merge

## Summary
Per the [latest MCP
spec](https://modelcontextprotocol.io/specification/2025-06-18/basic#meta),
the `_meta` field is reserved for metadata. In the [Typescript
Schema](0695a497eb/schema/2025-06-18/schema.ts (L37-L40)),
`progressToken` is defined as a value to be attached to subsequent
notifications for that request.

The
[CallToolRequestParams](0695a497eb/schema/2025-06-18/schema.ts (L806-L817))
extends this definition but overwrites the params field. This ambiguity
makes our generated type definitions tricky, so I'm going to skip
`progressToken` field for now and just send back the `requestId`
instead.
 
In a future PR, we can clarify, update our `generate_mcp_types.py`
script, and update our progressToken logic accordingly.

## Testing
- [x] Added unit tests
- [x] Manually tested with mcp client

codex-rs/Cargo.lock

@@ -463,18 +463,18 @@ checksum = "df8670b8c7b9dae1793364eafadf7239c40d669904660c5960d74cfd80b46a53"
 
 [[package]]
 name = "castaway"
-version = "0.2.3"
+version = "0.2.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0abae9be0aaf9ea96a3b1b8b1b55c602ca751eba1b1500220cea4ecbafe7c0d5"
+checksum = "dec551ab6e7578819132c713a93c022a05d60159dc86e7a7050223577484c55a"
 dependencies = [
  "rustversion",
 ]
 
 [[package]]
 name = "cc"
-version = "1.2.29"
+version = "1.2.30"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5c1599538de2394445747c8cf7935946e3cc27e9625f889d979bfb2aaf569362"
+checksum = "deec109607ca693028562ed836a5f1c4b8bd77755c4e132fc5ce11b0b6211ae7"
 dependencies = [
  "jobserver",
  "libc",
@@ -570,9 +570,9 @@ checksum = "b94f61472cee1439c0b966b47e3aca9ae07e45d070759512cd390ea2bebc6675"
 
 [[package]]
 name = "clipboard-win"
-version = "5.4.0"
+version = "5.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "15efe7a882b08f34e38556b14f2fb3daa98769d06c7f0c1b076dfd0d983bc892"
+checksum = "bde03770d3df201d4fb868f2c9c59e66a3e4e2bd06692a0fe701e7103c7e84d4"
 dependencies = [
  "error-code",
 ]
@@ -605,6 +605,18 @@ dependencies = [
  "tree-sitter-bash",
 ]
 
+[[package]]
+name = "codex-arg0"
+version = "0.0.0"
+dependencies = [
+ "anyhow",
+ "codex-apply-patch",
+ "codex-core",
+ "codex-linux-sandbox",
+ "dotenvy",
+ "tokio",
+]
+
 [[package]]
 name = "codex-chatgpt"
 version = "0.0.0"
@@ -628,11 +640,11 @@ dependencies = [
  "anyhow",
  "clap",
  "clap_complete",
+ "codex-arg0",
  "codex-chatgpt",
  "codex-common",
  "codex-core",
  "codex-exec",
- "codex-linux-sandbox",
  "codex-login",
  "codex-mcp-server",
  "codex-tui",
@@ -683,6 +695,7 @@ dependencies = [
  "serde",
  "serde_json",
  "sha1",
+ "shlex",
  "strum_macros 0.27.2",
  "tempfile",
  "thiserror 2.0.12",
@@ -696,6 +709,7 @@ dependencies = [
  "tree-sitter-bash",
  "uuid",
  "walkdir",
+ "whoami",
  "wildmatch",
  "wiremock",
 ]
@@ -705,14 +719,17 @@ name = "codex-exec"
 version = "0.0.0"
 dependencies = [
  "anyhow",
+ "assert_cmd",
  "chrono",
  "clap",
+ "codex-arg0",
  "codex-common",
  "codex-core",
- "codex-linux-sandbox",
  "owo-colors",
+ "predicates",
  "serde_json",
  "shlex",
+ "tempfile",
  "tokio",
  "tracing",
  "tracing-subscriber",
@@ -759,7 +776,6 @@ dependencies = [
  "clap",
  "codex-common",
  "codex-core",
- "dotenvy",
  "landlock",
  "libc",
  "seccompiler",
@@ -797,8 +813,8 @@ version = "0.0.0"
 dependencies = [
  "anyhow",
  "assert_cmd",
+ "codex-arg0",
  "codex-core",
- "codex-linux-sandbox",
  "mcp-types",
  "mcp_test_support",
  "pretty_assertions",
@@ -824,10 +840,10 @@ dependencies = [
  "base64 0.22.1",
  "clap",
  "codex-ansi-escape",
+ "codex-arg0",
  "codex-common",
  "codex-core",
  "codex-file-search",
- "codex-linux-sandbox",
  "codex-login",
  "color-eyre",
  "crossterm",
@@ -840,6 +856,8 @@ dependencies = [
  "ratatui",
  "ratatui-image",
  "regex-lite",
+ "reqwest",
+ "serde",
  "serde_json",
  "shlex",
  "strum 0.27.2",
@@ -976,9 +994,9 @@ dependencies = [
 
 [[package]]
 name = "crc32fast"
-version = "1.4.2"
+version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a97769d94ddab943e4510d138150169a2758b5ef3eb191a9ee688de3e23ef7b3"
+checksum = "9481c1c90cbf2ac953f07c8d4a58aa3945c425b7185c9154d67a65e4230da511"
 dependencies = [
  "cfg-if",
 ]
@@ -1525,7 +1543,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0ce92ff622d6dadf7349484f42c93271a0d49b7cc4d466a936405bacbe10aa78"
 dependencies = [
  "cfg-if",
- "rustix 1.0.7",
+ "rustix 1.0.8",
  "windows-sys 0.59.0",
 ]
 
@@ -1974,9 +1992,9 @@ dependencies = [
 
 [[package]]
 name = "hyper-util"
-version = "0.1.15"
+version = "0.1.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7f66d5bd4c6f02bf0542fad85d626775bab9258cf795a4256dcaf3161114d1df"
+checksum = "8d9b05277c7e8da2c93a568989bb6207bef0112e8d17df7a6eda4a3cf143bc5e"
 dependencies = [
  "base64 0.22.1",
  "bytes",
@@ -1990,7 +2008,7 @@ dependencies = [
  "libc",
  "percent-encoding",
  "pin-project-lite",
- "socket2",
+ "socket2 0.6.0",
  "system-configuration",
  "tokio",
  "tower-service",
@@ -2243,9 +2261,9 @@ dependencies = [
 
 [[package]]
 name = "instability"
-version = "0.3.7"
+version = "0.3.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0bf9fed6d91cfb734e7476a06bde8300a1b94e217e1b523b6f0cd1a01998c71d"
+checksum = "435d80800b936787d62688c927b6490e887c7ef5ff9ce922c6c6050fca75eb9a"
 dependencies = [
  "darling",
  "indoc",
@@ -2276,9 +2294,9 @@ dependencies = [
 
 [[package]]
 name = "io-uring"
-version = "0.7.8"
+version = "0.7.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b86e202f00093dcba4275d4636b93ef9dd75d025ae560d2521b45ea28ab49013"
+checksum = "d93587f37623a1a17d94ef2bc9ada592f5465fe7732084ab7beefabe5c77c0c4"
 dependencies = [
  "bitflags 2.9.1",
  "cfg-if",
@@ -2482,9 +2500,9 @@ dependencies = [
 
 [[package]]
 name = "libredox"
-version = "0.1.4"
+version = "0.1.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1580801010e535496706ba011c15f8532df6b42297d2e471fec38ceadd8c0638"
+checksum = "4488594b9328dee448adb906d8b126d9b7deb7cf5c22161ee591610bb1be83c0"
 dependencies = [
  "bitflags 2.9.1",
  "libc",
@@ -3357,8 +3375,7 @@ dependencies = [
 [[package]]
 name = "ratatui"
 version = "0.29.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "eabd94c2f37801c20583fc49dd5cd6b0ba68c716787c2dd6ed18571e1e63117b"
+source = "git+https://github.com/nornagon/ratatui?branch=nornagon-v0.29.0-patch#bca287ddc5d38fe088c79e2eda22422b96226f2e"
 dependencies = [
  "bitflags 2.9.1",
  "cassowary",
@@ -3463,9 +3480,9 @@ dependencies = [
 
 [[package]]
 name = "redox_syscall"
-version = "0.5.13"
+version = "0.5.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0d04b7d0ee6b4a0207a0a7adb104d23ecb0b47d6beae7152d0fa34b692b29fd6"
+checksum = "7e8af0dde094006011e6a740d4879319439489813bd0bcdc7d821beaeeff48ec"
 dependencies = [
  "bitflags 2.9.1",
 ]
@@ -3613,9 +3630,9 @@ dependencies = [
 
 [[package]]
 name = "rgb"
-version = "0.8.51"
+version = "0.8.52"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a457e416a0f90d246a4c3288bd7a25b2304ca727f253f95be383dd17af56be8f"
+checksum = "0c6a884d2998352bb4daf0183589aec883f16a6da1f4dde84d8e2e9a5409a1ce"
 
 [[package]]
 name = "ring"
@@ -3691,22 +3708,22 @@ dependencies = [
 
 [[package]]
 name = "rustix"
-version = "1.0.7"
+version = "1.0.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c71e83d6afe7ff64890ec6b71d6a69bb8a610ab78ce364b3352876bb4c801266"
+checksum = "11181fbabf243db407ef8df94a6ce0b2f9a733bd8be4ad02b4eda9602296cac8"
 dependencies = [
  "bitflags 2.9.1",
  "errno",
  "libc",
  "linux-raw-sys 0.9.4",
- "windows-sys 0.59.0",
+ "windows-sys 0.60.2",
 ]
 
 [[package]]
 name = "rustls"
-version = "0.23.28"
+version = "0.23.29"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7160e3e10bf4535308537f3c4e1641468cd0e485175d6163087c0393c7d46643"
+checksum = "2491382039b29b9b11ff08b76ff6c97cf287671dbb74f0be44bda389fffe9bd1"
 dependencies = [
  "once_cell",
  "rustls-pki-types",
@@ -3726,9 +3743,9 @@ dependencies = [
 
 [[package]]
 name = "rustls-webpki"
-version = "0.103.3"
+version = "0.103.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e4a72fe2bcf7a6ac6fd7d0b9e5cb68aeb7d4c0a0271730218b3e92d43b4eb435"
+checksum = "0a17884ae0c1b773f1ccd2bd4a8c72f16da897310a98b0e84bf349ad5ead92fc"
 dependencies = [
  "ring",
  "rustls-pki-types",
@@ -3954,9 +3971,9 @@ dependencies = [
 
 [[package]]
 name = "serde_json"
-version = "1.0.140"
+version = "1.0.141"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "20068b6e96dc6c9bd23e01df8827e6c7e1f2fddd43c21810382803c136b99373"
+checksum = "30b9eff21ebe718216c6ec64e1d9ac57087aad11efc64e32002bce4a0d4c03d3"
 dependencies = [
  "indexmap 2.10.0",
  "itoa",
@@ -4149,6 +4166,16 @@ dependencies = [
  "windows-sys 0.52.0",
 ]
 
+[[package]]
+name = "socket2"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "233504af464074f9d066d7b5416c5f9b894a5862a6506e306f7b816cdd6f1807"
+dependencies = [
+ "libc",
+ "windows-sys 0.59.0",
+]
+
 [[package]]
 name = "stable_deref_trait"
 version = "1.2.0"
@@ -4440,7 +4467,7 @@ dependencies = [
  "fastrand",
  "getrandom 0.3.3",
  "once_cell",
- "rustix 1.0.7",
+ "rustix 1.0.8",
  "windows-sys 0.59.0",
 ]
 
@@ -4461,7 +4488,7 @@ version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "45c6481c4829e4cc63825e62c49186a34538b7b2750b73b266581ffb612fb5ed"
 dependencies = [
- "rustix 1.0.7",
+ "rustix 1.0.8",
  "windows-sys 0.59.0",
 ]
 
@@ -4607,7 +4634,7 @@ dependencies = [
  "pin-project-lite",
  "signal-hook-registry",
  "slab",
- "socket2",
+ "socket2 0.5.10",
  "tokio-macros",
  "windows-sys 0.52.0",
 ]
@@ -4749,9 +4776,9 @@ dependencies = [
 
 [[package]]
 name = "toml_writer"
-version = "1.0.0"
+version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b679217f2848de74cabd3e8fc5e6d66f40b7da40f8e1954d92054d9010690fd5"
+checksum = "fcc842091f2def52017664b53082ecbbeb5c7731092bad69d2c63050401dfd64"
 
 [[package]]
 name = "tower"
@@ -5128,6 +5155,12 @@ dependencies = [
  "wit-bindgen-rt",
 ]
 
+[[package]]
+name = "wasite"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b8dad83b4f25e74f184f64c43b150b91efe7647395b42289f38e50566d82855b"
+
 [[package]]
 name = "wasm-bindgen"
 version = "0.2.100"
@@ -5228,6 +5261,17 @@ version = "0.1.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a751b3277700db47d3e574514de2eced5e54dc8a5436a3bf7a0b248b2cee16f3"
 
+[[package]]
+name = "whoami"
+version = "1.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6994d13118ab492c3c80c1f81928718159254c53c472bf9ce36f8dae4add02a7"
+dependencies = [
+ "redox_syscall",
+ "wasite",
+ "web-sys",
+]
+
 [[package]]
 name = "wildmatch"
 version = "2.4.0"
@@ -5556,9 +5600,9 @@ checksum = "271414315aff87387382ec3d271b52d7ae78726f5d44ac98b4f4030c91880486"
 
 [[package]]
 name = "winnow"
-version = "0.7.11"
+version = "0.7.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "74c7b26e3480b707944fc872477815d29a8e429d2f93a1ce000f5fa84a15cbcd"
+checksum = "f3edebf492c8125044983378ecb5766203ad3b4c2f7a922bd7dd207f6d443e95"
 dependencies = [
  "memchr",
 ]

codex-rs/Cargo.toml

@@ -3,6 +3,7 @@ resolver = "2"
 members = [
     "ansi-escape",
     "apply-patch",
+    "arg0",
     "cli",
     "common",
     "core",
@@ -40,3 +41,8 @@ strip = "symbols"
 
 # See https://github.com/openai/codex/issues/1411 for details.
 codegen-units = 1
+
+[patch.crates-io]
+# ratatui = { path = "../../ratatui" }
+ratatui = { git = "https://github.com/nornagon/ratatui", branch = "nornagon-v0.29.0-patch" }
+

codex-rs/arg0/Cargo.toml

@@ -0,0 +1,19 @@
+[package]
+name = "codex-arg0"
+version = { workspace = true }
+edition = "2024"
+
+[lib]
+name = "codex_arg0"
+path = "src/lib.rs"
+
+[lints]
+workspace = true
+
+[dependencies]
+anyhow = "1"
+codex-apply-patch = { path = "../apply-patch" }
+codex-core = { path = "../core" }
+codex-linux-sandbox = { path = "../linux-sandbox" }
+dotenvy = "0.15.7"
+tokio = { version = "1", features = ["rt-multi-thread"] }

codex-rs/arg0/src/lib.rs

@@ -0,0 +1,89 @@
+use std::future::Future;
+use std::path::Path;
+use std::path::PathBuf;
+
+/// While we want to deploy the Codex CLI as a single executable for simplicity,
+/// we also want to expose some of its functionality as distinct CLIs, so we use
+/// the "arg0 trick" to determine which CLI to dispatch. This effectively allows
+/// us to simulate deploying multiple executables as a single binary on Mac and
+/// Linux (but not Windows).
+///
+/// When the current executable is invoked through the hard-link or alias named
+/// `codex-linux-sandbox` we *directly* execute
+/// [`codex_linux_sandbox::run_main`] (which never returns). Otherwise we:
+///
+/// 1.  Use [`dotenvy::from_path`] and [`dotenvy::dotenv`] to modify the
+///     environment before creating any threads.
+/// 2.  Construct a Tokio multi-thread runtime.
+/// 3.  Derive the path to the current executable (so children can re-invoke the
+///     sandbox) when running on Linux.
+/// 4.  Execute the provided async `main_fn` inside that runtime, forwarding any
+///     error. Note that `main_fn` receives `codex_linux_sandbox_exe:
+///     Option<PathBuf>`, as an argument, which is generally needed as part of
+///     constructing [`codex_core::config::Config`].
+///
+/// This function should be used to wrap any `main()` function in binary crates
+/// in this workspace that depends on these helper CLIs.
+pub fn arg0_dispatch_or_else<F, Fut>(main_fn: F) -> anyhow::Result<()>
+where
+    F: FnOnce(Option<PathBuf>) -> Fut,
+    Fut: Future<Output = anyhow::Result<()>>,
+{
+    // Determine if we were invoked via the special alias.
+    let mut args = std::env::args_os();
+    let argv0 = args.next().unwrap_or_default();
+    let exe_name = Path::new(&argv0)
+        .file_name()
+        .and_then(|s| s.to_str())
+        .unwrap_or("");
+
+    if exe_name == "codex-linux-sandbox" {
+        // Safety: [`run_main`] never returns.
+        codex_linux_sandbox::run_main();
+    }
+
+    let argv1 = args.next().unwrap_or_default();
+    if argv1 == "--codex-run-as-apply-patch" {
+        let patch_arg = args.next().and_then(|s| s.to_str().map(|s| s.to_owned()));
+        let exit_code = match patch_arg {
+            Some(patch_arg) => {
+                let mut stdout = std::io::stdout();
+                let mut stderr = std::io::stderr();
+                match codex_apply_patch::apply_patch(&patch_arg, &mut stdout, &mut stderr) {
+                    Ok(()) => 0,
+                    Err(_) => 1,
+                }
+            }
+            None => {
+                eprintln!("Error: --codex-run-as-apply-patch requires a UTF-8 PATCH argument.");
+                1
+            }
+        };
+        std::process::exit(exit_code);
+    }
+
+    // This modifies the environment, which is not thread-safe, so do this
+    // before creating any threads/the Tokio runtime.
+    load_dotenv();
+
+    // Regular invocation – create a Tokio runtime and execute the provided
+    // async entry-point.
+    let runtime = tokio::runtime::Runtime::new()?;
+    runtime.block_on(async move {
+        let codex_linux_sandbox_exe: Option<PathBuf> = if cfg!(target_os = "linux") {
+            std::env::current_exe().ok()
+        } else {
+            None
+        };
+
+        main_fn(codex_linux_sandbox_exe).await
+    })
+}
+
+/// Load env vars from ~/.codex/.env and `$(pwd)/.env`.
+fn load_dotenv() {
+    if let Ok(codex_home) = codex_core::config::find_codex_home() {
+        dotenvy::from_path(codex_home.join(".env")).ok();
+    }
+    dotenvy::dotenv().ok();
+}

codex-rs/cli/Cargo.toml

@@ -18,12 +18,12 @@ workspace = true
 anyhow = "1"
 clap = { version = "4", features = ["derive"] }
 clap_complete = "4"
+codex-arg0 = { path = "../arg0" }
 codex-chatgpt = { path = "../chatgpt" }
 codex-core = { path = "../core" }
 codex-common = { path = "../common", features = ["cli"] }
 codex-exec = { path = "../exec" }
 codex-login = { path = "../login" }
-codex-linux-sandbox = { path = "../linux-sandbox" }
 codex-mcp-server = { path = "../mcp-server" }
 codex-tui = { path = "../tui" }
 serde_json = "1"

codex-rs/cli/src/main.rs

@@ -2,6 +2,7 @@ use clap::CommandFactory;
 use clap::Parser;
 use clap_complete::Shell;
 use clap_complete::generate;
+use codex_arg0::arg0_dispatch_or_else;
 use codex_chatgpt::apply_command::ApplyCommand;
 use codex_chatgpt::apply_command::run_apply_command;
 use codex_cli::LandlockCommand;
@@ -92,7 +93,7 @@ struct LoginCommand {
 }
 
 fn main() -> anyhow::Result<()> {
-    codex_linux_sandbox::run_with_sandbox(|codex_linux_sandbox_exe| async move {
+    arg0_dispatch_or_else(|codex_linux_sandbox_exe| async move {
         cli_main(codex_linux_sandbox_exe).await?;
         Ok(())
     })

codex-rs/cli/src/proto.rs

@@ -4,6 +4,7 @@ use std::sync::Arc;
 use clap::Parser;
 use codex_common::CliConfigOverrides;
 use codex_core::Codex;
+use codex_core::CodexSpawnOk;
 use codex_core::config::Config;
 use codex_core::config::ConfigOverrides;
 use codex_core::protocol::Submission;
@@ -35,7 +36,7 @@ pub async fn run_main(opts: ProtoCli) -> anyhow::Result<()> {
 
     let config = Config::load_with_cli_overrides(overrides_vec, ConfigOverrides::default())?;
     let ctrl_c = notify_on_sigint();
-    let (codex, _init_id, _session_id) = Codex::spawn(config, ctrl_c.clone()).await?;
+    let CodexSpawnOk { codex, .. } = Codex::spawn(config, ctrl_c.clone()).await?;
     let codex = Arc::new(codex);
 
     // Task that reads JSON lines from stdin and forwards to Submission Queue

codex-rs/core/Cargo.toml

@@ -30,6 +30,7 @@ reqwest = { version = "0.12", features = ["json", "stream"] }
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 sha1 = "0.10.6"
+shlex = "1.3.0"
 strum_macros = "0.27.2"
 thiserror = "2.0.12"
 time = { version = "0.3", features = ["formatting", "local-offset", "macros"] }
@@ -47,6 +48,8 @@ tree-sitter = "0.25.8"
 tree-sitter-bash = "0.25.0"
 uuid = { version = "1", features = ["serde", "v4"] }
 wildmatch = "2.4.0"
+whoami = "1.6.0"
+
 
 [target.'cfg(target_os = "linux")'.dependencies]
 landlock = "0.4.1"

codex-rs/core/README.md

@@ -2,9 +2,18 @@
 
 This crate implements the business logic for Codex. It is designed to be used by the various Codex UIs written in Rust.
 
-Though for non-Rust UIs, we are also working to define a _protocol_ for talking to Codex. See:
+## Dependencies
 
-- [Specification](../docs/protocol_v1.md)
-- [Rust types](./src/protocol.rs)
+Note that `codex-core` makes some assumptions about certain helper utilities being available in the environment. Currently, this
 
-You can use the `proto` subcommand using the executable in the [`cli` crate](../cli) to speak the protocol using newline-delimited-JSON over stdin/stdout.
+### macOS
+
+Expects `/usr/bin/sandbox-exec` to be present.
+
+### Linux
+
+Expects the binary containing `codex-core` to run the equivalent of `codex debug landlock` when `arg0` is `codex-linux-sandbox`. See the `codex-arg0` crate for details.
+
+### All Platforms
+
+Expects the binary containing `codex-core` to simulate the virtual `apply_patch` CLI when `arg1` is `--codex-run-as-apply-patch`. See the `codex-arg0` crate for details.

codex-rs/core/src/apply_patch.rs

@@ -0,0 +1,406 @@
+use crate::codex::Session;
+use crate::models::FunctionCallOutputPayload;
+use crate::models::ResponseInputItem;
+use crate::protocol::Event;
+use crate::protocol::EventMsg;
+use crate::protocol::FileChange;
+use crate::protocol::PatchApplyBeginEvent;
+use crate::protocol::PatchApplyEndEvent;
+use crate::protocol::ReviewDecision;
+use crate::safety::SafetyCheck;
+use crate::safety::assess_patch_safety;
+use anyhow::Context;
+use codex_apply_patch::AffectedPaths;
+use codex_apply_patch::ApplyPatchAction;
+use codex_apply_patch::ApplyPatchFileChange;
+use codex_apply_patch::print_summary;
+use std::collections::HashMap;
+use std::path::Path;
+use std::path::PathBuf;
+
+pub(crate) async fn apply_patch(
+    sess: &Session,
+    sub_id: String,
+    call_id: String,
+    action: ApplyPatchAction,
+) -> ResponseInputItem {
+    let writable_roots_snapshot = {
+        #[allow(clippy::unwrap_used)]
+        let guard = sess.writable_roots.lock().unwrap();
+        guard.clone()
+    };
+
+    let auto_approved = match assess_patch_safety(
+        &action,
+        sess.approval_policy,
+        &writable_roots_snapshot,
+        &sess.cwd,
+    ) {
+        SafetyCheck::AutoApprove { .. } => true,
+        SafetyCheck::AskUser => {
+            // Compute a readable summary of path changes to include in the
+            // approval request so the user can make an informed decision.
+            let rx_approve = sess
+                .request_patch_approval(sub_id.clone(), call_id.clone(), &action, None, None)
+                .await;
+            match rx_approve.await.unwrap_or_default() {
+                ReviewDecision::Approved | ReviewDecision::ApprovedForSession => false,
+                ReviewDecision::Denied | ReviewDecision::Abort => {
+                    return ResponseInputItem::FunctionCallOutput {
+                        call_id,
+                        output: FunctionCallOutputPayload {
+                            content: "patch rejected by user".to_string(),
+                            success: Some(false),
+                        },
+                    };
+                }
+            }
+        }
+        SafetyCheck::Reject { reason } => {
+            return ResponseInputItem::FunctionCallOutput {
+                call_id,
+                output: FunctionCallOutputPayload {
+                    content: format!("patch rejected: {reason}"),
+                    success: Some(false),
+                },
+            };
+        }
+    };
+
+    // Verify write permissions before touching the filesystem.
+    let writable_snapshot = {
+        #[allow(clippy::unwrap_used)]
+        sess.writable_roots.lock().unwrap().clone()
+    };
+
+    if let Some(offending) = first_offending_path(&action, &writable_snapshot, &sess.cwd) {
+        let root = offending.parent().unwrap_or(&offending).to_path_buf();
+
+        let reason = Some(format!(
+            "grant write access to {} for this session",
+            root.display()
+        ));
+
+        let rx = sess
+            .request_patch_approval(
+                sub_id.clone(),
+                call_id.clone(),
+                &action,
+                reason.clone(),
+                Some(root.clone()),
+            )
+            .await;
+
+        if !matches!(
+            rx.await.unwrap_or_default(),
+            ReviewDecision::Approved | ReviewDecision::ApprovedForSession
+        ) {
+            return ResponseInputItem::FunctionCallOutput {
+                call_id,
+                output: FunctionCallOutputPayload {
+                    content: "patch rejected by user".to_string(),
+                    success: Some(false),
+                },
+            };
+        }
+
+        // user approved, extend writable roots for this session
+        #[allow(clippy::unwrap_used)]
+        sess.writable_roots.lock().unwrap().push(root);
+    }
+
+    let _ = sess
+        .tx_event
+        .send(Event {
+            id: sub_id.clone(),
+            msg: EventMsg::PatchApplyBegin(PatchApplyBeginEvent {
+                call_id: call_id.clone(),
+                auto_approved,
+                changes: convert_apply_patch_to_protocol(&action),
+            }),
+        })
+        .await;
+
+    let mut stdout = Vec::new();
+    let mut stderr = Vec::new();
+    // Enforce writable roots. If a write is blocked, collect offending root
+    // and prompt the user to extend permissions.
+    let mut result = apply_changes_from_apply_patch_and_report(&action, &mut stdout, &mut stderr);
+
+    if let Err(err) = &result {
+        if err.kind() == std::io::ErrorKind::PermissionDenied {
+            // Determine first offending path.
+            let offending_opt = action
+                .changes()
+                .iter()
+                .flat_map(|(path, change)| match change {
+                    ApplyPatchFileChange::Add { .. } => vec![path.as_ref()],
+                    ApplyPatchFileChange::Delete => vec![path.as_ref()],
+                    ApplyPatchFileChange::Update {
+                        move_path: Some(move_path),
+                        ..
+                    } => {
+                        vec![path.as_ref(), move_path.as_ref()]
+                    }
+                    ApplyPatchFileChange::Update {
+                        move_path: None, ..
+                    } => vec![path.as_ref()],
+                })
+                .find_map(|path: &Path| {
+                    // ApplyPatchAction promises to guarantee absolute paths.
+                    if !path.is_absolute() {
+                        panic!("apply_patch invariant failed: path is not absolute: {path:?}");
+                    }
+
+                    let writable = {
+                        #[allow(clippy::unwrap_used)]
+                        let roots = sess.writable_roots.lock().unwrap();
+                        roots.iter().any(|root| path.starts_with(root))
+                    };
+                    if writable {
+                        None
+                    } else {
+                        Some(path.to_path_buf())
+                    }
+                });
+
+            if let Some(offending) = offending_opt {
+                let root = offending.parent().unwrap_or(&offending).to_path_buf();
+
+                let reason = Some(format!(
+                    "grant write access to {} for this session",
+                    root.display()
+                ));
+                let rx = sess
+                    .request_patch_approval(
+                        sub_id.clone(),
+                        call_id.clone(),
+                        &action,
+                        reason.clone(),
+                        Some(root.clone()),
+                    )
+                    .await;
+                if matches!(
+                    rx.await.unwrap_or_default(),
+                    ReviewDecision::Approved | ReviewDecision::ApprovedForSession
+                ) {
+                    // Extend writable roots.
+                    #[allow(clippy::unwrap_used)]
+                    sess.writable_roots.lock().unwrap().push(root);
+                    stdout.clear();
+                    stderr.clear();
+                    result = apply_changes_from_apply_patch_and_report(
+                        &action,
+                        &mut stdout,
+                        &mut stderr,
+                    );
+                }
+            }
+        }
+    }
+
+    // Emit PatchApplyEnd event.
+    let success_flag = result.is_ok();
+    let _ = sess
+        .tx_event
+        .send(Event {
+            id: sub_id.clone(),
+            msg: EventMsg::PatchApplyEnd(PatchApplyEndEvent {
+                call_id: call_id.clone(),
+                stdout: String::from_utf8_lossy(&stdout).to_string(),
+                stderr: String::from_utf8_lossy(&stderr).to_string(),
+                success: success_flag,
+            }),
+        })
+        .await;
+
+    match result {
+        Ok(_) => ResponseInputItem::FunctionCallOutput {
+            call_id,
+            output: FunctionCallOutputPayload {
+                content: String::from_utf8_lossy(&stdout).to_string(),
+                success: None,
+            },
+        },
+        Err(e) => ResponseInputItem::FunctionCallOutput {
+            call_id,
+            output: FunctionCallOutputPayload {
+                content: format!("error: {e:#}, stderr: {}", String::from_utf8_lossy(&stderr)),
+                success: Some(false),
+            },
+        },
+    }
+}
+
+/// Return the first path in `hunks` that is NOT under any of the
+/// `writable_roots` (after normalising). If all paths are acceptable,
+/// returns None.
+fn first_offending_path(
+    action: &ApplyPatchAction,
+    writable_roots: &[PathBuf],
+    cwd: &Path,
+) -> Option<PathBuf> {
+    let changes = action.changes();
+    for (path, change) in changes {
+        let candidate = match change {
+            ApplyPatchFileChange::Add { .. } => path,
+            ApplyPatchFileChange::Delete => path,
+            ApplyPatchFileChange::Update { move_path, .. } => move_path.as_ref().unwrap_or(path),
+        };
+
+        let abs = if candidate.is_absolute() {
+            candidate.clone()
+        } else {
+            cwd.join(candidate)
+        };
+
+        let mut allowed = false;
+        for root in writable_roots {
+            let root_abs = if root.is_absolute() {
+                root.clone()
+            } else {
+                cwd.join(root)
+            };
+            if abs.starts_with(&root_abs) {
+                allowed = true;
+                break;
+            }
+        }
+
+        if !allowed {
+            return Some(candidate.clone());
+        }
+    }
+    None
+}
+
+pub(crate) fn convert_apply_patch_to_protocol(
+    action: &ApplyPatchAction,
+) -> HashMap<PathBuf, FileChange> {
+    let changes = action.changes();
+    let mut result = HashMap::with_capacity(changes.len());
+    for (path, change) in changes {
+        let protocol_change = match change {
+            ApplyPatchFileChange::Add { content } => FileChange::Add {
+                content: content.clone(),
+            },
+            ApplyPatchFileChange::Delete => FileChange::Delete,
+            ApplyPatchFileChange::Update {
+                unified_diff,
+                move_path,
+                new_content: _new_content,
+            } => FileChange::Update {
+                unified_diff: unified_diff.clone(),
+                move_path: move_path.clone(),
+            },
+        };
+        result.insert(path.clone(), protocol_change);
+    }
+    result
+}
+
+fn apply_changes_from_apply_patch_and_report(
+    action: &ApplyPatchAction,
+    stdout: &mut impl std::io::Write,
+    stderr: &mut impl std::io::Write,
+) -> std::io::Result<()> {
+    match apply_changes_from_apply_patch(action) {
+        Ok(affected_paths) => {
+            print_summary(&affected_paths, stdout)?;
+        }
+        Err(err) => {
+            writeln!(stderr, "{err:?}")?;
+        }
+    }
+
+    Ok(())
+}
+
+fn apply_changes_from_apply_patch(action: &ApplyPatchAction) -> anyhow::Result<AffectedPaths> {
+    let mut added: Vec<PathBuf> = Vec::new();
+    let mut modified: Vec<PathBuf> = Vec::new();
+    let mut deleted: Vec<PathBuf> = Vec::new();
+
+    let changes = action.changes();
+    for (path, change) in changes {
+        match change {
+            ApplyPatchFileChange::Add { content } => {
+                if let Some(parent) = path.parent() {
+                    if !parent.as_os_str().is_empty() {
+                        std::fs::create_dir_all(parent).with_context(|| {
+                            format!("Failed to create parent directories for {}", path.display())
+                        })?;
+                    }
+                }
+                std::fs::write(path, content)
+                    .with_context(|| format!("Failed to write file {}", path.display()))?;
+                added.push(path.clone());
+            }
+            ApplyPatchFileChange::Delete => {
+                std::fs::remove_file(path)
+                    .with_context(|| format!("Failed to delete file {}", path.display()))?;
+                deleted.push(path.clone());
+            }
+            ApplyPatchFileChange::Update {
+                unified_diff: _unified_diff,
+                move_path,
+                new_content,
+            } => {
+                if let Some(move_path) = move_path {
+                    if let Some(parent) = move_path.parent() {
+                        if !parent.as_os_str().is_empty() {
+                            std::fs::create_dir_all(parent).with_context(|| {
+                                format!(
+                                    "Failed to create parent directories for {}",
+                                    move_path.display()
+                                )
+                            })?;
+                        }
+                    }
+
+                    std::fs::rename(path, move_path)
+                        .with_context(|| format!("Failed to rename file {}", path.display()))?;
+                    std::fs::write(move_path, new_content)?;
+                    modified.push(move_path.clone());
+                    deleted.push(path.clone());
+                } else {
+                    std::fs::write(path, new_content)?;
+                    modified.push(path.clone());
+                }
+            }
+        }
+    }
+
+    Ok(AffectedPaths {
+        added,
+        modified,
+        deleted,
+    })
+}
+
+pub(crate) fn get_writable_roots(cwd: &Path) -> Vec<PathBuf> {
+    let mut writable_roots = Vec::new();
+    if cfg!(target_os = "macos") {
+        // On macOS, $TMPDIR is private to the user.
+        writable_roots.push(std::env::temp_dir());
+
+        // Allow pyenv to update its shims directory. Without this, any tool
+        // that happens to be managed by `pyenv` will fail with an error like:
+        //
+        //   pyenv: cannot rehash: $HOME/.pyenv/shims isn't writable
+        //
+        // which is emitted every time `pyenv` tries to run `rehash` (for
+        // example, after installing a new Python package that drops an entry
+        // point). Although the sandbox is intentionally read‑only by default,
+        // writing to the user's local `pyenv` directory is safe because it
+        // is already user‑writable and scoped to the current user account.
+        if let Ok(home_dir) = std::env::var("HOME") {
+            let pyenv_dir = PathBuf::from(home_dir).join(".pyenv");
+            writable_roots.push(pyenv_dir);
+        }
+    }
+
+    writable_roots.push(cwd.to_path_buf());
+
+    writable_roots
+}

codex-rs/core/src/codex.rs

@@ -4,22 +4,17 @@
 use std::borrow::Cow;
 use std::collections::HashMap;
 use std::collections::HashSet;
-use std::path::Path;
 use std::path::PathBuf;
 use std::sync::Arc;
 use std::sync::Mutex;
 use std::sync::atomic::AtomicU64;
 use std::time::Duration;
 
-use anyhow::Context;
 use async_channel::Receiver;
 use async_channel::Sender;
-use codex_apply_patch::AffectedPaths;
 use codex_apply_patch::ApplyPatchAction;
-use codex_apply_patch::ApplyPatchFileChange;
 use codex_apply_patch::MaybeApplyPatchVerified;
 use codex_apply_patch::maybe_parse_apply_patch_verified;
-use codex_apply_patch::print_summary;
 use futures::prelude::*;
 use mcp_types::CallToolResult;
 use serde::Serialize;
@@ -34,6 +29,9 @@ use tracing::trace;
 use tracing::warn;
 use uuid::Uuid;
 
+use crate::apply_patch::convert_apply_patch_to_protocol;
+use crate::apply_patch::get_writable_roots;
+use crate::apply_patch::{self};
 use crate::client::ModelClient;
 use crate::client_common::Prompt;
 use crate::client_common::ResponseEvent;
@@ -71,11 +69,8 @@ use crate::protocol::EventMsg;
 use crate::protocol::ExecApprovalRequestEvent;
 use crate::protocol::ExecCommandBeginEvent;
 use crate::protocol::ExecCommandEndEvent;
-use crate::protocol::FileChange;
 use crate::protocol::InputItem;
 use crate::protocol::Op;
-use crate::protocol::PatchApplyBeginEvent;
-use crate::protocol::PatchApplyEndEvent;
 use crate::protocol::ReviewDecision;
 use crate::protocol::SandboxPolicy;
 use crate::protocol::SessionConfiguredEvent;
@@ -84,7 +79,7 @@ use crate::protocol::TaskCompleteEvent;
 use crate::rollout::RolloutRecorder;
 use crate::safety::SafetyCheck;
 use crate::safety::assess_command_safety;
-use crate::safety::assess_patch_safety;
+use crate::shell;
 use crate::user_notification::UserNotification;
 use crate::util::backoff;
 
@@ -96,11 +91,18 @@ pub struct Codex {
     rx_event: Receiver<Event>,
 }
 
+/// Wrapper returned by [`Codex::spawn`] containing the spawned [`Codex`],
+/// the submission id for the initial `ConfigureSession` request and the
+/// unique session id.
+pub struct CodexSpawnOk {
+    pub codex: Codex,
+    pub init_id: String,
+    pub session_id: Uuid,
+}
+
 impl Codex {
-    /// Spawn a new [`Codex`] and initialize the session. Returns the instance
-    /// of `Codex` and the ID of the `SessionInitialized` event that was
-    /// submitted to start the session.
-    pub async fn spawn(config: Config, ctrl_c: Arc<Notify>) -> CodexResult<(Codex, String, Uuid)> {
+    /// Spawn a new [`Codex`] and initialize the session.
+    pub async fn spawn(config: Config, ctrl_c: Arc<Notify>) -> CodexResult<CodexSpawnOk> {
         // experimental resume path (undocumented)
         let resume_path = config.experimental_resume.clone();
         info!("resume_path: {resume_path:?}");
@@ -138,7 +140,11 @@ impl Codex {
         };
         let init_id = codex.submit(configure_session).await?;
 
-        Ok((codex, init_id, session_id))
+        Ok(CodexSpawnOk {
+            codex,
+            init_id,
+            session_id,
+        })
     }
 
     /// Submit the `op` wrapped in a `Submission` with a unique ID.
@@ -177,19 +183,19 @@ impl Codex {
 /// A session has at most 1 running task at a time, and can be interrupted by user input.
 pub(crate) struct Session {
     client: ModelClient,
-    tx_event: Sender<Event>,
+    pub(crate) tx_event: Sender<Event>,
     ctrl_c: Arc<Notify>,
 
     /// The session's current working directory. All relative paths provided by
     /// the model as well as sandbox policies are resolved against this path
     /// instead of `std::env::current_dir()`.
-    cwd: PathBuf,
+    pub(crate) cwd: PathBuf,
     base_instructions: Option<String>,
     user_instructions: Option<String>,
-    approval_policy: AskForApproval,
+    pub(crate) approval_policy: AskForApproval,
     sandbox_policy: SandboxPolicy,
     shell_environment_policy: ShellEnvironmentPolicy,
-    writable_roots: Mutex<Vec<PathBuf>>,
+    pub(crate) writable_roots: Mutex<Vec<PathBuf>>,
     disable_response_storage: bool,
 
     /// Manager for external MCP servers/tools.
@@ -204,6 +210,7 @@ pub(crate) struct Session {
     rollout: Mutex<Option<RolloutRecorder>>,
     state: Mutex<State>,
     codex_linux_sandbox_exe: Option<PathBuf>,
+    user_shell: shell::Shell,
 }
 
 impl Session {
@@ -212,6 +219,23 @@ impl Session {
             .map(PathBuf::from)
             .map_or_else(|| self.cwd.clone(), |p| self.cwd.join(p))
     }
+    /// Erases all previous messages from the conversation history (zdr_transcript), if present.
+    pub fn erase_conversation_history(&self) {
+        let mut state = self.state.lock().unwrap();
+        if let Some(transcript) = state.zdr_transcript.as_mut() {
+            transcript.clear();
+        }
+
+        // When using the experimental OpenAI Responses API with server-side
+        // storage enabled, `previous_response_id` is used to let the model
+        // access the earlier part of the conversation **without** having to
+        // resend the full transcript. To truly wipe all historical context
+        // we must drop this identifier as well, otherwise the backend will
+        // still be able to retrieve the prior messages via the ID even
+        // though our local transcript has been cleared. See
+        // https://platform.openai.com/docs/guides/responses for details.
+        state.previous_response_id = None;
+    }
 }
 
 /// Mutable state of the agent
@@ -551,6 +575,11 @@ async fn submission_loop(
 
         debug!(?sub, "Submission");
         match sub.op {
+            Op::EraseConversationHistory => {
+                if let Some(sess) = sess.as_ref() {
+                    sess.erase_conversation_history();
+                }
+            }
             Op::Interrupt => {
                 let sess = match sess.as_ref() {
                     Some(sess) => sess,
@@ -676,6 +705,7 @@ async fn submission_loop(
                         });
                     }
                 }
+                let default_shell = shell::default_user_shell().await;
                 sess = Some(Arc::new(Session {
                     client,
                     tx_event: tx_event.clone(),
@@ -693,6 +723,7 @@ async fn submission_loop(
                     rollout: Mutex::new(rollout_recorder),
                     codex_linux_sandbox_exe: config.codex_linux_sandbox_exe.clone(),
                     disable_response_storage,
+                    user_shell: default_shell,
                 }));
 
                 // Patch restored state into the newly created session.
@@ -1383,6 +1414,18 @@ fn parse_container_exec_arguments(
     }
 }
 
+fn maybe_run_with_user_profile(params: ExecParams, sess: &Session) -> ExecParams {
+    if sess.shell_environment_policy.use_profile {
+        let command = sess
+            .user_shell
+            .format_default_shell_invocation(params.command.clone());
+        if let Some(command) = command {
+            return ExecParams { command, ..params };
+        }
+    }
+    params
+}
+
 async fn handle_container_exec_with_params(
     params: ExecParams,
     sess: &Session,
@@ -1392,7 +1435,7 @@ async fn handle_container_exec_with_params(
     // check if this was a patch, and apply it if so
     match maybe_parse_apply_patch_verified(&params.command, &params.cwd) {
         MaybeApplyPatchVerified::Body(changes) => {
-            return apply_patch(sess, sub_id, call_id, changes).await;
+            return apply_patch::apply_patch(sess, sub_id, call_id, changes).await;
         }
         MaybeApplyPatchVerified::CorrectnessError(parse_error) => {
             // It looks like an invocation of `apply_patch`, but we
@@ -1469,6 +1512,7 @@ async fn handle_container_exec_with_params(
     sess.notify_exec_command_begin(&sub_id, &call_id, &params)
         .await;
 
+    let params = maybe_run_with_user_profile(params, sess);
     let output_result = process_exec_tool_call(
         params.clone(),
         sandbox_type,
@@ -1640,384 +1684,6 @@ async fn handle_sandbox_error(
     }
 }
 
-async fn apply_patch(
-    sess: &Session,
-    sub_id: String,
-    call_id: String,
-    action: ApplyPatchAction,
-) -> ResponseInputItem {
-    let writable_roots_snapshot = {
-        let guard = sess.writable_roots.lock().unwrap();
-        guard.clone()
-    };
-
-    let auto_approved = match assess_patch_safety(
-        &action,
-        sess.approval_policy,
-        &writable_roots_snapshot,
-        &sess.cwd,
-    ) {
-        SafetyCheck::AutoApprove { .. } => true,
-        SafetyCheck::AskUser => {
-            // Compute a readable summary of path changes to include in the
-            // approval request so the user can make an informed decision.
-            let rx_approve = sess
-                .request_patch_approval(sub_id.clone(), call_id.clone(), &action, None, None)
-                .await;
-            match rx_approve.await.unwrap_or_default() {
-                ReviewDecision::Approved | ReviewDecision::ApprovedForSession => false,
-                ReviewDecision::Denied | ReviewDecision::Abort => {
-                    return ResponseInputItem::FunctionCallOutput {
-                        call_id,
-                        output: FunctionCallOutputPayload {
-                            content: "patch rejected by user".to_string(),
-                            success: Some(false),
-                        },
-                    };
-                }
-            }
-        }
-        SafetyCheck::Reject { reason } => {
-            return ResponseInputItem::FunctionCallOutput {
-                call_id,
-                output: FunctionCallOutputPayload {
-                    content: format!("patch rejected: {reason}"),
-                    success: Some(false),
-                },
-            };
-        }
-    };
-
-    // Verify write permissions before touching the filesystem.
-    let writable_snapshot = { sess.writable_roots.lock().unwrap().clone() };
-
-    if let Some(offending) = first_offending_path(&action, &writable_snapshot, &sess.cwd) {
-        let root = offending.parent().unwrap_or(&offending).to_path_buf();
-
-        let reason = Some(format!(
-            "grant write access to {} for this session",
-            root.display()
-        ));
-
-        let rx = sess
-            .request_patch_approval(
-                sub_id.clone(),
-                call_id.clone(),
-                &action,
-                reason.clone(),
-                Some(root.clone()),
-            )
-            .await;
-
-        if !matches!(
-            rx.await.unwrap_or_default(),
-            ReviewDecision::Approved | ReviewDecision::ApprovedForSession
-        ) {
-            return ResponseInputItem::FunctionCallOutput {
-                call_id,
-                output: FunctionCallOutputPayload {
-                    content: "patch rejected by user".to_string(),
-                    success: Some(false),
-                },
-            };
-        }
-
-        // user approved, extend writable roots for this session
-        sess.writable_roots.lock().unwrap().push(root);
-    }
-
-    let _ = sess
-        .tx_event
-        .send(Event {
-            id: sub_id.clone(),
-            msg: EventMsg::PatchApplyBegin(PatchApplyBeginEvent {
-                call_id: call_id.clone(),
-                auto_approved,
-                changes: convert_apply_patch_to_protocol(&action),
-            }),
-        })
-        .await;
-
-    let mut stdout = Vec::new();
-    let mut stderr = Vec::new();
-    // Enforce writable roots. If a write is blocked, collect offending root
-    // and prompt the user to extend permissions.
-    let mut result = apply_changes_from_apply_patch_and_report(&action, &mut stdout, &mut stderr);
-
-    if let Err(err) = &result {
-        if err.kind() == std::io::ErrorKind::PermissionDenied {
-            // Determine first offending path.
-            let offending_opt = action
-                .changes()
-                .iter()
-                .flat_map(|(path, change)| match change {
-                    ApplyPatchFileChange::Add { .. } => vec![path.as_ref()],
-                    ApplyPatchFileChange::Delete => vec![path.as_ref()],
-                    ApplyPatchFileChange::Update {
-                        move_path: Some(move_path),
-                        ..
-                    } => {
-                        vec![path.as_ref(), move_path.as_ref()]
-                    }
-                    ApplyPatchFileChange::Update {
-                        move_path: None, ..
-                    } => vec![path.as_ref()],
-                })
-                .find_map(|path: &Path| {
-                    // ApplyPatchAction promises to guarantee absolute paths.
-                    if !path.is_absolute() {
-                        panic!("apply_patch invariant failed: path is not absolute: {path:?}");
-                    }
-
-                    let writable = {
-                        let roots = sess.writable_roots.lock().unwrap();
-                        roots.iter().any(|root| path.starts_with(root))
-                    };
-                    if writable {
-                        None
-                    } else {
-                        Some(path.to_path_buf())
-                    }
-                });
-
-            if let Some(offending) = offending_opt {
-                let root = offending.parent().unwrap_or(&offending).to_path_buf();
-
-                let reason = Some(format!(
-                    "grant write access to {} for this session",
-                    root.display()
-                ));
-                let rx = sess
-                    .request_patch_approval(
-                        sub_id.clone(),
-                        call_id.clone(),
-                        &action,
-                        reason.clone(),
-                        Some(root.clone()),
-                    )
-                    .await;
-                if matches!(
-                    rx.await.unwrap_or_default(),
-                    ReviewDecision::Approved | ReviewDecision::ApprovedForSession
-                ) {
-                    // Extend writable roots.
-                    sess.writable_roots.lock().unwrap().push(root);
-                    stdout.clear();
-                    stderr.clear();
-                    result = apply_changes_from_apply_patch_and_report(
-                        &action,
-                        &mut stdout,
-                        &mut stderr,
-                    );
-                }
-            }
-        }
-    }
-
-    // Emit PatchApplyEnd event.
-    let success_flag = result.is_ok();
-    let _ = sess
-        .tx_event
-        .send(Event {
-            id: sub_id.clone(),
-            msg: EventMsg::PatchApplyEnd(PatchApplyEndEvent {
-                call_id: call_id.clone(),
-                stdout: String::from_utf8_lossy(&stdout).to_string(),
-                stderr: String::from_utf8_lossy(&stderr).to_string(),
-                success: success_flag,
-            }),
-        })
-        .await;
-
-    match result {
-        Ok(_) => ResponseInputItem::FunctionCallOutput {
-            call_id,
-            output: FunctionCallOutputPayload {
-                content: String::from_utf8_lossy(&stdout).to_string(),
-                success: None,
-            },
-        },
-        Err(e) => ResponseInputItem::FunctionCallOutput {
-            call_id,
-            output: FunctionCallOutputPayload {
-                content: format!("error: {e:#}, stderr: {}", String::from_utf8_lossy(&stderr)),
-                success: Some(false),
-            },
-        },
-    }
-}
-
-/// Return the first path in `hunks` that is NOT under any of the
-/// `writable_roots` (after normalising). If all paths are acceptable,
-/// returns None.
-fn first_offending_path(
-    action: &ApplyPatchAction,
-    writable_roots: &[PathBuf],
-    cwd: &Path,
-) -> Option<PathBuf> {
-    let changes = action.changes();
-    for (path, change) in changes {
-        let candidate = match change {
-            ApplyPatchFileChange::Add { .. } => path,
-            ApplyPatchFileChange::Delete => path,
-            ApplyPatchFileChange::Update { move_path, .. } => move_path.as_ref().unwrap_or(path),
-        };
-
-        let abs = if candidate.is_absolute() {
-            candidate.clone()
-        } else {
-            cwd.join(candidate)
-        };
-
-        let mut allowed = false;
-        for root in writable_roots {
-            let root_abs = if root.is_absolute() {
-                root.clone()
-            } else {
-                cwd.join(root)
-            };
-            if abs.starts_with(&root_abs) {
-                allowed = true;
-                break;
-            }
-        }
-
-        if !allowed {
-            return Some(candidate.clone());
-        }
-    }
-    None
-}
-
-fn convert_apply_patch_to_protocol(action: &ApplyPatchAction) -> HashMap<PathBuf, FileChange> {
-    let changes = action.changes();
-    let mut result = HashMap::with_capacity(changes.len());
-    for (path, change) in changes {
-        let protocol_change = match change {
-            ApplyPatchFileChange::Add { content } => FileChange::Add {
-                content: content.clone(),
-            },
-            ApplyPatchFileChange::Delete => FileChange::Delete,
-            ApplyPatchFileChange::Update {
-                unified_diff,
-                move_path,
-                new_content: _new_content,
-            } => FileChange::Update {
-                unified_diff: unified_diff.clone(),
-                move_path: move_path.clone(),
-            },
-        };
-        result.insert(path.clone(), protocol_change);
-    }
-    result
-}
-
-fn apply_changes_from_apply_patch_and_report(
-    action: &ApplyPatchAction,
-    stdout: &mut impl std::io::Write,
-    stderr: &mut impl std::io::Write,
-) -> std::io::Result<()> {
-    match apply_changes_from_apply_patch(action) {
-        Ok(affected_paths) => {
-            print_summary(&affected_paths, stdout)?;
-        }
-        Err(err) => {
-            writeln!(stderr, "{err:?}")?;
-        }
-    }
-
-    Ok(())
-}
-
-fn apply_changes_from_apply_patch(action: &ApplyPatchAction) -> anyhow::Result<AffectedPaths> {
-    let mut added: Vec<PathBuf> = Vec::new();
-    let mut modified: Vec<PathBuf> = Vec::new();
-    let mut deleted: Vec<PathBuf> = Vec::new();
-
-    let changes = action.changes();
-    for (path, change) in changes {
-        match change {
-            ApplyPatchFileChange::Add { content } => {
-                if let Some(parent) = path.parent() {
-                    if !parent.as_os_str().is_empty() {
-                        std::fs::create_dir_all(parent).with_context(|| {
-                            format!("Failed to create parent directories for {}", path.display())
-                        })?;
-                    }
-                }
-                std::fs::write(path, content)
-                    .with_context(|| format!("Failed to write file {}", path.display()))?;
-                added.push(path.clone());
-            }
-            ApplyPatchFileChange::Delete => {
-                std::fs::remove_file(path)
-                    .with_context(|| format!("Failed to delete file {}", path.display()))?;
-                deleted.push(path.clone());
-            }
-            ApplyPatchFileChange::Update {
-                unified_diff: _unified_diff,
-                move_path,
-                new_content,
-            } => {
-                if let Some(move_path) = move_path {
-                    if let Some(parent) = move_path.parent() {
-                        if !parent.as_os_str().is_empty() {
-                            std::fs::create_dir_all(parent).with_context(|| {
-                                format!(
-                                    "Failed to create parent directories for {}",
-                                    move_path.display()
-                                )
-                            })?;
-                        }
-                    }
-
-                    std::fs::rename(path, move_path)
-                        .with_context(|| format!("Failed to rename file {}", path.display()))?;
-                    std::fs::write(move_path, new_content)?;
-                    modified.push(move_path.clone());
-                    deleted.push(path.clone());
-                } else {
-                    std::fs::write(path, new_content)?;
-                    modified.push(path.clone());
-                }
-            }
-        }
-    }
-
-    Ok(AffectedPaths {
-        added,
-        modified,
-        deleted,
-    })
-}
-
-fn get_writable_roots(cwd: &Path) -> Vec<PathBuf> {
-    let mut writable_roots = Vec::new();
-    if cfg!(target_os = "macos") {
-        // On macOS, $TMPDIR is private to the user.
-        writable_roots.push(std::env::temp_dir());
-
-        // Allow pyenv to update its shims directory. Without this, any tool
-        // that happens to be managed by `pyenv` will fail with an error like:
-        //
-        //   pyenv: cannot rehash: $HOME/.pyenv/shims isn't writable
-        //
-        // which is emitted every time `pyenv` tries to run `rehash` (for
-        // example, after installing a new Python package that drops an entry
-        // point). Although the sandbox is intentionally read‑only by default,
-        // writing to the user's local `pyenv` directory is safe because it
-        // is already user‑writable and scoped to the current user account.
-        if let Ok(home_dir) = std::env::var("HOME") {
-            let pyenv_dir = PathBuf::from(home_dir).join(".pyenv");
-            writable_roots.push(pyenv_dir);
-        }
-    }
-
-    writable_roots.push(cwd.to_path_buf());
-
-    writable_roots
-}
-
 /// Exec output is a pre-serialized JSON payload
 fn format_exec_output(output: &str, exit_code: i32, duration: Duration) -> String {
     #[derive(Serialize)]

codex-rs/core/src/codex_wrapper.rs

@@ -1,6 +1,7 @@
 use std::sync::Arc;
 
 use crate::Codex;
+use crate::CodexSpawnOk;
 use crate::config::Config;
 use crate::protocol::Event;
 use crate::protocol::EventMsg;
@@ -8,14 +9,27 @@ use crate::util::notify_on_sigint;
 use tokio::sync::Notify;
 use uuid::Uuid;
 
+/// Represents an active Codex conversation, including the first event
+/// (which is [`EventMsg::SessionConfigured`]).
+pub struct CodexConversation {
+    pub codex: Codex,
+    pub session_id: Uuid,
+    pub session_configured: Event,
+    pub ctrl_c: Arc<Notify>,
+}
+
 /// Spawn a new [`Codex`] and initialize the session.
 ///
 /// Returns the wrapped [`Codex`] **and** the `SessionInitialized` event that
 /// is received as a response to the initial `ConfigureSession` submission so
 /// that callers can surface the information to the UI.
-pub async fn init_codex(config: Config) -> anyhow::Result<(Codex, Event, Arc<Notify>, Uuid)> {
+pub async fn init_codex(config: Config) -> anyhow::Result<CodexConversation> {
     let ctrl_c = notify_on_sigint();
-    let (codex, init_id, session_id) = Codex::spawn(config, ctrl_c.clone()).await?;
+    let CodexSpawnOk {
+        codex,
+        init_id,
+        session_id,
+    } = Codex::spawn(config, ctrl_c.clone()).await?;
 
     // The first event must be `SessionInitialized`. Validate and forward it to
     // the caller so that they can display it in the conversation history.
@@ -34,5 +48,10 @@ pub async fn init_codex(config: Config) -> anyhow::Result<(Codex, Event, Arc<Not
         ));
     }
 
-    Ok((codex, event, ctrl_c, session_id))
+    Ok(CodexConversation {
+        codex,
+        session_id,
+        session_configured: event,
+        ctrl_c,
+    })
 }

codex-rs/core/src/config_types.rs

@@ -130,6 +130,8 @@ pub struct ShellEnvironmentPolicyToml {
 
     /// List of regular expressions.
     pub include_only: Option<Vec<String>>,
+
+    pub experimental_use_profile: Option<bool>,
 }
 
 pub type EnvironmentVariablePattern = WildMatchPattern<'*', '?'>;
@@ -158,6 +160,9 @@ pub struct ShellEnvironmentPolicy {
 
     /// Environment variable names to retain in the environment.
     pub include_only: Vec<EnvironmentVariablePattern>,
+
+    /// If true, the shell profile will be used to run the command.
+    pub use_profile: bool,
 }
 
 impl From<ShellEnvironmentPolicyToml> for ShellEnvironmentPolicy {
@@ -177,6 +182,7 @@ impl From<ShellEnvironmentPolicyToml> for ShellEnvironmentPolicy {
             .into_iter()
             .map(|s| EnvironmentVariablePattern::new_case_insensitive(&s))
             .collect();
+        let use_profile = toml.experimental_use_profile.unwrap_or(false);
 
         Self {
             inherit,
@@ -184,6 +190,7 @@ impl From<ShellEnvironmentPolicyToml> for ShellEnvironmentPolicy {
             exclude,
             r#set,
             include_only,
+            use_profile,
         }
     }
 }

codex-rs/core/src/conversation_history.rs

@@ -30,6 +30,11 @@ impl ConversationHistory {
             }
         }
     }
+
+    /// Clears the conversation history.
+    pub(crate) fn clear(&mut self) {
+        self.items.clear();
+    }
 }
 
 /// Anything that is not a system message or "reasoning" message is considered
@@ -44,3 +49,31 @@ fn is_api_message(message: &ResponseItem) -> bool {
         ResponseItem::Other => false,
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::models::ResponseItem;
+
+    #[test]
+    fn clear_removes_all_items() {
+        let mut hist = ConversationHistory::new();
+
+        use crate::models::ContentItem;
+
+        let items = [ResponseItem::Message {
+            role: "user".into(),
+            content: vec![ContentItem::InputText {
+                text: "hello".into(),
+            }],
+        }];
+
+        hist.record_items(items.iter());
+
+        assert_eq!(hist.contents().len(), 1, "sanity – item should be present");
+
+        hist.clear();
+
+        assert!(hist.contents().is_empty(), "all items should be removed");
+    }
+}

codex-rs/core/src/exec.rs

@@ -17,6 +17,7 @@ use tokio::io::BufReader;
 use tokio::process::Child;
 use tokio::process::Command;
 use tokio::sync::Notify;
+use tracing::trace;
 
 use crate::error::CodexErr;
 use crate::error::Result;
@@ -82,7 +83,8 @@ pub async fn process_exec_tool_call(
 ) -> Result<ExecToolCallOutput> {
     let start = Instant::now();
 
-    let raw_output_result = match sandbox_type {
+    let raw_output_result: std::result::Result<RawExecToolCallOutput, CodexErr> = match sandbox_type
+    {
         SandboxType::None => exec(params, sandbox_policy, ctrl_c).await,
         SandboxType::MacosSeatbelt => {
             let ExecParams {
@@ -372,6 +374,10 @@ async fn spawn_child_async(
     stdio_policy: StdioPolicy,
     env: HashMap<String, String>,
 ) -> std::io::Result<Child> {
+    trace!(
+        "spawn_child_async: {program:?} {args:?} {arg0:?} {cwd:?} {sandbox_policy:?} {stdio_policy:?} {env:?}"
+    );
+
     let mut cmd = Command::new(&program);
     #[cfg(unix)]
     cmd.arg0(arg0.map_or_else(|| program.to_string_lossy().to_string(), String::from));

codex-rs/core/src/lib.rs

@@ -5,12 +5,14 @@
 // the TUI or the tracing stack).
 #![deny(clippy::print_stdout, clippy::print_stderr)]
 
+mod apply_patch;
 mod bash;
 mod chat_completions;
 mod client;
 mod client_common;
 pub mod codex;
 pub use codex::Codex;
+pub use codex::CodexSpawnOk;
 pub mod codex_wrapper;
 pub mod config;
 pub mod config_profile;
@@ -36,6 +38,7 @@ mod project_doc;
 pub mod protocol;
 mod rollout;
 mod safety;
+pub mod shell;
 mod user_notification;
 pub mod util;
 

codex-rs/core/src/mcp_connection_manager.rs

@@ -8,6 +8,7 @@
 
 use std::collections::HashMap;
 use std::collections::HashSet;
+use std::ffi::OsString;
 use std::time::Duration;
 
 use anyhow::Context;
@@ -127,7 +128,12 @@ impl McpConnectionManager {
 
             join_set.spawn(async move {
                 let McpServerConfig { command, args, env } = cfg;
-                let client_res = McpClient::new_stdio_client(command, args, env).await;
+                let client_res = McpClient::new_stdio_client(
+                    command.into(),
+                    args.into_iter().map(OsString::from).collect(),
+                    env,
+                )
+                .await;
                 match client_res {
                     Ok(client) => {
                         // Initialize the client.

codex-rs/core/src/protocol.rs

@@ -35,6 +35,8 @@ pub struct Submission {
 #[allow(clippy::large_enum_variant)]
 #[non_exhaustive]
 pub enum Op {
+    /// Erase all conversation history for the current session.
+    EraseConversationHistory,
     /// Configure the model session.
     ConfigureSession {
         /// Provider identifier ("openai", "openrouter", ...).
@@ -278,8 +280,9 @@ pub struct Event {
 }
 
 /// Response event from the agent
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, Display)]
 #[serde(tag = "type", rename_all = "snake_case")]
+#[strum(serialize_all = "snake_case")]
 pub enum EventMsg {
     /// Error while executing a submission
     Error(ErrorEvent),

codex-rs/core/src/rollout.rs

@@ -288,11 +288,13 @@ fn create_log_file(config: &Config, session_id: Uuid) -> std::io::Result<LogFile
 }
 
 async fn rollout_writer(
-    mut file: tokio::fs::File,
+    file: tokio::fs::File,
     mut rx: mpsc::Receiver<RolloutCmd>,
     mut meta: Option<SessionMeta>,
     cwd: std::path::PathBuf,
-) {
+) -> std::io::Result<()> {
+    let mut writer = JsonlWriter { file };
+
     // If we have a meta, collect git info asynchronously and write meta first
     if let Some(session_meta) = meta.take() {
         let git_info = collect_git_info(&cwd).await;
@@ -302,11 +304,7 @@ async fn rollout_writer(
         };
 
         // Write the SessionMeta as the first item in the file
-        if let Ok(json) = serde_json::to_string(&session_meta_with_git) {
-            let _ = file.write_all(json.as_bytes()).await;
-            let _ = file.write_all(b"\n").await;
-            let _ = file.flush().await;
-        }
+        writer.write_line(&session_meta_with_git).await?;
     }
 
     // Process rollout commands
@@ -320,15 +318,11 @@ async fn rollout_writer(
                         | ResponseItem::FunctionCall { .. }
                         | ResponseItem::FunctionCallOutput { .. }
                         | ResponseItem::Reasoning { .. } => {
-                            if let Ok(json) = serde_json::to_string(&item) {
-                                let _ = file.write_all(json.as_bytes()).await;
-                                let _ = file.write_all(b"\n").await;
-                            }
+                            writer.write_line(&item).await?;
                         }
                         ResponseItem::Other => {}
                     }
                 }
-                let _ = file.flush().await;
             }
             RolloutCmd::UpdateState(state) => {
                 #[derive(Serialize)]
@@ -337,18 +331,32 @@ async fn rollout_writer(
                     #[serde(flatten)]
                     state: &'a SessionStateSnapshot,
                 }
-                if let Ok(json) = serde_json::to_string(&StateLine {
-                    record_type: "state",
-                    state: &state,
-                }) {
-                    let _ = file.write_all(json.as_bytes()).await;
-                    let _ = file.write_all(b"\n").await;
-                    let _ = file.flush().await;
-                }
+                writer
+                    .write_line(&StateLine {
+                        record_type: "state",
+                        state: &state,
+                    })
+                    .await?;
             }
             RolloutCmd::Shutdown { ack } => {
                 let _ = ack.send(());
             }
         }
     }
+
+    Ok(())
+}
+
+struct JsonlWriter {
+    file: tokio::fs::File,
+}
+
+impl JsonlWriter {
+    async fn write_line(&mut self, item: &impl serde::Serialize) -> std::io::Result<()> {
+        let mut json = serde_json::to_string(item)?;
+        json.push('\n');
+        let _ = self.file.write_all(json.as_bytes()).await;
+        self.file.flush().await?;
+        Ok(())
+    }
 }

codex-rs/core/src/shell.rs

@@ -0,0 +1,204 @@
+use shlex;
+
+#[derive(Debug, PartialEq, Eq)]
+pub struct ZshShell {
+    shell_path: String,
+    zshrc_path: String,
+}
+
+#[derive(Debug, PartialEq, Eq)]
+pub enum Shell {
+    Zsh(ZshShell),
+    Unknown,
+}
+
+impl Shell {
+    pub fn format_default_shell_invocation(&self, command: Vec<String>) -> Option<Vec<String>> {
+        match self {
+            Shell::Zsh(zsh) => {
+                if !std::path::Path::new(&zsh.zshrc_path).exists() {
+                    return None;
+                }
+
+                let mut result = vec![zsh.shell_path.clone(), "-c".to_string()];
+                if let Ok(joined) = shlex::try_join(command.iter().map(|s| s.as_str())) {
+                    result.push(format!("source {} && ({joined})", zsh.zshrc_path));
+                } else {
+                    return None;
+                }
+                Some(result)
+            }
+            Shell::Unknown => None,
+        }
+    }
+}
+
+#[cfg(target_os = "macos")]
+pub async fn default_user_shell() -> Shell {
+    use tokio::process::Command;
+    use whoami;
+
+    let user = whoami::username();
+    let home = format!("/Users/{user}");
+    let output = Command::new("dscl")
+        .args([".", "-read", &home, "UserShell"])
+        .output()
+        .await
+        .ok();
+    match output {
+        Some(o) => {
+            if !o.status.success() {
+                return Shell::Unknown;
+            }
+            let stdout = String::from_utf8_lossy(&o.stdout);
+            for line in stdout.lines() {
+                if let Some(shell_path) = line.strip_prefix("UserShell: ") {
+                    if shell_path.ends_with("/zsh") {
+                        return Shell::Zsh(ZshShell {
+                            shell_path: shell_path.to_string(),
+                            zshrc_path: format!("{home}/.zshrc"),
+                        });
+                    }
+                }
+            }
+
+            Shell::Unknown
+        }
+        _ => Shell::Unknown,
+    }
+}
+
+#[cfg(not(target_os = "macos"))]
+pub async fn default_user_shell() -> Shell {
+    Shell::Unknown
+}
+
+#[cfg(test)]
+#[cfg(target_os = "macos")]
+mod tests {
+    use super::*;
+    use std::process::Command;
+
+    #[tokio::test]
+    #[expect(clippy::unwrap_used)]
+    async fn test_current_shell_detects_zsh() {
+        let shell = Command::new("sh")
+            .arg("-c")
+            .arg("echo $SHELL")
+            .output()
+            .unwrap();
+
+        let home = std::env::var("HOME").unwrap();
+        let shell_path = String::from_utf8_lossy(&shell.stdout).trim().to_string();
+        if shell_path.ends_with("/zsh") {
+            assert_eq!(
+                default_user_shell().await,
+                Shell::Zsh(ZshShell {
+                    shell_path: shell_path.to_string(),
+                    zshrc_path: format!("{home}/.zshrc",),
+                })
+            );
+        }
+    }
+
+    #[tokio::test]
+    async fn test_run_with_profile_zshrc_not_exists() {
+        let shell = Shell::Zsh(ZshShell {
+            shell_path: "/bin/zsh".to_string(),
+            zshrc_path: "/does/not/exist/.zshrc".to_string(),
+        });
+        let actual_cmd = shell.format_default_shell_invocation(vec!["myecho".to_string()]);
+        assert_eq!(actual_cmd, None);
+    }
+
+    #[expect(clippy::unwrap_used)]
+    #[tokio::test]
+    async fn test_run_with_profile_escaping_and_execution() {
+        let shell_path = "/bin/zsh";
+
+        let cases = vec![
+            (
+                vec!["myecho"],
+                vec![shell_path, "-c", "source ZSHRC_PATH && (myecho)"],
+                Some("It works!\n"),
+            ),
+            (
+                vec!["bash", "-lc", "echo 'single' \"double\""],
+                vec![
+                    shell_path,
+                    "-c",
+                    "source ZSHRC_PATH && (bash -lc \"echo 'single' \\\"double\\\"\")",
+                ],
+                Some("single double\n"),
+            ),
+        ];
+        for (input, expected_cmd, expected_output) in cases {
+            use std::collections::HashMap;
+            use std::path::PathBuf;
+            use std::sync::Arc;
+
+            use tokio::sync::Notify;
+
+            use crate::exec::ExecParams;
+            use crate::exec::SandboxType;
+            use crate::exec::process_exec_tool_call;
+            use crate::protocol::SandboxPolicy;
+
+            // create a temp directory with a zshrc file in it
+            let temp_home = tempfile::tempdir().unwrap();
+            let zshrc_path = temp_home.path().join(".zshrc");
+            std::fs::write(
+                &zshrc_path,
+                r#"
+                    set -x
+                    function myecho {
+                        echo 'It works!'
+                    }
+                    "#,
+            )
+            .unwrap();
+            let shell = Shell::Zsh(ZshShell {
+                shell_path: shell_path.to_string(),
+                zshrc_path: zshrc_path.to_str().unwrap().to_string(),
+            });
+
+            let actual_cmd = shell
+                .format_default_shell_invocation(input.iter().map(|s| s.to_string()).collect());
+            let expected_cmd = expected_cmd
+                .iter()
+                .map(|s| {
+                    s.replace("ZSHRC_PATH", zshrc_path.to_str().unwrap())
+                        .to_string()
+                })
+                .collect();
+
+            assert_eq!(actual_cmd, Some(expected_cmd));
+            // Actually run the command and check output/exit code
+            let output = process_exec_tool_call(
+                ExecParams {
+                    command: actual_cmd.unwrap(),
+                    cwd: PathBuf::from(temp_home.path()),
+                    timeout_ms: None,
+                    env: HashMap::from([(
+                        "HOME".to_string(),
+                        temp_home.path().to_str().unwrap().to_string(),
+                    )]),
+                },
+                SandboxType::None,
+                Arc::new(Notify::new()),
+                &SandboxPolicy::DangerFullAccess,
+                &None,
+            )
+            .await
+            .unwrap();
+
+            assert_eq!(output.exit_code, 0, "input: {input:?} output: {output:?}");
+            if let Some(expected) = expected_output {
+                assert_eq!(
+                    output.stdout, expected,
+                    "input: {input:?} output: {output:?}"
+                );
+            }
+        }
+    }
+}

codex-rs/core/tests/client.rs

@@ -1,4 +1,5 @@
 use codex_core::Codex;
+use codex_core::CodexSpawnOk;
 use codex_core::ModelProviderInfo;
 use codex_core::exec::CODEX_SANDBOX_NETWORK_DISABLED_ENV_VAR;
 use codex_core::protocol::EventMsg;
@@ -72,7 +73,7 @@ async fn includes_session_id_and_model_headers_in_request() {
     let mut config = load_default_config_for_test(&codex_home);
     config.model_provider = model_provider;
     let ctrl_c = std::sync::Arc::new(tokio::sync::Notify::new());
-    let (codex, _init_id, _session_id) = Codex::spawn(config, ctrl_c.clone()).await.unwrap();
+    let CodexSpawnOk { codex, .. } = Codex::spawn(config, ctrl_c.clone()).await.unwrap();
 
     codex
         .submit(Op::UserInput {
@@ -148,7 +149,7 @@ async fn includes_base_instructions_override_in_request() {
     config.model_provider = model_provider;
 
     let ctrl_c = std::sync::Arc::new(tokio::sync::Notify::new());
-    let (codex, ..) = Codex::spawn(config, ctrl_c.clone()).await.unwrap();
+    let CodexSpawnOk { codex, .. } = Codex::spawn(config, ctrl_c.clone()).await.unwrap();
 
     codex
         .submit(Op::UserInput {

codex-rs/core/tests/live_agent.rs

@@ -20,6 +20,7 @@
 use std::time::Duration;
 
 use codex_core::Codex;
+use codex_core::CodexSpawnOk;
 use codex_core::error::CodexErr;
 use codex_core::protocol::AgentMessageEvent;
 use codex_core::protocol::ErrorEvent;
@@ -48,7 +49,7 @@ async fn spawn_codex() -> Result<Codex, CodexErr> {
     let mut config = load_default_config_for_test(&codex_home);
     config.model_provider.request_max_retries = Some(2);
     config.model_provider.stream_max_retries = Some(2);
-    let (agent, _init_id, _session_id) =
+    let CodexSpawnOk { codex: agent, .. } =
         Codex::spawn(config, std::sync::Arc::new(Notify::new())).await?;
 
     Ok(agent)

codex-rs/core/tests/stream_no_completed.rs

@@ -4,6 +4,7 @@
 use std::time::Duration;
 
 use codex_core::Codex;
+use codex_core::CodexSpawnOk;
 use codex_core::ModelProviderInfo;
 use codex_core::exec::CODEX_SANDBOX_NETWORK_DISABLED_ENV_VAR;
 use codex_core::protocol::EventMsg;
@@ -94,7 +95,7 @@ async fn retries_on_early_close() {
     let codex_home = TempDir::new().unwrap();
     let mut config = load_default_config_for_test(&codex_home);
     config.model_provider = model_provider;
-    let (codex, _init_id, _session_id) = Codex::spawn(config, ctrl_c).await.unwrap();
+    let CodexSpawnOk { codex, .. } = Codex::spawn(config, ctrl_c).await.unwrap();
 
     codex
         .submit(Op::UserInput {

codex-rs/exec/Cargo.toml

@@ -18,13 +18,13 @@ workspace = true
 anyhow = "1"
 chrono = "0.4.40"
 clap = { version = "4", features = ["derive"] }
+codex-arg0 = { path = "../arg0" }
 codex-core = { path = "../core" }
 codex-common = { path = "../common", features = [
     "cli",
     "elapsed",
     "sandbox_summary",
 ] }
-codex-linux-sandbox = { path = "../linux-sandbox" }
 owo-colors = "4.2.0"
 serde_json = "1"
 shlex = "1.3.0"
@@ -37,3 +37,8 @@ tokio = { version = "1", features = [
 ] }
 tracing = { version = "0.1.41", features = ["log"] }
 tracing-subscriber = { version = "0.3.19", features = ["env-filter"] }
+
+[dev-dependencies]
+assert_cmd = "2"
+predicates = "3"
+tempfile = "3.13.0"

codex-rs/exec/src/lib.rs

@@ -9,7 +9,8 @@ use std::path::PathBuf;
 use std::sync::Arc;
 
 pub use cli::Cli;
-use codex_core::codex_wrapper;
+use codex_core::codex_wrapper::CodexConversation;
+use codex_core::codex_wrapper::{self};
 use codex_core::config::Config;
 use codex_core::config::ConfigOverrides;
 use codex_core::config_types::SandboxMode;
@@ -155,9 +156,14 @@ pub async fn run_main(cli: Cli, codex_linux_sandbox_exe: Option<PathBuf>) -> any
         .with_writer(std::io::stderr)
         .try_init();
 
-    let (codex_wrapper, event, ctrl_c, _session_id) = codex_wrapper::init_codex(config).await?;
+    let CodexConversation {
+        codex: codex_wrapper,
+        session_configured,
+        ctrl_c,
+        ..
+    } = codex_wrapper::init_codex(config).await?;
     let codex = Arc::new(codex_wrapper);
-    info!("Codex initialized with event: {event:?}");
+    info!("Codex initialized with event: {session_configured:?}");
 
     let (tx, mut rx) = tokio::sync::mpsc::unbounded_channel::<Event>();
     {

codex-rs/exec/src/main.rs

@@ -10,6 +10,7 @@
 //! This allows us to ship a completely separate set of functionality as part
 //! of the `codex-exec` binary.
 use clap::Parser;
+use codex_arg0::arg0_dispatch_or_else;
 use codex_common::CliConfigOverrides;
 use codex_exec::Cli;
 use codex_exec::run_main;
@@ -24,7 +25,7 @@ struct TopCli {
 }
 
 fn main() -> anyhow::Result<()> {
-    codex_linux_sandbox::run_with_sandbox(|codex_linux_sandbox_exe| async move {
+    arg0_dispatch_or_else(|codex_linux_sandbox_exe| async move {
         let top_cli = TopCli::parse();
         // Merge root-level overrides into inner CLI struct so downstream logic remains unchanged.
         let mut inner = top_cli.inner;

codex-rs/exec/tests/apply_patch.rs

@@ -0,0 +1,38 @@
+use anyhow::Context;
+use assert_cmd::prelude::*;
+use std::fs;
+use std::process::Command;
+use tempfile::tempdir;
+
+/// While we may add an `apply-patch` subcommand to the `codex` CLI multitool
+/// at some point, we must ensure that the smaller `codex-exec` CLI can still
+/// emulate the `apply_patch` CLI.
+#[test]
+fn test_standalone_exec_cli_can_use_apply_patch() -> anyhow::Result<()> {
+    let tmp = tempdir()?;
+    let relative_path = "source.txt";
+    let absolute_path = tmp.path().join(relative_path);
+    fs::write(&absolute_path, "original content\n")?;
+
+    Command::cargo_bin("codex-exec")
+        .context("should find binary for codex-exec")?
+        .arg("--codex-run-as-apply-patch")
+        .arg(
+            r#"*** Begin Patch
+*** Update File: source.txt
+@@
+-original content
++modified by apply_patch
+*** End Patch"#,
+        )
+        .current_dir(tmp.path())
+        .assert()
+        .success()
+        .stdout("Success. Updated the following files:\nM source.txt\n")
+        .stderr(predicates::str::is_empty());
+    assert_eq!(
+        fs::read_to_string(absolute_path)?,
+        "modified by apply_patch\n"
+    );
+    Ok(())
+}

codex-rs/linux-sandbox/Cargo.toml

@@ -14,15 +14,16 @@ path = "src/lib.rs"
 [lints]
 workspace = true
 
-[dependencies]
+[target.'cfg(target_os = "linux")'.dependencies]
 anyhow = "1"
 clap = { version = "4", features = ["derive"] }
 codex-common = { path = "../common", features = ["cli"] }
 codex-core = { path = "../core" }
-dotenvy = "0.15.7"
-tokio = { version = "1", features = ["rt-multi-thread"] }
+libc = "0.2.172"
+landlock = "0.4.1"
+seccompiler = "0.5.0"
 
-[dev-dependencies]
+[target.'cfg(target_os = "linux")'.dev-dependencies]
 tempfile = "3"
 tokio = { version = "1", features = [
     "io-std",
@@ -31,8 +32,3 @@ tokio = { version = "1", features = [
     "rt-multi-thread",
     "signal",
 ] }
-
-[target.'cfg(target_os = "linux")'.dependencies]
-libc = "0.2.172"
-landlock = "0.4.1"
-seccompiler = "0.5.0"

codex-rs/linux-sandbox/src/lib.rs

@@ -4,72 +4,11 @@ mod landlock;
 mod linux_run_main;
 
 #[cfg(target_os = "linux")]
-pub use linux_run_main::run_main;
-
-use std::future::Future;
-use std::path::PathBuf;
-
-/// Helper that consolidates the common boilerplate found in several Codex
-/// binaries (`codex`, `codex-exec`, `codex-tui`) around dispatching to the
-/// `codex-linux-sandbox` sub-command.
-///
-/// When the current executable is invoked through the hard-link or alias
-/// named `codex-linux-sandbox` we *directly* execute [`run_main`](crate::run_main)
-/// (which never returns). Otherwise we:
-/// 1.  Construct a Tokio multi-thread runtime.
-/// 2.  Derive the path to the current executable (so children can re-invoke
-///     the sandbox) when running on Linux.
-/// 3.  Execute the provided async `main_fn` inside that runtime, forwarding
-///     any error.
-///
-/// This function eliminates duplicated code across the various `main.rs`
-/// entry-points.
-pub fn run_with_sandbox<F, Fut>(main_fn: F) -> anyhow::Result<()>
-where
-    F: FnOnce(Option<PathBuf>) -> Fut,
-    Fut: Future<Output = anyhow::Result<()>>,
-{
-    use std::path::Path;
-
-    // Determine if we were invoked via the special alias.
-    let argv0 = std::env::args().next().unwrap_or_default();
-    let exe_name = Path::new(&argv0)
-        .file_name()
-        .and_then(|s| s.to_str())
-        .unwrap_or("");
-
-    if exe_name == "codex-linux-sandbox" {
-        // Safety: [`run_main`] never returns.
-        crate::run_main();
-    }
-
-    // This modifies the environment, which is not thread-safe, so do this
-    // before creating any threads/the Tokio runtime.
-    load_dotenv();
-
-    // Regular invocation – create a Tokio runtime and execute the provided
-    // async entry-point.
-    let runtime = tokio::runtime::Runtime::new()?;
-    runtime.block_on(async move {
-        let codex_linux_sandbox_exe: Option<PathBuf> = if cfg!(target_os = "linux") {
-            std::env::current_exe().ok()
-        } else {
-            None
-        };
-
-        main_fn(codex_linux_sandbox_exe).await
-    })
+pub fn run_main() -> ! {
+    linux_run_main::run_main();
 }
 
 #[cfg(not(target_os = "linux"))]
 pub fn run_main() -> ! {
     panic!("codex-linux-sandbox is only supported on Linux");
 }
-
-/// Load env vars from ~/.codex/.env and `$(pwd)/.env`.
-fn load_dotenv() {
-    if let Ok(codex_home) = codex_core::config::find_codex_home() {
-        dotenvy::from_path(codex_home.join(".env")).ok();
-    }
-    dotenvy::dotenv().ok();
-}

codex-rs/mcp-client/src/main.rs

@@ -10,6 +10,7 @@
 //! program. The utility connects, issues a `tools/list` request and prints the
 //! server's response as pretty JSON.
 
+use std::ffi::OsString;
 use std::time::Duration;
 
 use anyhow::Context;
@@ -37,7 +38,7 @@ async fn main() -> Result<()> {
         .try_init();
 
     // Collect command-line arguments excluding the program name itself.
-    let mut args: Vec<String> = std::env::args().skip(1).collect();
+    let mut args: Vec<OsString> = std::env::args_os().skip(1).collect();
 
     if args.is_empty() || args[0] == "--help" || args[0] == "-h" {
         eprintln!("Usage: mcp-client <program> [args..]\n\nExample: mcp-client codex-mcp-server");

codex-rs/mcp-client/src/mcp_client.rs

@@ -12,6 +12,7 @@
 //! issue requests and receive strongly-typed results.
 
 use std::collections::HashMap;
+use std::ffi::OsString;
 use std::sync::Arc;
 use std::sync::atomic::AtomicI64;
 use std::sync::atomic::Ordering;
@@ -82,8 +83,8 @@ impl McpClient {
     /// Caller is responsible for sending the `initialize` request. See
     /// [`initialize`](Self::initialize) for details.
     pub async fn new_stdio_client(
-        program: String,
-        args: Vec<String>,
+        program: OsString,
+        args: Vec<OsString>,
         env: Option<HashMap<String, String>>,
     ) -> std::io::Result<Self> {
         let mut child = Command::new(program)

codex-rs/mcp-server/Cargo.toml

@@ -16,8 +16,8 @@ workspace = true
 
 [dependencies]
 anyhow = "1"
+codex-arg0 = { path = "../arg0" }
 codex-core = { path = "../core" }
-codex-linux-sandbox = { path = "../linux-sandbox" }
 mcp-types = { path = "../mcp-types" }
 schemars = "0.8.22"
 serde = { version = "1", features = ["derive"] }

codex-rs/mcp-server/src/codex_tool_runner.rs

@@ -6,6 +6,7 @@ use std::collections::HashMap;
 use std::sync::Arc;
 
 use codex_core::Codex;
+use codex_core::codex_wrapper::CodexConversation;
 use codex_core::codex_wrapper::init_codex;
 use codex_core::config::Config as CodexConfig;
 use codex_core::protocol::AgentMessageEvent;
@@ -26,6 +27,7 @@ use uuid::Uuid;
 
 use crate::exec_approval::handle_exec_approval_request;
 use crate::outgoing_message::OutgoingMessageSender;
+use crate::outgoing_message::OutgoingNotificationMeta;
 use crate::patch_approval::handle_patch_approval_request;
 
 pub(crate) const INVALID_PARAMS_ERROR_CODE: i64 = -32602;
@@ -42,7 +44,12 @@ pub async fn run_codex_tool_session(
     session_map: Arc<Mutex<HashMap<Uuid, Arc<Codex>>>>,
     running_requests_id_to_codex_uuid: Arc<Mutex<HashMap<RequestId, Uuid>>>,
 ) {
-    let (codex, first_event, _ctrl_c, session_id) = match init_codex(config).await {
+    let CodexConversation {
+        codex,
+        session_configured,
+        session_id,
+        ..
+    } = match init_codex(config).await {
         Ok(res) => res,
         Err(e) => {
             let result = CallToolResult {
@@ -65,8 +72,12 @@ pub async fn run_codex_tool_session(
     session_map.lock().await.insert(session_id, codex.clone());
     drop(session_map);
 
-    // Send initial SessionConfigured event.
-    outgoing.send_event_as_notification(&first_event).await;
+    outgoing
+        .send_event_as_notification(
+            &session_configured,
+            Some(OutgoingNotificationMeta::new(Some(id.clone()))),
+        )
+        .await;
 
     // Use the original MCP request ID as the `sub_id` for the Codex submission so that
     // any events emitted for this tool-call can be correlated with the
@@ -150,7 +161,12 @@ async fn run_codex_tool_session_inner(
     loop {
         match codex.next_event().await {
             Ok(event) => {
-                outgoing.send_event_as_notification(&event).await;
+                outgoing
+                    .send_event_as_notification(
+                        &event,
+                        Some(OutgoingNotificationMeta::new(Some(request_id.clone()))),
+                    )
+                    .await;
 
                 match event.msg {
                     EventMsg::ExecApprovalRequest(ExecApprovalRequestEvent {

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

@@ -13,6 +13,7 @@ use tokio::sync::mpsc;
 use tracing::debug;
 use tracing::error;
 use tracing::info;
+use tracing_subscriber::EnvFilter;
 
 mod codex_tool_config;
 mod codex_tool_runner;
@@ -43,6 +44,7 @@ pub async fn run_main(codex_linux_sandbox_exe: Option<PathBuf>) -> IoResult<()>
     // control the log level with `RUST_LOG`.
     tracing_subscriber::fmt()
         .with_writer(std::io::stderr)
+        .with_env_filter(EnvFilter::from_default_env())
         .init();
 
     // Set up channels.

codex-rs/mcp-server/src/main.rs

@@ -1,7 +1,8 @@
+use codex_arg0::arg0_dispatch_or_else;
 use codex_mcp_server::run_main;
 
 fn main() -> anyhow::Result<()> {
-    codex_linux_sandbox::run_with_sandbox(|codex_linux_sandbox_exe| async move {
+    arg0_dispatch_or_else(|codex_linux_sandbox_exe| async move {
         run_main(codex_linux_sandbox_exe).await?;
         Ok(())
     })

codex-rs/mcp-server/src/outgoing_message.rs

@@ -18,6 +18,7 @@ use tokio::sync::mpsc;
 use tokio::sync::oneshot;
 use tracing::warn;
 
+/// Sends messages to the client and manages request callbacks.
 pub(crate) struct OutgoingMessageSender {
     next_request_id: AtomicI64,
     sender: mpsc::Sender<OutgoingMessage>,
@@ -78,16 +79,47 @@ impl OutgoingMessageSender {
         let _ = self.sender.send(outgoing_message).await;
     }
 
-    pub(crate) async fn send_event_as_notification(&self, event: &Event) {
-        #[expect(clippy::expect_used)]
-        let params = Some(serde_json::to_value(event).expect("Event must serialize"));
+    pub(crate) async fn send_event_as_notification(
+        &self,
+        event: &Event,
+        meta: Option<OutgoingNotificationMeta>,
+    ) {
+        #[allow(clippy::expect_used)]
+        let event_json = serde_json::to_value(event).expect("Event must serialize");
+
+        let params = if let Ok(params) = serde_json::to_value(OutgoingNotificationParams {
+            meta,
+            event: event_json.clone(),
+        }) {
+            params
+        } else {
+            warn!("Failed to serialize event as OutgoingNotificationParams");
+            event_json
+        };
+
         let outgoing_message = OutgoingMessage::Notification(OutgoingNotification {
             method: "codex/event".to_string(),
+            params: Some(params.clone()),
+        });
+        let _ = self.sender.send(outgoing_message).await;
+
+        self.send_event_as_notification_new_schema(event, Some(params.clone()))
+            .await;
+    }
+
+    // should be backwards compatible.
+    // it will replace send_event_as_notification eventually.
+    async fn send_event_as_notification_new_schema(
+        &self,
+        event: &Event,
+        params: Option<serde_json::Value>,
+    ) {
+        let outgoing_message = OutgoingMessage::Notification(OutgoingNotification {
+            method: event.msg.to_string(),
             params,
         });
         let _ = self.sender.send(outgoing_message).await;
     }
-
     pub(crate) async fn send_error(&self, id: RequestId, error: JSONRPCErrorError) {
         let outgoing_message = OutgoingMessage::Error(OutgoingError { id, error });
         let _ = self.sender.send(outgoing_message).await;
@@ -152,6 +184,30 @@ pub(crate) struct OutgoingNotification {
     pub params: Option<serde_json::Value>,
 }
 
+#[derive(Debug, Clone, PartialEq, Serialize)]
+pub(crate) struct OutgoingNotificationParams {
+    #[serde(rename = "_meta", default, skip_serializing_if = "Option::is_none")]
+    pub meta: Option<OutgoingNotificationMeta>,
+
+    #[serde(flatten)]
+    pub event: serde_json::Value,
+}
+
+// Additional mcp-specific data to be added to a [`codex_core::protocol::Event`] as notification.params._meta
+// MCP Spec: https://modelcontextprotocol.io/specification/2025-06-18/basic#meta
+// Typescript Schema: https://github.com/modelcontextprotocol/modelcontextprotocol/blob/0695a497eb50a804fc0e88c18a93a21a675d6b3e/schema/2025-06-18/schema.ts
+#[derive(Debug, Clone, PartialEq, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub(crate) struct OutgoingNotificationMeta {
+    pub request_id: Option<RequestId>,
+}
+
+impl OutgoingNotificationMeta {
+    pub(crate) fn new(request_id: Option<RequestId>) -> Self {
+        Self { request_id }
+    }
+}
+
 #[derive(Debug, Clone, PartialEq, Serialize)]
 pub(crate) struct OutgoingResponse {
     pub id: RequestId,
@@ -163,3 +219,113 @@ pub(crate) struct OutgoingError {
     pub error: JSONRPCErrorError,
     pub id: RequestId,
 }
+
+#[cfg(test)]
+mod tests {
+    #![allow(clippy::unwrap_used)]
+
+    use codex_core::protocol::EventMsg;
+    use codex_core::protocol::SessionConfiguredEvent;
+    use pretty_assertions::assert_eq;
+    use serde_json::json;
+    use uuid::Uuid;
+
+    use super::*;
+
+    #[tokio::test]
+    async fn test_send_event_as_notification() {
+        let (outgoing_tx, mut outgoing_rx) = mpsc::channel::<OutgoingMessage>(2);
+        let outgoing_message_sender = OutgoingMessageSender::new(outgoing_tx);
+
+        let event = Event {
+            id: "1".to_string(),
+            msg: EventMsg::SessionConfigured(SessionConfiguredEvent {
+                session_id: Uuid::new_v4(),
+                model: "gpt-4o".to_string(),
+                history_log_id: 1,
+                history_entry_count: 1000,
+            }),
+        };
+
+        outgoing_message_sender
+            .send_event_as_notification(&event, None)
+            .await;
+
+        let result = outgoing_rx.recv().await.unwrap();
+        let OutgoingMessage::Notification(OutgoingNotification { method, params }) = result else {
+            panic!("expected Notification for first message");
+        };
+        assert_eq!(method, "codex/event");
+
+        let Ok(expected_params) = serde_json::to_value(&event) else {
+            panic!("Event must serialize");
+        };
+        assert_eq!(params, Some(expected_params.clone()));
+
+        let result2 = outgoing_rx.recv().await.unwrap();
+        let OutgoingMessage::Notification(OutgoingNotification {
+            method: method2,
+            params: params2,
+        }) = result2
+        else {
+            panic!("expected Notification for second message");
+        };
+        assert_eq!(method2, event.msg.to_string());
+        assert_eq!(params2, Some(expected_params));
+    }
+
+    #[tokio::test]
+    async fn test_send_event_as_notification_with_meta() {
+        let (outgoing_tx, mut outgoing_rx) = mpsc::channel::<OutgoingMessage>(2);
+        let outgoing_message_sender = OutgoingMessageSender::new(outgoing_tx);
+
+        let session_configured_event = SessionConfiguredEvent {
+            session_id: Uuid::new_v4(),
+            model: "gpt-4o".to_string(),
+            history_log_id: 1,
+            history_entry_count: 1000,
+        };
+        let event = Event {
+            id: "1".to_string(),
+            msg: EventMsg::SessionConfigured(session_configured_event.clone()),
+        };
+        let meta = OutgoingNotificationMeta {
+            request_id: Some(RequestId::String("123".to_string())),
+        };
+
+        outgoing_message_sender
+            .send_event_as_notification(&event, Some(meta))
+            .await;
+
+        let result = outgoing_rx.recv().await.unwrap();
+        let OutgoingMessage::Notification(OutgoingNotification { method, params }) = result else {
+            panic!("expected Notification for first message");
+        };
+        assert_eq!(method, "codex/event");
+        let expected_params = json!({
+            "_meta": {
+                "requestId": "123",
+            },
+            "id": "1",
+            "msg": {
+                "session_id": session_configured_event.session_id,
+                "model": session_configured_event.model,
+                "history_log_id": session_configured_event.history_log_id,
+                "history_entry_count": session_configured_event.history_entry_count,
+                "type": "session_configured",
+            }
+        });
+        assert_eq!(params.unwrap(), expected_params);
+
+        let result2 = outgoing_rx.recv().await.unwrap();
+        let OutgoingMessage::Notification(OutgoingNotification {
+            method: method2,
+            params: params2,
+        }) = result2
+        else {
+            panic!("expected Notification for second message");
+        };
+        assert_eq!(method2, event.msg.to_string());
+        assert_eq!(params2.unwrap(), expected_params);
+    }
+}

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

@@ -270,27 +270,49 @@ impl McpProcess {
     pub async fn read_stream_until_configured_response_message(
         &mut self,
     ) -> anyhow::Result<String> {
+        let mut sid_old: Option<String> = None;
+        let mut sid_new: Option<String> = None;
         loop {
             let message = self.read_jsonrpc_message().await?;
             eprint!("message: {message:?}");
 
             match message {
                 JSONRPCMessage::Notification(notification) => {
-                    if notification.method == "codex/event" {
-                        if let Some(params) = notification.params {
+                    if let Some(params) = notification.params {
+                        // Back-compat schema: method == "codex/event" and msg.type == "session_configured"
+                        if notification.method == "codex/event" {
                             if let Some(msg) = params.get("msg") {
-                                if let Some(msg_type) = msg.get("type") {
-                                    if msg_type == "session_configured" {
-                                        if let Some(session_id) = msg.get("session_id") {
-                                            return Ok(session_id
-                                                .to_string()
-                                                .trim_matches('"')
-                                                .to_string());
-                                        }
+                                if msg.get("type").and_then(|v| v.as_str())
+                                    == Some("session_configured")
+                                {
+                                    if let Some(session_id) =
+                                        msg.get("session_id").and_then(|v| v.as_str())
+                                    {
+                                        sid_old = Some(session_id.to_string());
                                     }
                                 }
                             }
                         }
+                        // New schema: method is the Display of EventMsg::SessionConfigured => "SessionConfigured"
+                        if notification.method == "session_configured" {
+                            if let Some(msg) = params.get("msg") {
+                                if let Some(session_id) =
+                                    msg.get("session_id").and_then(|v| v.as_str())
+                                {
+                                    sid_new = Some(session_id.to_string());
+                                }
+                            }
+                        }
+                    }
+
+                    if sid_old.is_some() && sid_new.is_some() {
+                        // Both seen, they must match
+                        assert_eq!(
+                            sid_old.as_ref().unwrap(),
+                            sid_new.as_ref().unwrap(),
+                            "session_id mismatch between old and new schema"
+                        );
+                        return Ok(sid_old.unwrap());
                     }
                 }
                 JSONRPCMessage::Request(_) => {

codex-rs/tui/Cargo.toml

@@ -19,6 +19,7 @@ anyhow = "1"
 base64 = "0.22.1"
 clap = { version = "4", features = ["derive"] }
 codex-ansi-escape = { path = "../ansi-escape" }
+codex-arg0 = { path = "../arg0" }
 codex-core = { path = "../core" }
 codex-common = { path = "../common", features = [
     "cli",
@@ -26,7 +27,6 @@ codex-common = { path = "../common", features = [
     "sandbox_summary",
 ] }
 codex-file-search = { path = "../file-search" }
-codex-linux-sandbox = { path = "../linux-sandbox" }
 codex-login = { path = "../login" }
 color-eyre = "0.6.3"
 crossterm = { version = "0.28.1", features = ["bracketed-paste"] }
@@ -35,8 +35,9 @@ lazy_static = "1"
 mcp-types = { path = "../mcp-types" }
 path-clean = "1.0.1"
 ratatui = { version = "0.29.0", features = [
-    "unstable-widget-ref",
+    "scrolling-regions",
     "unstable-rendered-line-info",
+    "unstable-widget-ref",
 ] }
 ratatui-image = "8.0.0"
 regex-lite = "0.1"
@@ -60,6 +61,8 @@ tui-textarea = "0.7.0"
 unicode-segmentation = "1.12.0"
 unicode-width = "0.1"
 uuid = "1"
+reqwest = { version = "0.12", features = ["json"] }
+serde = { version = "1", features = ["derive"] }
 
 [dev-dependencies]
 insta = "1.43.1"

codex-rs/tui/src/app.rs

@@ -88,32 +88,51 @@ impl App<'_> {
         {
             let app_event_tx = app_event_tx.clone();
             std::thread::spawn(move || {
-                while let Ok(event) = crossterm::event::read() {
-                    match event {
-                        crossterm::event::Event::Key(key_event) => {
-                            app_event_tx.send(AppEvent::KeyEvent(key_event));
-                        }
-                        crossterm::event::Event::Resize(_, _) => {
-                            app_event_tx.send(AppEvent::RequestRedraw);
-                        }
-                        crossterm::event::Event::Mouse(MouseEvent {
-                            kind: MouseEventKind::ScrollUp,
-                            ..
-                        }) => {
-                            scroll_event_helper.scroll_up();
-                        }
-                        crossterm::event::Event::Mouse(MouseEvent {
-                            kind: MouseEventKind::ScrollDown,
-                            ..
-                        }) => {
-                            scroll_event_helper.scroll_down();
-                        }
-                        crossterm::event::Event::Paste(pasted) => {
-                            app_event_tx.send(AppEvent::Paste(pasted));
-                        }
-                        _ => {
-                            // Ignore any other events.
+                loop {
+                    // This timeout is necessary to avoid holding the event lock
+                    // that crossterm::event::read() acquires. In particular,
+                    // reading the cursor position (crossterm::cursor::position())
+                    // needs to acquire the event lock, and so will fail if it
+                    // can't acquire it within 2 sec. Resizing the terminal
+                    // crashes the app if the cursor position can't be read.
+                    if let Ok(true) = crossterm::event::poll(Duration::from_millis(100)) {
+                        if let Ok(event) = crossterm::event::read() {
+                            match event {
+                                crossterm::event::Event::Key(key_event) => {
+                                    app_event_tx.send(AppEvent::KeyEvent(key_event));
+                                }
+                                crossterm::event::Event::Resize(_, _) => {
+                                    app_event_tx.send(AppEvent::RequestRedraw);
+                                }
+                                crossterm::event::Event::Mouse(MouseEvent {
+                                    kind: MouseEventKind::ScrollUp,
+                                    ..
+                                }) => {
+                                    scroll_event_helper.scroll_up();
+                                }
+                                crossterm::event::Event::Mouse(MouseEvent {
+                                    kind: MouseEventKind::ScrollDown,
+                                    ..
+                                }) => {
+                                    scroll_event_helper.scroll_down();
+                                }
+                                crossterm::event::Event::Paste(pasted) => {
+                                    // Many terminals convert newlines to \r when
+                                    // pasting, e.g. [iTerm2][]. But [tui-textarea
+                                    // expects \n][tui-textarea]. This seems like a bug
+                                    // in tui-textarea IMO, but work around it for now.
+                                    // [tui-textarea]: https://github.com/rhysd/tui-textarea/blob/4d18622eeac13b309e0ff6a55a46ac6706da68cf/src/textarea.rs#L782-L783
+                                    // [iTerm2]: https://github.com/gnachman/iTerm2/blob/5d0c0d9f68523cbd0494dad5422998964a2ecd8d/sources/iTermPasteHelper.m#L206-L216
+                                    let pasted = pasted.replace("\r", "\n");
+                                    app_event_tx.send(AppEvent::Paste(pasted));
+                                }
+                                _ => {
+                                    // Ignore any other events.
+                                }
+                            }
                         }
+                    } else {
+                        // Timeout expired, no `Event` is available
                     }
                 }
             });
@@ -310,6 +329,11 @@ impl App<'_> {
                             widget.add_diff_output(text);
                         }
                     }
+                    SlashCommand::Compact => {
+                        if let AppState::Chat { widget } = &mut self.app_state {
+                            widget.start_compact();
+                        }
+                    }
                 },
                 AppEvent::StartFileSearch(query) => {
                     self.file_search.on_user_query(query);
@@ -319,6 +343,11 @@ impl App<'_> {
                         widget.apply_file_search_result(query, matches);
                     }
                 }
+                AppEvent::CompactComplete(result) => {
+                    if let AppState::Chat { widget } = &mut self.app_state {
+                        widget.apply_compact_summary(result);
+                    }
+                }
             }
         }
         terminal.clear()?;

codex-rs/tui/src/app_event.rs

@@ -51,5 +51,10 @@ pub(crate) enum AppEvent {
         matches: Vec<FileMatch>,
     },
 
+    /// Result of the asynchronous `/compact` summarization.
+    CompactComplete(Result<String, String>),
+
+    /// Insert the most recently appended history entry directly into the
+    /// terminal scrollback. Carries already formatted lines.
     InsertHistory(Vec<Line<'static>>),
 }

codex-rs/tui/src/bottom_pane/approval_modal_view.rs

@@ -9,6 +9,7 @@ use crate::user_approval_widget::UserApprovalWidget;
 
 use super::BottomPane;
 use super::BottomPaneView;
+use super::CancellationEvent;
 
 /// Modal overlay asking the user to approve/deny a sequence of requests.
 pub(crate) struct ApprovalModalView<'a> {
@@ -46,6 +47,12 @@ impl<'a> BottomPaneView<'a> for ApprovalModalView<'a> {
         self.maybe_advance();
     }
 
+    fn on_ctrl_c(&mut self, _pane: &mut BottomPane<'a>) -> CancellationEvent {
+        self.current.on_ctrl_c();
+        self.queue.clear();
+        CancellationEvent::Handled
+    }
+
     fn is_complete(&self) -> bool {
         self.current.is_complete() && self.queue.is_empty()
     }
@@ -59,3 +66,39 @@ impl<'a> BottomPaneView<'a> for ApprovalModalView<'a> {
         None
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::app_event::AppEvent;
+    use std::path::PathBuf;
+    use std::sync::mpsc::channel;
+
+    fn make_exec_request() -> ApprovalRequest {
+        ApprovalRequest::Exec {
+            id: "test".to_string(),
+            command: vec!["echo".to_string(), "hi".to_string()],
+            cwd: PathBuf::from("/tmp"),
+            reason: None,
+        }
+    }
+
+    #[test]
+    fn ctrl_c_aborts_and_clears_queue() {
+        let (tx_raw, _rx) = channel::<AppEvent>();
+        let tx = AppEventSender::new(tx_raw);
+        let first = make_exec_request();
+        let mut view = ApprovalModalView::new(first, tx);
+        view.enqueue_request(make_exec_request());
+
+        let (tx_raw2, _rx2) = channel::<AppEvent>();
+        let mut pane = BottomPane::new(super::super::BottomPaneParams {
+            app_event_tx: AppEventSender::new(tx_raw2),
+            has_input_focus: true,
+        });
+        assert_eq!(CancellationEvent::Handled, view.on_ctrl_c(&mut pane));
+        assert!(view.queue.is_empty());
+        assert!(view.current.is_complete());
+        assert!(view.is_complete());
+    }
+}

codex-rs/tui/src/bottom_pane/bottom_pane_view.rs

@@ -4,6 +4,7 @@ use ratatui::buffer::Buffer;
 use ratatui::layout::Rect;
 
 use super::BottomPane;
+use super::CancellationEvent;
 
 /// Type to use for a method that may require a redraw of the UI.
 pub(crate) enum ConditionalUpdate {
@@ -22,6 +23,11 @@ pub(crate) trait BottomPaneView<'a> {
         false
     }
 
+    /// Handle Ctrl-C while this view is active.
+    fn on_ctrl_c(&mut self, _pane: &mut BottomPane<'a>) -> CancellationEvent {
+        CancellationEvent::Ignored
+    }
+
     /// Render the view: this will be displayed in place of the composer.
     fn render(&self, area: Rect, buf: &mut Buffer);
 

codex-rs/tui/src/bottom_pane/chat_composer.rs

@@ -127,10 +127,6 @@ impl ChatComposer<'_> {
             .on_entry_response(log_id, offset, entry, &mut self.textarea)
     }
 
-    pub fn set_input_focus(&mut self, has_focus: bool) {
-        self.update_border(has_focus);
-    }
-
     pub fn handle_paste(&mut self, pasted: String) -> bool {
         let char_count = pasted.chars().count();
         if char_count > LARGE_PASTE_CHAR_THRESHOLD {
@@ -638,13 +634,6 @@ impl ChatComposer<'_> {
                 .border_style(bs.border_style),
         );
     }
-
-    pub(crate) fn is_popup_visible(&self) -> bool {
-        match self.active_popup {
-            ActivePopup::Command(_) | ActivePopup::File(_) => true,
-            ActivePopup::None => false,
-        }
-    }
 }
 
 impl WidgetRef for &ChatComposer<'_> {

codex-rs/tui/src/bottom_pane/mod.rs

@@ -20,6 +20,12 @@ mod command_popup;
 mod file_search_popup;
 mod status_indicator_view;
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub(crate) enum CancellationEvent {
+    Ignored,
+    Handled,
+}
+
 pub(crate) use chat_composer::ChatComposer;
 pub(crate) use chat_composer::InputResult;
 
@@ -80,6 +86,33 @@ impl BottomPane<'_> {
         }
     }
 
+    /// Handle Ctrl-C in the bottom pane. If a modal view is active it gets a
+    /// chance to consume the event (e.g. to dismiss itself).
+    pub(crate) fn on_ctrl_c(&mut self) -> CancellationEvent {
+        let mut view = match self.active_view.take() {
+            Some(view) => view,
+            None => return CancellationEvent::Ignored,
+        };
+
+        let event = view.on_ctrl_c(self);
+        match event {
+            CancellationEvent::Handled => {
+                if !view.is_complete() {
+                    self.active_view = Some(view);
+                } else if self.is_task_running {
+                    self.active_view = Some(Box::new(StatusIndicatorView::new(
+                        self.app_event_tx.clone(),
+                    )));
+                }
+                self.show_ctrl_c_quit_hint();
+            }
+            CancellationEvent::Ignored => {
+                self.active_view = Some(view);
+            }
+        }
+        event
+    }
+
     pub fn handle_paste(&mut self, pasted: String) {
         if self.active_view.is_none() {
             let needs_redraw = self.composer.handle_paste(pasted);
@@ -104,12 +137,6 @@ impl BottomPane<'_> {
         }
     }
 
-    /// Update the UI to reflect whether this `BottomPane` has input focus.
-    pub(crate) fn set_input_focus(&mut self, has_focus: bool) {
-        self.has_input_focus = has_focus;
-        self.composer.set_input_focus(has_focus);
-    }
-
     pub(crate) fn show_ctrl_c_quit_hint(&mut self) {
         self.ctrl_c_quit_hint = true;
         self.composer
@@ -203,11 +230,6 @@ impl BottomPane<'_> {
         self.app_event_tx.send(AppEvent::RequestRedraw)
     }
 
-    /// Returns true when a popup inside the composer is visible.
-    pub(crate) fn is_popup_visible(&self) -> bool {
-        self.active_view.is_none() && self.composer.is_popup_visible()
-    }
-
     // --- History helpers ---
 
     pub(crate) fn set_history_metadata(&mut self, log_id: u64, entry_count: usize) {
@@ -245,3 +267,34 @@ impl WidgetRef for &BottomPane<'_> {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::app_event::AppEvent;
+    use std::path::PathBuf;
+    use std::sync::mpsc::channel;
+
+    fn exec_request() -> ApprovalRequest {
+        ApprovalRequest::Exec {
+            id: "1".to_string(),
+            command: vec!["echo".into(), "ok".into()],
+            cwd: PathBuf::from("."),
+            reason: None,
+        }
+    }
+
+    #[test]
+    fn ctrl_c_on_modal_consumes_and_shows_quit_hint() {
+        let (tx_raw, _rx) = channel::<AppEvent>();
+        let tx = AppEventSender::new(tx_raw);
+        let mut pane = BottomPane::new(BottomPaneParams {
+            app_event_tx: tx,
+            has_input_focus: true,
+        });
+        pane.push_approval_request(exec_request());
+        assert_eq!(CancellationEvent::Handled, pane.on_ctrl_c());
+        assert!(pane.ctrl_c_quit_hint_visible());
+        assert_eq!(CancellationEvent::Ignored, pane.on_ctrl_c());
+    }
+}

codex-rs/tui/src/chatwidget.rs

@@ -1,6 +1,7 @@
 use std::path::PathBuf;
 use std::sync::Arc;
 
+use codex_core::codex_wrapper::CodexConversation;
 use codex_core::codex_wrapper::init_codex;
 use codex_core::config::Config;
 use codex_core::protocol::AgentMessageDeltaEvent;
@@ -33,8 +34,13 @@ use crate::app_event::AppEvent;
 use crate::app_event_sender::AppEventSender;
 use crate::bottom_pane::BottomPane;
 use crate::bottom_pane::BottomPaneParams;
+use crate::bottom_pane::CancellationEvent;
 use crate::bottom_pane::InputResult;
+use crate::compact::Role;
+use crate::compact::TranscriptEntry;
+use crate::compact::generate_compact_summary;
 use crate::conversation_history_widget::ConversationHistoryWidget;
+use crate::exec_command::strip_bash_lc_and_escape;
 use crate::history_cell::PatchEventType;
 use crate::user_approval_widget::ApprovalRequest;
 use codex_file_search::FileMatch;
@@ -44,21 +50,15 @@ pub(crate) struct ChatWidget<'a> {
     codex_op_tx: UnboundedSender<Op>,
     conversation_history: ConversationHistoryWidget,
     bottom_pane: BottomPane<'a>,
-    input_focus: InputFocus,
     config: Config,
     initial_user_message: Option<UserMessage>,
     token_usage: TokenUsage,
+    // Buffer for streaming assistant reasoning text; emitted on final event.
     reasoning_buffer: String,
-    // Buffer for streaming assistant answer text; we do not surface partial
-    // We wait for the final AgentMessage event and then emit the full text
-    // at once into scrollback so the history contains a single message.
+    // Buffer for streaming assistant answer text; emitted on final event.
     answer_buffer: String,
-}
-
-#[derive(Clone, Copy, Eq, PartialEq)]
-enum InputFocus {
-    HistoryPane,
-    BottomPane,
+    // Transcript of chat for `/compact` summarization.
+    transcript: Vec<TranscriptEntry>,
 }
 
 struct UserMessage {
@@ -96,19 +96,22 @@ impl ChatWidget<'_> {
         // Create the Codex asynchronously so the UI loads as quickly as possible.
         let config_for_agent_loop = config.clone();
         tokio::spawn(async move {
-            let (codex, session_event, _ctrl_c, _session_id) =
-                match init_codex(config_for_agent_loop).await {
-                    Ok(vals) => vals,
-                    Err(e) => {
-                        // TODO: surface this error to the user.
-                        tracing::error!("failed to initialize codex: {e}");
-                        return;
-                    }
-                };
+            let CodexConversation {
+                codex,
+                session_configured,
+                ..
+            } = match init_codex(config_for_agent_loop).await {
+                Ok(vals) => vals,
+                Err(e) => {
+                    // TODO: surface this error to the user.
+                    tracing::error!("failed to initialize codex: {e}");
+                    return;
+                }
+            };
 
             // Forward the captured `SessionInitialized` event that was consumed
             // inside `init_codex()` so it can be rendered in the UI.
-            app_event_tx_clone.send(AppEvent::CodexEvent(session_event.clone()));
+            app_event_tx_clone.send(AppEvent::CodexEvent(session_configured.clone()));
             let codex = Arc::new(codex);
             let codex_clone = codex.clone();
             tokio::spawn(async move {
@@ -133,7 +136,6 @@ impl ChatWidget<'_> {
                 app_event_tx,
                 has_input_focus: true,
             }),
-            input_focus: InputFocus::BottomPane,
             config,
             initial_user_message: create_initial_user_message(
                 initial_prompt.unwrap_or_default(),
@@ -142,49 +144,23 @@ impl ChatWidget<'_> {
             token_usage: TokenUsage::default(),
             reasoning_buffer: String::new(),
             answer_buffer: String::new(),
+            transcript: Vec::new(),
         }
     }
 
     pub(crate) fn handle_key_event(&mut self, key_event: KeyEvent) {
         self.bottom_pane.clear_ctrl_c_quit_hint();
-        // Special-case <Tab>: normally toggles focus between history and bottom panes.
-        // However, when the slash-command popup is visible we forward the key
-        // to the bottom pane so it can handle auto-completion.
-        if matches!(key_event.code, crossterm::event::KeyCode::Tab)
-            && !self.bottom_pane.is_popup_visible()
-        {
-            self.input_focus = match self.input_focus {
-                InputFocus::HistoryPane => InputFocus::BottomPane,
-                InputFocus::BottomPane => InputFocus::HistoryPane,
-            };
-            self.conversation_history
-                .set_input_focus(self.input_focus == InputFocus::HistoryPane);
-            self.bottom_pane
-                .set_input_focus(self.input_focus == InputFocus::BottomPane);
-            self.request_redraw();
-            return;
-        }
 
-        match self.input_focus {
-            InputFocus::HistoryPane => {
-                let needs_redraw = self.conversation_history.handle_key_event(key_event);
-                if needs_redraw {
-                    self.request_redraw();
-                }
+        match self.bottom_pane.handle_key_event(key_event) {
+            InputResult::Submitted(text) => {
+                self.submit_user_message(text.into());
             }
-            InputFocus::BottomPane => match self.bottom_pane.handle_key_event(key_event) {
-                InputResult::Submitted(text) => {
-                    self.submit_user_message(text.into());
-                }
-                InputResult::None => {}
-            },
+            InputResult::None => {}
         }
     }
 
     pub(crate) fn handle_paste(&mut self, text: String) {
-        if matches!(self.input_focus, InputFocus::BottomPane) {
-            self.bottom_pane.handle_paste(text);
-        }
+        self.bottom_pane.handle_paste(text);
     }
 
     /// Emits the last entry's plain lines from conversation_history, if any.
@@ -227,8 +203,14 @@ impl ChatWidget<'_> {
 
         // Only show text portion in conversation history for now.
         if !text.is_empty() {
+            // Forward a copy for history and emit into scrollback.
             self.conversation_history.add_user_message(text.clone());
             self.emit_last_history_entry();
+            // Record in transcript for `/compact`.
+            self.transcript.push(TranscriptEntry {
+                role: Role::User,
+                text,
+            });
         }
         self.conversation_history.scroll_to_bottom();
     }
@@ -259,10 +241,7 @@ impl ChatWidget<'_> {
                 self.request_redraw();
             }
             EventMsg::AgentMessage(AgentMessageEvent { message }) => {
-                // Final assistant answer. Prefer the fully provided message
-                // from the event; if it is empty fall back to any accumulated
-                // delta buffer (some providers may only stream deltas and send
-                // an empty final message).
+                // Final assistant answer. Prefer the fully provided message.
                 let full = if message.is_empty() {
                     std::mem::take(&mut self.answer_buffer)
                 } else {
@@ -271,8 +250,13 @@ impl ChatWidget<'_> {
                 };
                 if !full.is_empty() {
                     self.conversation_history
-                        .add_agent_message(&self.config, full);
+                        .add_agent_message(&self.config, full.clone());
                     self.emit_last_history_entry();
+                    // Record final answer in transcript for `/compact`.
+                    self.transcript.push(TranscriptEntry {
+                        role: Role::Assistant,
+                        text: full,
+                    });
                 }
                 self.request_redraw();
             }
@@ -332,6 +316,20 @@ impl ChatWidget<'_> {
                 cwd,
                 reason,
             }) => {
+                // Print the command to the history so it is visible in the
+                // transcript *before* the modal asks for approval.
+                let cmdline = strip_bash_lc_and_escape(&command);
+                let text = format!(
+                    "command requires approval:\n$ {cmdline}{reason}",
+                    reason = reason
+                        .as_ref()
+                        .map(|r| format!("\n{r}"))
+                        .unwrap_or_default()
+                );
+                self.conversation_history.add_background_event(text);
+                self.emit_last_history_entry();
+                self.conversation_history.scroll_to_bottom();
+
                 let request = ApprovalRequest::Exec {
                     id,
                     command,
@@ -339,6 +337,7 @@ impl ChatWidget<'_> {
                     reason,
                 };
                 self.bottom_pane.push_approval_request(request);
+                self.request_redraw();
             }
             EventMsg::ApplyPatchApprovalRequest(ApplyPatchApprovalRequestEvent {
                 call_id: _,
@@ -483,22 +482,108 @@ impl ChatWidget<'_> {
         self.bottom_pane.on_file_search_result(query, matches);
     }
 
+    // (removed deprecated synchronous `compact` implementation)
+
+    /// Kick off an asynchronous summarization of the current transcript.
+    /// Returns immediately so the UI stays responsive.
+    pub(crate) fn start_compact(&mut self) {
+        // Show status indicator immediately.
+        self.bottom_pane.set_task_running(true);
+        self.bottom_pane
+            .update_status_text("Summarizing context…".to_string());
+        self.request_redraw();
+
+        // Clone data required for the background task.
+        let transcript = self.transcript.clone();
+        let model = self.config.model.clone();
+        let config_clone = self.config.clone();
+        let app_event_tx = self.app_event_tx.clone();
+
+        // Spawn the summarization on a blocking thread to avoid CPU-bound work
+        // stalling the async runtime (and thus the UI).
+        tokio::task::spawn_blocking(move || {
+            let rt = tokio::runtime::Handle::current();
+            rt.block_on(async move {
+                let result = generate_compact_summary(&transcript, &model, &config_clone).await;
+                let evt = match result {
+                    Ok(summary) => AppEvent::CompactComplete(Ok(summary)),
+                    Err(e) => AppEvent::CompactComplete(Err(format!("{e}"))),
+                };
+                app_event_tx.send(evt);
+            });
+        });
+    }
+
+    /// Apply the completed summary returned by the background task.
+    pub(crate) fn apply_compact_summary(&mut self, result: Result<String, String>) {
+        match result {
+            Ok(summary) => {
+                self.conversation_history.clear_agent_history();
+                self.transcript.clear();
+                // clear session history in backend
+                self.submit_op(Op::EraseConversationHistory);
+                self.conversation_history
+                    .add_agent_message(&self.config, summary.clone());
+                self.transcript = vec![TranscriptEntry {
+                    role: Role::Assistant,
+                    text: summary,
+                }];
+
+                // Re-configure the Codex session so that the backend agent starts with
+                // a clean conversation context.
+                let op = Op::ConfigureSession {
+                    provider: self.config.model_provider.clone(),
+                    model: self.config.model.clone(),
+                    model_reasoning_effort: self.config.model_reasoning_effort,
+                    model_reasoning_summary: self.config.model_reasoning_summary,
+                    user_instructions: self.config.user_instructions.clone(),
+                    base_instructions: self.config.base_instructions.clone(),
+                    approval_policy: self.config.approval_policy,
+                    sandbox_policy: self.config.sandbox_policy.clone(),
+                    disable_response_storage: self.config.disable_response_storage,
+                    notify: self.config.notify.clone(),
+                    cwd: self.config.cwd.clone(),
+                    resume_path: None,
+                };
+                self.submit_op(op);
+
+                // Reset the recorded token usage because we start a fresh
+                // conversation context. This ensures the *context remaining*
+                // indicator in the composer is updated immediately.
+                self.token_usage = TokenUsage::default();
+                self.bottom_pane
+                    .set_token_usage(self.token_usage.clone(), self.config.model_context_window);
+            }
+            Err(msg) => {
+                self.conversation_history.add_error(msg);
+            }
+        }
+
+        // Hide status indicator and refresh UI.
+        self.bottom_pane.set_task_running(false);
+        self.request_redraw();
+    }
+
     /// Handle Ctrl-C key press.
-    /// Returns true if the key press was handled, false if it was not.
-    /// If the key press was not handled, the caller should handle it (likely by exiting the process).
-    pub(crate) fn on_ctrl_c(&mut self) -> bool {
+    /// Returns CancellationEvent::Handled if the event was consumed by the UI, or
+    /// CancellationEvent::Ignored if the caller should handle it (e.g. exit).
+    pub(crate) fn on_ctrl_c(&mut self) -> CancellationEvent {
+        match self.bottom_pane.on_ctrl_c() {
+            CancellationEvent::Handled => return CancellationEvent::Handled,
+            CancellationEvent::Ignored => {}
+        }
         if self.bottom_pane.is_task_running() {
             self.bottom_pane.clear_ctrl_c_quit_hint();
             self.submit_op(Op::Interrupt);
             self.answer_buffer.clear();
             self.reasoning_buffer.clear();
-            false
+            CancellationEvent::Ignored
         } else if self.bottom_pane.ctrl_c_quit_hint_visible() {
             self.submit_op(Op::Shutdown);
-            true
+            CancellationEvent::Handled
         } else {
             self.bottom_pane.show_ctrl_c_quit_hint();
-            false
+            CancellationEvent::Ignored
         }
     }
 

codex-rs/tui/src/compact.rs

@@ -0,0 +1,91 @@
+use anyhow::Result;
+use anyhow::anyhow;
+use codex_core::config::Config;
+use codex_core::openai_api_key::get_openai_api_key;
+use serde::Serialize;
+
+#[derive(Clone)]
+pub enum Role {
+    User,
+    Assistant,
+}
+
+#[derive(Clone)]
+pub struct TranscriptEntry {
+    pub role: Role,
+    pub text: String,
+}
+
+impl TranscriptEntry {
+    fn role_str(&self) -> &'static str {
+        match self.role {
+            Role::User => "user",
+            Role::Assistant => "assistant",
+        }
+    }
+}
+
+#[derive(Serialize)]
+struct Message<'a> {
+    role: &'a str,
+    content: String,
+}
+
+#[derive(Serialize)]
+struct Payload<'a> {
+    model: &'a str,
+    messages: Vec<Message<'a>>,
+}
+
+/// Generate a concise summary of the provided transcript using the OpenAI chat
+/// completions API.
+pub async fn generate_compact_summary(
+    transcript: &[TranscriptEntry],
+    model: &str,
+    config: &Config,
+) -> Result<String> {
+    let conversation_text = transcript
+        .iter()
+        .map(|e| format!("{}: {}", e.role_str(), e.text))
+        .collect::<Vec<_>>()
+        .join("\n");
+
+    let messages = vec![
+        Message {
+            role: "assistant",
+            content: "You are an expert coding assistant. Your goal is to generate a concise, structured summary of the conversation below that captures all essential information needed to continue development after context replacement. Include tasks performed, code areas modified or reviewed, key decisions or assumptions, test results or errors, and outstanding tasks or next steps.".to_string(),
+        },
+        Message {
+            role: "user",
+            content: format!(
+                "Here is the conversation so far:\n{conversation_text}\n\nPlease summarize this conversation, covering:\n1. Tasks performed and outcomes\n2. Code files, modules, or functions modified or examined\n3. Important decisions or assumptions made\n4. Errors encountered and test or build results\n5. Remaining tasks, open questions, or next steps\nProvide the summary in a clear, concise format."
+            ),
+        },
+    ];
+
+    let api_key = get_openai_api_key().ok_or_else(|| anyhow!("OpenAI API key not set"))?;
+    let client = reqwest::Client::new();
+    let base = config.model_provider.base_url.trim_end_matches('/');
+    let url = format!("{}/chat/completions", base);
+
+    let payload = Payload { model, messages };
+    let res = client
+        .post(url)
+        .bearer_auth(api_key)
+        .json(&payload)
+        .send()
+        .await?;
+
+    let body: serde_json::Value = res.json().await?;
+    if let Some(summary) = body
+        .get("choices")
+        .and_then(|c| c.get(0))
+        .and_then(|c| c.get("message"))
+        .and_then(|m| m.get("content"))
+        .and_then(|v| v.as_str())
+    {
+        Ok(summary.to_string())
+    } else {
+        Ok("Unable to generate summary.".to_string())
+    }
+}

codex-rs/tui/src/conversation_history_widget.rs

@@ -5,8 +5,6 @@ use crate::history_cell::PatchEventType;
 use codex_core::config::Config;
 use codex_core::protocol::FileChange;
 use codex_core::protocol::SessionConfiguredEvent;
-use crossterm::event::KeyCode;
-use crossterm::event::KeyEvent;
 use ratatui::prelude::*;
 use ratatui::style::Style;
 use ratatui::widgets::*;
@@ -47,33 +45,6 @@ impl ConversationHistoryWidget {
         }
     }
 
-    pub(crate) fn set_input_focus(&mut self, has_input_focus: bool) {
-        self.has_input_focus = has_input_focus;
-    }
-
-    /// Returns true if it needs a redraw.
-    pub(crate) fn handle_key_event(&mut self, key_event: KeyEvent) -> bool {
-        match key_event.code {
-            KeyCode::Up | KeyCode::Char('k') => {
-                self.scroll_up(1);
-                true
-            }
-            KeyCode::Down | KeyCode::Char('j') => {
-                self.scroll_down(1);
-                true
-            }
-            KeyCode::PageUp | KeyCode::Char('b') => {
-                self.scroll_page_up();
-                true
-            }
-            KeyCode::PageDown | KeyCode::Char(' ') => {
-                self.scroll_page_down();
-                true
-            }
-            _ => false,
-        }
-    }
-
     /// Negative delta scrolls up; positive delta scrolls down.
     pub(crate) fn scroll(&mut self, delta: i32) {
         match delta.cmp(&0) {
@@ -122,53 +93,6 @@ impl ConversationHistoryWidget {
         }
     }
 
-    /// Scroll up by one full viewport height (Page Up).
-    fn scroll_page_up(&mut self) {
-        let viewport_height = self.last_viewport_height.get().max(1);
-
-        // If we are currently in the "stick to bottom" mode, first convert the
-        // implicit scroll position (`usize::MAX`) into an explicit offset that
-        // represents the very bottom of the scroll region.  This mirrors the
-        // logic from `scroll_up()`.
-        if self.scroll_position == usize::MAX {
-            self.scroll_position = self
-                .num_rendered_lines
-                .get()
-                .saturating_sub(viewport_height);
-        }
-
-        // Move up by a full page.
-        self.scroll_position = self.scroll_position.saturating_sub(viewport_height);
-    }
-
-    /// Scroll down by one full viewport height (Page Down).
-    fn scroll_page_down(&mut self) {
-        // Nothing to do if we're already stuck to the bottom.
-        if self.scroll_position == usize::MAX {
-            return;
-        }
-
-        let viewport_height = self.last_viewport_height.get().max(1);
-        let num_lines = self.num_rendered_lines.get();
-
-        // Calculate the maximum explicit scroll offset that is still within
-        // range. This matches the logic in `scroll_down()` and the render
-        // method.
-        let max_scroll = num_lines.saturating_sub(viewport_height);
-
-        // Attempt to move down by a full page.
-        let new_pos = self.scroll_position.saturating_add(viewport_height);
-
-        if new_pos >= max_scroll {
-            // We have reached (or passed) the bottom – switch back to
-            // automatic stick‑to‑bottom mode so that subsequent output keeps
-            // the viewport pinned.
-            self.scroll_position = usize::MAX;
-        } else {
-            self.scroll_position = new_pos;
-        }
-    }
-
     pub fn scroll_to_bottom(&mut self) {
         self.scroll_position = usize::MAX;
     }
@@ -198,6 +122,10 @@ impl ConversationHistoryWidget {
         self.add_to_history(HistoryCell::new_agent_message(config, message));
     }
 
+    pub fn clear_agent_history(&mut self) {
+        self.clear_all();
+    }
+
     pub fn add_agent_reasoning(&mut self, config: &Config, text: String) {
         self.add_to_history(HistoryCell::new_agent_reasoning(config, text));
     }
@@ -249,6 +177,10 @@ impl ConversationHistoryWidget {
         });
     }
 
+    fn clear_all(&mut self) {
+        self.entries.clear();
+    }
+
     /// Return the lines for the most recently appended entry (if any) so the
     /// parent widget can surface them via the new scrollback insertion path.
     pub(crate) fn last_entry_plain_lines(&self) -> Option<Vec<Line<'static>>> {

codex-rs/tui/src/insert_history.rs

@@ -1,178 +1,245 @@
+use std::fmt;
+use std::io;
+use std::io::Write;
+
 use crate::tui;
-use ratatui::layout::Rect;
-use ratatui::style::Style;
+use crossterm::Command;
+use crossterm::queue;
+use crossterm::style::Color as CColor;
+use crossterm::style::Colors;
+use crossterm::style::Print;
+use crossterm::style::SetAttribute;
+use crossterm::style::SetBackgroundColor;
+use crossterm::style::SetColors;
+use crossterm::style::SetForegroundColor;
+use ratatui::layout::Position;
+use ratatui::layout::Size;
+use ratatui::prelude::Backend;
+use ratatui::style::Color;
+use ratatui::style::Modifier;
 use ratatui::text::Line;
 use ratatui::text::Span;
-use ratatui::widgets::Paragraph;
-use ratatui::widgets::Widget;
-use unicode_width::UnicodeWidthChar;
-
-/// Insert a batch of history lines into the terminal scrollback above the
-/// inline viewport.
-///
-/// The incoming `lines` are the logical lines supplied by the
-/// `ConversationHistory`. They may contain embedded newlines and arbitrary
-/// runs of whitespace inside individual [`Span`]s. All of that must be
-/// normalised before writing to the backing terminal buffer because the
-/// ratatui [`Paragraph`] widget does not perform soft‑wrapping when used in
-/// conjunction with [`Terminal::insert_before`].
-///
-/// This function performs a minimal wrapping / normalisation pass:
-///
-/// * A terminal width is determined via `Terminal::size()` (falling back to
-///   80 columns if the size probe fails).
-/// * Each logical line is broken into words and whitespace. Consecutive
-///   whitespace is collapsed to a single space; leading whitespace is
-///   discarded.
-/// * Words that do not fit on the current line cause a soft wrap. Extremely
-///   long words (longer than the terminal width) are split character by
-///   character so they still populate the display instead of overflowing the
-///   line.
-/// * Explicit `\n` characters inside a span force a hard line break.
-/// * Empty lines (including a trailing newline at the end of the batch) are
-///   preserved so vertical spacing remains faithful to the logical history.
-///
-/// Finally the physical lines are rendered directly into the terminal's
-/// scrollback region using [`Terminal::insert_before`]. Any backend error is
-/// ignored: failing to insert history is non‑fatal and a subsequent redraw
-/// will eventually repaint a consistent view.
-fn display_width(s: &str) -> usize {
-    s.chars()
-        .map(|c| UnicodeWidthChar::width(c).unwrap_or(0))
-        .sum()
-}
-
-struct LineBuilder {
-    term_width: usize,
-    spans: Vec<Span<'static>>,
-    width: usize,
-}
-
-impl LineBuilder {
-    fn new(term_width: usize) -> Self {
-        Self {
-            term_width,
-            spans: Vec::new(),
-            width: 0,
-        }
-    }
-
-    fn flush_line(&mut self, out: &mut Vec<Line<'static>>) {
-        out.push(Line::from(std::mem::take(&mut self.spans)));
-        self.width = 0;
-    }
-
-    fn push_segment(&mut self, text: String, style: Style) {
-        self.width += display_width(&text);
-        self.spans.push(Span::styled(text, style));
-    }
-
-    fn push_word(&mut self, word: &mut String, style: Style, out: &mut Vec<Line<'static>>) {
-        if word.is_empty() {
-            return;
-        }
-        let w_len = display_width(word);
-        if self.width > 0 && self.width + w_len > self.term_width {
-            self.flush_line(out);
-        }
-        if w_len > self.term_width && self.width == 0 {
-            // Split an overlong word across multiple lines.
-            let mut cur = String::new();
-            let mut cur_w = 0;
-            for ch in word.chars() {
-                let ch_w = UnicodeWidthChar::width(ch).unwrap_or(0);
-                if cur_w + ch_w > self.term_width && cur_w > 0 {
-                    self.push_segment(cur.clone(), style);
-                    self.flush_line(out);
-                    cur.clear();
-                    cur_w = 0;
-                }
-                cur.push(ch);
-                cur_w += ch_w;
-            }
-            if !cur.is_empty() {
-                self.push_segment(cur, style);
-            }
-        } else {
-            self.push_segment(word.clone(), style);
-        }
-        word.clear();
-    }
-
-    fn consume_whitespace(&mut self, ws: &mut String, style: Style, out: &mut Vec<Line<'static>>) {
-        if ws.is_empty() {
-            return;
-        }
-        let space_w = display_width(ws);
-        if self.width > 0 && self.width + space_w > self.term_width {
-            self.flush_line(out);
-        }
-        if self.width > 0 {
-            self.push_segment(" ".to_string(), style);
-        }
-        ws.clear();
-    }
-}
 
+/// Insert `lines` above the viewport.
 pub(crate) fn insert_history_lines(terminal: &mut tui::Tui, lines: Vec<Line<'static>>) {
-    let term_width = terminal.size().map(|a| a.width).unwrap_or(80) as usize;
-    let mut physical: Vec<Line<'static>> = Vec::new();
+    let screen_size = terminal.backend().size().unwrap_or(Size::new(0, 0));
 
-    for logical in lines.into_iter() {
-        if logical.spans.is_empty() {
-            physical.push(logical);
-            continue;
-        }
+    let mut area = terminal.get_frame().area();
 
-        let mut builder = LineBuilder::new(term_width);
-        let mut buf_space = String::new();
+    let wrapped_lines = wrapped_line_count(&lines, area.width);
+    let cursor_top = if area.bottom() < screen_size.height {
+        // If the viewport is not at the bottom of the screen, scroll it down to make room.
+        // Don't scroll it past the bottom of the screen.
+        let scroll_amount = wrapped_lines.min(screen_size.height - area.bottom());
+        terminal
+            .backend_mut()
+            .scroll_region_down(area.top()..screen_size.height, scroll_amount)
+            .ok();
+        let cursor_top = area.top() - 1;
+        area.y += scroll_amount;
+        terminal.set_viewport_area(area);
+        cursor_top
+    } else {
+        area.top() - 1
+    };
 
-        for span in logical.spans.into_iter() {
-            let style = span.style;
-            let mut buf_word = String::new();
+    // Limit the scroll region to the lines from the top of the screen to the
+    // top of the viewport. With this in place, when we add lines inside this
+    // area, only the lines in this area will be scrolled. We place the cursor
+    // at the end of the scroll region, and add lines starting there.
+    //
+    // ┌─Screen───────────────────────┐
+    // │┌╌Scroll region╌╌╌╌╌╌╌╌╌╌╌╌╌╌┐│
+    // │┆                            ┆│
+    // │┆                            ┆│
+    // │┆                            ┆│
+    // │█╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┘│
+    // │╭─Viewport───────────────────╮│
+    // ││                            ││
+    // │╰────────────────────────────╯│
+    // └──────────────────────────────┘
+    queue!(std::io::stdout(), SetScrollRegion(1..area.top())).ok();
 
-            for ch in span.content.chars() {
-                if ch == '\n' {
-                    builder.push_word(&mut buf_word, style, &mut physical);
-                    buf_space.clear();
-                    builder.flush_line(&mut physical);
-                    continue;
-                }
-                if ch.is_whitespace() {
-                    builder.push_word(&mut buf_word, style, &mut physical);
-                    buf_space.push(ch);
-                } else {
-                    builder.consume_whitespace(&mut buf_space, style, &mut physical);
-                    buf_word.push(ch);
-                }
-                if builder.width >= term_width {
-                    builder.flush_line(&mut physical);
-                }
-            }
-            builder.push_word(&mut buf_word, style, &mut physical);
-            // whitespace intentionally left to allow collapsing across spans
-        }
-        if !builder.spans.is_empty() {
-            physical.push(Line::from(std::mem::take(&mut builder.spans)));
-        } else {
-            // Preserve explicit blank line (e.g. due to a trailing newline).
-            physical.push(Line::from(Vec::<Span<'static>>::new()));
-        }
+    terminal
+        .set_cursor_position(Position::new(0, cursor_top))
+        .ok();
+
+    for line in lines {
+        queue!(std::io::stdout(), Print("\r\n")).ok();
+        write_spans(&mut std::io::stdout(), line.iter()).ok();
     }
 
-    let total = physical.len() as u16;
-    terminal
-        .insert_before(total, |buf| {
-            let width = buf.area.width;
-            for (i, line) in physical.into_iter().enumerate() {
-                let area = Rect {
-                    x: 0,
-                    y: i as u16,
-                    width,
-                    height: 1,
-                };
-                Paragraph::new(line).render(area, buf);
-            }
-        })
-        .ok();
+    queue!(std::io::stdout(), ResetScrollRegion).ok();
+}
+
+fn wrapped_line_count(lines: &[Line], width: u16) -> u16 {
+    let mut count = 0;
+    for line in lines {
+        count += line_height(line, width);
+    }
+    count
+}
+
+fn line_height(line: &Line, width: u16) -> u16 {
+    use unicode_width::UnicodeWidthStr;
+    // get the total display width of the line, accounting for double-width chars
+    let total_width = line
+        .spans
+        .iter()
+        .map(|span| span.content.width())
+        .sum::<usize>();
+    // divide by width to get the number of lines, rounding up
+    if width == 0 {
+        1
+    } else {
+        (total_width as u16).div_ceil(width).max(1)
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct SetScrollRegion(pub std::ops::Range<u16>);
+
+impl Command for SetScrollRegion {
+    fn write_ansi(&self, f: &mut impl fmt::Write) -> fmt::Result {
+        write!(f, "\x1b[{};{}r", self.0.start, self.0.end)
+    }
+
+    #[cfg(windows)]
+    fn execute_winapi(&self) -> std::io::Result<()> {
+        panic!("tried to execute SetScrollRegion command using WinAPI, use ANSI instead");
+    }
+
+    #[cfg(windows)]
+    fn is_ansi_code_supported(&self) -> bool {
+        // TODO(nornagon): is this supported on Windows?
+        true
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct ResetScrollRegion;
+
+impl Command for ResetScrollRegion {
+    fn write_ansi(&self, f: &mut impl fmt::Write) -> fmt::Result {
+        write!(f, "\x1b[r")
+    }
+
+    #[cfg(windows)]
+    fn execute_winapi(&self) -> std::io::Result<()> {
+        panic!("tried to execute ResetScrollRegion command using WinAPI, use ANSI instead");
+    }
+
+    #[cfg(windows)]
+    fn is_ansi_code_supported(&self) -> bool {
+        // TODO(nornagon): is this supported on Windows?
+        true
+    }
+}
+
+struct ModifierDiff {
+    pub from: Modifier,
+    pub to: Modifier,
+}
+
+impl ModifierDiff {
+    fn queue<W>(self, mut w: W) -> io::Result<()>
+    where
+        W: io::Write,
+    {
+        use crossterm::style::Attribute as CAttribute;
+        let removed = self.from - self.to;
+        if removed.contains(Modifier::REVERSED) {
+            queue!(w, SetAttribute(CAttribute::NoReverse))?;
+        }
+        if removed.contains(Modifier::BOLD) {
+            queue!(w, SetAttribute(CAttribute::NormalIntensity))?;
+            if self.to.contains(Modifier::DIM) {
+                queue!(w, SetAttribute(CAttribute::Dim))?;
+            }
+        }
+        if removed.contains(Modifier::ITALIC) {
+            queue!(w, SetAttribute(CAttribute::NoItalic))?;
+        }
+        if removed.contains(Modifier::UNDERLINED) {
+            queue!(w, SetAttribute(CAttribute::NoUnderline))?;
+        }
+        if removed.contains(Modifier::DIM) {
+            queue!(w, SetAttribute(CAttribute::NormalIntensity))?;
+        }
+        if removed.contains(Modifier::CROSSED_OUT) {
+            queue!(w, SetAttribute(CAttribute::NotCrossedOut))?;
+        }
+        if removed.contains(Modifier::SLOW_BLINK) || removed.contains(Modifier::RAPID_BLINK) {
+            queue!(w, SetAttribute(CAttribute::NoBlink))?;
+        }
+
+        let added = self.to - self.from;
+        if added.contains(Modifier::REVERSED) {
+            queue!(w, SetAttribute(CAttribute::Reverse))?;
+        }
+        if added.contains(Modifier::BOLD) {
+            queue!(w, SetAttribute(CAttribute::Bold))?;
+        }
+        if added.contains(Modifier::ITALIC) {
+            queue!(w, SetAttribute(CAttribute::Italic))?;
+        }
+        if added.contains(Modifier::UNDERLINED) {
+            queue!(w, SetAttribute(CAttribute::Underlined))?;
+        }
+        if added.contains(Modifier::DIM) {
+            queue!(w, SetAttribute(CAttribute::Dim))?;
+        }
+        if added.contains(Modifier::CROSSED_OUT) {
+            queue!(w, SetAttribute(CAttribute::CrossedOut))?;
+        }
+        if added.contains(Modifier::SLOW_BLINK) {
+            queue!(w, SetAttribute(CAttribute::SlowBlink))?;
+        }
+        if added.contains(Modifier::RAPID_BLINK) {
+            queue!(w, SetAttribute(CAttribute::RapidBlink))?;
+        }
+
+        Ok(())
+    }
+}
+
+fn write_spans<'a, I>(mut writer: &mut impl Write, content: I) -> io::Result<()>
+where
+    I: Iterator<Item = &'a Span<'a>>,
+{
+    let mut fg = Color::Reset;
+    let mut bg = Color::Reset;
+    let mut modifier = Modifier::empty();
+    for span in content {
+        let mut next_modifier = modifier;
+        next_modifier.insert(span.style.add_modifier);
+        next_modifier.remove(span.style.sub_modifier);
+        if next_modifier != modifier {
+            let diff = ModifierDiff {
+                from: modifier,
+                to: next_modifier,
+            };
+            diff.queue(&mut writer)?;
+            modifier = next_modifier;
+        }
+        let next_fg = span.style.fg.unwrap_or(Color::Reset);
+        let next_bg = span.style.bg.unwrap_or(Color::Reset);
+        if next_fg != fg || next_bg != bg {
+            queue!(
+                writer,
+                SetColors(Colors::new(next_fg.into(), next_bg.into()))
+            )?;
+            fg = next_fg;
+            bg = next_bg;
+        }
+
+        queue!(writer, Print(span.content.clone()))?;
+    }
+
+    queue!(
+        writer,
+        SetForegroundColor(CColor::Reset),
+        SetBackgroundColor(CColor::Reset),
+        SetAttribute(crossterm::style::Attribute::Reset),
+    )
 }

codex-rs/tui/src/lib.rs

@@ -27,6 +27,7 @@ mod cell_widget;
 mod chatwidget;
 mod citation_regex;
 mod cli;
+mod compact;
 mod conversation_history_widget;
 mod exec_command;
 mod file_search;

codex-rs/tui/src/main.rs

@@ -1,4 +1,5 @@
 use clap::Parser;
+use codex_arg0::arg0_dispatch_or_else;
 use codex_common::CliConfigOverrides;
 use codex_tui::Cli;
 use codex_tui::run_main;
@@ -13,7 +14,7 @@ struct TopCli {
 }
 
 fn main() -> anyhow::Result<()> {
-    codex_linux_sandbox::run_with_sandbox(|codex_linux_sandbox_exe| async move {
+    arg0_dispatch_or_else(|codex_linux_sandbox_exe| async move {
         let top_cli = TopCli::parse();
         let mut inner = top_cli.inner;
         inner

codex-rs/tui/src/slash_command.rs

@@ -14,6 +14,7 @@ pub enum SlashCommand {
     // more frequently used commands should be listed first.
     New,
     Diff,
+    Compact,
     Quit,
 }
 
@@ -26,6 +27,7 @@ impl SlashCommand {
             SlashCommand::Diff => {
                 "Show git diff of the working directory (including untracked files)"
             }
+            SlashCommand::Compact => "Condense context into a summary.",
         }
     }
 

codex-rs/tui/src/user_approval_widget.rs

@@ -203,6 +203,12 @@ impl UserApprovalWidget<'_> {
         }
     }
 
+    /// Handle Ctrl-C pressed by the user while the modal is visible.
+    /// Behaves like pressing Escape: abort the request and close the modal.
+    pub(crate) fn on_ctrl_c(&mut self) {
+        self.send_decision(ReviewDecision::Abort);
+    }
+
     fn handle_select_key(&mut self, key_event: KeyEvent) {
         match key_event.code {
             KeyCode::Up => {
@@ -265,7 +271,28 @@ impl UserApprovalWidget<'_> {
         self.send_decision_with_feedback(decision, String::new())
     }
 
-    fn send_decision_with_feedback(&mut self, decision: ReviewDecision, _feedback: String) {
+    fn send_decision_with_feedback(&mut self, decision: ReviewDecision, feedback: String) {
+        let mut lines: Vec<Line<'static>> = Vec::new();
+        match &self.approval_request {
+            ApprovalRequest::Exec { command, .. } => {
+                let cmd = strip_bash_lc_and_escape(command);
+                lines.push(Line::from("approval decision"));
+                lines.push(Line::from(format!("$ {cmd}")));
+                lines.push(Line::from(format!("decision: {decision:?}")));
+            }
+            ApprovalRequest::ApplyPatch { .. } => {
+                lines.push(Line::from(format!("patch approval decision: {decision:?}")));
+            }
+        }
+        if !feedback.trim().is_empty() {
+            lines.push(Line::from("feedback:"));
+            for l in feedback.lines() {
+                lines.push(Line::from(l.to_string()));
+            }
+        }
+        lines.push(Line::from(""));
+        self.app_event_tx.send(AppEvent::InsertHistory(lines));
+
         let op = match &self.approval_request {
             ApprovalRequest::Exec { id, .. } => Op::ExecApproval {
                 id: id.clone(),
@@ -277,12 +304,6 @@ impl UserApprovalWidget<'_> {
             },
         };
 
-        // Ignore feedback for now – the current `Op` variants do not carry it.
-
-        // Forward the Op to the agent. The caller (ChatWidget) will trigger a
-        // redraw after it processes the resulting state change, so we avoid
-        // issuing an extra Redraw here to prevent a transient frame where the
-        // modal is still visible.
         self.app_event_tx.send(AppEvent::CodexOp(op));
         self.done = true;
     }