream;
+pub use responses::stream_from_fixture;
--- a/codex-rs/codex-api/src/sse/responses.rs
+++ b/codex-rs/codex-api/src/sse/responses.rs
@@ -0,0 +1,672 @@
+use crate::common::ResponseEvent;
+use crate::common::ResponseStream;
+use crate::error::ApiError;
+use crate::rate_limits::parse_rate_limit;
+use crate::telemetry::SseTelemetry;
+use codex_client::ByteStream;
+use codex_client::StreamResponse;
+use codex_client::TransportError;
+use codex_protocol::models::ResponseItem;
+use codex_protocol::protocol::TokenUsage;
+use eventsource_stream::Eventsource;
+use futures::StreamExt;
+use futures::TryStreamExt;
+use serde::Deserialize;
+use serde_json::Value;
+use std::io::BufRead;
+use std::path::Path;
+use std::sync::Arc;
+use std::time::Duration;
+use tokio::sync::mpsc;
+use tokio::time::Instant;
+use tokio::time::timeout;
+use tokio_util::io::ReaderStream;
+use tracing::debug;
+use tracing::trace;
+
+/// Streams SSE events from an on-disk fixture for tests.
+pub fn stream_from_fixture(
+    path: impl AsRef<Path>,
+    idle_timeout: Duration,
+) -> Result<ResponseStream, ApiError> {
+    let file =
+        std::fs::File::open(path.as_ref()).map_err(|err| ApiError::Stream(err.to_string()))?;
+    let mut content = String::new();
+    for line in std::io::BufReader::new(file).lines() {
+        let line = line.map_err(|err| ApiError::Stream(err.to_string()))?;
+        content.push_str(&line);
+        content.push_str("\n\n");
+    }
+
+    let reader = std::io::Cursor::new(content);
+    let stream = ReaderStream::new(reader).map_err(|err| TransportError::Network(err.to_string()));
+    let (tx_event, rx_event) = mpsc::channel::<Result<ResponseEvent, ApiError>>(1600);
+    tokio::spawn(process_sse(Box::pin(stream), tx_event, idle_timeout, None));
+    Ok(ResponseStream { rx_event })
+}
+
+pub fn spawn_response_stream(
+    stream_response: StreamResponse,
+    idle_timeout: Duration,
+    telemetry: Option<Arc<dyn SseTelemetry>>,
+) -> ResponseStream {
+    let rate_limits = parse_rate_limit(&stream_response.headers);
+    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;
+        }
+        process_sse(stream_response.bytes, tx_event, idle_timeout, telemetry).await;
+    });
+
+    ResponseStream { rx_event }
+}
+
+#[derive(Debug, Deserialize)]
+#[allow(dead_code)]
+struct Error {
+    r#type: Option<String>,
+    code: Option<String>,
+    message: Option<String>,
+    plan_type: Option<String>,
+    resets_at: Option<i64>,
+}
+
+#[derive(Debug, Deserialize)]
+#[allow(dead_code)]
+struct ResponseCompleted {
+    id: String,
+    #[serde(default)]
+    usage: Option<ResponseCompletedUsage>,
+}
+
+#[derive(Debug, Deserialize)]
+struct ResponseCompletedUsage {
+    input_tokens: i64,
+    input_tokens_details: Option<ResponseCompletedInputTokensDetails>,
+    output_tokens: i64,
+    output_tokens_details: Option<ResponseCompletedOutputTokensDetails>,
+    total_tokens: i64,
+}
+
+impl From<ResponseCompletedUsage> for TokenUsage {
+    fn from(val: ResponseCompletedUsage) -> Self {
+        TokenUsage {
+            input_tokens: val.input_tokens,
+            cached_input_tokens: val
+                .input_tokens_details
+                .map(|d| d.cached_tokens)
+                .unwrap_or(0),
+            output_tokens: val.output_tokens,
+            reasoning_output_tokens: val
+                .output_tokens_details
+                .map(|d| d.reasoning_tokens)
+                .unwrap_or(0),
+            total_tokens: val.total_tokens,
+        }
+    }
+}
+
+#[derive(Debug, Deserialize)]
+struct ResponseCompletedInputTokensDetails {
+    cached_tokens: i64,
+}
+
+#[derive(Debug, Deserialize)]
+struct ResponseCompletedOutputTokensDetails {
+    reasoning_tokens: i64,
+}
+
+#[derive(Deserialize, Debug)]
+struct SseEvent {
+    #[serde(rename = "type")]
+    kind: String,
+    response: Option<Value>,
+    item: Option<Value>,
+    delta: Option<String>,
+    summary_index: Option<i64>,
+    content_index: Option<i64>,
+}
+
+pub async fn process_sse(
+    stream: ByteStream,
+    tx_event: mpsc::Sender<Result<ResponseEvent, ApiError>>,
+    idle_timeout: Duration,
+    telemetry: Option<Arc<dyn SseTelemetry>>,
+) {
+    let mut stream = stream.eventsource();
+    let mut response_completed: Option<ResponseCompleted> = None;
+    let mut response_error: Option<ApiError> = None;
+
+    loop {
+        let start = Instant::now();
+        let response = timeout(idle_timeout, stream.next()).await;
+        if let Some(t) = telemetry.as_ref() {
+            t.on_sse_poll(&response, start.elapsed());
+        }
+        let sse = match response {
+            Ok(Some(Ok(sse))) => sse,
+            Ok(Some(Err(e))) => {
+                debug!("SSE Error: {e:#}");
+                let _ = tx_event.send(Err(ApiError::Stream(e.to_string()))).await;
+                return;
+            }
+            Ok(None) => {
+                match response_completed.take() {
+                    Some(ResponseCompleted { id, usage }) => {
+                        let event = ResponseEvent::Completed {
+                            response_id: id,
+                            token_usage: usage.map(Into::into),
+                        };
+                        let _ = tx_event.send(Ok(event)).await;
+                    }
+                    None => {
+                        let error = response_error.unwrap_or(ApiError::Stream(
+                            "stream closed before response.completed".into(),
+                        ));
+                        let _ = tx_event.send(Err(error)).await;
+                    }
+                }
+                return;
+            }
+            Err(_) => {
+                let _ = tx_event
+                    .send(Err(ApiError::Stream("idle timeout waiting for SSE".into())))
+                    .await;
+                return;
+            }
+        };
+
+        let raw = sse.data.clone();
+        trace!("SSE event: {raw}");
+
+        let event: SseEvent = match serde_json::from_str(&sse.data) {
+            Ok(event) => event,
+            Err(e) => {
+                debug!("Failed to parse SSE event: {e}, data: {}", &sse.data);
+                continue;
+            }
+        };
+
+        match event.kind.as_str() {
+            "response.output_item.done" => {
+                let Some(item_val) = event.item else { continue };
+                let Ok(item) = serde_json::from_value::<ResponseItem>(item_val) else {
+                    debug!("failed to parse ResponseItem from output_item.done");
+                    continue;
+                };
+
+                let event = ResponseEvent::OutputItemDone(item);
+                if tx_event.send(Ok(event)).await.is_err() {
+                    return;
+                }
+            }
+            "response.output_text.delta" => {
+                if let Some(delta) = event.delta {
+                    let event = ResponseEvent::OutputTextDelta(delta);
+                    if tx_event.send(Ok(event)).await.is_err() {
+                        return;
+                    }
+                }
+            }
+            "response.reasoning_summary_text.delta" => {
+                if let (Some(delta), Some(summary_index)) = (event.delta, event.summary_index) {
+                    let event = ResponseEvent::ReasoningSummaryDelta {
+                        delta,
+                        summary_index,
+                    };
+                    if tx_event.send(Ok(event)).await.is_err() {
+                        return;
+                    }
+                }
+            }
+            "response.reasoning_text.delta" => {
+                if let (Some(delta), Some(content_index)) = (event.delta, event.content_index) {
+                    let event = ResponseEvent::ReasoningContentDelta {
+                        delta,
+                        content_index,
+                    };
+                    if tx_event.send(Ok(event)).await.is_err() {
+                        return;
+                    }
+                }
+            }
+            "response.created" => {
+                if event.response.is_some() {
+                    let _ = tx_event.send(Ok(ResponseEvent::Created {})).await;
+                }
+            }
+            "response.failed" => {
+                if let Some(resp_val) = event.response {
+                    response_error =
+                        Some(ApiError::Stream("response.failed event received".into()));
+
+                    if let Some(error) = resp_val.get("error")
+                        && let Ok(error) = serde_json::from_value::<Error>(error.clone())
+                    {
+                        if is_context_window_error(&error) {
+                            response_error = Some(ApiError::ContextWindowExceeded);
+                        } else if is_quota_exceeded_error(&error) {
+                            response_error = Some(ApiError::QuotaExceeded);
+                        } else if is_usage_not_included(&error) {
+                            response_error = Some(ApiError::UsageNotIncluded);
+                        } else {
+                            let delay = try_parse_retry_after(&error);
+                            let message = error.message.clone().unwrap_or_default();
+                            response_error = Some(ApiError::Retryable { message, delay });
+                        }
+                    }
+                }
+            }
+            "response.completed" => {
+                if let Some(resp_val) = event.response {
+                    match serde_json::from_value::<ResponseCompleted>(resp_val) {
+                        Ok(r) => {
+                            response_completed = Some(r);
+                        }
+                        Err(e) => {
+                            let error = format!("failed to parse ResponseCompleted: {e}");
+                            debug!(error);
+                            response_error = Some(ApiError::Stream(error));
+                            continue;
+                        }
+                    };
+                };
+            }
+            "response.output_item.added" => {
+                let Some(item_val) = event.item else { continue };
+                let Ok(item) = serde_json::from_value::<ResponseItem>(item_val) else {
+                    debug!("failed to parse ResponseItem from output_item.done");
+                    continue;
+                };
+
+                let event = ResponseEvent::OutputItemAdded(item);
+                if tx_event.send(Ok(event)).await.is_err() {
+                    return;
+                }
+            }
+            "response.reasoning_summary_part.added" => {
+                if let Some(summary_index) = event.summary_index {
+                    let event = ResponseEvent::ReasoningSummaryPartAdded { summary_index };
+                    if tx_event.send(Ok(event)).await.is_err() {
+                        return;
+                    }
+                }
+            }
+            _ => {}
+        }
+    }
+}
+
+fn try_parse_retry_after(err: &Error) -> Option<Duration> {
+    if err.code.as_deref() != Some("rate_limit_exceeded") {
+        return None;
+    }
+
+    let re = rate_limit_regex();
+    if let Some(message) = &err.message
+        && let Some(captures) = re.captures(message)
+    {
+        let seconds = captures.get(1);
+        let unit = captures.get(2);
+
+        if let (Some(value), Some(unit)) = (seconds, unit) {
+            let value = value.as_str().parse::<f64>().ok()?;
+            let unit = unit.as_str().to_ascii_lowercase();
+
+            if unit == "s" || unit.starts_with("second") {
+                return Some(Duration::from_secs_f64(value));
+            } else if unit == "ms" {
+                return Some(Duration::from_millis(value as u64));
+            }
+        }
+    }
+    None
+}
+
+fn is_context_window_error(error: &Error) -> bool {
+    error.code.as_deref() == Some("context_length_exceeded")
+}
+
+fn is_quota_exceeded_error(error: &Error) -> bool {
+    error.code.as_deref() == Some("insufficient_quota")
+}
+
+fn is_usage_not_included(error: &Error) -> bool {
+    error.code.as_deref() == Some("usage_not_included")
+}
+
+fn rate_limit_regex() -> &'static regex_lite::Regex {
+    static RE: std::sync::OnceLock<regex_lite::Regex> = std::sync::OnceLock::new();
+    #[expect(clippy::unwrap_used)]
+    RE.get_or_init(|| {
+        regex_lite::Regex::new(r"(?i)try again in\s*(\d+(?:\.\d+)?)\s*(s|ms|seconds?)").unwrap()
+    })
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use assert_matches::assert_matches;
+    use codex_protocol::models::ResponseItem;
+    use pretty_assertions::assert_eq;
+    use serde_json::json;
+    use tokio::sync::mpsc;
+    use tokio_test::io::Builder as IoBuilder;
+
+    async fn collect_events(chunks: &[&[u8]]) -> Vec<Result<ResponseEvent, ApiError>> {
+        let mut builder = IoBuilder::new();
+        for chunk in chunks {
+            builder.read(chunk);
+        }
+
+        let reader = builder.build();
+        let stream =
+            ReaderStream::new(reader).map_err(|err| TransportError::Network(err.to_string()));
+        let (tx, mut rx) = mpsc::channel::<Result<ResponseEvent, ApiError>>(16);
+        tokio::spawn(process_sse(Box::pin(stream), tx, idle_timeout(), None));
+
+        let mut events = Vec::new();
+        while let Some(ev) = rx.recv().await {
+            events.push(ev);
+        }
+        events
+    }
+
+    async fn run_sse(events: Vec<serde_json::Value>) -> Vec<ResponseEvent> {
+        let mut body = String::new();
+        for e in events {
+            let kind = e
+                .get("type")
+                .and_then(|v| v.as_str())
+                .expect("fixture event missing type");
+            if e.as_object().map(|o| o.len() == 1).unwrap_or(false) {
+                body.push_str(&format!("event: {kind}\n\n"));
+            } else {
+                body.push_str(&format!("event: {kind}\ndata: {e}\n\n"));
+            }
+        }
+
+        let (tx, mut rx) = mpsc::channel::<Result<ResponseEvent, ApiError>>(8);
+        let stream = ReaderStream::new(std::io::Cursor::new(body))
+            .map_err(|err| TransportError::Network(err.to_string()));
+        tokio::spawn(process_sse(Box::pin(stream), tx, idle_timeout(), None));
+
+        let mut out = Vec::new();
+        while let Some(ev) = rx.recv().await {
+            out.push(ev.expect("channel closed"));
+        }
+        out
+    }
+
+    fn idle_timeout() -> Duration {
+        Duration::from_millis(1000)
+    }
+
+    #[tokio::test]
+    async fn parses_items_and_completed() {
+        let item1 = json!({
+            "type": "response.output_item.done",
+            "item": {
+                "type": "message",
+                "role": "assistant",
+                "content": [{"type": "output_text", "text": "Hello"}]
+            }
+        })
+        .to_string();
+
+        let item2 = json!({
+            "type": "response.output_item.done",
+            "item": {
+                "type": "message",
+                "role": "assistant",
+                "content": [{"type": "output_text", "text": "World"}]
+            }
+        })
+        .to_string();
+
+        let completed = json!({
+            "type": "response.completed",
+            "response": { "id": "resp1" }
+        })
+        .to_string();
+
+        let sse1 = format!("event: response.output_item.done\ndata: {item1}\n\n");
+        let sse2 = format!("event: response.output_item.done\ndata: {item2}\n\n");
+        let sse3 = format!("event: response.completed\ndata: {completed}\n\n");
+
+        let events = collect_events(&[sse1.as_bytes(), sse2.as_bytes(), sse3.as_bytes()]).await;
+
+        assert_eq!(events.len(), 3);
+
+        assert_matches!(
+            &events[0],
+            Ok(ResponseEvent::OutputItemDone(ResponseItem::Message { role, .. }))
+                if role == "assistant"
+        );
+
+        assert_matches!(
+            &events[1],
+            Ok(ResponseEvent::OutputItemDone(ResponseItem::Message { role, .. }))
+                if role == "assistant"
+        );
+
+        match &events[2] {
+            Ok(ResponseEvent::Completed {
+                response_id,
+                token_usage,
+            }) => {
+                assert_eq!(response_id, "resp1");
+                assert!(token_usage.is_none());
+            }
+            other => panic!("unexpected third event: {other:?}"),
+        }
+    }
+
+    #[tokio::test]
+    async fn error_when_missing_completed() {
+        let item1 = json!({
+            "type": "response.output_item.done",
+            "item": {
+                "type": "message",
+                "role": "assistant",
+                "content": [{"type": "output_text", "text": "Hello"}]
+            }
+        })
+        .to_string();
+
+        let sse1 = format!("event: response.output_item.done\ndata: {item1}\n\n");
+
+        let events = collect_events(&[sse1.as_bytes()]).await;
+
+        assert_eq!(events.len(), 2);
+
+        assert_matches!(events[0], Ok(ResponseEvent::OutputItemDone(_)));
+
+        match &events[1] {
+            Err(ApiError::Stream(msg)) => {
+                assert_eq!(msg, "stream closed before response.completed")
+            }
+            other => panic!("unexpected second event: {other:?}"),
+        }
+    }
+
+    #[tokio::test]
+    async fn error_when_error_event() {
+        let raw_error = r#"{"type":"response.failed","sequence_number":3,"response":{"id":"resp_689bcf18d7f08194bf3440ba62fe05d803fee0cdac429894","object":"response","created_at":1755041560,"status":"failed","background":false,"error":{"code":"rate_limit_exceeded","message":"Rate limit reached for gpt-5.1 in organization org-AAA on tokens per min (TPM): Limit 30000, Used 22999, Requested 12528. Please try again in 11.054s. Visit https://platform.openai.com/account/rate-limits to learn more."}, "usage":null,"user":null,"metadata":{}}}"#;
+
+        let sse1 = format!("event: response.failed\ndata: {raw_error}\n\n");
+
+        let events = collect_events(&[sse1.as_bytes()]).await;
+
+        assert_eq!(events.len(), 1);
+
+        match &events[0] {
+            Err(ApiError::Retryable { message, delay }) => {
+                assert_eq!(
+                    message,
+                    "Rate limit reached for gpt-5.1 in organization org-AAA on tokens per min (TPM): Limit 30000, Used 22999, Requested 12528. Please try again in 11.054s. Visit https://platform.openai.com/account/rate-limits to learn more."
+                );
+                assert_eq!(*delay, Some(Duration::from_secs_f64(11.054)));
+            }
+            other => panic!("unexpected second event: {other:?}"),
+        }
+    }
+
+    #[tokio::test]
+    async fn context_window_error_is_fatal() {
+        let raw_error = r#"{"type":"response.failed","sequence_number":3,"response":{"id":"resp_5c66275b97b9baef1ed95550adb3b7ec13b17aafd1d2f11b","object":"response","created_at":1759510079,"status":"failed","background":false,"error":{"code":"context_length_exceeded","message":"Your input exceeds the context window of this model. Please adjust your input and try again."},"usage":null,"user":null,"metadata":{}}}"#;
+
+        let sse1 = format!("event: response.failed\ndata: {raw_error}\n\n");
+
+        let events = collect_events(&[sse1.as_bytes()]).await;
+
+        assert_eq!(events.len(), 1);
+
+        assert_matches!(events[0], Err(ApiError::ContextWindowExceeded));
+    }
+
+    #[tokio::test]
+    async fn context_window_error_with_newline_is_fatal() {
+        let raw_error = r#"{"type":"response.failed","sequence_number":4,"response":{"id":"resp_fatal_newline","object":"response","created_at":1759510080,"status":"failed","background":false,"error":{"code":"context_length_exceeded","message":"Your input exceeds the context window of this model. Please adjust your input and try\nagain."},"usage":null,"user":null,"metadata":{}}}"#;
+
+        let sse1 = format!("event: response.failed\ndata: {raw_error}\n\n");
+
+        let events = collect_events(&[sse1.as_bytes()]).await;
+
+        assert_eq!(events.len(), 1);
+
+        assert_matches!(events[0], Err(ApiError::ContextWindowExceeded));
+    }
+
+    #[tokio::test]
+    async fn quota_exceeded_error_is_fatal() {
+        let raw_error = r#"{"type":"response.failed","sequence_number":3,"response":{"id":"resp_fatal_quota","object":"response","created_at":1759771626,"status":"failed","background":false,"error":{"code":"insufficient_quota","message":"You exceeded your current quota, please check your plan and billing details. For more information on this error, read the docs: https://platform.openai.com/docs/guides/error-codes/api-errors."},"incomplete_details":null}}"#;
+
+        let sse1 = format!("event: response.failed\ndata: {raw_error}\n\n");
+
+        let events = collect_events(&[sse1.as_bytes()]).await;
+
+        assert_eq!(events.len(), 1);
+
+        assert_matches!(events[0], Err(ApiError::QuotaExceeded));
+    }
+
+    #[tokio::test]
+    async fn table_driven_event_kinds() {
+        struct TestCase {
+            name: &'static str,
+            event: serde_json::Value,
+            expect_first: fn(&ResponseEvent) -> bool,
+            expected_len: usize,
+        }
+
+        fn is_created(ev: &ResponseEvent) -> bool {
+            matches!(ev, ResponseEvent::Created)
+        }
+        fn is_output(ev: &ResponseEvent) -> bool {
+            matches!(ev, ResponseEvent::OutputItemDone(_))
+        }
+        fn is_completed(ev: &ResponseEvent) -> bool {
+            matches!(ev, ResponseEvent::Completed { .. })
+        }
+
+        let completed = json!({
+            "type": "response.completed",
+            "response": {
+                "id": "c",
+                "usage": {
+                    "input_tokens": 0,
+                    "input_tokens_details": null,
+                    "output_tokens": 0,
+                    "output_tokens_details": null,
+                    "total_tokens": 0
+                },
+                "output": []
+            }
+        });
+
+        let cases = vec![
+            TestCase {
+                name: "created",
+                event: json!({"type": "response.created", "response": {}}),
+                expect_first: is_created,
+                expected_len: 2,
+            },
+            TestCase {
+                name: "output_item.done",
+                event: json!({
+                    "type": "response.output_item.done",
+                    "item": {
+                        "type": "message",
+                        "role": "assistant",
+                        "content": [
+                            {"type": "output_text", "text": "hi"}
+                        ]
+                    }
+                }),
+                expect_first: is_output,
+                expected_len: 2,
+            },
+            TestCase {
+                name: "unknown",
+                event: json!({"type": "response.new_tool_event"}),
+                expect_first: is_completed,
+                expected_len: 1,
+            },
+        ];
+
+        for case in cases {
+            let mut evs = vec![case.event];
+            evs.push(completed.clone());
+
+            let out = run_sse(evs).await;
+            assert_eq!(out.len(), case.expected_len, "case {}", case.name);
+            assert!(
+                (case.expect_first)(&out[0]),
+                "first event mismatch in case {}",
+                case.name
+            );
+        }
+    }
+
+    #[test]
+    fn test_try_parse_retry_after() {
+        let err = Error {
+            r#type: None,
+            message: Some("Rate limit reached for gpt-5.1 in organization org- on tokens per min (TPM): Limit 1, Used 1, Requested 19304. Please try again in 28ms. Visit https://platform.openai.com/account/rate-limits to learn more.".to_string()),
+            code: Some("rate_limit_exceeded".to_string()),
+            plan_type: None,
+            resets_at: None,
+        };
+
+        let delay = try_parse_retry_after(&err);
+        assert_eq!(delay, Some(Duration::from_millis(28)));
+    }
+
+    #[test]
+    fn test_try_parse_retry_after_no_delay() {
+        let err = Error {
+            r#type: None,
+            message: Some("Rate limit reached for gpt-5.1 in organization <ORG> on tokens per min (TPM): Limit 30000, Used 6899, Requested 24050. Please try again in 1.898s. Visit https://platform.openai.com/account/rate-limits to learn more.".to_string()),
+            code: Some("rate_limit_exceeded".to_string()),
+            plan_type: None,
+            resets_at: None,
+        };
+        let delay = try_parse_retry_after(&err);
+        assert_eq!(delay, Some(Duration::from_secs_f64(1.898)));
+    }
+
+    #[test]
+    fn test_try_parse_retry_after_azure() {
+        let err = Error {
+            r#type: None,
+            message: Some("Rate limit exceeded. Try again in 35 seconds.".to_string()),
+            code: Some("rate_limit_exceeded".to_string()),
+            plan_type: None,
+            resets_at: None,
+        };
+        let delay = try_parse_retry_after(&err);
+        assert_eq!(delay, Some(Duration::from_secs(35)));
+    }
+}
--- a/codex-rs/codex-api/src/telemetry.rs
+++ b/codex-rs/codex-api/src/telemetry.rs
@@ -0,0 +1,84 @@
+use codex_client::Request;
+use codex_client::RequestTelemetry;
+use codex_client::Response;
+use codex_client::RetryPolicy;
+use codex_client::StreamResponse;
+use codex_client::TransportError;
+use codex_client::run_with_retry;
+use http::StatusCode;
+use std::future::Future;
+use std::sync::Arc;
+use std::time::Duration;
+use tokio::time::Instant;
+
+/// Generic telemetry.
+pub trait SseTelemetry: Send + Sync {
+    fn on_sse_poll(
+        &self,
+        result: &Result<
+            Option<
+                Result<
+                    eventsource_stream::Event,
+                    eventsource_stream::EventStreamError<TransportError>,
+                >,
+            >,
+            tokio::time::error::Elapsed,
+        >,
+        duration: Duration,
+    );
+}
+
+pub(crate) trait WithStatus {
+    fn status(&self) -> StatusCode;
+}
+
+fn http_status(err: &TransportError) -> Option<StatusCode> {
+    match err {
+        TransportError::Http { status, .. } => Some(*status),
+        _ => None,
+    }
+}
+
+impl WithStatus for Response {
+    fn status(&self) -> StatusCode {
+        self.status
+    }
+}
+
+impl WithStatus for StreamResponse {
+    fn status(&self) -> StatusCode {
+        self.status
+    }
+}
+
+pub(crate) async fn run_with_request_telemetry<T, F, Fut>(
+    policy: RetryPolicy,
+    telemetry: Option<Arc<dyn RequestTelemetry>>,
+    make_request: impl FnMut() -> Request,
+    send: F,
+) -> Result<T, TransportError>
+where
+    T: WithStatus,
+    F: Clone + Fn(Request) -> Fut,
+    Fut: Future<Output = Result<T, TransportError>>,
+{
+    // Wraps `run_with_retry` to attach per-attempt request telemetry for both
+    // unary and streaming HTTP calls.
+    run_with_retry(policy, make_request, move |req, attempt| {
+        let telemetry = telemetry.clone();
+        let send = send.clone();
+        async move {
+            let start = Instant::now();
+            let result = send(req).await;
+            if let Some(t) = telemetry.as_ref() {
+                let (status, err) = match &result {
+                    Ok(resp) => (Some(resp.status()), None),
+                    Err(err) => (http_status(err), Some(err)),
+                };
+                t.on_request(attempt, status, err, start.elapsed());
+            }
+            result
+        }
+    })
+    .await
+}
--- a/codex-rs/codex-api/tests/clients.rs
+++ b/codex-rs/codex-api/tests/clients.rs
@@ -0,0 +1,315 @@
+use std::sync::Arc;
+use std::sync::Mutex;
+use std::time::Duration;
+
+use anyhow::Result;
+use async_trait::async_trait;
+use bytes::Bytes;
+use codex_api::AuthProvider;
+use codex_api::ChatClient;
+use codex_api::Provider;
+use codex_api::ResponsesClient;
+use codex_api::ResponsesOptions;
+use codex_api::WireApi;
+use codex_client::HttpTransport;
+use codex_client::Request;
+use codex_client::Response;
+use codex_client::StreamResponse;
+use codex_client::TransportError;
+use codex_protocol::models::ContentItem;
+use codex_protocol::models::ResponseItem;
+use http::HeaderMap;
+use http::StatusCode;
+use pretty_assertions::assert_eq;
+use serde_json::Value;
+
+fn assert_path_ends_with(requests: &[Request], suffix: &str) {
+    assert_eq!(requests.len(), 1);
+    let url = &requests[0].url;
+    assert!(
+        url.ends_with(suffix),
+        "expected url to end with {suffix}, got {url}"
+    );
+}
+
+#[derive(Debug, Default, Clone)]
+struct RecordingState {
+    stream_requests: Arc<Mutex<Vec<Request>>>,
+}
+
+impl RecordingState {
+    fn record(&self, req: Request) {
+        let mut guard = self
+            .stream_requests
+            .lock()
+            .unwrap_or_else(|err| panic!("mutex poisoned: {err}"));
+        guard.push(req);
+    }
+
+    fn take_stream_requests(&self) -> Vec<Request> {
+        let mut guard = self
+            .stream_requests
+            .lock()
+            .unwrap_or_else(|err| panic!("mutex poisoned: {err}"));
+        std::mem::take(&mut *guard)
+    }
+}
+
+#[derive(Clone)]
+struct RecordingTransport {
+    state: RecordingState,
+}
+
+impl RecordingTransport {
+    fn new(state: RecordingState) -> Self {
+        Self { state }
+    }
+}
+
+#[async_trait]
+impl HttpTransport for RecordingTransport {
+    async fn execute(&self, _req: Request) -> Result<Response, TransportError> {
+        Err(TransportError::Build("execute should not run".to_string()))
+    }
+
+    async fn stream(&self, req: Request) -> Result<StreamResponse, TransportError> {
+        self.state.record(req);
+
+        let stream = futures::stream::iter(Vec::<Result<Bytes, TransportError>>::new());
+        Ok(StreamResponse {
+            status: StatusCode::OK,
+            headers: HeaderMap::new(),
+            bytes: Box::pin(stream),
+        })
+    }
+}
+
+#[derive(Clone, Default)]
+struct NoAuth;
+
+impl AuthProvider for NoAuth {
+    fn bearer_token(&self) -> Option<String> {
+        None
+    }
+}
+
+#[derive(Clone)]
+struct StaticAuth {
+    token: String,
+    account_id: String,
+}
+
+impl StaticAuth {
+    fn new(token: &str, account_id: &str) -> Self {
+        Self {
+            token: token.to_string(),
+            account_id: account_id.to_string(),
+        }
+    }
+}
+
+impl AuthProvider for StaticAuth {
+    fn bearer_token(&self) -> Option<String> {
+        Some(self.token.clone())
+    }
+
+    fn account_id(&self) -> Option<String> {
+        Some(self.account_id.clone())
+    }
+}
+
+fn provider(name: &str, wire: WireApi) -> Provider {
+    Provider {
+        name: name.to_string(),
+        base_url: "https://example.com/v1".to_string(),
+        query_params: None,
+        wire,
+        headers: HeaderMap::new(),
+        retry: codex_api::provider::RetryConfig {
+            max_attempts: 1,
+            base_delay: Duration::from_millis(1),
+            retry_429: false,
+            retry_5xx: false,
+            retry_transport: true,
+        },
+        stream_idle_timeout: Duration::from_millis(10),
+    }
+}
+
+#[derive(Clone)]
+struct FlakyTransport {
+    state: Arc<Mutex<i64>>,
+}
+
+impl Default for FlakyTransport {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl FlakyTransport {
+    fn new() -> Self {
+        Self {
+            state: Arc::new(Mutex::new(0)),
+        }
+    }
+
+    fn attempts(&self) -> i64 {
+        *self
+            .state
+            .lock()
+            .unwrap_or_else(|err| panic!("mutex poisoned: {err}"))
+    }
+}
+
+#[async_trait]
+impl HttpTransport for FlakyTransport {
+    async fn execute(&self, _req: Request) -> Result<Response, TransportError> {
+        Err(TransportError::Build("execute should not run".to_string()))
+    }
+
+    async fn stream(&self, _req: Request) -> Result<StreamResponse, TransportError> {
+        let mut attempts = self
+            .state
+            .lock()
+            .unwrap_or_else(|err| panic!("mutex poisoned: {err}"));
+        *attempts += 1;
+
+        if *attempts == 1 {
+            return Err(TransportError::Network("first attempt fails".to_string()));
+        }
+
+        let stream = futures::stream::iter(vec![Ok(Bytes::from(
+            r#"event: message
+data: {"id":"resp-1","output":[{"type":"message","role":"assistant","content":[{"type":"output_text","text":"hi"}]}]}
+
+"#,
+        ))]);
+
+        Ok(StreamResponse {
+            status: StatusCode::OK,
+            headers: HeaderMap::new(),
+            bytes: Box::pin(stream),
+        })
+    }
+}
+
+#[tokio::test]
+async fn chat_client_uses_chat_completions_path_for_chat_wire() -> Result<()> {
+    let state = RecordingState::default();
+    let transport = RecordingTransport::new(state.clone());
+    let client = ChatClient::new(transport, provider("openai", WireApi::Chat), NoAuth);
+
+    let body = serde_json::json!({ "echo": true });
+    let _stream = client.stream(body, HeaderMap::new()).await?;
+
+    let requests = state.take_stream_requests();
+    assert_path_ends_with(&requests, "/chat/completions");
+    Ok(())
+}
+
+#[tokio::test]
+async fn chat_client_uses_responses_path_for_responses_wire() -> Result<()> {
+    let state = RecordingState::default();
+    let transport = RecordingTransport::new(state.clone());
+    let client = ChatClient::new(transport, provider("openai", WireApi::Responses), NoAuth);
+
+    let body = serde_json::json!({ "echo": true });
+    let _stream = client.stream(body, HeaderMap::new()).await?;
+
+    let requests = state.take_stream_requests();
+    assert_path_ends_with(&requests, "/responses");
+    Ok(())
+}
+
+#[tokio::test]
+async fn responses_client_uses_responses_path_for_responses_wire() -> Result<()> {
+    let state = RecordingState::default();
+    let transport = RecordingTransport::new(state.clone());
+    let client = ResponsesClient::new(transport, provider("openai", WireApi::Responses), NoAuth);
+
+    let body = serde_json::json!({ "echo": true });
+    let _stream = client.stream(body, HeaderMap::new()).await?;
+
+    let requests = state.take_stream_requests();
+    assert_path_ends_with(&requests, "/responses");
+    Ok(())
+}
+
+#[tokio::test]
+async fn responses_client_uses_chat_path_for_chat_wire() -> Result<()> {
+    let state = RecordingState::default();
+    let transport = RecordingTransport::new(state.clone());
+    let client = ResponsesClient::new(transport, provider("openai", WireApi::Chat), NoAuth);
+
+    let body = serde_json::json!({ "echo": true });
+    let _stream = client.stream(body, HeaderMap::new()).await?;
+
+    let requests = state.take_stream_requests();
+    assert_path_ends_with(&requests, "/chat/completions");
+    Ok(())
+}
+
+#[tokio::test]
+async fn streaming_client_adds_auth_headers() -> Result<()> {
+    let state = RecordingState::default();
+    let transport = RecordingTransport::new(state.clone());
+    let auth = StaticAuth::new("secret-token", "acct-1");
+    let client = ResponsesClient::new(transport, provider("openai", WireApi::Responses), auth);
+
+    let body = serde_json::json!({ "model": "gpt-test" });
+    let _stream = client.stream(body, HeaderMap::new()).await?;
+
+    let requests = state.take_stream_requests();
+    assert_eq!(requests.len(), 1);
+    let req = &requests[0];
+
+    let auth_header = req.headers.get(http::header::AUTHORIZATION);
+    assert!(auth_header.is_some(), "missing auth header");
+    assert_eq!(
+        auth_header.unwrap().to_str().ok(),
+        Some("Bearer secret-token")
+    );
+
+    let account_header = req.headers.get("ChatGPT-Account-ID");
+    assert!(account_header.is_some(), "missing account header");
+    assert_eq!(account_header.unwrap().to_str().ok(), Some("acct-1"));
+
+    let accept_header = req.headers.get(http::header::ACCEPT);
+    assert!(accept_header.is_some(), "missing Accept header");
+    assert_eq!(
+        accept_header.unwrap().to_str().ok(),
+        Some("text/event-stream")
+    );
+    Ok(())
+}
+
+#[tokio::test]
+async fn streaming_client_retries_on_transport_error() -> Result<()> {
+    let transport = FlakyTransport::new();
+
+    let mut provider = provider("openai", WireApi::Responses);
+    provider.retry.max_attempts = 2;
+
+    let client = ResponsesClient::new(transport.clone(), provider, NoAuth);
+
+    let prompt = codex_api::Prompt {
+        instructions: "Say hi".to_string(),
+        input: vec![ResponseItem::Message {
+            id: None,
+            role: "user".to_string(),
+            content: vec![ContentItem::InputText {
+                text: "hi".to_string(),
+            }],
+        }],
+        tools: Vec::<Value>::new(),
+        parallel_tool_calls: false,
+        output_schema: None,
+    };
+
+    let options = ResponsesOptions::default();
+
+    let _stream = client.stream_prompt("gpt-test", &prompt, options).await?;
+    assert_eq!(transport.attempts(), 2);
+    Ok(())
+}
--- a/codex-rs/codex-api/tests/sse_end_to_end.rs
+++ b/codex-rs/codex-api/tests/sse_end_to_end.rs
@@ -0,0 +1,229 @@
+use std::time::Duration;
+
+use anyhow::Result;
+use async_trait::async_trait;
+use bytes::Bytes;
+use codex_api::AggregateStreamExt;
+use codex_api::AuthProvider;
+use codex_api::Provider;
+use codex_api::ResponseEvent;
+use codex_api::ResponsesClient;
+use codex_api::WireApi;
+use codex_client::HttpTransport;
+use codex_client::Request;
+use codex_client::Response;
+use codex_client::StreamResponse;
+use codex_client::TransportError;
+use codex_protocol::models::ContentItem;
+use codex_protocol::models::ResponseItem;
+use futures::StreamExt;
+use http::HeaderMap;
+use http::StatusCode;
+use pretty_assertions::assert_eq;
+use serde_json::Value;
+
+#[derive(Clone)]
+struct FixtureSseTransport {
+    body: String,
+}
+
+impl FixtureSseTransport {
+    fn new(body: String) -> Self {
+        Self { body }
+    }
+}
+
+#[async_trait]
+impl HttpTransport for FixtureSseTransport {
+    async fn execute(&self, _req: Request) -> Result<Response, TransportError> {
+        Err(TransportError::Build("execute should not run".to_string()))
+    }
+
+    async fn stream(&self, _req: Request) -> Result<StreamResponse, TransportError> {
+        let stream = futures::stream::iter(vec![Ok::<Bytes, TransportError>(Bytes::from(
+            self.body.clone(),
+        ))]);
+        Ok(StreamResponse {
+            status: StatusCode::OK,
+            headers: HeaderMap::new(),
+            bytes: Box::pin(stream),
+        })
+    }
+}
+
+#[derive(Clone, Default)]
+struct NoAuth;
+
+impl AuthProvider for NoAuth {
+    fn bearer_token(&self) -> Option<String> {
+        None
+    }
+}
+
+fn provider(name: &str, wire: WireApi) -> Provider {
+    Provider {
+        name: name.to_string(),
+        base_url: "https://example.com/v1".to_string(),
+        query_params: None,
+        wire,
+        headers: HeaderMap::new(),
+        retry: codex_api::provider::RetryConfig {
+            max_attempts: 1,
+            base_delay: Duration::from_millis(1),
+            retry_429: false,
+            retry_5xx: false,
+            retry_transport: true,
+        },
+        stream_idle_timeout: Duration::from_millis(50),
+    }
+}
+
+fn build_responses_body(events: Vec<Value>) -> String {
+    let mut body = String::new();
+    for e in events {
+        let kind = e
+            .get("type")
+            .and_then(|v| v.as_str())
+            .unwrap_or_else(|| panic!("fixture event missing type in SSE fixture: {e}"));
+        if e.as_object().map(|o| o.len() == 1).unwrap_or(false) {
+            body.push_str(&format!("event: {kind}\n\n"));
+        } else {
+            body.push_str(&format!("event: {kind}\ndata: {e}\n\n"));
+        }
+    }
+    body
+}
+
+#[tokio::test]
+async fn responses_stream_parses_items_and_completed_end_to_end() -> Result<()> {
+    let item1 = serde_json::json!({
+        "type": "response.output_item.done",
+        "item": {
+            "type": "message",
+            "role": "assistant",
+            "content": [{"type": "output_text", "text": "Hello"}]
+        }
+    });
+
+    let item2 = serde_json::json!({
+        "type": "response.output_item.done",
+        "item": {
+            "type": "message",
+            "role": "assistant",
+            "content": [{"type": "output_text", "text": "World"}]
+        }
+    });
+
+    let completed = serde_json::json!({
+        "type": "response.completed",
+        "response": { "id": "resp1" }
+    });
+
+    let body = build_responses_body(vec![item1, item2, completed]);
+    let transport = FixtureSseTransport::new(body);
+    let client = ResponsesClient::new(transport, provider("openai", WireApi::Responses), NoAuth);
+
+    let mut stream = client
+        .stream(serde_json::json!({"echo": true}), HeaderMap::new())
+        .await?;
+
+    let mut events = Vec::new();
+    while let Some(ev) = stream.next().await {
+        events.push(ev?);
+    }
+
+    let events: Vec<ResponseEvent> = events
+        .into_iter()
+        .filter(|ev| !matches!(ev, ResponseEvent::RateLimits(_)))
+        .collect();
+
+    assert_eq!(events.len(), 3);
+
+    match &events[0] {
+        ResponseEvent::OutputItemDone(ResponseItem::Message { role, .. }) => {
+            assert_eq!(role, "assistant");
+        }
+        other => panic!("unexpected first event: {other:?}"),
+    }
+
+    match &events[1] {
+        ResponseEvent::OutputItemDone(ResponseItem::Message { role, .. }) => {
+            assert_eq!(role, "assistant");
+        }
+        other => panic!("unexpected second event: {other:?}"),
+    }
+
+    match &events[2] {
+        ResponseEvent::Completed {
+            response_id,
+            token_usage,
+        } => {
+            assert_eq!(response_id, "resp1");
+            assert!(token_usage.is_none());
+        }
+        other => panic!("unexpected third event: {other:?}"),
+    }
+
+    Ok(())
+}
+
+#[tokio::test]
+async fn responses_stream_aggregates_output_text_deltas() -> Result<()> {
+    let delta1 = serde_json::json!({
+        "type": "response.output_text.delta",
+        "delta": "Hello, "
+    });
+
+    let delta2 = serde_json::json!({
+        "type": "response.output_text.delta",
+        "delta": "world"
+    });
+
+    let completed = serde_json::json!({
+        "type": "response.completed",
+        "response": { "id": "resp-agg" }
+    });
+
+    let body = build_responses_body(vec![delta1, delta2, completed]);
+    let transport = FixtureSseTransport::new(body);
+    let client = ResponsesClient::new(transport, provider("openai", WireApi::Responses), NoAuth);
+
+    let stream = client
+        .stream(serde_json::json!({"echo": true}), HeaderMap::new())
+        .await?;
+
+    let mut stream = stream.aggregate();
+    let mut events = Vec::new();
+    while let Some(ev) = stream.next().await {
+        events.push(ev?);
+    }
+
+    let events: Vec<ResponseEvent> = events
+        .into_iter()
+        .filter(|ev| !matches!(ev, ResponseEvent::RateLimits(_)))
+        .collect();
+
+    assert_eq!(events.len(), 2);
+
+    match &events[0] {
+        ResponseEvent::OutputItemDone(ResponseItem::Message { content, .. }) => {
+            let mut aggregated = String::new();
+            for item in content {
+                if let ContentItem::OutputText { text } = item {
+                    aggregated.push_str(text);
+                }
+            }
+            assert_eq!(aggregated, "Hello, world");
+        }
+        other => panic!("unexpected first event: {other:?}"),
+    }
+
+    match &events[1] {
+        ResponseEvent::Completed { response_id, .. } => {
+            assert_eq!(response_id, "resp-agg");
+        }
+        other => panic!("unexpected second event: {other:?}"),
+    }
+
+    Ok(())
+}
--- a/codex-rs/codex-backend-openapi-models/Cargo.toml
+++ b/codex-rs/codex-backend-openapi-models/Cargo.toml
@@ -1,7 +1,8 @@
 [package]
 name = "codex-backend-openapi-models"
-version = { workspace = true }
-edition = "2024"
+version.workspace = true
+edition.workspace = true
+license.workspace = true

 [lib]
 name = "codex_backend_openapi_models"
--- a/codex-rs/codex-client/Cargo.toml
+++ b/codex-rs/codex-client/Cargo.toml
@@ -0,0 +1,22 @@
+[package]
+edition.workspace = true
+license.workspace = true
+name = "codex-client"
+version.workspace = true
+
+[dependencies]
+async-trait = { workspace = true }
+bytes = { workspace = true }
+eventsource-stream = { workspace = true }
+futures = { workspace = true }
+http = { workspace = true }
+rand = { workspace = true }
+reqwest = { workspace = true, features = ["json", "stream"] }
+serde = { workspace = true, features = ["derive"] }
+serde_json = { workspace = true }
+thiserror = { workspace = true }
+tokio = { workspace = true, features = ["macros", "rt", "time", "sync"] }
+tracing = { workspace = true }
+
+[lints]
+workspace = true
--- a/codex-rs/codex-client/README.md
+++ b/codex-rs/codex-client/README.md
@@ -0,0 +1,8 @@
+# codex-client
+
+Generic transport layer that wraps HTTP requests, retries, and streaming primitives without any Codex/OpenAI awareness.
+
+- Defines `HttpTransport` and a default `ReqwestTransport` plus thin `Request`/`Response` types.
+- Provides retry utilities (`RetryPolicy`, `RetryOn`, `run_with_retry`, `backoff`) that callers plug into for unary and streaming calls.
+- Supplies the `sse_stream` helper to turn byte streams into raw SSE `data:` frames with idle timeouts and surfaced stream errors.
+- Consumed by higher-level crates like `codex-api`; it stays neutral on endpoints, headers, or API-specific error shapes.
--- a/codex-rs/codex-client/src/error.rs
+++ b/codex-rs/codex-client/src/error.rs
@@ -0,0 +1,29 @@
+use http::HeaderMap;
+use http::StatusCode;
+use thiserror::Error;
+
+#[derive(Debug, Error)]
+pub enum TransportError {
+    #[error("http {status}: {body:?}")]
+    Http {
+        status: StatusCode,
+        headers: Option<HeaderMap>,
+        body: Option<String>,
+    },
+    #[error("retry limit reached")]
+    RetryLimit,
+    #[error("timeout")]
+    Timeout,
+    #[error("network error: {0}")]
+    Network(String),
+    #[error("request build error: {0}")]
+    Build(String),
+}
+
+#[derive(Debug, Error)]
+pub enum StreamError {
+    #[error("stream failed: {0}")]
+    Stream(String),
+    #[error("timeout")]
+    Timeout,
+}
--- a/codex-rs/codex-client/src/lib.rs
+++ b/codex-rs/codex-client/src/lib.rs
@@ -0,0 +1,21 @@
+mod error;
+mod request;
+mod retry;
+mod sse;
+mod telemetry;
+mod transport;
+
+pub use crate::error::StreamError;
+pub use crate::error::TransportError;
+pub use crate::request::Request;
+pub use crate::request::Response;
+pub use crate::retry::RetryOn;
+pub use crate::retry::RetryPolicy;
+pub use crate::retry::backoff;
+pub use crate::retry::run_with_retry;
+pub use crate::sse::sse_stream;
+pub use crate::telemetry::RequestTelemetry;
+pub use crate::transport::ByteStream;
+pub use crate::transport::HttpTransport;
+pub use crate::transport::ReqwestTransport;
+pub use crate::transport::StreamResponse;
--- a/codex-rs/codex-client/src/request.rs
+++ b/codex-rs/codex-client/src/request.rs
@@ -0,0 +1,39 @@
+use bytes::Bytes;
+use http::Method;
+use reqwest::header::HeaderMap;
+use serde::Serialize;
+use serde_json::Value;
+use std::time::Duration;
+
+#[derive(Debug, Clone)]
+pub struct Request {
+    pub method: Method,
+    pub url: String,
+    pub headers: HeaderMap,
+    pub body: Option<Value>,
+    pub timeout: Option<Duration>,
+}
+
+impl Request {
+    pub fn new(method: Method, url: String) -> Self {
+        Self {
+            method,
+            url,
+            headers: HeaderMap::new(),
+            body: None,
+            timeout: None,
+        }
+    }
+
+    pub fn with_json<T: Serialize>(mut self, body: &T) -> Self {
+        self.body = serde_json::to_value(body).ok();
+        self
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct Response {
+    pub status: http::StatusCode,
+    pub headers: HeaderMap,
+    pub body: Bytes,
+}
--- a/codex-rs/codex-client/src/retry.rs
+++ b/codex-rs/codex-client/src/retry.rs
@@ -0,0 +1,73 @@
+use crate::error::TransportError;
+use crate::request::Request;
+use rand::Rng;
+use std::future::Future;
+use std::time::Duration;
+use tokio::time::sleep;
+
+#[derive(Debug, Clone)]
+pub struct RetryPolicy {
+    pub max_attempts: u64,
+    pub base_delay: Duration,
+    pub retry_on: RetryOn,
+}
+
+#[derive(Debug, Clone)]
+pub struct RetryOn {
+    pub retry_429: bool,
+    pub retry_5xx: bool,
+    pub retry_transport: bool,
+}
+
+impl RetryOn {
+    pub fn should_retry(&self, err: &TransportError, attempt: u64, max_attempts: u64) -> bool {
+        if attempt >= max_attempts {
+            return false;
+        }
+        match err {
+            TransportError::Http { status, .. } => {
+                (self.retry_429 && status.as_u16() == 429)
+                    || (self.retry_5xx && status.is_server_error())
+            }
+            TransportError::Timeout | TransportError::Network(_) => self.retry_transport,
+            _ => false,
+        }
+    }
+}
+
+pub fn backoff(base: Duration, attempt: u64) -> Duration {
+    if attempt == 0 {
+        return base;
+    }
+    let exp = 2u64.saturating_pow(attempt as u32 - 1);
+    let millis = base.as_millis() as u64;
+    let raw = millis.saturating_mul(exp);
+    let jitter: f64 = rand::rng().random_range(0.9..1.1);
+    Duration::from_millis((raw as f64 * jitter) as u64)
+}
+
+pub async fn run_with_retry<T, F, Fut>(
+    policy: RetryPolicy,
+    mut make_req: impl FnMut() -> Request,
+    op: F,
+) -> Result<T, TransportError>
+where
+    F: Fn(Request, u64) -> Fut,
+    Fut: Future<Output = Result<T, TransportError>>,
+{
+    for attempt in 0..=policy.max_attempts {
+        let req = make_req();
+        match op(req, attempt).await {
+            Ok(resp) => return Ok(resp),
+            Err(err)
+                if policy
+                    .retry_on
+                    .should_retry(&err, attempt, policy.max_attempts) =>
+            {
+                sleep(backoff(policy.base_delay, attempt + 1)).await;
+            }
+            Err(err) => return Err(err),
+        }
+    }
+    Err(TransportError::RetryLimit)
+}
--- a/codex-rs/codex-client/src/sse.rs
+++ b/codex-rs/codex-client/src/sse.rs
@@ -0,0 +1,48 @@
+use crate::error::StreamError;
+use crate::transport::ByteStream;
+use eventsource_stream::Eventsource;
+use futures::StreamExt;
+use tokio::sync::mpsc;
+use tokio::time::Duration;
+use tokio::time::timeout;
+
+/// Minimal SSE helper that forwards raw `data:` frames as UTF-8 strings.
+///
+/// Errors and idle timeouts are sent as `Err(StreamError)` before the task exits.
+pub fn sse_stream(
+    stream: ByteStream,
+    idle_timeout: Duration,
+    tx: mpsc::Sender<Result<String, StreamError>>,
+) {
+    tokio::spawn(async move {
+        let mut stream = stream
+            .map(|res| res.map_err(|e| StreamError::Stream(e.to_string())))
+            .eventsource();
+
+        loop {
+            match timeout(idle_timeout, stream.next()).await {
+                Ok(Some(Ok(ev))) => {
+                    if tx.send(Ok(ev.data.clone())).await.is_err() {
+                        return;
+                    }
+                }
+                Ok(Some(Err(e))) => {
+                    let _ = tx.send(Err(StreamError::Stream(e.to_string()))).await;
+                    return;
+                }
+                Ok(None) => {
+                    let _ = tx
+                        .send(Err(StreamError::Stream(
+                            "stream closed before completion".into(),
+                        )))
+                        .await;
+                    return;
+                }
+                Err(_) => {
+                    let _ = tx.send(Err(StreamError::Timeout)).await;
+                    return;
+                }
+            }
+        }
+    });
+}
--- a/codex-rs/codex-client/src/telemetry.rs
+++ b/codex-rs/codex-client/src/telemetry.rs
@@ -0,0 +1,14 @@
+use crate::error::TransportError;
+use http::StatusCode;
+use std::time::Duration;
+
+/// API specific telemetry.
+pub trait RequestTelemetry: Send + Sync {
+    fn on_request(
+        &self,
+        attempt: u64,
+        status: Option<StatusCode>,
+        error: Option<&TransportError>,
+        duration: Duration,
+    );
+}
--- a/codex-rs/codex-client/src/transport.rs
+++ b/codex-rs/codex-client/src/transport.rs
@@ -0,0 +1,119 @@
+use crate::error::TransportError;
+use crate::request::Request;
+use crate::request::Response;
+use async_trait::async_trait;
+use bytes::Bytes;
+use futures::StreamExt;
+use futures::stream::BoxStream;
+use http::HeaderMap;
+use http::Method;
+use http::StatusCode;
+use tracing::Level;
+use tracing::enabled;
+use tracing::trace;
+
+pub type ByteStream = BoxStream<'static, Result<Bytes, TransportError>>;
+
+pub struct StreamResponse {
+    pub status: StatusCode,
+    pub headers: HeaderMap,
+    pub bytes: ByteStream,
+}
+
+#[async_trait]
+pub trait HttpTransport: Send + Sync {
+    async fn execute(&self, req: Request) -> Result<Response, TransportError>;
+    async fn stream(&self, req: Request) -> Result<StreamResponse, TransportError>;
+}
+
+#[derive(Clone, Debug)]
+pub struct ReqwestTransport {
+    client: reqwest::Client,
+}
+
+impl ReqwestTransport {
+    pub fn new(client: reqwest::Client) -> Self {
+        Self { client }
+    }
+
+    fn build(&self, req: Request) -> Result<reqwest::RequestBuilder, TransportError> {
+        let mut builder = self
+            .client
+            .request(
+                Method::from_bytes(req.method.as_str().as_bytes()).unwrap_or(Method::GET),
+                &req.url,
+            )
+            .headers(req.headers);
+        if let Some(timeout) = req.timeout {
+            builder = builder.timeout(timeout);
+        }
+        if let Some(body) = req.body {
+            builder = builder.json(&body);
+        }
+        Ok(builder)
+    }
+
+    fn map_error(err: reqwest::Error) -> TransportError {
+        if err.is_timeout() {
+            TransportError::Timeout
+        } else {
+            TransportError::Network(err.to_string())
+        }
+    }
+}
+
+#[async_trait]
+impl HttpTransport for ReqwestTransport {
+    async fn execute(&self, req: Request) -> Result<Response, TransportError> {
+        let builder = self.build(req)?;
+        let resp = builder.send().await.map_err(Self::map_error)?;
+        let status = resp.status();
+        let headers = resp.headers().clone();
+        let bytes = resp.bytes().await.map_err(Self::map_error)?;
+        if !status.is_success() {
+            let body = String::from_utf8(bytes.to_vec()).ok();
+            return Err(TransportError::Http {
+                status,
+                headers: Some(headers),
+                body,
+            });
+        }
+        Ok(Response {
+            status,
+            headers,
+            body: bytes,
+        })
+    }
+
+    async fn stream(&self, req: Request) -> Result<StreamResponse, TransportError> {
+        if enabled!(Level::TRACE) {
+            trace!(
+                "{} to {}: {}",
+                req.method,
+                req.url,
+                req.body.as_ref().unwrap_or_default()
+            );
+        }
+
+        let builder = self.build(req)?;
+        let resp = builder.send().await.map_err(Self::map_error)?;
+        let status = resp.status();
+        let headers = resp.headers().clone();
+        if !status.is_success() {
+            let body = resp.text().await.ok();
+            return Err(TransportError::Http {
+                status,
+                headers: Some(headers),
+                body,
+            });
+        }
+        let stream = resp
+            .bytes_stream()
+            .map(|result| result.map_err(Self::map_error));
+        Ok(StreamResponse {
+            status,
+            headers,
+            bytes: Box::pin(stream),
+        })
+    }
+}
--- a/codex-rs/common/Cargo.toml
+++ b/codex-rs/common/Cargo.toml
@@ -1,7 +1,8 @@
 [package]
-edition = "2024"
 name = "codex-common"
-version = { workspace = true }
+version.workspace = true
+edition.workspace = true
+license.workspace = true

 [lints]
 workspace = true
--- a/codex-rs/core/Cargo.toml
+++ b/codex-rs/core/Cargo.toml
@@ -1,7 +1,8 @@
 [package]
-edition = "2024"
 name = "codex-core"
-version = { workspace = true }
+version.workspace = true
+edition.workspace = true
+license.workspace = true

 [lib]
 doctest = false
@@ -17,12 +18,12 @@ askama = { workspace = true }
 async-channel = { workspace = true }
 async-trait = { workspace = true }
 base64 = { workspace = true }
-bytes = { workspace = true }
 chrono = { workspace = true, features = ["serde"] }
 chardetng = { workspace = true }
 codex-app-server-protocol = { workspace = true }
 codex-apply-patch = { workspace = true }
 codex-async-utils = { workspace = true }
+codex-api = { workspace = true }
 codex-execpolicy = { workspace = true }
 codex-file-search = { workspace = true }
 codex-git = { workspace = true }
@@ -51,6 +52,7 @@ regex-lite = { workspace = true }
 reqwest = { workspace = true, features = ["json", "stream"] }
 serde = { workspace = true, features = ["derive"] }
 serde_json = { workspace = true }
+serde_yaml = { workspace = true }
 sha1 = { workspace = true }
 sha2 = { workspace = true }
 shlex = { workspace = true }
@@ -86,6 +88,9 @@ uuid = { workspace = true, features = ["serde", "v4", "v5"] }
 which = { workspace = true }
 wildmatch = { workspace = true }

+[features]
+deterministic_process_ids = []
+

 [target.'cfg(target_os = "linux")'.dependencies]
 landlock = { workspace = true }
@@ -114,6 +119,7 @@ keyring = { workspace = true, features = ["sync-secret-service"] }
 assert_cmd = { workspace = true }
 assert_matches = { workspace = true }
 codex-arg0 = { workspace = true }
+codex-core = { path = ".", features = ["deterministic_process_ids"] }
 core_test_support = { workspace = true }
 ctor = { workspace = true }
 escargot = { workspace = true }
@@ -121,7 +127,6 @@ image = { workspace = true, features = ["jpeg", "png"] }
 maplit = { workspace = true }
 predicates = { workspace = true }
 pretty_assertions = { workspace = true }
-insta = { version = "1.39", features = ["yaml"] }
 serial_test = { workspace = true }
 tempfile = { workspace = true }
 tokio-test = { workspace = true }
--- a/codex-rs/core/root_agent_prompt.md
+++ b/codex-rs/core/root_agent_prompt.md
@@ -1,22 +0,0 @@
-You are the **root agent** in a multi‑agent Codex session.
-
-Your job is to solve the user’s task end‑to‑end. Use subagents as semi‑autonomous workers when that makes the work simpler, safer, or more parallel, and otherwise act directly in the conversation as a normal assistant.
-
-Use subagents as follows:
-
- Spawn or fork a subagent when a piece of work can be isolated behind a clear prompt, or when you want an independent view on a problem.
- Let subagents run independently. You do not need to keep generating output while they work; focus your own turns on planning, orchestration, and integrating results.
- Use `subagent_send_message` to give a subagent follow-up instructions, send it short status updates or summaries, or interrupt and redirect it.
- Use `subagent_await` when you need to wait for a particular subagent before continuing; you do not have to await every subagent you spawn, because they can also report progress and results to you via `subagent_send_message` and completions will be surfaced to you automatically.
- When you see a `subagent_await` call/output injected into the transcript without you calling the tool, that came from the autosubmit path: the system drained the inbox (e.g., a subagent completion) while the root was idle and recorded a synthetic `subagent_await` so you can read and react without issuing the tool yourself.
- Use `subagent_logs` when you only need to inspect what a subagent has been doing recently, not to change its state.
- Use `subagent_list`, `subagent_prune`, and `subagent_cancel` to keep the set of active subagents small and relevant.
- When you spawn a subagent or start a watchdog and there’s nothing else useful to do, issue the tool call right away and say you’re waiting for results (or for the watchdog to start). If you can do other useful work in parallel, do that instead of stalling, and only await when necessary.
-
-Be concise and direct. Delegate multi‑step or long‑running work to subagents, summarize what they have done for the user, and always keep the conversation focused on the user’s goal.**
-
-Example: long‑running supervision with a watchdog
- Spawn a supervisor to own `PLAN.md`: e.g., `subagent_spawn` label `supervisor`, prompt it to keep the plan fresh, launch workers, and heartbeat every few minutes.
- Attach a watchdog to the supervisor (or to yourself) that pings on a cadence and asks for progress: call `subagent_watchdog` with `{agent_id: <supervisor_id>, interval_s: 300, message: "Watchdog ping — report current status and PLAN progress", cancel: false}`.
- The supervisor should reply to each ping with a brief status and, if needed, spawn/interrupt workers; the root can cancel or retarget by invoking `subagent_watchdog` again with `cancel: true`.
- You can also set a self‑watchdog on the root agent to ensure you keep emitting status updates during multi‑hour tasks.***
--- a/codex-rs/core/src/api_bridge.rs
+++ b/codex-rs/core/src/api_bridge.rs
@@ -0,0 +1,154 @@
+use chrono::DateTime;
+use chrono::Utc;
+use codex_api::AuthProvider as ApiAuthProvider;
+use codex_api::TransportError;
+use codex_api::error::ApiError;
+use codex_api::rate_limits::parse_rate_limit;
+use http::HeaderMap;
+use serde::Deserialize;
+
+use crate::auth::CodexAuth;
+use crate::error::CodexErr;
+use crate::error::RetryLimitReachedError;
+use crate::error::UnexpectedResponseError;
+use crate::error::UsageLimitReachedError;
+use crate::model_provider_info::ModelProviderInfo;
+use crate::token_data::PlanType;
+
+pub(crate) fn map_api_error(err: ApiError) -> CodexErr {
+    match err {
+        ApiError::ContextWindowExceeded => CodexErr::ContextWindowExceeded,
+        ApiError::QuotaExceeded => CodexErr::QuotaExceeded,
+        ApiError::UsageNotIncluded => CodexErr::UsageNotIncluded,
+        ApiError::Retryable { message, delay } => CodexErr::Stream(message, delay),
+        ApiError::Stream(msg) => CodexErr::Stream(msg, None),
+        ApiError::Api { status, message } => CodexErr::UnexpectedStatus(UnexpectedResponseError {
+            status,
+            body: message,
+            request_id: None,
+        }),
+        ApiError::Transport(transport) => match transport {
+            TransportError::Http {
+                status,
+                headers,
+                body,
+            } => {
+                if status == http::StatusCode::INTERNAL_SERVER_ERROR {
+                    CodexErr::InternalServerError
+                } else if status == http::StatusCode::TOO_MANY_REQUESTS {
+                    if let Some(body) = body
+                        && let Ok(err) = serde_json::from_str::<UsageErrorResponse>(&body)
+                    {
+                        if err.error.error_type.as_deref() == Some("usage_limit_reached") {
+                            let rate_limits = headers.as_ref().and_then(parse_rate_limit);
+                            let resets_at = err
+                                .error
+                                .resets_at
+                                .and_then(|seconds| DateTime::<Utc>::from_timestamp(seconds, 0));
+                            return CodexErr::UsageLimitReached(UsageLimitReachedError {
+                                plan_type: err.error.plan_type,
+                                resets_at,
+                                rate_limits,
+                            });
+                        } else if err.error.error_type.as_deref() == Some("usage_not_included") {
+                            return CodexErr::UsageNotIncluded;
+                        }
+                    }
+
+                    CodexErr::RetryLimit(RetryLimitReachedError {
+                        status,
+                        request_id: extract_request_id(headers.as_ref()),
+                    })
+                } else {
+                    CodexErr::UnexpectedStatus(UnexpectedResponseError {
+                        status,
+                        body: body.unwrap_or_default(),
+                        request_id: extract_request_id(headers.as_ref()),
+                    })
+                }
+            }
+            TransportError::RetryLimit => CodexErr::RetryLimit(RetryLimitReachedError {
+                status: http::StatusCode::INTERNAL_SERVER_ERROR,
+                request_id: None,
+            }),
+            TransportError::Timeout => CodexErr::Timeout,
+            TransportError::Network(msg) | TransportError::Build(msg) => {
+                CodexErr::Stream(msg, None)
+            }
+        },
+        ApiError::RateLimit(msg) => CodexErr::Stream(msg, None),
+    }
+}
+
+fn extract_request_id(headers: Option<&HeaderMap>) -> Option<String> {
+    headers.and_then(|map| {
+        ["cf-ray", "x-request-id", "x-oai-request-id"]
+            .iter()
+            .find_map(|name| {
+                map.get(*name)
+                    .and_then(|v| v.to_str().ok())
+                    .map(str::to_string)
+            })
+    })
+}
+
+pub(crate) async fn auth_provider_from_auth(
+    auth: Option<CodexAuth>,
+    provider: &ModelProviderInfo,
+) -> crate::error::Result<CoreAuthProvider> {
+    if let Some(api_key) = provider.api_key()? {
+        return Ok(CoreAuthProvider {
+            token: Some(api_key),
+            account_id: None,
+        });
+    }
+
+    if let Some(token) = provider.experimental_bearer_token.clone() {
+        return Ok(CoreAuthProvider {
+            token: Some(token),
+            account_id: None,
+        });
+    }
+
+    if let Some(auth) = auth {
+        let token = auth.get_token().await?;
+        Ok(CoreAuthProvider {
+            token: Some(token),
+            account_id: auth.get_account_id(),
+        })
+    } else {
+        Ok(CoreAuthProvider {
+            token: None,
+            account_id: None,
+        })
+    }
+}
+
+#[derive(Debug, Deserialize)]
+struct UsageErrorResponse {
+    error: UsageErrorBody,
+}
+
+#[derive(Debug, Deserialize)]
+struct UsageErrorBody {
+    #[serde(rename = "type")]
+    error_type: Option<String>,
+    plan_type: Option<PlanType>,
+    resets_at: Option<i64>,
+}
+
+#[derive(Clone, Default)]
+pub(crate) struct CoreAuthProvider {
+    token: Option<String>,
+    account_id: Option<String>,
+}
+
+impl ApiAuthProvider for CoreAuthProvider {
+    fn bearer_token(&self) -> Option<String> {
+        self.token.clone()
+    }
+
+    fn account_id(&self) -> Option<String> {
+        self.account_id.clone()
+    }
+}
--- a/codex-rs/core/src/apply_patch.rs
+++ b/codex-rs/core/src/apply_patch.rs
@@ -70,7 +70,9 @@ pub(crate) async fn apply_patch(
                )
                .await;
            match rx_approve.await.unwrap_or_default() {
-                ReviewDecision::Approved | ReviewDecision::ApprovedForSession => {
+                ReviewDecision::Approved
+                | ReviewDecision::ApprovedAllowPrefix { .. }
+                | ReviewDecision::ApprovedForSession => {
                    InternalApplyPatchInvocation::DelegateToExec(ApplyPatchExec {
                        action,
                        user_explicitly_approved_this_action: true,
--- a/codex-rs/core/src/chat_completions.rs
+++ b/codex-rs/core/src/chat_completions.rs
@@ -1,981 +0,0 @@
-use std::time::Duration;
-
-use crate::ModelProviderInfo;
-use crate::client_common::Prompt;
-use crate::client_common::ResponseEvent;
-use crate::client_common::ResponseStream;
-use crate::default_client::CodexHttpClient;
-use crate::error::CodexErr;
-use crate::error::ConnectionFailedError;
-use crate::error::ResponseStreamFailed;
-use crate::error::Result;
-use crate::error::RetryLimitReachedError;
-use crate::error::UnexpectedResponseError;
-use crate::model_family::ModelFamily;
-use crate::tools::spec::create_tools_json_for_chat_completions_api;
-use crate::util::backoff;
-use bytes::Bytes;
-use codex_otel::otel_event_manager::OtelEventManager;
-use codex_protocol::models::ContentItem;
-use codex_protocol::models::FunctionCallOutputContentItem;
-use codex_protocol::models::ReasoningItemContent;
-use codex_protocol::models::ResponseItem;
-use codex_protocol::protocol::SessionSource;
-use codex_protocol::protocol::SubAgentSource;
-use eventsource_stream::Eventsource;
-use futures::Stream;
-use futures::StreamExt;
-use futures::TryStreamExt;
-use reqwest::StatusCode;
-use serde_json::json;
-use std::pin::Pin;
-use std::task::Context;
-use std::task::Poll;
-use tokio::sync::mpsc;
-use tokio::time::timeout;
-use tracing::debug;
-use tracing::trace;
-
-/// Implementation for the classic Chat Completions API.
-pub(crate) async fn stream_chat_completions(
-    prompt: &Prompt,
-    model_family: &ModelFamily,
-    client: &CodexHttpClient,
-    provider: &ModelProviderInfo,
-    otel_event_manager: &OtelEventManager,
-    session_source: &SessionSource,
-) -> Result<ResponseStream> {
-    if prompt.output_schema.is_some() {
-        return Err(CodexErr::UnsupportedOperation(
-            "output_schema is not supported for Chat Completions API".to_string(),
-        ));
-    }
-
-    // Build messages array
-    let mut messages = Vec::<serde_json::Value>::new();
-
-    let full_instructions = prompt.get_full_instructions(model_family);
-    messages.push(json!({"role": "system", "content": full_instructions}));
-
-    let input = prompt.get_formatted_input();
-
-    // Pre-scan: map Reasoning blocks to the adjacent assistant anchor after the last user.
-    // - If the last emitted message is a user message, drop all reasoning.
-    // - Otherwise, for each Reasoning item after the last user message, attach it
-    //   to the immediate previous assistant message (stop turns) or the immediate
-    //   next assistant anchor (tool-call turns: function/local shell call, or assistant message).
-    let mut reasoning_by_anchor_index: std::collections::HashMap<usize, String> =
-        std::collections::HashMap::new();
-
-    // Determine the last role that would be emitted to Chat Completions.
-    let mut last_emitted_role: Option<&str> = None;
-    for item in &input {
-        match item {
-            ResponseItem::Message { role, .. } => last_emitted_role = Some(role.as_str()),
-            ResponseItem::FunctionCall { .. } | ResponseItem::LocalShellCall { .. } => {
-                last_emitted_role = Some("assistant")
-            }
-            ResponseItem::FunctionCallOutput { .. } => last_emitted_role = Some("tool"),
-            ResponseItem::Reasoning { .. } | ResponseItem::Other => {}
-            ResponseItem::CustomToolCall { .. } => {}
-            ResponseItem::CustomToolCallOutput { .. } => {}
-            ResponseItem::WebSearchCall { .. } => {}
-            ResponseItem::GhostSnapshot { .. } => {}
-            ResponseItem::CompactionSummary { .. } => {}
-        }
-    }
-
-    // Find the last user message index in the input.
-    let mut last_user_index: Option<usize> = None;
-    for (idx, item) in input.iter().enumerate() {
-        if let ResponseItem::Message { role, .. } = item
-            && role == "user"
-        {
-            last_user_index = Some(idx);
-        }
-    }
-
-    // Attach reasoning only if the conversation does not end with a user message.
-    if !matches!(last_emitted_role, Some("user")) {
-        for (idx, item) in input.iter().enumerate() {
-            // Only consider reasoning that appears after the last user message.
-            if let Some(u_idx) = last_user_index
-                && idx <= u_idx
-            {
-                continue;
-            }
-
-            if let ResponseItem::Reasoning {
-                content: Some(items),
-                ..
-            } = item
-            {
-                let mut text = String::new();
-                for entry in items {
-                    match entry {
-                        ReasoningItemContent::ReasoningText { text: segment }
-                        | ReasoningItemContent::Text { text: segment } => text.push_str(segment),
-                    }
-                }
-                if text.trim().is_empty() {
-                    continue;
-                }
-
-                // Prefer immediate previous assistant message (stop turns)
-                let mut attached = false;
-                if idx > 0
-                    && let ResponseItem::Message { role, .. } = &input[idx - 1]
-                    && role == "assistant"
-                {
-                    reasoning_by_anchor_index
-                        .entry(idx - 1)
-                        .and_modify(|v| v.push_str(&text))
-                        .or_insert(text.clone());
-                    attached = true;
-                }
-
-                // Otherwise, attach to immediate next assistant anchor (tool-calls or assistant message)
-                if !attached && idx + 1 < input.len() {
-                    match &input[idx + 1] {
-                        ResponseItem::FunctionCall { .. } | ResponseItem::LocalShellCall { .. } => {
-                            reasoning_by_anchor_index
-                                .entry(idx + 1)
-                                .and_modify(|v| v.push_str(&text))
-                                .or_insert(text.clone());
-                        }
-                        ResponseItem::Message { role, .. } if role == "assistant" => {
-                            reasoning_by_anchor_index
-                                .entry(idx + 1)
-                                .and_modify(|v| v.push_str(&text))
-                                .or_insert(text.clone());
-                        }
-                        _ => {}
-                    }
-                }
-            }
-        }
-    }
-
-    // Track last assistant text we emitted to avoid duplicate assistant messages
-    // in the outbound Chat Completions payload (can happen if a final
-    // aggregated assistant message was recorded alongside an earlier partial).
-    let mut last_assistant_text: Option<String> = None;
-
-    for (idx, item) in input.iter().enumerate() {
-        match item {
-            ResponseItem::Message { role, content, .. } => {
-                // Build content either as a plain string (typical for assistant text)
-                // or as an array of content items when images are present (user/tool multimodal).
-                let mut text = String::new();
-                let mut items: Vec<serde_json::Value> = Vec::new();
-                let mut saw_image = false;
-
-                for c in content {
-                    match c {
-                        ContentItem::InputText { text: t }
-                        | ContentItem::OutputText { text: t } => {
-                            text.push_str(t);
-                            items.push(json!({"type":"text","text": t}));
-                        }
-                        ContentItem::InputImage { image_url } => {
-                            saw_image = true;
-                            items.push(json!({"type":"image_url","image_url": {"url": image_url}}));
-                        }
-                    }
-                }
-
-                // Skip exact-duplicate assistant messages.
-                if role == "assistant" {
-                    if let Some(prev) = &last_assistant_text
-                        && prev == &text
-                    {
-                        continue;
-                    }
-                    last_assistant_text = Some(text.clone());
-                }
-
-                // For assistant messages, always send a plain string for compatibility.
-                // For user messages, if an image is present, send an array of content items.
-                let content_value = if role == "assistant" {
-                    json!(text)
-                } else if saw_image {
-                    json!(items)
-                } else {
-                    json!(text)
-                };
-
-                let mut msg = json!({"role": role, "content": content_value});
-                if role == "assistant"
-                    && let Some(reasoning) = reasoning_by_anchor_index.get(&idx)
-                    && let Some(obj) = msg.as_object_mut()
-                {
-                    obj.insert("reasoning".to_string(), json!(reasoning));
-                }
-                messages.push(msg);
-            }
-            ResponseItem::FunctionCall {
-                name,
-                arguments,
-                call_id,
-                ..
-            } => {
-                let mut msg = json!({
-                    "role": "assistant",
-                    "content": null,
-                    "tool_calls": [{
-                        "id": call_id,
-                        "type": "function",
-                        "function": {
-                            "name": name,
-                            "arguments": arguments,
-                        }
-                    }]
-                });
-                if let Some(reasoning) = reasoning_by_anchor_index.get(&idx)
-                    && let Some(obj) = msg.as_object_mut()
-                {
-                    obj.insert("reasoning".to_string(), json!(reasoning));
-                }
-                messages.push(msg);
-            }
-            ResponseItem::LocalShellCall {
-                id,
-                call_id: _,
-                status,
-                action,
-            } => {
-                // Confirm with API team.
-                let mut msg = json!({
-                    "role": "assistant",
-                    "content": null,
-                    "tool_calls": [{
-                        "id": id.clone().unwrap_or_else(|| "".to_string()),
-                        "type": "local_shell_call",
-                        "status": status,
-                        "action": action,
-                    }]
-                });
-                if let Some(reasoning) = reasoning_by_anchor_index.get(&idx)
-                    && let Some(obj) = msg.as_object_mut()
-                {
-                    obj.insert("reasoning".to_string(), json!(reasoning));
-                }
-                messages.push(msg);
-            }
-            ResponseItem::FunctionCallOutput { call_id, output } => {
-                // Prefer structured content items when available (e.g., images)
-                // otherwise fall back to the legacy plain-string content.
-                let content_value = if let Some(items) = &output.content_items {
-                    let mapped: Vec<serde_json::Value> = items
-                        .iter()
-                        .map(|it| match it {
-                            FunctionCallOutputContentItem::InputText { text } => {
-                                json!({"type":"text","text": text})
-                            }
-                            FunctionCallOutputContentItem::InputImage { image_url } => {
-                                json!({"type":"image_url","image_url": {"url": image_url}})
-                            }
-                        })
-                        .collect();
-                    json!(mapped)
-                } else {
-                    json!(output.content)
-                };
-
-                messages.push(json!({
-                    "role": "tool",
-                    "tool_call_id": call_id,
-                    "content": content_value,
-                }));
-            }
-            ResponseItem::CustomToolCall {
-                id,
-                call_id: _,
-                name,
-                input,
-                status: _,
-            } => {
-                messages.push(json!({
-                    "role": "assistant",
-                    "content": null,
-                    "tool_calls": [{
-                        "id": id,
-                        "type": "custom",
-                        "custom": {
-                            "name": name,
-                            "input": input,
-                        }
-                    }]
-                }));
-            }
-            ResponseItem::CustomToolCallOutput { call_id, output } => {
-                messages.push(json!({
-                    "role": "tool",
-                    "tool_call_id": call_id,
-                    "content": output,
-                }));
-            }
-            ResponseItem::GhostSnapshot { .. } => {
-                // Ghost snapshots annotate history but are not sent to the model.
-                continue;
-            }
-            ResponseItem::Reasoning { .. }
-            | ResponseItem::WebSearchCall { .. }
-            | ResponseItem::Other
-            | ResponseItem::CompactionSummary { .. } => {
-                // Omit these items from the conversation history.
-                continue;
-            }
-        }
-    }
-
-    let tools_json = create_tools_json_for_chat_completions_api(&prompt.tools)?;
-    let payload = json!({
-        "model": model_family.slug,
-        "messages": messages,
-        "stream": true,
-        "tools": tools_json,
-    });
-
-    debug!(
-        "POST to {}: {}",
-        provider.get_full_url(&None),
-        payload.to_string()
-    );
-
-    let mut attempt = 0;
-    let max_retries = provider.request_max_retries();
-    loop {
-        attempt += 1;
-
-        let mut req_builder = provider.create_request_builder(client, &None).await?;
-
-        // Include subagent header only for subagent sessions.
-        if let SessionSource::SubAgent(sub) = session_source.clone() {
-            let subagent = if let SubAgentSource::Other(label) = sub {
-                label
-            } else {
-                serde_json::to_value(&sub)
-                    .ok()
-                    .and_then(|v| v.as_str().map(std::string::ToString::to_string))
-                    .unwrap_or_else(|| "other".to_string())
-            };
-            req_builder = req_builder.header("x-openai-subagent", subagent);
-        }
-
-        let res = otel_event_manager
-            .log_request(attempt, || {
-                req_builder
-                    .header(reqwest::header::ACCEPT, "text/event-stream")
-                    .json(&payload)
-                    .send()
-            })
-            .await;
-
-        match res {
-            Ok(resp) if resp.status().is_success() => {
-                let (tx_event, rx_event) = mpsc::channel::<Result<ResponseEvent>>(1600);
-                let stream = resp.bytes_stream().map_err(|e| {
-                    CodexErr::ResponseStreamFailed(ResponseStreamFailed {
-                        source: e,
-                        request_id: None,
-                    })
-                });
-                tokio::spawn(process_chat_sse(
-                    stream,
-                    tx_event,
-                    provider.stream_idle_timeout(),
-                    otel_event_manager.clone(),
-                ));
-                return Ok(ResponseStream { rx_event });
-            }
-            Ok(res) => {
-                let status = res.status();
-                if !(status == StatusCode::TOO_MANY_REQUESTS || status.is_server_error()) {
-                    let body = (res.text().await).unwrap_or_default();
-                    return Err(CodexErr::UnexpectedStatus(UnexpectedResponseError {
-                        status,
-                        body,
-                        request_id: None,
-                    }));
-                }
-
-                if attempt > max_retries {
-                    return Err(CodexErr::RetryLimit(RetryLimitReachedError {
-                        status,
-                        request_id: None,
-                    }));
-                }
-
-                let retry_after_secs = res
-                    .headers()
-                    .get(reqwest::header::RETRY_AFTER)
-                    .and_then(|v| v.to_str().ok())
-                    .and_then(|s| s.parse::<u64>().ok());
-
-                let delay = retry_after_secs
-                    .map(|s| Duration::from_millis(s * 1_000))
-                    .unwrap_or_else(|| backoff(attempt));
-                tokio::time::sleep(delay).await;
-            }
-            Err(e) => {
-                if attempt > max_retries {
-                    return Err(CodexErr::ConnectionFailed(ConnectionFailedError {
-                        source: e,
-                    }));
-                }
-                let delay = backoff(attempt);
-                tokio::time::sleep(delay).await;
-            }
-        }
-    }
-}
-
-async fn append_assistant_text(
-    tx_event: &mpsc::Sender<Result<ResponseEvent>>,
-    assistant_item: &mut Option<ResponseItem>,
-    text: String,
-) {
-    if assistant_item.is_none() {
-        let item = ResponseItem::Message {
-            id: None,
-            role: "assistant".to_string(),
-            content: vec![],
-        };
-        *assistant_item = Some(item.clone());
-        let _ = tx_event
-            .send(Ok(ResponseEvent::OutputItemAdded(item)))
-            .await;
-    }
-
-    if let Some(ResponseItem::Message { content, .. }) = assistant_item {
-        content.push(ContentItem::OutputText { text: text.clone() });
-        let _ = tx_event
-            .send(Ok(ResponseEvent::OutputTextDelta(text.clone())))
-            .await;
-    }
-}
-
-async fn append_reasoning_text(
-    tx_event: &mpsc::Sender<Result<ResponseEvent>>,
-    reasoning_item: &mut Option<ResponseItem>,
-    text: String,
-) {
-    if reasoning_item.is_none() {
-        let item = ResponseItem::Reasoning {
-            id: String::new(),
-            summary: Vec::new(),
-            content: Some(vec![]),
-            encrypted_content: None,
-        };
-        *reasoning_item = Some(item.clone());
-        let _ = tx_event
-            .send(Ok(ResponseEvent::OutputItemAdded(item)))
-            .await;
-    }
-
-    if let Some(ResponseItem::Reasoning {
-        content: Some(content),
-        ..
-    }) = reasoning_item
-    {
-        let content_index = content.len() as i64;
-        content.push(ReasoningItemContent::ReasoningText { text: text.clone() });
-
-        let _ = tx_event
-            .send(Ok(ResponseEvent::ReasoningContentDelta {
-                delta: text.clone(),
-                content_index,
-            }))
-            .await;
-    }
-}
-/// Lightweight SSE processor for the Chat Completions streaming format. The
-/// output is mapped onto Codex's internal [`ResponseEvent`] so that the rest
-/// of the pipeline can stay agnostic of the underlying wire format.
-async fn process_chat_sse<S>(
-    stream: S,
-    tx_event: mpsc::Sender<Result<ResponseEvent>>,
-    idle_timeout: Duration,
-    otel_event_manager: OtelEventManager,
-) where
-    S: Stream<Item = Result<Bytes>> + Unpin,
-{
-    let mut stream = stream.eventsource();
-
-    // State to accumulate a function call across streaming chunks.
-    // OpenAI may split the `arguments` string over multiple `delta` events
-    // until the chunk whose `finish_reason` is `tool_calls` is emitted. We
-    // keep collecting the pieces here and forward a single
-    // `ResponseItem::FunctionCall` once the call is complete.
-    #[derive(Default)]
-    struct FunctionCallState {
-        name: Option<String>,
-        arguments: String,
-        call_id: Option<String>,
-        active: bool,
-    }
-
-    let mut fn_call_state = FunctionCallState::default();
-    let mut assistant_item: Option<ResponseItem> = None;
-    let mut reasoning_item: Option<ResponseItem> = None;
-
-    loop {
-        let start = std::time::Instant::now();
-        let response = timeout(idle_timeout, stream.next()).await;
-        let duration = start.elapsed();
-        otel_event_manager.log_sse_event(&response, duration);
-
-        let sse = match response {
-            Ok(Some(Ok(ev))) => ev,
-            Ok(Some(Err(e))) => {
-                let _ = tx_event
-                    .send(Err(CodexErr::Stream(e.to_string(), None)))
-                    .await;
-                return;
-            }
-            Ok(None) => {
-                // Stream closed gracefully – emit Completed with dummy id.
-                let _ = tx_event
-                    .send(Ok(ResponseEvent::Completed {
-                        response_id: String::new(),
-                        token_usage: None,
-                    }))
-                    .await;
-                return;
-            }
-            Err(_) => {
-                let _ = tx_event
-                    .send(Err(CodexErr::Stream(
-                        "idle timeout waiting for SSE".into(),
-                        None,
-                    )))
-                    .await;
-                return;
-            }
-        };
-
-        // OpenAI Chat streaming sends a literal string "[DONE]" when finished.
-        if sse.data.trim() == "[DONE]" {
-            // Emit any finalized items before closing so downstream consumers receive
-            // terminal events for both assistant content and raw reasoning.
-            if let Some(item) = assistant_item {
-                let _ = tx_event.send(Ok(ResponseEvent::OutputItemDone(item))).await;
-            }
-
-            if let Some(item) = reasoning_item {
-                let _ = tx_event.send(Ok(ResponseEvent::OutputItemDone(item))).await;
-            }
-
-            let _ = tx_event
-                .send(Ok(ResponseEvent::Completed {
-                    response_id: String::new(),
-                    token_usage: None,
-                }))
-                .await;
-            return;
-        }
-
-        // Parse JSON chunk
-        let chunk: serde_json::Value = match serde_json::from_str(&sse.data) {
-            Ok(v) => v,
-            Err(_) => continue,
-        };
-        trace!("chat_completions received SSE chunk: {chunk:?}");
-
-        let choice_opt = chunk.get("choices").and_then(|c| c.get(0));
-
-        if let Some(choice) = choice_opt {
-            // Handle assistant content tokens as streaming deltas.
-            if let Some(content) = choice
-                .get("delta")
-                .and_then(|d| d.get("content"))
-                .and_then(|c| c.as_str())
-                && !content.is_empty()
-            {
-                append_assistant_text(&tx_event, &mut assistant_item, content.to_string()).await;
-            }
-
-            // Forward any reasoning/thinking deltas if present.
-            // Some providers stream `reasoning` as a plain string while others
-            // nest the text under an object (e.g. `{ "reasoning": { "text": "…" } }`).
-            if let Some(reasoning_val) = choice.get("delta").and_then(|d| d.get("reasoning")) {
-                let mut maybe_text = reasoning_val
-                    .as_str()
-                    .map(str::to_string)
-                    .filter(|s| !s.is_empty());
-
-                if maybe_text.is_none() && reasoning_val.is_object() {
-                    if let Some(s) = reasoning_val
-                        .get("text")
-                        .and_then(|t| t.as_str())
-                        .filter(|s| !s.is_empty())
-                    {
-                        maybe_text = Some(s.to_string());
-                    } else if let Some(s) = reasoning_val
-                        .get("content")
-                        .and_then(|t| t.as_str())
-                        .filter(|s| !s.is_empty())
-                    {
-                        maybe_text = Some(s.to_string());
-                    }
-                }
-
-                if let Some(reasoning) = maybe_text {
-                    // Accumulate so we can emit a terminal Reasoning item at the end.
-                    append_reasoning_text(&tx_event, &mut reasoning_item, reasoning).await;
-                }
-            }
-
-            // Some providers only include reasoning on the final message object.
-            if let Some(message_reasoning) = choice.get("message").and_then(|m| m.get("reasoning"))
-            {
-                // Accept either a plain string or an object with { text | content }
-                if let Some(s) = message_reasoning.as_str() {
-                    if !s.is_empty() {
-                        append_reasoning_text(&tx_event, &mut reasoning_item, s.to_string()).await;
-                    }
-                } else if let Some(obj) = message_reasoning.as_object()
-                    && let Some(s) = obj
-                        .get("text")
-                        .and_then(|v| v.as_str())
-                        .or_else(|| obj.get("content").and_then(|v| v.as_str()))
-                    && !s.is_empty()
-                {
-                    append_reasoning_text(&tx_event, &mut reasoning_item, s.to_string()).await;
-                }
-            }
-
-            // Handle streaming function / tool calls.
-            if let Some(tool_calls) = choice
-                .get("delta")
-                .and_then(|d| d.get("tool_calls"))
-                .and_then(|tc| tc.as_array())
-                && let Some(tool_call) = tool_calls.first()
-            {
-                // Mark that we have an active function call in progress.
-                fn_call_state.active = true;
-
-                // Extract call_id if present.
-                if let Some(id) = tool_call.get("id").and_then(|v| v.as_str()) {
-                    fn_call_state.call_id.get_or_insert_with(|| id.to_string());
-                }
-
-                // Extract function details if present.
-                if let Some(function) = tool_call.get("function") {
-                    if let Some(name) = function.get("name").and_then(|n| n.as_str()) {
-                        fn_call_state.name.get_or_insert_with(|| name.to_string());
-                    }
-
-                    if let Some(args_fragment) = function.get("arguments").and_then(|a| a.as_str())
-                    {
-                        fn_call_state.arguments.push_str(args_fragment);
-                    }
-                }
-            }
-
-            // Emit end-of-turn when finish_reason signals completion.
-            if let Some(finish_reason) = choice.get("finish_reason").and_then(|v| v.as_str())
-                && !finish_reason.is_empty()
-            {
-                match finish_reason {
-                    "tool_calls" if fn_call_state.active => {
-                        // First, flush the terminal raw reasoning so UIs can finalize
-                        // the reasoning stream before any exec/tool events begin.
-                        if let Some(item) = reasoning_item.take() {
-                            let _ = tx_event.send(Ok(ResponseEvent::OutputItemDone(item))).await;
-                        }
-
-                        // Then emit the FunctionCall response item.
-                        let item = ResponseItem::FunctionCall {
-                            id: None,
-                            name: fn_call_state.name.clone().unwrap_or_else(|| "".to_string()),
-                            arguments: fn_call_state.arguments.clone(),
-                            call_id: fn_call_state.call_id.clone().unwrap_or_else(String::new),
-                        };
-
-                        let _ = tx_event.send(Ok(ResponseEvent::OutputItemDone(item))).await;
-                    }
-                    "stop" => {
-                        // Regular turn without tool-call. Emit the final assistant message
-                        // as a single OutputItemDone so non-delta consumers see the result.
-                        if let Some(item) = assistant_item.take() {
-                            let _ = tx_event.send(Ok(ResponseEvent::OutputItemDone(item))).await;
-                        }
-                        // Also emit a terminal Reasoning item so UIs can finalize raw reasoning.
-                        if let Some(item) = reasoning_item.take() {
-                            let _ = tx_event.send(Ok(ResponseEvent::OutputItemDone(item))).await;
-                        }
-                    }
-                    _ => {}
-                }
-
-                // Emit Completed regardless of reason so the agent can advance.
-                let _ = tx_event
-                    .send(Ok(ResponseEvent::Completed {
-                        response_id: String::new(),
-                        token_usage: None,
-                    }))
-                    .await;
-
-                // Prepare for potential next turn (should not happen in same stream).
-                // fn_call_state = FunctionCallState::default();
-
-                return; // End processing for this SSE stream.
-            }
-        }
-    }
-}
-
-/// Optional client-side aggregation helper
-///
-/// Stream adapter that merges the incremental `OutputItemDone` chunks coming from
-/// [`process_chat_sse`] into a *running* assistant message, **suppressing the
-/// per-token deltas**.  The stream stays silent while the model is thinking
-/// and only emits two events per turn:
-///
-///   1. `ResponseEvent::OutputItemDone` with the *complete* assistant message
-///      (fully concatenated).
-///   2. The original `ResponseEvent::Completed` right after it.
-///
-/// This mirrors the behaviour the TypeScript CLI exposes to its higher layers.
-///
-/// The adapter is intentionally *lossless*: callers who do **not** opt in via
-/// [`AggregateStreamExt::aggregate()`] keep receiving the original unmodified
-/// events.
-#[derive(Copy, Clone, Eq, PartialEq)]
-enum AggregateMode {
-    AggregatedOnly,
-    Streaming,
-}
-pub(crate) struct AggregatedChatStream<S> {
-    inner: S,
-    cumulative: String,
-    cumulative_reasoning: String,
-    pending: std::collections::VecDeque<ResponseEvent>,
-    mode: AggregateMode,
-}
-
-impl<S> Stream for AggregatedChatStream<S>
-where
-    S: Stream<Item = Result<ResponseEvent>> + Unpin,
-{
-    type Item = Result<ResponseEvent>;
-
-    fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
-        let this = self.get_mut();
-
-        // First, flush any buffered events from the previous call.
-        if let Some(ev) = this.pending.pop_front() {
-            return Poll::Ready(Some(Ok(ev)));
-        }
-
-        loop {
-            match Pin::new(&mut this.inner).poll_next(cx) {
-                Poll::Pending => return Poll::Pending,
-                Poll::Ready(None) => return Poll::Ready(None),
-                Poll::Ready(Some(Err(e))) => return Poll::Ready(Some(Err(e))),
-                Poll::Ready(Some(Ok(ResponseEvent::OutputItemDone(item)))) => {
-                    // If this is an incremental assistant message chunk, accumulate but
-                    // do NOT emit yet. Forward any other item (e.g. FunctionCall) right
-                    // away so downstream consumers see it.
-
-                    let is_assistant_message = matches!(
-                        &item,
-                        codex_protocol::models::ResponseItem::Message { role, .. } if role == "assistant"
-                    );
-
-                    if is_assistant_message {
-                        match this.mode {
-                            AggregateMode::AggregatedOnly => {
-                                // Only use the final assistant message if we have not
-                                // seen any deltas; otherwise, deltas already built the
-                                // cumulative text and this would duplicate it.
-                                if this.cumulative.is_empty()
-                                    && let codex_protocol::models::ResponseItem::Message {
-                                        content,
-                                        ..
-                                    } = &item
-                                    && let Some(text) = content.iter().find_map(|c| match c {
-                                        codex_protocol::models::ContentItem::OutputText {
-                                            text,
-                                        } => Some(text),
-                                        _ => None,
-                                    })
-                                {
-                                    this.cumulative.push_str(text);
-                                }
-                                // Swallow assistant message here; emit on Completed.
-                                continue;
-                            }
-                            AggregateMode::Streaming => {
-                                // In streaming mode, if we have not seen any deltas, forward
-                                // the final assistant message directly. If deltas were seen,
-                                // suppress the final message to avoid duplication.
-                                if this.cumulative.is_empty() {
-                                    return Poll::Ready(Some(Ok(ResponseEvent::OutputItemDone(
-                                        item,
-                                    ))));
-                                } else {
-                                    continue;
-                                }
-                            }
-                        }
-                    }
-
-                    // Not an assistant message – forward immediately.
-                    return Poll::Ready(Some(Ok(ResponseEvent::OutputItemDone(item))));
-                }
-                Poll::Ready(Some(Ok(ResponseEvent::RateLimits(snapshot)))) => {
-                    return Poll::Ready(Some(Ok(ResponseEvent::RateLimits(snapshot))));
-                }
-                Poll::Ready(Some(Ok(ResponseEvent::Completed {
-                    response_id,
-                    token_usage,
-                }))) => {
-                    // Build any aggregated items in the correct order: Reasoning first, then Message.
-                    let mut emitted_any = false;
-
-                    if !this.cumulative_reasoning.is_empty()
-                        && matches!(this.mode, AggregateMode::AggregatedOnly)
-                    {
-                        let aggregated_reasoning =
-                            codex_protocol::models::ResponseItem::Reasoning {
-                                id: String::new(),
-                                summary: Vec::new(),
-                                content: Some(vec![
-                                    codex_protocol::models::ReasoningItemContent::ReasoningText {
-                                        text: std::mem::take(&mut this.cumulative_reasoning),
-                                    },
-                                ]),
-                                encrypted_content: None,
-                            };
-                        this.pending
-                            .push_back(ResponseEvent::OutputItemDone(aggregated_reasoning));
-                        emitted_any = true;
-                    }
-
-                    // Always emit the final aggregated assistant message when any
-                    // content deltas have been observed. In AggregatedOnly mode this
-                    // is the sole assistant output; in Streaming mode this finalizes
-                    // the streamed deltas into a terminal OutputItemDone so callers
-                    // can persist/render the message once per turn.
-                    if !this.cumulative.is_empty() {
-                        let aggregated_message = codex_protocol::models::ResponseItem::Message {
-                            id: None,
-                            role: "assistant".to_string(),
-                            content: vec![codex_protocol::models::ContentItem::OutputText {
-                                text: std::mem::take(&mut this.cumulative),
-                            }],
-                        };
-                        this.pending
-                            .push_back(ResponseEvent::OutputItemDone(aggregated_message));
-                        emitted_any = true;
-                    }
-
-                    // Always emit Completed last when anything was aggregated.
-                    if emitted_any {
-                        this.pending.push_back(ResponseEvent::Completed {
-                            response_id: response_id.clone(),
-                            token_usage: token_usage.clone(),
-                        });
-                        // Return the first pending event now.
-                        if let Some(ev) = this.pending.pop_front() {
-                            return Poll::Ready(Some(Ok(ev)));
-                        }
-                    }
-
-                    // Nothing aggregated – forward Completed directly.
-                    return Poll::Ready(Some(Ok(ResponseEvent::Completed {
-                        response_id,
-                        token_usage,
-                    })));
-                }
-                Poll::Ready(Some(Ok(ResponseEvent::Created))) => {
-                    // These events are exclusive to the Responses API and
-                    // will never appear in a Chat Completions stream.
-                    continue;
-                }
-                Poll::Ready(Some(Ok(ResponseEvent::OutputTextDelta(delta)))) => {
-                    // Always accumulate deltas so we can emit a final OutputItemDone at Completed.
-                    this.cumulative.push_str(&delta);
-                    if matches!(this.mode, AggregateMode::Streaming) {
-                        // In streaming mode, also forward the delta immediately.
-                        return Poll::Ready(Some(Ok(ResponseEvent::OutputTextDelta(delta))));
-                    } else {
-                        continue;
-                    }
-                }
-                Poll::Ready(Some(Ok(ResponseEvent::ReasoningContentDelta {
-                    delta,
-                    content_index,
-                }))) => {
-                    // Always accumulate reasoning deltas so we can emit a final Reasoning item at Completed.
-                    this.cumulative_reasoning.push_str(&delta);
-                    if matches!(this.mode, AggregateMode::Streaming) {
-                        // In streaming mode, also forward the delta immediately.
-                        return Poll::Ready(Some(Ok(ResponseEvent::ReasoningContentDelta {
-                            delta,
-                            content_index,
-                        })));
-                    } else {
-                        continue;
-                    }
-                }
-                Poll::Ready(Some(Ok(ResponseEvent::ReasoningSummaryDelta { .. }))) => {
-                    continue;
-                }
-                Poll::Ready(Some(Ok(ResponseEvent::ReasoningSummaryPartAdded { .. }))) => {
-                    continue;
-                }
-                Poll::Ready(Some(Ok(ResponseEvent::OutputItemAdded(item)))) => {
-                    return Poll::Ready(Some(Ok(ResponseEvent::OutputItemAdded(item))));
-                }
-            }
-        }
-    }
-}
-
-/// Extension trait that activates aggregation on any stream of [`ResponseEvent`].
-pub(crate) trait AggregateStreamExt: Stream<Item = Result<ResponseEvent>> + Sized {
-    /// Returns a new stream that emits **only** the final assistant message
-    /// per turn instead of every incremental delta.  The produced
-    /// `ResponseEvent` sequence for a typical text turn looks like:
-    ///
-    /// ```ignore
-    ///     OutputItemDone(<full message>)
-    ///     Completed
-    /// ```
-    ///
-    /// No other `OutputItemDone` events will be seen by the caller.
-    ///
-    /// Usage:
-    ///
-    /// ```ignore
-    /// let agg_stream = client.stream(&prompt).await?.aggregate();
-    /// while let Some(event) = agg_stream.next().await {
-    ///     // event now contains cumulative text
-    /// }
-    /// ```
-    fn aggregate(self) -> AggregatedChatStream<Self> {
-        AggregatedChatStream::new(self, AggregateMode::AggregatedOnly)
-    }
-}
-
-impl<T> AggregateStreamExt for T where T: Stream<Item = Result<ResponseEvent>> + Sized {}
-
-impl<S> AggregatedChatStream<S> {
-    fn new(inner: S, mode: AggregateMode) -> Self {
-        AggregatedChatStream {
-            inner,
-            cumulative: String::new(),
-            cumulative_reasoning: String::new(),
-            pending: std::collections::VecDeque::new(),
-            mode,
-        }
-    }
-
-    pub(crate) fn streaming_mode(inner: S) -> Self {
-        Self::new(inner, AggregateMode::Streaming)
-    }
-}
--- a/codex-rs/core/src/client.rs
+++ b/codex-rs/core/src/client.rs
--- a/codex-rs/core/src/client_common.rs
+++ b/codex-rs/core/src/client_common.rs
@@ -1,16 +1,11 @@
 use crate::client_common::tools::ToolSpec;
 use crate::error::Result;
 use crate::model_family::ModelFamily;
-use crate::protocol::RateLimitSnapshot;
-use crate::protocol::TokenUsage;
+pub use codex_api::common::ResponseEvent;
 use codex_apply_patch::APPLY_PATCH_TOOL_INSTRUCTIONS;
-use codex_protocol::config_types::ReasoningEffort as ReasoningEffortConfig;
-use codex_protocol::config_types::ReasoningSummary as ReasoningSummaryConfig;
-use codex_protocol::config_types::Verbosity as VerbosityConfig;
 use codex_protocol::models::ResponseItem;
 use futures::Stream;
 use serde::Deserialize;
-use serde::Serialize;
 use serde_json::Value;
 use std::borrow::Cow;
 use std::collections::HashSet;
@@ -184,104 +179,6 @@ fn strip_total_output_header(output: &str) -> Option<(&str, u32)> {
    Some((remainder, total_lines))
 }

-#[derive(Debug)]
-pub enum ResponseEvent {
-    Created,
-    OutputItemDone(ResponseItem),
-    OutputItemAdded(ResponseItem),
-    Completed {
-        response_id: String,
-        token_usage: Option<TokenUsage>,
-    },
-    OutputTextDelta(String),
-    ReasoningSummaryDelta {
-        delta: String,
-        summary_index: i64,
-    },
-    ReasoningContentDelta {
-        delta: String,
-        content_index: i64,
-    },
-    ReasoningSummaryPartAdded {
-        summary_index: i64,
-    },
-    RateLimits(RateLimitSnapshot),
-}
-
-#[derive(Debug, Serialize)]
-pub(crate) struct Reasoning {
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub(crate) effort: Option<ReasoningEffortConfig>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub(crate) summary: Option<ReasoningSummaryConfig>,
-}
-
-#[derive(Debug, Serialize, Default, Clone)]
-#[serde(rename_all = "snake_case")]
-pub(crate) enum TextFormatType {
-    #[default]
-    JsonSchema,
-}
-
-#[derive(Debug, Serialize, Default, Clone)]
-pub(crate) struct TextFormat {
-    pub(crate) r#type: TextFormatType,
-    pub(crate) strict: bool,
-    pub(crate) schema: Value,
-    pub(crate) name: String,
-}
-
-/// Controls under the `text` field in the Responses API for GPT-5.
-#[derive(Debug, Serialize, Default, Clone)]
-pub(crate) struct TextControls {
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub(crate) verbosity: Option<OpenAiVerbosity>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub(crate) format: Option<TextFormat>,
-}
-
-#[derive(Debug, Serialize, Default, Clone)]
-#[serde(rename_all = "lowercase")]
-pub(crate) enum OpenAiVerbosity {
-    Low,
-    #[default]
-    Medium,
-    High,
-}
-
-impl From<VerbosityConfig> for OpenAiVerbosity {
-    fn from(v: VerbosityConfig) -> Self {
-        match v {
-            VerbosityConfig::Low => OpenAiVerbosity::Low,
-            VerbosityConfig::Medium => OpenAiVerbosity::Medium,
-            VerbosityConfig::High => OpenAiVerbosity::High,
-        }
-    }
-}
-
-/// Request object that is serialized as JSON and POST'ed when using the
-/// Responses API.
-#[derive(Debug, Serialize)]
-pub(crate) struct ResponsesApiRequest<'a> {
-    pub(crate) model: &'a str,
-    pub(crate) instructions: &'a str,
-    // TODO(mbolin): ResponseItem::Other should not be serialized. Currently,
-    // we code defensively to avoid this case, but perhaps we should use a
-    // separate enum for serialization.
-    pub(crate) input: &'a Vec<ResponseItem>,
-    pub(crate) tools: &'a [serde_json::Value],
-    pub(crate) tool_choice: &'static str,
-    pub(crate) parallel_tool_calls: bool,
-    pub(crate) reasoning: Option<Reasoning>,
-    pub(crate) store: bool,
-    pub(crate) stream: bool,
-    pub(crate) include: Vec<String>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub(crate) prompt_cache_key: Option<String>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub(crate) text: Option<TextControls>,
-}
-
 pub(crate) mod tools {
    use crate::tools::spec::JsonSchema;
    use serde::Deserialize;
@@ -341,25 +238,6 @@ pub(crate) mod tools {
    }
 }

-pub(crate) fn create_text_param_for_request(
-    verbosity: Option<VerbosityConfig>,
-    output_schema: &Option<Value>,
-) -> Option<TextControls> {
-    if verbosity.is_none() && output_schema.is_none() {
-        return None;
-    }
-
-    Some(TextControls {
-        verbosity: verbosity.map(std::convert::Into::into),
-        format: output_schema.as_ref().map(|schema| TextFormat {
-            r#type: TextFormatType::JsonSchema,
-            strict: true,
-            schema: schema.clone(),
-            name: "codex_output_schema".to_string(),
-        }),
-    })
-}
-
 pub struct ResponseStream {
    pub(crate) rx_event: mpsc::Receiver<Result<ResponseEvent>>,
 }
@@ -375,6 +253,10 @@ impl Stream for ResponseStream {
 #[cfg(test)]
 mod tests {
    use crate::model_family::find_family_for_model;
+    use codex_api::ResponsesApiRequest;
+    use codex_api::common::OpenAiVerbosity;
+    use codex_api::common::TextControls;
+    use codex_api::create_text_param_for_request;
    use pretty_assertions::assert_eq;

    use super::*;
--- a/codex-rs/core/src/codex.rs
+++ b/codex-rs/core/src/codex.rs
--- a/codex-rs/core/src/codex_delegate.rs
+++ b/codex-rs/core/src/codex_delegate.rs
@@ -4,7 +4,6 @@ use std::sync::atomic::AtomicU64;
 use async_channel::Receiver;
 use async_channel::Sender;
 use codex_async_utils::OrCancelExt;
-use codex_protocol::ConversationId;
 use codex_protocol::protocol::ApplyPatchApprovalRequestEvent;
 use codex_protocol::protocol::Event;
 use codex_protocol::protocol::EventMsg;
@@ -14,6 +13,8 @@ use codex_protocol::protocol::SessionSource;
 use codex_protocol::protocol::SubAgentSource;
 use codex_protocol::protocol::Submission;
 use codex_protocol::user_input::UserInput;
+use std::time::Duration;
+use tokio::time::timeout;
 use tokio_util::sync::CancellationToken;

 use crate::AuthManager;
@@ -31,16 +32,13 @@ use codex_protocol::protocol::InitialHistory;
 /// The returned `events_rx` yields non-approval events emitted by the sub-agent.
 /// Approval requests are handled via `parent_session` and are not surfaced.
 /// The returned `ops_tx` allows the caller to submit additional `Op`s to the sub-agent.
-#[allow(clippy::too_many_arguments)]
 pub(crate) async fn run_codex_conversation_interactive(
    config: Config,
    auth_manager: Arc<AuthManager>,
    parent_session: Arc<Session>,
    parent_ctx: Arc<TurnContext>,
    cancel_token: CancellationToken,
-    desired_conversation_id: Option<ConversationId>,
    initial_history: Option<InitialHistory>,
-    source: SubAgentSource,
 ) -> Result<Codex, CodexErr> {
    let (tx_sub, rx_sub) = async_channel::bounded(SUBMISSION_CHANNEL_CAPACITY);
    let (tx_ops, rx_ops) = async_channel::bounded(SUBMISSION_CHANNEL_CAPACITY);
@@ -49,8 +47,7 @@ pub(crate) async fn run_codex_conversation_interactive(
        config,
        auth_manager,
        initial_history.unwrap_or(InitialHistory::New),
-        SessionSource::SubAgent(source),
-        desired_conversation_id,
+        SessionSource::SubAgent(SubAgentSource::Review),
    )
    .await?;
    let codex = Arc::new(codex);
@@ -65,14 +62,13 @@ pub(crate) async fn run_codex_conversation_interactive(
    let parent_ctx_clone = Arc::clone(&parent_ctx);
    let codex_for_events = Arc::clone(&codex);
    tokio::spawn(async move {
-        let _ = forward_events(
+        forward_events(
            codex_for_events,
            tx_sub,
            parent_session_clone,
            parent_ctx_clone,
-            cancel_token_events.clone(),
+            cancel_token_events,
        )
-        .or_cancel(&cancel_token_events)
        .await;
    });

@@ -86,7 +82,6 @@ pub(crate) async fn run_codex_conversation_interactive(
        next_id: AtomicU64::new(0),
        tx_sub: tx_ops,
        rx_event: rx_sub,
-        conversation_id: codex.conversation_id(),
    })
 }

@@ -111,16 +106,13 @@ pub(crate) async fn run_codex_conversation_one_shot(
        parent_session,
        parent_ctx,
        child_cancel.clone(),
-        None,
        initial_history,
-        SubAgentSource::Review,
    )
    .await?;

    // Send the initial input to kick off the one-shot turn.
    io.submit(Op::UserInput { items: input }).await?;

-    let conversation_id = io.conversation_id();
    // Bridge events so we can observe completion and shut down automatically.
    let (tx_bridge, rx_bridge) = async_channel::bounded(SUBMISSION_CHANNEL_CAPACITY);
    let ops_tx = io.tx_sub.clone();
@@ -155,7 +147,6 @@ pub(crate) async fn run_codex_conversation_one_shot(
        next_id: AtomicU64::new(0),
        rx_event: rx_bridge,
        tx_sub: tx_closed,
-        conversation_id,
    })
 }

@@ -166,53 +157,92 @@ async fn forward_events(
    parent_ctx: Arc<TurnContext>,
    cancel_token: CancellationToken,
 ) {
-    while let Ok(event) = codex.next_event().await {
-        match event {
-            // ignore all legacy delta events
-            Event {
-                id: _,
-                msg: EventMsg::AgentMessageDelta(_) | EventMsg::AgentReasoningDelta(_),
-            } => continue,
-            Event {
-                id: _,
-                msg: EventMsg::SessionConfigured(_),
-            } => continue,
-            Event {
-                id,
-                msg: EventMsg::ExecApprovalRequest(event),
-            } => {
-                // Initiate approval via parent session; do not surface to consumer.
-                handle_exec_approval(
-                    &codex,
-                    id,
-                    &parent_session,
-                    &parent_ctx,
-                    event,
-                    &cancel_token,
-                )
-                .await;
+    let cancelled = cancel_token.cancelled();
+    tokio::pin!(cancelled);
+
+    loop {
+        tokio::select! {
+            _ = &mut cancelled => {
+                shutdown_delegate(&codex).await;
+                break;
            }
-            Event {
-                id,
-                msg: EventMsg::ApplyPatchApprovalRequest(event),
-            } => {
-                handle_patch_approval(
-                    &codex,
-                    id,
-                    &parent_session,
-                    &parent_ctx,
-                    event,
-                    &cancel_token,
-                )
-                .await;
-            }
-            other => {
-                let _ = tx_sub.send(other).await;
+            event = codex.next_event() => {
+                let event = match event {
+                    Ok(event) => event,
+                    Err(_) => break,
+                };
+                match event {
+                    // ignore all legacy delta events
+                    Event {
+                        id: _,
+                        msg: EventMsg::AgentMessageDelta(_) | EventMsg::AgentReasoningDelta(_),
+                    } => {}
+                    Event {
+                        id: _,
+                        msg: EventMsg::SessionConfigured(_),
+                    } => {}
+                    Event {
+                        id,
+                        msg: EventMsg::ExecApprovalRequest(event),
+                    } => {
+                        // Initiate approval via parent session; do not surface to consumer.
+                        handle_exec_approval(
+                            &codex,
+                            id,
+                            &parent_session,
+                            &parent_ctx,
+                            event,
+                            &cancel_token,
+                        )
+                        .await;
+                    }
+                    Event {
+                        id,
+                        msg: EventMsg::ApplyPatchApprovalRequest(event),
+                    } => {
+                        handle_patch_approval(
+                            &codex,
+                            id,
+                            &parent_session,
+                            &parent_ctx,
+                            event,
+                            &cancel_token,
+                        )
+                        .await;
+                    }
+                    other => {
+                        match tx_sub.send(other).or_cancel(&cancel_token).await {
+                            Ok(Ok(())) => {}
+                            _ => {
+                                shutdown_delegate(&codex).await;
+                                break;
+                            }
+                        }
+                    }
+                }
            }
        }
    }
 }

+/// Ask the delegate to stop and drain its events so background sends do not hit a closed channel.
+async fn shutdown_delegate(codex: &Codex) {
+    let _ = codex.submit(Op::Interrupt).await;
+    let _ = codex.submit(Op::Shutdown {}).await;
+
+    let _ = timeout(Duration::from_millis(500), async {
+        while let Ok(event) = codex.next_event().await {
+            if matches!(
+                event.msg,
+                EventMsg::TurnAborted(_) | EventMsg::TaskComplete(_)
+            ) {
+                break;
+            }
+        }
+    })
+    .await;
+}
+
 /// Forward ops from a caller to a sub-agent, respecting cancellation.
 async fn forward_ops(
    codex: Arc<Codex>,
@@ -245,6 +275,7 @@ async fn handle_exec_approval(
        event.cwd,
        event.reason,
        event.risk,
+        event.allow_prefix,
    );
    let decision = await_approval_with_cancel(
        approval_fut,
@@ -308,3 +339,85 @@ where
        }
    }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use async_channel::bounded;
+    use codex_protocol::models::ResponseItem;
+    use codex_protocol::protocol::RawResponseItemEvent;
+    use codex_protocol::protocol::TurnAbortReason;
+    use codex_protocol::protocol::TurnAbortedEvent;
+    use pretty_assertions::assert_eq;
+
+    #[tokio::test]
+    async fn forward_events_cancelled_while_send_blocked_shuts_down_delegate() {
+        let (tx_events, rx_events) = bounded(1);
+        let (tx_sub, rx_sub) = bounded(SUBMISSION_CHANNEL_CAPACITY);
+        let codex = Arc::new(Codex {
+            next_id: AtomicU64::new(0),
+            tx_sub,
+            rx_event: rx_events,
+        });
+
+        let (session, ctx, _rx_evt) = crate::codex::make_session_and_context_with_rx();
+
+        let (tx_out, rx_out) = bounded(1);
+        tx_out
+            .send(Event {
+                id: "full".to_string(),
+                msg: EventMsg::TurnAborted(TurnAbortedEvent {
+                    reason: TurnAbortReason::Interrupted,
+                }),
+            })
+            .await
+            .unwrap();
+
+        let cancel = CancellationToken::new();
+        let forward = tokio::spawn(forward_events(
+            Arc::clone(&codex),
+            tx_out.clone(),
+            session,
+            ctx,
+            cancel.clone(),
+        ));
+
+        tx_events
+            .send(Event {
+                id: "evt".to_string(),
+                msg: EventMsg::RawResponseItem(RawResponseItemEvent {
+                    item: ResponseItem::CustomToolCall {
+                        id: None,
+                        status: None,
+                        call_id: "call-1".to_string(),
+                        name: "tool".to_string(),
+                        input: "{}".to_string(),
+                    },
+                }),
+            })
+            .await
+            .unwrap();
+
+        drop(tx_events);
+        cancel.cancel();
+        timeout(std::time::Duration::from_millis(1000), forward)
+            .await
+            .expect("forward_events hung")
+            .expect("forward_events join error");
+
+        let received = rx_out.recv().await.expect("prefilled event missing");
+        assert_eq!("full", received.id);
+        let mut ops = Vec::new();
+        while let Ok(sub) = rx_sub.try_recv() {
+            ops.push(sub.op);
+        }
+        assert!(
+            ops.iter().any(|op| matches!(op, Op::Interrupt)),
+            "expected Interrupt op after cancellation"
+        );
+        assert!(
+            ops.iter().any(|op| matches!(op, Op::Shutdown)),
+            "expected Shutdown op after cancellation"
+        );
+    }
+}
--- a/codex-rs/core/src/compact.rs
+++ b/codex-rs/core/src/compact.rs
@@ -8,8 +8,8 @@ use crate::codex::get_last_assistant_message_from_turn;
 use crate::error::CodexErr;
 use crate::error::Result as CodexResult;
 use crate::features::Feature;
-use crate::protocol::AgentMessageEvent;
 use crate::protocol::CompactedItem;
+use crate::protocol::ContextCompactedEvent;
 use crate::protocol::EventMsg;
 use crate::protocol::TaskStartedEvent;
 use crate::protocol::TurnContextItem;
@@ -175,9 +175,7 @@ async fn run_compact_task_inner(
    });
    sess.persist_rollout_items(&[rollout_item]).await;

-    let event = EventMsg::AgentMessage(AgentMessageEvent {
-        message: "Compact task completed".to_string(),
-    });
+    let event = EventMsg::ContextCompacted(ContextCompactedEvent {});
    sess.send_event(&turn_context, event).await;

    let warning = EventMsg::Warning(WarningEvent {
--- a/codex-rs/core/src/compact_remote.rs
+++ b/codex-rs/core/src/compact_remote.rs
@@ -4,8 +4,8 @@ use crate::Prompt;
 use crate::codex::Session;
 use crate::codex::TurnContext;
 use crate::error::Result as CodexResult;
-use crate::protocol::AgentMessageEvent;
 use crate::protocol::CompactedItem;
+use crate::protocol::ContextCompactedEvent;
 use crate::protocol::EventMsg;
 use crate::protocol::RolloutItem;
 use crate::protocol::TaskStartedEvent;
@@ -74,9 +74,7 @@ async fn run_remote_compact_task_inner_impl(
    sess.persist_rollout_items(&[RolloutItem::Compacted(compacted_item)])
        .await;

-    let event = EventMsg::AgentMessage(AgentMessageEvent {
-        message: "Compact task completed".to_string(),
-    });
+    let event = EventMsg::ContextCompacted(ContextCompactedEvent {});
    sess.send_event(turn_context, event).await;

    Ok(())
--- a/codex-rs/core/src/config/mod.rs
+++ b/codex-rs/core/src/config/mod.rs
@@ -34,6 +34,7 @@ use crate::project_doc::DEFAULT_PROJECT_DOC_FILENAME;
 use crate::project_doc::LOCAL_PROJECT_DOC_FILENAME;
 use crate::protocol::AskForApproval;
 use crate::protocol::SandboxPolicy;
+use crate::util::resolve_path;
 use codex_app_server_protocol::Tools;
 use codex_app_server_protocol::UserSavedConfig;
 use codex_protocol::config_types::ForcedLoginMethod;
@@ -52,7 +53,6 @@ use std::collections::HashMap;
 use std::io::ErrorKind;
 use std::path::Path;
 use std::path::PathBuf;
-use tracing::warn;

 use crate::config::profile::ConfigProfile;
 use toml::Value as TomlValue;
@@ -71,11 +71,7 @@ pub const GPT_5_CODEX_MEDIUM_MODEL: &str = "gpt-5.1-codex";
 /// the context window.
 pub(crate) const PROJECT_DOC_MAX_BYTES: usize = 32 * 1024; // 32 KiB

-pub(crate) const DEFAULT_MAX_ACTIVE_SUBAGENTS: usize = 8;
-pub(crate) const MIN_MAX_ACTIVE_SUBAGENTS: usize = 1;
-pub(crate) const MAX_MAX_ACTIVE_SUBAGENTS: usize = 64;
-
-pub(crate) const CONFIG_TOML_FILE: &str = "config.toml";
+pub const CONFIG_TOML_FILE: &str = "config.toml";

 /// Application configuration loaded from disk and merged with overrides.
 #[derive(Debug, Clone, PartialEq)]
@@ -109,9 +105,6 @@ pub struct Config {
    /// for either of approval_policy or sandbox_mode.
    pub did_user_set_custom_approval_policy_or_sandbox_mode: bool,

-    /// Maximum number of concurrently active subagents allowed in a session.
-    pub max_active_subagents: usize,
-
    /// On Windows, indicates that a previously configured workspace-write sandbox
    /// was coerced to read-only because native auto mode is unsupported.
    pub forced_auto_mode_downgraded_on_windows: bool,
@@ -136,30 +129,6 @@ pub struct Config {
    /// Developer instructions override injected as a separate message.
    pub developer_instructions: Option<String>,

-    /// When true, messages from the root agent to a subagent should be
-    /// surfaced as `user` role messages in the child’s history instead of
-    /// relying solely on tool calls and inbox semantics. This is useful for
-    /// evaluations that compare direct user-style turns versus tool-mediated
-    /// messaging. When false, root-to-child communication is modeled purely
-    /// via tools and the subagent inbox.
-    pub root_agent_uses_user_messages: bool,
-
-    /// When true, the root agent will, at turn boundaries, drain subagent
-    /// inboxes and inject synthetic `subagent_await` calls + outputs into the
-    /// message stream, and may auto-start a new turn when idle. When false,
-    /// subagent inboxes are only surfaced when explicitly awaited or at
-    /// subagent-specific yield points.
-    pub subagent_root_inbox_autosubmit: bool,
-
-    /// Controls where synthetic `subagent_await` tool calls and outputs for
-    /// inbox delivery are injected relative to real tool call outputs inside a
-    /// turn. When true, inbox-derived `subagent_await` items are recorded
-    /// *before* tool outputs (Option B: closer to chronological ordering). When
-    /// false (default), they are recorded *after* tool outputs (Option A:
-    /// closer to training-time behavior where the model generally sees its own
-    /// tool call and result before additional context).
-    pub subagent_inbox_inject_before_tools: bool,
-
    /// Compact prompt override.
    pub compact_prompt: Option<String>,

@@ -277,7 +246,6 @@ pub struct Config {
    pub experimental_sandbox_command_assessment: bool,

    /// If set to `true`, used only the experimental unified exec tool.
-    #[allow(dead_code)]
    pub use_experimental_unified_exec_tool: bool,

    /// If set to `true`, use the experimental official Rust MCP client.
@@ -300,6 +268,11 @@ pub struct Config {
    /// Collection of various notices we show the user
    pub notices: Notice,

+    /// 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`.
+    pub check_for_update_on_startup: bool,
+
    /// When true, disables burst-paste detection for typed input entirely.
    /// All characters are inserted as they are received, and no buffering
    /// or placeholder replacement will occur for fast keypress bursts.
@@ -629,30 +602,6 @@ pub struct ConfigToml {
    /// Compact prompt used for history compaction.
    pub compact_prompt: Option<String>,

-    /// When true, messages from the root agent to subagents should be
-    /// represented as `user` role messages in the child’s history. When
-    /// false or unset, root-to-child communication is modeled purely via
-    /// `subagent_send_message` and inbox delivery.
-    #[serde(default)]
-    pub root_agent_uses_user_messages: Option<bool>,
-
-    /// When true, the root agent drains subagent inboxes at turn boundaries
-    /// and may auto-start new turns when idle. When false or unset, the root
-    /// only observes subagent inboxes via explicit `subagent_await` calls or
-    /// subagent-driven yield points.
-    #[serde(default)]
-    pub subagent_root_inbox_autosubmit: Option<bool>,
-
-    /// When true, inbox-derived `subagent_await` calls and outputs are
-    /// injected *before* tool outputs inside a turn (Option B, closer to
-    /// strict chronological ordering). When false or unset, synthetic\n    /// `subagent_await` entries are injected *after* tool outputs (Option A,
-    /// closer to training-time patterns where the model generally sees its own
-    /// tool call and result before extra context).\n    #[serde(default)]
-    pub subagent_inbox_inject_before_tools: Option<bool>,
-
-    /// Maximum number of concurrently active subagents allowed in a session.
-    pub max_active_subagents: Option<usize>,
-
    /// When set, restricts ChatGPT login to a specific workspace identifier.
    #[serde(default)]
    pub forced_chatgpt_workspace_id: Option<String>,
@@ -742,6 +691,11 @@ pub struct ConfigToml {
    #[serde(default)]
    pub features: Option<FeaturesToml>,

+    /// 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`.
+    pub check_for_update_on_startup: Option<bool>,
+
    /// When true, disables burst-paste detection for typed input entirely.
    /// All characters are inserted as they are received, and no buffering
    /// or placeholder replacement will occur for fast keypress bursts.
@@ -946,10 +900,6 @@ pub struct ConfigOverrides {
    pub base_instructions: Option<String>,
    pub developer_instructions: Option<String>,
    pub compact_prompt: Option<String>,
-    pub max_active_subagents: Option<usize>,
-    pub root_agent_uses_user_messages: Option<bool>,
-    pub subagent_root_inbox_autosubmit: Option<bool>,
-    pub subagent_inbox_inject_before_tools: Option<bool>,
    pub include_apply_patch_tool: Option<bool>,
    pub show_raw_agent_reasoning: Option<bool>,
    pub tools_web_search_request: Option<bool>,
@@ -987,33 +937,6 @@ pub fn resolve_oss_provider(
 }

 impl Config {
-    /// Clone the existing config with a model override, re-deriving any model-specific fields.
-    pub fn clone_with_model_override(&self, model: &str) -> std::io::Result<Self> {
-        if model.trim().is_empty() {
-            return Err(std::io::Error::new(
-                std::io::ErrorKind::InvalidInput,
-                "model cannot be empty",
-            ));
-        }
-
-        let mut cfg = self.clone();
-        cfg.model = model.trim().to_string();
-
-        let model_family = find_family_for_model(&cfg.model)
-            .unwrap_or_else(|| derive_default_model_family(&cfg.model));
-        cfg.model_family = model_family;
-
-        if let Some(info) = get_model_info(&cfg.model_family) {
-            cfg.model_context_window = Some(info.context_window);
-            cfg.model_auto_compact_token_limit = info.auto_compact_token_limit;
-        } else {
-            cfg.model_context_window = None;
-            cfg.model_auto_compact_token_limit = None;
-        }
-
-        Ok(cfg)
-    }
-
    /// 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(
@@ -1036,10 +959,6 @@ impl Config {
            base_instructions,
            developer_instructions,
            compact_prompt,
-            max_active_subagents,
-            root_agent_uses_user_messages,
-            subagent_root_inbox_autosubmit: _,
-            subagent_inbox_inject_before_tools: _,
            include_apply_patch_tool: include_apply_patch_tool_override,
            show_raw_agent_reasoning,
            tools_web_search_request: override_tools_web_search_request,
@@ -1098,15 +1017,8 @@ impl Config {
        let additional_writable_roots: Vec<PathBuf> = additional_writable_roots
            .into_iter()
            .map(|path| {
-                let absolute = if path.is_absolute() {
-                    path
-                } else {
-                    resolved_cwd.join(path)
-                };
-                match canonicalize(&absolute) {
-                    Ok(canonical) => canonical,
-                    Err(_) => absolute,
-                }
+                let absolute = resolve_path(&resolved_cwd, &path);
+                canonicalize(&absolute).unwrap_or(absolute)
            })
            .collect();
        let active_project = cfg
@@ -1172,7 +1084,6 @@ impl Config {

        let include_apply_patch_tool_flag = features.enabled(Feature::ApplyPatchFreeform);
        let tools_web_search_request = features.enabled(Feature::WebSearchRequest);
-        #[allow(dead_code)]
        let use_experimental_unified_exec_tool = features.enabled(Feature::UnifiedExec);
        let use_experimental_use_rmcp_client = features.enabled(Feature::RmcpClient);
        let experimental_sandbox_command_assessment =
@@ -1255,36 +1166,7 @@ impl Config {
            .or(cfg.review_model)
            .unwrap_or_else(default_review_model);

-        let raw_max_active_subagents = max_active_subagents
-            .or(config_profile.max_active_subagents)
-            .or(cfg.max_active_subagents)
-            .unwrap_or(DEFAULT_MAX_ACTIVE_SUBAGENTS);
-
-        if raw_max_active_subagents < MIN_MAX_ACTIVE_SUBAGENTS {
-            return Err(std::io::Error::new(
-                std::io::ErrorKind::InvalidInput,
-                format!(
-                    "max_active_subagents must be at least {MIN_MAX_ACTIVE_SUBAGENTS}, got {raw_max_active_subagents}"
-                ),
-            ));
-        }
-
-        let max_active_subagents = if raw_max_active_subagents > MAX_MAX_ACTIVE_SUBAGENTS {
-            warn!(
-                "max_active_subagents clamped from {} to {}",
-                raw_max_active_subagents, MAX_MAX_ACTIVE_SUBAGENTS
-            );
-            MAX_MAX_ACTIVE_SUBAGENTS
-        } else {
-            raw_max_active_subagents
-        };
-
-        let root_agent_uses_user_messages = root_agent_uses_user_messages
-            .or(cfg.root_agent_uses_user_messages)
-            .unwrap_or(true);
-        let subagent_root_inbox_autosubmit = cfg.subagent_root_inbox_autosubmit.unwrap_or(true);
-        let subagent_inbox_inject_before_tools =
-            cfg.subagent_inbox_inject_before_tools.unwrap_or(false);
+        let check_for_update_on_startup = cfg.check_for_update_on_startup.unwrap_or(true);

        let config = Self {
            model,
@@ -1304,9 +1186,6 @@ impl Config {
            user_instructions,
            base_instructions,
            developer_instructions,
-            root_agent_uses_user_messages,
-            subagent_root_inbox_autosubmit,
-            subagent_inbox_inject_before_tools,
            compact_prompt,
            // The config.toml omits "_mode" because it's a config file. However, "_mode"
            // is important in code to differentiate the mode from the store implementation.
@@ -1341,7 +1220,6 @@ impl Config {
                .show_raw_agent_reasoning
                .or(show_raw_agent_reasoning)
                .unwrap_or(false),
-            max_active_subagents,
            model_reasoning_effort: config_profile
                .model_reasoning_effort
                .or(cfg.model_reasoning_effort),
@@ -1366,6 +1244,7 @@ impl Config {
            active_project,
            windows_wsl_setup_acknowledged: cfg.windows_wsl_setup_acknowledged.unwrap_or(false),
            notices: cfg.notice.unwrap_or_default(),
+            check_for_update_on_startup,
            disable_paste_burst: cfg.disable_paste_burst.unwrap_or(false),
            tui_notifications: cfg
                .tui
@@ -1414,11 +1293,7 @@ impl Config {
            return Ok(None);
        };

-        let full_path = if p.is_relative() {
-            cwd.join(p)
-        } else {
-            p.to_path_buf()
-        };
+        let full_path = resolve_path(cwd, p);

        let contents = std::fs::read_to_string(&full_path).map_err(|e| {
            std::io::Error::new(
@@ -1739,73 +1614,6 @@ trust_level = "trusted"
        Ok(())
    }

-    #[test]
-    fn max_active_subagents_defaults_and_overrides() -> std::io::Result<()> {
-        let temp_dir = TempDir::new()?;
-
-        let config = Config::load_from_base_config_with_overrides(
-            ConfigToml::default(),
-            ConfigOverrides::default(),
-            temp_dir.path().to_path_buf(),
-        )?;
-        assert_eq!(config.max_active_subagents, DEFAULT_MAX_ACTIVE_SUBAGENTS);
-
-        let custom = ConfigToml {
-            max_active_subagents: Some(3),
-            ..ConfigToml::default()
-        };
-        let config = Config::load_from_base_config_with_overrides(
-            custom,
-            ConfigOverrides::default(),
-            temp_dir.path().to_path_buf(),
-        )?;
-        assert_eq!(config.max_active_subagents, 3);
-
-        let overrides = ConfigOverrides {
-            max_active_subagents: Some(2),
-            ..Default::default()
-        };
-        let config = Config::load_from_base_config_with_overrides(
-            ConfigToml::default(),
-            overrides,
-            temp_dir.path().to_path_buf(),
-        )?;
-        assert_eq!(config.max_active_subagents, 2);
-
-        Ok(())
-    }
-
-    #[test]
-    fn max_active_subagents_validates_bounds() {
-        let temp_dir = TempDir::new().expect("tempdir");
-
-        // Below minimum should error.
-        let cfg_zero = ConfigToml {
-            max_active_subagents: Some(0),
-            ..ConfigToml::default()
-        };
-        let err = Config::load_from_base_config_with_overrides(
-            cfg_zero,
-            ConfigOverrides::default(),
-            temp_dir.path().to_path_buf(),
-        )
-        .expect_err("expected invalid input error");
-        assert_eq!(err.kind(), std::io::ErrorKind::InvalidInput);
-
-        // Above ceiling should clamp.
-        let cfg_high = ConfigToml {
-            max_active_subagents: Some(MAX_MAX_ACTIVE_SUBAGENTS + 10),
-            ..ConfigToml::default()
-        };
-        let config = Config::load_from_base_config_with_overrides(
-            cfg_high,
-            ConfigOverrides::default(),
-            temp_dir.path().to_path_buf(),
-        )
-        .expect("clamped config");
-        assert_eq!(config.max_active_subagents, MAX_MAX_ACTIVE_SUBAGENTS);
-    }
-
    #[test]
    fn config_defaults_to_file_cli_auth_store_mode() -> std::io::Result<()> {
        let codex_home = TempDir::new()?;
@@ -3150,7 +2958,6 @@ model_verbosity = "high"
                approval_policy: AskForApproval::Never,
                sandbox_policy: SandboxPolicy::new_read_only_policy(),
                did_user_set_custom_approval_policy_or_sandbox_mode: true,
-                max_active_subagents: DEFAULT_MAX_ACTIVE_SUBAGENTS,
                forced_auto_mode_downgraded_on_windows: false,
                shell_environment_policy: ShellEnvironmentPolicy::default(),
                user_instructions: None,
@@ -3188,13 +2995,11 @@ model_verbosity = "high"
                active_project: ProjectConfig { trust_level: None },
                windows_wsl_setup_acknowledged: false,
                notices: Default::default(),
+                check_for_update_on_startup: true,
                disable_paste_burst: false,
                tui_notifications: Default::default(),
                animations: true,
                otel: OtelConfig::default(),
-                root_agent_uses_user_messages: true,
-                subagent_root_inbox_autosubmit: true,
-                subagent_inbox_inject_before_tools: false,
            },
            o3_profile_config
        );
@@ -3226,7 +3031,6 @@ model_verbosity = "high"
            approval_policy: AskForApproval::UnlessTrusted,
            sandbox_policy: SandboxPolicy::new_read_only_policy(),
            did_user_set_custom_approval_policy_or_sandbox_mode: true,
-            max_active_subagents: DEFAULT_MAX_ACTIVE_SUBAGENTS,
            forced_auto_mode_downgraded_on_windows: false,
            shell_environment_policy: ShellEnvironmentPolicy::default(),
            user_instructions: None,
@@ -3264,13 +3068,11 @@ model_verbosity = "high"
            active_project: ProjectConfig { trust_level: None },
            windows_wsl_setup_acknowledged: false,
            notices: Default::default(),
+            check_for_update_on_startup: true,
            disable_paste_burst: false,
            tui_notifications: Default::default(),
            animations: true,
            otel: OtelConfig::default(),
-            root_agent_uses_user_messages: true,
-            subagent_root_inbox_autosubmit: true,
-            subagent_inbox_inject_before_tools: false,
        };

        assert_eq!(expected_gpt3_profile_config, gpt3_profile_config);
@@ -3317,7 +3119,6 @@ model_verbosity = "high"
            approval_policy: AskForApproval::OnFailure,
            sandbox_policy: SandboxPolicy::new_read_only_policy(),
            did_user_set_custom_approval_policy_or_sandbox_mode: true,
-            max_active_subagents: DEFAULT_MAX_ACTIVE_SUBAGENTS,
            forced_auto_mode_downgraded_on_windows: false,
            shell_environment_policy: ShellEnvironmentPolicy::default(),
            user_instructions: None,
@@ -3355,13 +3156,11 @@ model_verbosity = "high"
            active_project: ProjectConfig { trust_level: None },
            windows_wsl_setup_acknowledged: false,
            notices: Default::default(),
+            check_for_update_on_startup: true,
            disable_paste_burst: false,
            tui_notifications: Default::default(),
            animations: true,
            otel: OtelConfig::default(),
-            root_agent_uses_user_messages: true,
-            subagent_root_inbox_autosubmit: true,
-            subagent_inbox_inject_before_tools: false,
        };

        assert_eq!(expected_zdr_profile_config, zdr_profile_config);
@@ -3394,7 +3193,6 @@ model_verbosity = "high"
            approval_policy: AskForApproval::OnFailure,
            sandbox_policy: SandboxPolicy::new_read_only_policy(),
            did_user_set_custom_approval_policy_or_sandbox_mode: true,
-            max_active_subagents: DEFAULT_MAX_ACTIVE_SUBAGENTS,
            forced_auto_mode_downgraded_on_windows: false,
            shell_environment_policy: ShellEnvironmentPolicy::default(),
            user_instructions: None,
@@ -3432,13 +3230,11 @@ model_verbosity = "high"
            active_project: ProjectConfig { trust_level: None },
            windows_wsl_setup_acknowledged: false,
            notices: Default::default(),
+            check_for_update_on_startup: true,
            disable_paste_burst: false,
            tui_notifications: Default::default(),
            animations: true,
            otel: OtelConfig::default(),
-            root_agent_uses_user_messages: true,
-            subagent_root_inbox_autosubmit: true,
-            subagent_inbox_inject_before_tools: false,
        };

        assert_eq!(expected_gpt5_profile_config, gpt5_profile_config);
--- a/Show More
+++ b/Show More