fmt + clippy: codex-core deterministic shell tool tests, conflict cleanup

This PR changes get history op to get path. Then, forking will use a
path. This will help us have one unified codepath for resuming/forking
conversations. Will also help in having rollout history in order. It
also fixes a bug where you won't see the UI when resuming after forking.

.github/workflows/ci.yml

@@ -14,33 +14,18 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v5
 
-      - name: Setup Node.js
-        uses: actions/setup-node@v4
-        with:
-          node-version: 22
-
       - name: Setup pnpm
         uses: pnpm/action-setup@v4
         with:
-          version: 10.8.1
           run_install: false
 
-      - name: Get pnpm store directory
-        id: pnpm-cache
-        shell: bash
-        run: |
-          echo "store_path=$(pnpm store path --silent)" >> $GITHUB_OUTPUT
-
-      - name: Setup pnpm cache
-        uses: actions/cache@v4
+      - name: Setup Node.js
+        uses: actions/setup-node@v5
         with:
-          path: ${{ steps.pnpm-cache.outputs.store_path }}
-          key: ${{ runner.os }}-pnpm-store-${{ hashFiles('**/pnpm-lock.yaml') }}
-          restore-keys: |
-            ${{ runner.os }}-pnpm-store-
+          node-version: 22
 
       - name: Install dependencies
-        run: pnpm install
+        run: pnpm install --frozen-lockfile
 
       # Run all tasks using workspace filters
 

.github/workflows/rust-ci.yml

@@ -63,6 +63,24 @@ jobs:
       - name: cargo fmt
         run: cargo fmt -- --config imports_granularity=Item --check
 
+  cargo_shear:
+    name: cargo shear
+    runs-on: ubuntu-24.04
+    needs: changed
+    if: ${{ needs.changed.outputs.codex == 'true' || needs.changed.outputs.workflows == 'true' || github.event_name == 'push' }}
+    defaults:
+      run:
+        working-directory: codex-rs
+    steps:
+      - uses: actions/checkout@v5
+      - uses: dtolnay/rust-toolchain@1.89
+      - uses: taiki-e/install-action@0c5db7f7f897c03b771660e91d065338615679f4 # v2
+        with:
+          tool: cargo-shear
+          version: 1.5.1
+      - name: cargo shear
+        run: cargo shear
+
   # --- CI to validate on different os/targets --------------------------------
   lint_build_test:
     name: ${{ matrix.runner }} - ${{ matrix.target }}${{ matrix.profile == 'release' && ' (release)' || '' }}
@@ -160,12 +178,17 @@ jobs:
           find . -name Cargo.toml -mindepth 2 -maxdepth 2 -print0 \
             | xargs -0 -n1 -I{} bash -c 'cd "$(dirname "{}")" && cargo check --profile ${{ matrix.profile }}'
 
-      - name: cargo test
+      - uses: taiki-e/install-action@0c5db7f7f897c03b771660e91d065338615679f4 # v2
+        with:
+          tool: nextest
+          version: 0.9.103
+
+      - name: tests
         id: test
-        # `cargo test` takes too long for release builds to run them on every PR
+        # Tests take too long for release builds to run them on every PR.
         if: ${{ matrix.profile != 'release' }}
         continue-on-error: true
-        run: cargo test --all-features --target ${{ matrix.target }} --profile ${{ matrix.profile }}
+        run: cargo nextest run --all-features --no-fail-fast --target ${{ matrix.target }}
         env:
           RUST_BACKTRACE: 1
 
@@ -182,7 +205,7 @@ jobs:
   # --- Gatherer job that you mark as the ONLY required status -----------------
   results:
     name: CI results (required)
-    needs: [changed, general, lint_build_test]
+    needs: [changed, general, cargo_shear, lint_build_test]
     if: always()
     runs-on: ubuntu-24.04
     steps:
@@ -190,6 +213,7 @@ jobs:
         shell: bash
         run: |
           echo "general: ${{ needs.general.result }}"
+          echo "shear  : ${{ needs.cargo_shear.result }}"
           echo "matrix : ${{ needs.lint_build_test.result }}"
 
           # If nothing relevant changed (PR touching only root README, etc.),
@@ -201,4 +225,5 @@ jobs:
 
           # Otherwise require the jobs to have succeeded
           [[ '${{ needs.general.result }}' == 'success' ]] || { echo 'general failed'; exit 1; }
+          [[ '${{ needs.cargo_shear.result }}' == 'success' ]] || { echo 'cargo_shear failed'; exit 1; }
           [[ '${{ needs.lint_build_test.result }}' == 'success' ]] || { echo 'matrix failed'; exit 1; }

codex-rs/README.md

@@ -35,7 +35,7 @@ npx @modelcontextprotocol/inspector codex mcp
 
 You can enable notifications by configuring a script that is run whenever the agent finishes a turn. The [notify documentation](../docs/config.md#notify) includes a detailed example that explains how to get desktop notifications via [terminal-notifier](https://github.com/julienXX/terminal-notifier) on macOS.
 
-### `codex exec` to run Codex programmatially/non-interactively
+### `codex exec` to run Codex programmatically/non-interactively
 
 To run Codex non-interactively, run `codex exec PROMPT` (you can also pass the prompt via `stdin`) and Codex will work on your task until it decides that it is done and exits. Output is printed to the terminal directly. You can set the `RUST_LOG` environment variable to see more about what's going on.
 

codex-rs/apply-patch/src/lib.rs

@@ -726,9 +726,9 @@ fn compute_replacements(
             line_index = start_idx + pattern.len();
         } else {
             return Err(ApplyPatchError::ComputeReplacements(format!(
-                "Failed to find expected lines {:?} in {}",
-                chunk.old_lines,
-                path.display()
+                "Failed to find expected lines in {}:\n{}",
+                path.display(),
+                chunk.old_lines.join("\n"),
             )));
         }
     }

codex-rs/chatgpt/Cargo.toml

@@ -12,7 +12,6 @@ clap = { version = "4", features = ["derive"] }
 codex-common = { path = "../common", features = ["cli"] }
 codex-core = { path = "../core" }
 codex-protocol = { path = "../protocol" }
-reqwest = { version = "0.12", features = ["json", "stream"] }
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 tokio = { version = "1", features = ["full"] }

codex-rs/chatgpt/src/apply_command.rs

@@ -31,7 +31,7 @@ pub async fn run_apply_command(
         ConfigOverrides::default(),
     )?;
 
-    init_chatgpt_token_from_auth(&config.codex_home, &config.responses_originator_header).await?;
+    init_chatgpt_token_from_auth(&config.codex_home).await?;
 
     let task_response = get_task(&config, apply_cli.task_id).await?;
     apply_diff_from_task(task_response, cwd).await

codex-rs/chatgpt/src/chatgpt_client.rs

@@ -13,10 +13,10 @@ pub(crate) async fn chatgpt_get_request<T: DeserializeOwned>(
     path: String,
 ) -> anyhow::Result<T> {
     let chatgpt_base_url = &config.chatgpt_base_url;
-    init_chatgpt_token_from_auth(&config.codex_home, &config.responses_originator_header).await?;
+    init_chatgpt_token_from_auth(&config.codex_home).await?;
 
     // Make direct HTTP request to ChatGPT backend API with the token
-    let client = create_client(&config.responses_originator_header);
+    let client = create_client();
     let url = format!("{chatgpt_base_url}{path}");
 
     let token =

codex-rs/chatgpt/src/chatgpt_token.rs

@@ -19,11 +19,8 @@ pub fn set_chatgpt_token_data(value: TokenData) {
 }
 
 /// Initialize the ChatGPT token from auth.json file
-pub async fn init_chatgpt_token_from_auth(
-    codex_home: &Path,
-    originator: &str,
-) -> std::io::Result<()> {
-    let auth = CodexAuth::from_codex_home(codex_home, AuthMode::ChatGPT, originator)?;
+pub async fn init_chatgpt_token_from_auth(codex_home: &Path) -> std::io::Result<()> {
+    let auth = CodexAuth::from_codex_home(codex_home, AuthMode::ChatGPT)?;
     if let Some(auth) = auth {
         let token_data = auth.get_token_data().await?;
         set_chatgpt_token_data(token_data);

codex-rs/cli/src/login.rs

@@ -12,8 +12,8 @@ use codex_protocol::mcp_protocol::AuthMode;
 use std::env;
 use std::path::PathBuf;
 
-pub async fn login_with_chatgpt(codex_home: PathBuf, originator: String) -> std::io::Result<()> {
-    let opts = ServerOptions::new(codex_home, CLIENT_ID.to_string(), originator);
+pub async fn login_with_chatgpt(codex_home: PathBuf) -> std::io::Result<()> {
+    let opts = ServerOptions::new(codex_home, CLIENT_ID.to_string());
     let server = run_login_server(opts)?;
 
     eprintln!(
@@ -27,12 +27,7 @@ pub async fn login_with_chatgpt(codex_home: PathBuf, originator: String) -> std:
 pub async fn run_login_with_chatgpt(cli_config_overrides: CliConfigOverrides) -> ! {
     let config = load_config_or_exit(cli_config_overrides);
 
-    match login_with_chatgpt(
-        config.codex_home,
-        config.responses_originator_header.clone(),
-    )
-    .await
-    {
+    match login_with_chatgpt(config.codex_home).await {
         Ok(_) => {
             eprintln!("Successfully logged in");
             std::process::exit(0);
@@ -65,11 +60,7 @@ pub async fn run_login_with_api_key(
 pub async fn run_login_status(cli_config_overrides: CliConfigOverrides) -> ! {
     let config = load_config_or_exit(cli_config_overrides);
 
-    match CodexAuth::from_codex_home(
-        &config.codex_home,
-        config.preferred_auth_method,
-        &config.responses_originator_header,
-    ) {
+    match CodexAuth::from_codex_home(&config.codex_home, config.preferred_auth_method) {
         Ok(Some(auth)) => match auth.mode {
             AuthMode::ApiKey => match auth.get_token().await {
                 Ok(api_key) => {

codex-rs/cli/src/proto.rs

@@ -40,7 +40,6 @@ pub async fn run_main(opts: ProtoCli) -> anyhow::Result<()> {
     let conversation_manager = ConversationManager::new(AuthManager::shared(
         config.codex_home.clone(),
         config.preferred_auth_method,
-        config.responses_originator_header.clone(),
     ));
     let NewConversation {
         conversation_id: _,

codex-rs/core/Cargo.toml

@@ -26,14 +26,12 @@ eventsource-stream = "0.2.3"
 futures = "0.3"
 libc = "0.2.175"
 mcp-types = { path = "../mcp-types" }
-mime_guess = "2.0"
 os_info = "3.12.0"
 portable-pty = "0.9.0"
 rand = "0.9"
 regex-lite = "0.1.7"
 reqwest = { version = "0.12", features = ["json", "stream"] }
 serde = { version = "1", features = ["derive"] }
-serde_bytes = "0.11"
 serde_json = "1"
 sha1 = "0.10.6"
 shlex = "1.3.0"
@@ -56,7 +54,7 @@ tracing = { version = "0.1.41", features = ["log"] }
 tree-sitter = "0.25.9"
 tree-sitter-bash = "0.25.0"
 uuid = { version = "1", features = ["serde", "v4"] }
-whoami = "1.6.1"
+which = "6"
 wildmatch = "2.4.0"
 
 
@@ -72,9 +70,6 @@ openssl-sys = { version = "*", features = ["vendored"] }
 [target.aarch64-unknown-linux-musl.dependencies]
 openssl-sys = { version = "*", features = ["vendored"] }
 
-[target.'cfg(target_os = "windows")'.dependencies]
-which = "6"
-
 [dev-dependencies]
 assert_cmd = "2"
 core_test_support = { path = "tests/common" }
@@ -85,3 +80,6 @@ tempfile = "3"
 tokio-test = "0.4"
 walkdir = "2.5.0"
 wiremock = "0.6"
+
+[package.metadata.cargo-shear]
+ignored = ["openssl-sys"]

codex-rs/core/src/auth.rs

@@ -75,9 +75,8 @@ impl CodexAuth {
     pub fn from_codex_home(
         codex_home: &Path,
         preferred_auth_method: AuthMode,
-        originator: &str,
     ) -> std::io::Result<Option<CodexAuth>> {
-        load_auth(codex_home, true, preferred_auth_method, originator)
+        load_auth(codex_home, true, preferred_auth_method)
     }
 
     pub async fn get_token_data(&self) -> Result<TokenData, std::io::Error> {
@@ -173,7 +172,7 @@ impl CodexAuth {
             mode: AuthMode::ChatGPT,
             auth_file: PathBuf::new(),
             auth_dot_json,
-            client: crate::default_client::create_client("codex_cli_rs"),
+            client: crate::default_client::create_client(),
         }
     }
 
@@ -188,10 +187,7 @@ impl CodexAuth {
     }
 
     pub fn from_api_key(api_key: &str) -> Self {
-        Self::from_api_key_with_client(
-            api_key,
-            crate::default_client::create_client(crate::default_client::DEFAULT_ORIGINATOR),
-        )
+        Self::from_api_key_with_client(api_key, crate::default_client::create_client())
     }
 }
 
@@ -232,13 +228,12 @@ fn load_auth(
     codex_home: &Path,
     include_env_var: bool,
     preferred_auth_method: AuthMode,
-    originator: &str,
 ) -> std::io::Result<Option<CodexAuth>> {
     // First, check to see if there is a valid auth.json file. If not, we fall
     // back to AuthMode::ApiKey using the OPENAI_API_KEY environment variable
     // (if it is set).
     let auth_file = get_auth_file(codex_home);
-    let client = crate::default_client::create_client(originator);
+    let client = crate::default_client::create_client();
     let auth_dot_json = match try_read_auth_json(&auth_file) {
         Ok(auth) => auth,
         // If auth.json does not exist, try to read the OPENAI_API_KEY from the
@@ -473,7 +468,7 @@ mod tests {
             auth_dot_json,
             auth_file: _,
             ..
-        } = super::load_auth(codex_home.path(), false, AuthMode::ChatGPT, "codex_cli_rs")
+        } = super::load_auth(codex_home.path(), false, AuthMode::ChatGPT)
             .unwrap()
             .unwrap();
         assert_eq!(None, api_key);
@@ -525,7 +520,7 @@ mod tests {
             auth_dot_json,
             auth_file: _,
             ..
-        } = super::load_auth(codex_home.path(), false, AuthMode::ChatGPT, "codex_cli_rs")
+        } = super::load_auth(codex_home.path(), false, AuthMode::ChatGPT)
             .unwrap()
             .unwrap();
         assert_eq!(None, api_key);
@@ -576,7 +571,7 @@ mod tests {
             auth_dot_json,
             auth_file: _,
             ..
-        } = super::load_auth(codex_home.path(), false, AuthMode::ChatGPT, "codex_cli_rs")
+        } = super::load_auth(codex_home.path(), false, AuthMode::ChatGPT)
             .unwrap()
             .unwrap();
         assert_eq!(Some("sk-test-key".to_string()), api_key);
@@ -596,7 +591,7 @@ mod tests {
         )
         .unwrap();
 
-        let auth = super::load_auth(dir.path(), false, AuthMode::ChatGPT, "codex_cli_rs")
+        let auth = super::load_auth(dir.path(), false, AuthMode::ChatGPT)
             .unwrap()
             .unwrap();
         assert_eq!(auth.mode, AuthMode::ApiKey);
@@ -680,7 +675,6 @@ mod tests {
 #[derive(Debug)]
 pub struct AuthManager {
     codex_home: PathBuf,
-    originator: String,
     inner: RwLock<CachedAuth>,
 }
 
@@ -689,13 +683,12 @@ impl AuthManager {
     /// preferred auth method. Errors loading auth are swallowed; `auth()` will
     /// simply return `None` in that case so callers can treat it as an
     /// unauthenticated state.
-    pub fn new(codex_home: PathBuf, preferred_auth_mode: AuthMode, originator: String) -> Self {
-        let auth = CodexAuth::from_codex_home(&codex_home, preferred_auth_mode, &originator)
+    pub fn new(codex_home: PathBuf, preferred_auth_mode: AuthMode) -> Self {
+        let auth = CodexAuth::from_codex_home(&codex_home, preferred_auth_mode)
             .ok()
             .flatten();
         Self {
             codex_home,
-            originator,
             inner: RwLock::new(CachedAuth {
                 preferred_auth_mode,
                 auth,
@@ -712,7 +705,6 @@ impl AuthManager {
         };
         Arc::new(Self {
             codex_home: PathBuf::new(),
-            originator: "codex_cli_rs".to_string(),
             inner: RwLock::new(cached),
         })
     }
@@ -734,7 +726,7 @@ impl AuthManager {
     /// whether the auth value changed.
     pub fn reload(&self) -> bool {
         let preferred = self.preferred_auth_method();
-        let new_auth = CodexAuth::from_codex_home(&self.codex_home, preferred, &self.originator)
+        let new_auth = CodexAuth::from_codex_home(&self.codex_home, preferred)
             .ok()
             .flatten();
         if let Ok(mut guard) = self.inner.write() {
@@ -755,12 +747,8 @@ impl AuthManager {
     }
 
     /// Convenience constructor returning an `Arc` wrapper.
-    pub fn shared(
-        codex_home: PathBuf,
-        preferred_auth_mode: AuthMode,
-        originator: String,
-    ) -> Arc<Self> {
-        Arc::new(Self::new(codex_home, preferred_auth_mode, originator))
+    pub fn shared(codex_home: PathBuf, preferred_auth_mode: AuthMode) -> Arc<Self> {
+        Arc::new(Self::new(codex_home, preferred_auth_mode))
     }
 
     /// Attempt to refresh the current auth token (if any). On success, reload

codex-rs/core/src/client.rs

@@ -84,7 +84,7 @@ impl ModelClient {
         summary: ReasoningSummaryConfig,
         conversation_id: ConversationId,
     ) -> Self {
-        let client = create_client(&config.responses_originator_header);
+        let client = create_client();
 
         Self {
             config,

codex-rs/core/src/config.rs

@@ -38,9 +38,7 @@ const OPENAI_DEFAULT_MODEL: &str = "gpt-5";
 /// the context window.
 pub(crate) const PROJECT_DOC_MAX_BYTES: usize = 32 * 1024; // 32 KiB
 
-const CONFIG_TOML_FILE: &str = "config.toml";
-
-const DEFAULT_RESPONSES_ORIGINATOR_HEADER: &str = "codex_cli_rs";
+pub(crate) const CONFIG_TOML_FILE: &str = "config.toml";
 
 /// Application configuration loaded from disk and merged with overrides.
 #[derive(Debug, Clone, PartialEq)]
@@ -169,16 +167,20 @@ pub struct Config {
 
     pub tools_web_search_request: bool,
 
-    /// The value for the `originator` header included with Responses API requests.
-    pub responses_originator_header: String,
-
     /// If set to `true`, the API key will be signed with the `originator` header.
     pub preferred_auth_method: AuthMode,
 
     pub use_experimental_streamable_shell_tool: bool,
 
+    /// If set to `true`, used only the experimental unified exec tool.
+    pub use_experimental_unified_exec_tool: bool,
+
     /// Include the `view_image` tool that lets the agent attach a local image path to context.
     pub include_view_image_tool: bool,
+
+    /// The active profile name used to derive this `Config` (if any).
+    pub active_profile: Option<String>,
+
     /// When true, disables burst-paste detection for typed input entirely.
     /// All characters are inserted as they are received, and no buffering
     /// or placeholder replacement will occur for fast keypress bursts.
@@ -262,17 +264,7 @@ pub fn load_config_as_toml(codex_home: &Path) -> std::io::Result<TomlValue> {
     }
 }
 
-/// Patch `CODEX_HOME/config.toml` project state.
-/// Use with caution.
-pub fn set_project_trusted(codex_home: &Path, project_path: &Path) -> anyhow::Result<()> {
-    let config_path = codex_home.join(CONFIG_TOML_FILE);
-    // Parse existing config if present; otherwise start a new document.
-    let mut doc = match std::fs::read_to_string(config_path.clone()) {
-        Ok(s) => s.parse::<DocumentMut>()?,
-        Err(e) if e.kind() == std::io::ErrorKind::NotFound => DocumentMut::new(),
-        Err(e) => return Err(e.into()),
-    };
-
+fn set_project_trusted_inner(doc: &mut DocumentMut, project_path: &Path) -> anyhow::Result<()> {
     // Ensure we render a human-friendly structure:
     //
     // [projects]
@@ -288,14 +280,26 @@ pub fn set_project_trusted(codex_home: &Path, project_path: &Path) -> anyhow::Re
     // Ensure top-level `projects` exists as a non-inline, explicit table. If it
     // exists but was previously represented as a non-table (e.g., inline),
     // replace it with an explicit table.
-    let mut created_projects_table = false;
     {
         let root = doc.as_table_mut();
-        let needs_table = !root.contains_key("projects")
-            || root.get("projects").and_then(|i| i.as_table()).is_none();
-        if needs_table {
-            root.insert("projects", toml_edit::table());
-            created_projects_table = true;
+        // If `projects` exists but isn't a standard table (e.g., it's an inline table),
+        // convert it to an explicit table while preserving existing entries.
+        let existing_projects = root.get("projects").cloned();
+        if existing_projects.as_ref().is_none_or(|i| !i.is_table()) {
+            let mut projects_tbl = toml_edit::Table::new();
+            projects_tbl.set_implicit(true);
+
+            // If there was an existing inline table, migrate its entries to explicit tables.
+            if let Some(inline_tbl) = existing_projects.as_ref().and_then(|i| i.as_inline_table()) {
+                for (k, v) in inline_tbl.iter() {
+                    if let Some(inner_tbl) = v.as_inline_table() {
+                        let new_tbl = inner_tbl.clone().into_table();
+                        projects_tbl.insert(k, toml_edit::Item::Table(new_tbl));
+                    }
+                }
+            }
+
+            root.insert("projects", toml_edit::Item::Table(projects_tbl));
         }
     }
     let Some(projects_tbl) = doc["projects"].as_table_mut() else {
@@ -304,12 +308,6 @@ pub fn set_project_trusted(codex_home: &Path, project_path: &Path) -> anyhow::Re
         ));
     };
 
-    // If we created the `projects` table ourselves, keep it implicit so we
-    // don't render a standalone `[projects]` header.
-    if created_projects_table {
-        projects_tbl.set_implicit(true);
-    }
-
     // Ensure the per-project entry is its own explicit table. If it exists but
     // is not a table (e.g., an inline table), replace it with an explicit table.
     let needs_proj_table = !projects_tbl.contains_key(project_key.as_str())
@@ -328,6 +326,21 @@ pub fn set_project_trusted(codex_home: &Path, project_path: &Path) -> anyhow::Re
     };
     proj_tbl.set_implicit(false);
     proj_tbl["trust_level"] = toml_edit::value("trusted");
+    Ok(())
+}
+
+/// Patch `CODEX_HOME/config.toml` project state.
+/// Use with caution.
+pub fn set_project_trusted(codex_home: &Path, project_path: &Path) -> anyhow::Result<()> {
+    let config_path = codex_home.join(CONFIG_TOML_FILE);
+    // Parse existing config if present; otherwise start a new document.
+    let mut doc = match std::fs::read_to_string(config_path.clone()) {
+        Ok(s) => s.parse::<DocumentMut>()?,
+        Err(e) if e.kind() == std::io::ErrorKind::NotFound => DocumentMut::new(),
+        Err(e) => return Err(e.into()),
+    };
+
+    set_project_trusted_inner(&mut doc, project_path)?;
 
     // ensure codex_home exists
     std::fs::create_dir_all(codex_home)?;
@@ -477,9 +490,7 @@ pub struct ConfigToml {
     pub experimental_instructions_file: Option<PathBuf>,
 
     pub experimental_use_exec_command_tool: Option<bool>,
-
-    /// The value for the `originator` header included with Responses API requests.
-    pub responses_originator_header_internal_override: Option<String>,
+    pub experimental_use_unified_exec_tool: Option<bool>,
 
     pub projects: Option<HashMap<String, ProjectConfig>>,
 
@@ -661,7 +672,11 @@ impl Config {
             tools_web_search_request: override_tools_web_search_request,
         } = overrides;
 
-        let config_profile = match config_profile_key.as_ref().or(cfg.profile.as_ref()) {
+        let active_profile_name = config_profile_key
+            .as_ref()
+            .or(cfg.profile.as_ref())
+            .cloned();
+        let config_profile = match active_profile_name.as_ref() {
             Some(key) => cfg
                 .profiles
                 .get(key)
@@ -773,10 +788,6 @@ impl Config {
             Self::get_base_instructions(experimental_instructions_path, &resolved_cwd)?;
         let base_instructions = base_instructions.or(file_base_instructions);
 
-        let responses_originator_header: String = cfg
-            .responses_originator_header_internal_override
-            .unwrap_or(DEFAULT_RESPONSES_ORIGINATOR_HEADER.to_owned());
-
         let config = Self {
             model,
             model_family,
@@ -826,12 +837,15 @@ impl Config {
             include_plan_tool: include_plan_tool.unwrap_or(false),
             include_apply_patch_tool: include_apply_patch_tool.unwrap_or(false),
             tools_web_search_request,
-            responses_originator_header,
             preferred_auth_method: cfg.preferred_auth_method.unwrap_or(AuthMode::ChatGPT),
             use_experimental_streamable_shell_tool: cfg
                 .experimental_use_exec_command_tool
                 .unwrap_or(false),
+            use_experimental_unified_exec_tool: cfg
+                .experimental_use_unified_exec_tool
+                .unwrap_or(true),
             include_view_image_tool,
+            active_profile: active_profile_name,
             disable_paste_burst: cfg.disable_paste_burst.unwrap_or(false),
         };
         Ok(config)
@@ -1203,10 +1217,11 @@ model_verbosity = "high"
                 include_plan_tool: false,
                 include_apply_patch_tool: false,
                 tools_web_search_request: false,
-                responses_originator_header: "codex_cli_rs".to_string(),
                 preferred_auth_method: AuthMode::ChatGPT,
                 use_experimental_streamable_shell_tool: false,
+                use_experimental_unified_exec_tool: true,
                 include_view_image_tool: true,
+                active_profile: Some("o3".to_string()),
                 disable_paste_burst: false,
             },
             o3_profile_config
@@ -1260,10 +1275,11 @@ model_verbosity = "high"
             include_plan_tool: false,
             include_apply_patch_tool: false,
             tools_web_search_request: false,
-            responses_originator_header: "codex_cli_rs".to_string(),
             preferred_auth_method: AuthMode::ChatGPT,
             use_experimental_streamable_shell_tool: false,
+            use_experimental_unified_exec_tool: true,
             include_view_image_tool: true,
+            active_profile: Some("gpt3".to_string()),
             disable_paste_burst: false,
         };
 
@@ -1332,10 +1348,11 @@ model_verbosity = "high"
             include_plan_tool: false,
             include_apply_patch_tool: false,
             tools_web_search_request: false,
-            responses_originator_header: "codex_cli_rs".to_string(),
             preferred_auth_method: AuthMode::ChatGPT,
             use_experimental_streamable_shell_tool: false,
+            use_experimental_unified_exec_tool: true,
             include_view_image_tool: true,
+            active_profile: Some("zdr".to_string()),
             disable_paste_burst: false,
         };
 
@@ -1390,10 +1407,11 @@ model_verbosity = "high"
             include_plan_tool: false,
             include_apply_patch_tool: false,
             tools_web_search_request: false,
-            responses_originator_header: "codex_cli_rs".to_string(),
             preferred_auth_method: AuthMode::ChatGPT,
             use_experimental_streamable_shell_tool: false,
+            use_experimental_unified_exec_tool: true,
             include_view_image_tool: true,
+            active_profile: Some("gpt5".to_string()),
             disable_paste_burst: false,
         };
 
@@ -1404,17 +1422,14 @@ model_verbosity = "high"
 
     #[test]
     fn test_set_project_trusted_writes_explicit_tables() -> anyhow::Result<()> {
-        let codex_home = TempDir::new().unwrap();
-        let project_dir = TempDir::new().unwrap();
+        let project_dir = Path::new("/some/path");
+        let mut doc = DocumentMut::new();
 
-        // Call the function under test
-        set_project_trusted(codex_home.path(), project_dir.path())?;
+        set_project_trusted_inner(&mut doc, project_dir)?;
 
-        // Read back the generated config.toml and assert exact contents
-        let config_path = codex_home.path().join(CONFIG_TOML_FILE);
-        let contents = std::fs::read_to_string(&config_path)?;
+        let contents = doc.to_string();
 
-        let raw_path = project_dir.path().to_string_lossy();
+        let raw_path = project_dir.to_string_lossy();
         let path_str = if raw_path.contains('\\') {
             format!("'{raw_path}'")
         } else {
@@ -1432,12 +1447,10 @@ trust_level = "trusted"
 
     #[test]
     fn test_set_project_trusted_converts_inline_to_explicit() -> anyhow::Result<()> {
-        let codex_home = TempDir::new().unwrap();
-        let project_dir = TempDir::new().unwrap();
+        let project_dir = Path::new("/some/path");
 
         // Seed config.toml with an inline project entry under [projects]
-        let config_path = codex_home.path().join(CONFIG_TOML_FILE);
-        let raw_path = project_dir.path().to_string_lossy();
+        let raw_path = project_dir.to_string_lossy();
         let path_str = if raw_path.contains('\\') {
             format!("'{raw_path}'")
         } else {
@@ -1449,13 +1462,12 @@ trust_level = "trusted"
 {path_str} = {{ trust_level = "untrusted" }}
 "#
         );
-        std::fs::create_dir_all(codex_home.path())?;
-        std::fs::write(&config_path, initial)?;
+        let mut doc = initial.parse::<DocumentMut>()?;
 
         // Run the function; it should convert to explicit tables and set trusted
-        set_project_trusted(codex_home.path(), project_dir.path())?;
+        set_project_trusted_inner(&mut doc, project_dir)?;
 
-        let contents = std::fs::read_to_string(&config_path)?;
+        let contents = doc.to_string();
 
         // Assert exact output after conversion to explicit table
         let expected = format!(
@@ -1470,5 +1482,37 @@ trust_level = "trusted"
         Ok(())
     }
 
-    // No test enforcing the presence of a standalone [projects] header.
+    #[test]
+    fn test_set_project_trusted_migrates_top_level_inline_projects_preserving_entries()
+    -> anyhow::Result<()> {
+        let initial = r#"toplevel = "baz"
+projects = { "/Users/mbolin/code/codex4" = { trust_level = "trusted", foo = "bar" } , "/Users/mbolin/code/codex3" = { trust_level = "trusted" } }
+model = "foo""#;
+        let mut doc = initial.parse::<DocumentMut>()?;
+
+        // Approve a new directory
+        let new_project = Path::new("/Users/mbolin/code/codex2");
+        set_project_trusted_inner(&mut doc, new_project)?;
+
+        let contents = doc.to_string();
+
+        // Since we created the [projects] table as part of migration, it is kept implicit.
+        // Expect explicit per-project tables, preserving prior entries and appending the new one.
+        let expected = r#"toplevel = "baz"
+model = "foo"
+
+[projects."/Users/mbolin/code/codex4"]
+trust_level = "trusted"
+foo = "bar"
+
+[projects."/Users/mbolin/code/codex3"]
+trust_level = "trusted"
+
+[projects."/Users/mbolin/code/codex2"]
+trust_level = "trusted"
+"#;
+        assert_eq!(contents, expected);
+
+        Ok(())
+    }
 }

codex-rs/core/src/config_edit.rs

@@ -0,0 +1,582 @@
+use crate::config::CONFIG_TOML_FILE;
+use anyhow::Result;
+use std::path::Path;
+use tempfile::NamedTempFile;
+use toml_edit::DocumentMut;
+
+pub const CONFIG_KEY_MODEL: &str = "model";
+pub const CONFIG_KEY_EFFORT: &str = "model_reasoning_effort";
+
+/// Persist overrides into `config.toml` using explicit key segments per
+/// override. This avoids ambiguity with keys that contain dots or spaces.
+pub async fn persist_overrides(
+    codex_home: &Path,
+    profile: Option<&str>,
+    overrides: &[(&[&str], &str)],
+) -> Result<()> {
+    let config_path = codex_home.join(CONFIG_TOML_FILE);
+
+    let mut doc = match tokio::fs::read_to_string(&config_path).await {
+        Ok(s) => s.parse::<DocumentMut>()?,
+        Err(e) if e.kind() == std::io::ErrorKind::NotFound => {
+            tokio::fs::create_dir_all(codex_home).await?;
+            DocumentMut::new()
+        }
+        Err(e) => return Err(e.into()),
+    };
+
+    let effective_profile = if let Some(p) = profile {
+        Some(p.to_owned())
+    } else {
+        doc.get("profile")
+            .and_then(|i| i.as_str())
+            .map(|s| s.to_string())
+    };
+
+    for (segments, val) in overrides.iter().copied() {
+        let value = toml_edit::value(val);
+        if let Some(ref name) = effective_profile {
+            if segments.first().copied() == Some("profiles") {
+                apply_toml_edit_override_segments(&mut doc, segments, value);
+            } else {
+                let mut seg_buf: Vec<&str> = Vec::with_capacity(2 + segments.len());
+                seg_buf.push("profiles");
+                seg_buf.push(name.as_str());
+                seg_buf.extend_from_slice(segments);
+                apply_toml_edit_override_segments(&mut doc, &seg_buf, value);
+            }
+        } else {
+            apply_toml_edit_override_segments(&mut doc, segments, value);
+        }
+    }
+
+    let tmp_file = NamedTempFile::new_in(codex_home)?;
+    tokio::fs::write(tmp_file.path(), doc.to_string()).await?;
+    tmp_file.persist(config_path)?;
+
+    Ok(())
+}
+
+/// Persist overrides where values may be optional. Any entries with `None`
+/// values are skipped. If all values are `None`, this becomes a no-op and
+/// returns `Ok(())` without touching the file.
+pub async fn persist_non_null_overrides(
+    codex_home: &Path,
+    profile: Option<&str>,
+    overrides: &[(&[&str], Option<&str>)],
+) -> Result<()> {
+    let filtered: Vec<(&[&str], &str)> = overrides
+        .iter()
+        .filter_map(|(k, v)| v.map(|vv| (*k, vv)))
+        .collect();
+
+    if filtered.is_empty() {
+        return Ok(());
+    }
+
+    persist_overrides(codex_home, profile, &filtered).await
+}
+
+/// Apply a single override onto a `toml_edit` document while preserving
+/// existing formatting/comments.
+/// The key is expressed as explicit segments to correctly handle keys that
+/// contain dots or spaces.
+fn apply_toml_edit_override_segments(
+    doc: &mut DocumentMut,
+    segments: &[&str],
+    value: toml_edit::Item,
+) {
+    use toml_edit::Item;
+
+    if segments.is_empty() {
+        return;
+    }
+
+    let mut current = doc.as_table_mut();
+    for seg in &segments[..segments.len() - 1] {
+        if !current.contains_key(seg) {
+            current[*seg] = Item::Table(toml_edit::Table::new());
+            if let Some(t) = current[*seg].as_table_mut() {
+                t.set_implicit(true);
+            }
+        }
+
+        let maybe_item = current.get_mut(seg);
+        let Some(item) = maybe_item else { return };
+
+        if !item.is_table() {
+            *item = Item::Table(toml_edit::Table::new());
+            if let Some(t) = item.as_table_mut() {
+                t.set_implicit(true);
+            }
+        }
+
+        let Some(tbl) = item.as_table_mut() else {
+            return;
+        };
+        current = tbl;
+    }
+
+    let last = segments[segments.len() - 1];
+    current[last] = value;
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use pretty_assertions::assert_eq;
+    use tempfile::tempdir;
+
+    /// Verifies model and effort are written at top-level when no profile is set.
+    #[tokio::test]
+    async fn set_default_model_and_effort_top_level_when_no_profile() {
+        let tmpdir = tempdir().expect("tmp");
+        let codex_home = tmpdir.path();
+
+        persist_overrides(
+            codex_home,
+            None,
+            &[
+                (&[CONFIG_KEY_MODEL], "gpt-5"),
+                (&[CONFIG_KEY_EFFORT], "high"),
+            ],
+        )
+        .await
+        .expect("persist");
+
+        let contents = read_config(codex_home).await;
+        let expected = r#"model = "gpt-5"
+model_reasoning_effort = "high"
+"#;
+        assert_eq!(contents, expected);
+    }
+
+    /// Verifies values are written under the active profile when `profile` is set.
+    #[tokio::test]
+    async fn set_defaults_update_profile_when_profile_set() {
+        let tmpdir = tempdir().expect("tmp");
+        let codex_home = tmpdir.path();
+
+        // Seed config with a profile selection but without profiles table
+        let seed = "profile = \"o3\"\n";
+        tokio::fs::write(codex_home.join(CONFIG_TOML_FILE), seed)
+            .await
+            .expect("seed write");
+
+        persist_overrides(
+            codex_home,
+            None,
+            &[
+                (&[CONFIG_KEY_MODEL], "o3"),
+                (&[CONFIG_KEY_EFFORT], "minimal"),
+            ],
+        )
+        .await
+        .expect("persist");
+
+        let contents = read_config(codex_home).await;
+        let expected = r#"profile = "o3"
+
+[profiles.o3]
+model = "o3"
+model_reasoning_effort = "minimal"
+"#;
+        assert_eq!(contents, expected);
+    }
+
+    /// Verifies profile names with dots/spaces are preserved via explicit segments.
+    #[tokio::test]
+    async fn set_defaults_update_profile_with_dot_and_space() {
+        let tmpdir = tempdir().expect("tmp");
+        let codex_home = tmpdir.path();
+
+        // Seed config with a profile name that contains a dot and a space
+        let seed = "profile = \"my.team name\"\n";
+        tokio::fs::write(codex_home.join(CONFIG_TOML_FILE), seed)
+            .await
+            .expect("seed write");
+
+        persist_overrides(
+            codex_home,
+            None,
+            &[
+                (&[CONFIG_KEY_MODEL], "o3"),
+                (&[CONFIG_KEY_EFFORT], "minimal"),
+            ],
+        )
+        .await
+        .expect("persist");
+
+        let contents = read_config(codex_home).await;
+        let expected = r#"profile = "my.team name"
+
+[profiles."my.team name"]
+model = "o3"
+model_reasoning_effort = "minimal"
+"#;
+        assert_eq!(contents, expected);
+    }
+
+    /// Verifies explicit profile override writes under that profile even without active profile.
+    #[tokio::test]
+    async fn set_defaults_update_when_profile_override_supplied() {
+        let tmpdir = tempdir().expect("tmp");
+        let codex_home = tmpdir.path();
+
+        // No profile key in config.toml
+        tokio::fs::write(codex_home.join(CONFIG_TOML_FILE), "")
+            .await
+            .expect("seed write");
+
+        // Persist with an explicit profile override
+        persist_overrides(
+            codex_home,
+            Some("o3"),
+            &[(&[CONFIG_KEY_MODEL], "o3"), (&[CONFIG_KEY_EFFORT], "high")],
+        )
+        .await
+        .expect("persist");
+
+        let contents = read_config(codex_home).await;
+        let expected = r#"[profiles.o3]
+model = "o3"
+model_reasoning_effort = "high"
+"#;
+        assert_eq!(contents, expected);
+    }
+
+    /// Verifies nested tables are created as needed when applying overrides.
+    #[tokio::test]
+    async fn persist_overrides_creates_nested_tables() {
+        let tmpdir = tempdir().expect("tmp");
+        let codex_home = tmpdir.path();
+
+        persist_overrides(
+            codex_home,
+            None,
+            &[
+                (&["a", "b", "c"], "v"),
+                (&["x"], "y"),
+                (&["profiles", "p1", CONFIG_KEY_MODEL], "gpt-5"),
+            ],
+        )
+        .await
+        .expect("persist");
+
+        let contents = read_config(codex_home).await;
+        let expected = r#"x = "y"
+
+[a.b]
+c = "v"
+
+[profiles.p1]
+model = "gpt-5"
+"#;
+        assert_eq!(contents, expected);
+    }
+
+    /// Verifies a scalar key becomes a table when nested keys are written.
+    #[tokio::test]
+    async fn persist_overrides_replaces_scalar_with_table() {
+        let tmpdir = tempdir().expect("tmp");
+        let codex_home = tmpdir.path();
+        let seed = "foo = \"bar\"\n";
+        tokio::fs::write(codex_home.join(CONFIG_TOML_FILE), seed)
+            .await
+            .expect("seed write");
+
+        persist_overrides(codex_home, None, &[(&["foo", "bar", "baz"], "ok")])
+            .await
+            .expect("persist");
+
+        let contents = read_config(codex_home).await;
+        let expected = r#"[foo.bar]
+baz = "ok"
+"#;
+        assert_eq!(contents, expected);
+    }
+
+    /// Verifies comments and spacing are preserved when writing under active profile.
+    #[tokio::test]
+    async fn set_defaults_preserve_comments() {
+        let tmpdir = tempdir().expect("tmp");
+        let codex_home = tmpdir.path();
+
+        // Seed a config with comments and spacing we expect to preserve
+        let seed = r#"# Global comment
+# Another line
+
+profile = "o3"
+
+# Profile settings
+[profiles.o3]
+# keep me
+existing = "keep"
+"#;
+        tokio::fs::write(codex_home.join(CONFIG_TOML_FILE), seed)
+            .await
+            .expect("seed write");
+
+        // Apply defaults; since profile is set, it should write under [profiles.o3]
+        persist_overrides(
+            codex_home,
+            None,
+            &[(&[CONFIG_KEY_MODEL], "o3"), (&[CONFIG_KEY_EFFORT], "high")],
+        )
+        .await
+        .expect("persist");
+
+        let contents = read_config(codex_home).await;
+        let expected = r#"# Global comment
+# Another line
+
+profile = "o3"
+
+# Profile settings
+[profiles.o3]
+# keep me
+existing = "keep"
+model = "o3"
+model_reasoning_effort = "high"
+"#;
+        assert_eq!(contents, expected);
+    }
+
+    /// Verifies comments and spacing are preserved when writing at top level.
+    #[tokio::test]
+    async fn set_defaults_preserve_global_comments() {
+        let tmpdir = tempdir().expect("tmp");
+        let codex_home = tmpdir.path();
+
+        // Seed a config WITHOUT a profile, containing comments and spacing
+        let seed = r#"# Top-level comments
+# should be preserved
+
+existing = "keep"
+"#;
+        tokio::fs::write(codex_home.join(CONFIG_TOML_FILE), seed)
+            .await
+            .expect("seed write");
+
+        // Since there is no profile, the defaults should be written at top-level
+        persist_overrides(
+            codex_home,
+            None,
+            &[
+                (&[CONFIG_KEY_MODEL], "gpt-5"),
+                (&[CONFIG_KEY_EFFORT], "minimal"),
+            ],
+        )
+        .await
+        .expect("persist");
+
+        let contents = read_config(codex_home).await;
+        let expected = r#"# Top-level comments
+# should be preserved
+
+existing = "keep"
+model = "gpt-5"
+model_reasoning_effort = "minimal"
+"#;
+        assert_eq!(contents, expected);
+    }
+
+    /// Verifies errors on invalid TOML propagate and file is not clobbered.
+    #[tokio::test]
+    async fn persist_overrides_errors_on_parse_failure() {
+        let tmpdir = tempdir().expect("tmp");
+        let codex_home = tmpdir.path();
+
+        // Write an intentionally invalid TOML file
+        let invalid = "invalid = [unclosed";
+        tokio::fs::write(codex_home.join(CONFIG_TOML_FILE), invalid)
+            .await
+            .expect("seed write");
+
+        // Attempting to persist should return an error and must not clobber the file.
+        let res = persist_overrides(codex_home, None, &[(&["x"], "y")]).await;
+        assert!(res.is_err(), "expected parse error to propagate");
+
+        // File should be unchanged
+        let contents = read_config(codex_home).await;
+        assert_eq!(contents, invalid);
+    }
+
+    /// Verifies changing model only preserves existing effort at top-level.
+    #[tokio::test]
+    async fn changing_only_model_preserves_existing_effort_top_level() {
+        let tmpdir = tempdir().expect("tmp");
+        let codex_home = tmpdir.path();
+
+        // Seed with an effort value only
+        let seed = "model_reasoning_effort = \"minimal\"\n";
+        tokio::fs::write(codex_home.join(CONFIG_TOML_FILE), seed)
+            .await
+            .expect("seed write");
+
+        // Change only the model
+        persist_overrides(codex_home, None, &[(&[CONFIG_KEY_MODEL], "o3")])
+            .await
+            .expect("persist");
+
+        let contents = read_config(codex_home).await;
+        let expected = r#"model_reasoning_effort = "minimal"
+model = "o3"
+"#;
+        assert_eq!(contents, expected);
+    }
+
+    /// Verifies changing effort only preserves existing model at top-level.
+    #[tokio::test]
+    async fn changing_only_effort_preserves_existing_model_top_level() {
+        let tmpdir = tempdir().expect("tmp");
+        let codex_home = tmpdir.path();
+
+        // Seed with a model value only
+        let seed = "model = \"gpt-5\"\n";
+        tokio::fs::write(codex_home.join(CONFIG_TOML_FILE), seed)
+            .await
+            .expect("seed write");
+
+        // Change only the effort
+        persist_overrides(codex_home, None, &[(&[CONFIG_KEY_EFFORT], "high")])
+            .await
+            .expect("persist");
+
+        let contents = read_config(codex_home).await;
+        let expected = r#"model = "gpt-5"
+model_reasoning_effort = "high"
+"#;
+        assert_eq!(contents, expected);
+    }
+
+    /// Verifies changing model only preserves existing effort in active profile.
+    #[tokio::test]
+    async fn changing_only_model_preserves_effort_in_active_profile() {
+        let tmpdir = tempdir().expect("tmp");
+        let codex_home = tmpdir.path();
+
+        // Seed with an active profile and an existing effort under that profile
+        let seed = r#"profile = "p1"
+
+[profiles.p1]
+model_reasoning_effort = "low"
+"#;
+        tokio::fs::write(codex_home.join(CONFIG_TOML_FILE), seed)
+            .await
+            .expect("seed write");
+
+        persist_overrides(codex_home, None, &[(&[CONFIG_KEY_MODEL], "o4-mini")])
+            .await
+            .expect("persist");
+
+        let contents = read_config(codex_home).await;
+        let expected = r#"profile = "p1"
+
+[profiles.p1]
+model_reasoning_effort = "low"
+model = "o4-mini"
+"#;
+        assert_eq!(contents, expected);
+    }
+
+    /// Verifies changing effort only preserves existing model in a profile override.
+    #[tokio::test]
+    async fn changing_only_effort_preserves_model_in_profile_override() {
+        let tmpdir = tempdir().expect("tmp");
+        let codex_home = tmpdir.path();
+
+        // No active profile key; we'll target an explicit override
+        let seed = r#"[profiles.team]
+model = "gpt-5"
+"#;
+        tokio::fs::write(codex_home.join(CONFIG_TOML_FILE), seed)
+            .await
+            .expect("seed write");
+
+        persist_overrides(
+            codex_home,
+            Some("team"),
+            &[(&[CONFIG_KEY_EFFORT], "minimal")],
+        )
+        .await
+        .expect("persist");
+
+        let contents = read_config(codex_home).await;
+        let expected = r#"[profiles.team]
+model = "gpt-5"
+model_reasoning_effort = "minimal"
+"#;
+        assert_eq!(contents, expected);
+    }
+
+    /// Verifies `persist_non_null_overrides` skips `None` entries and writes only present values at top-level.
+    #[tokio::test]
+    async fn persist_non_null_skips_none_top_level() {
+        let tmpdir = tempdir().expect("tmp");
+        let codex_home = tmpdir.path();
+
+        persist_non_null_overrides(
+            codex_home,
+            None,
+            &[
+                (&[CONFIG_KEY_MODEL], Some("gpt-5")),
+                (&[CONFIG_KEY_EFFORT], None),
+            ],
+        )
+        .await
+        .expect("persist");
+
+        let contents = read_config(codex_home).await;
+        let expected = "model = \"gpt-5\"\n";
+        assert_eq!(contents, expected);
+    }
+
+    /// Verifies no-op behavior when all provided overrides are `None` (no file created/modified).
+    #[tokio::test]
+    async fn persist_non_null_noop_when_all_none() {
+        let tmpdir = tempdir().expect("tmp");
+        let codex_home = tmpdir.path();
+
+        persist_non_null_overrides(
+            codex_home,
+            None,
+            &[(&["a"], None), (&["profiles", "p", "x"], None)],
+        )
+        .await
+        .expect("persist");
+
+        // Should not create config.toml on a pure no-op
+        assert!(!codex_home.join(CONFIG_TOML_FILE).exists());
+    }
+
+    /// Verifies entries are written under the specified profile and `None` entries are skipped.
+    #[tokio::test]
+    async fn persist_non_null_respects_profile_override() {
+        let tmpdir = tempdir().expect("tmp");
+        let codex_home = tmpdir.path();
+
+        persist_non_null_overrides(
+            codex_home,
+            Some("team"),
+            &[
+                (&[CONFIG_KEY_MODEL], Some("o3")),
+                (&[CONFIG_KEY_EFFORT], None),
+            ],
+        )
+        .await
+        .expect("persist");
+
+        let contents = read_config(codex_home).await;
+        let expected = r#"[profiles.team]
+model = "o3"
+"#;
+        assert_eq!(contents, expected);
+    }
+
+    // Test helper moved to bottom per review guidance.
+    async fn read_config(codex_home: &Path) -> String {
+        let p = codex_home.join(CONFIG_TOML_FILE);
+        tokio::fs::read_to_string(p).await.unwrap_or_default()
+    }
+}

codex-rs/core/src/conversation_manager.rs

@@ -1,12 +1,5 @@
-use std::collections::HashMap;
-use std::path::PathBuf;
-use std::sync::Arc;
-
 use crate::AuthManager;
 use crate::CodexAuth;
-use codex_protocol::mcp_protocol::ConversationId;
-use tokio::sync::RwLock;
-
 use crate::codex::Codex;
 use crate::codex::CodexSpawnOk;
 use crate::codex::INITIAL_SUBMIT_ID;
@@ -18,13 +11,14 @@ use crate::protocol::Event;
 use crate::protocol::EventMsg;
 use crate::protocol::SessionConfiguredEvent;
 use crate::rollout::RolloutRecorder;
+use codex_protocol::mcp_protocol::ConversationId;
 use codex_protocol::models::ResponseItem;
-
-#[derive(Debug, Clone, PartialEq)]
-pub enum InitialHistory {
-    New,
-    Resumed(Vec<ResponseItem>),
-}
+use codex_protocol::protocol::InitialHistory;
+use codex_protocol::protocol::RolloutItem;
+use std::collections::HashMap;
+use std::path::PathBuf;
+use std::sync::Arc;
+use tokio::sync::RwLock;
 
 /// Represents a newly created Codex conversation, including the first event
 /// (which is [`EventMsg::SessionConfigured`]).
@@ -77,7 +71,7 @@ impl ConversationManager {
             let CodexSpawnOk {
                 codex,
                 conversation_id,
-            } = { Codex::spawn(config, auth_manager, InitialHistory::New).await? };
+            } = Codex::spawn(config, auth_manager, InitialHistory::New).await?;
             self.finalize_spawn(codex, conversation_id).await
         }
     }
@@ -139,8 +133,15 @@ impl ConversationManager {
         self.finalize_spawn(codex, conversation_id).await
     }
 
-    pub async fn remove_conversation(&self, conversation_id: ConversationId) {
-        self.conversations.write().await.remove(&conversation_id);
+    /// Removes the conversation from the manager's internal map, though the
+    /// conversation is stored as `Arc<CodexConversation>`, it is possible that
+    /// other references to it exist elsewhere. Returns the conversation if the
+    /// conversation was found and removed.
+    pub async fn remove_conversation(
+        &self,
+        conversation_id: &ConversationId,
+    ) -> Option<Arc<CodexConversation>> {
+        self.conversations.write().await.remove(conversation_id)
     }
 
     /// Fork an existing conversation by dropping the last `drop_last_messages`
@@ -149,13 +150,13 @@ impl ConversationManager {
     /// caller's `config`). The new conversation will have a fresh id.
     pub async fn fork_conversation(
         &self,
-        conversation_history: Vec<ResponseItem>,
         num_messages_to_drop: usize,
         config: Config,
+        path: PathBuf,
     ) -> CodexResult<NewConversation> {
         // Compute the prefix up to the cut point.
-        let history =
-            truncate_after_dropping_last_messages(conversation_history, num_messages_to_drop);
+        let history = RolloutRecorder::get_rollout_history(&path).await?;
+        let history = truncate_after_dropping_last_messages(history, num_messages_to_drop);
 
         // Spawn a new conversation with the computed initial history.
         let auth_manager = self.auth_manager.clone();
@@ -170,31 +171,37 @@ impl ConversationManager {
 
 /// Return a prefix of `items` obtained by dropping the last `n` user messages
 /// and all items that follow them.
-fn truncate_after_dropping_last_messages(items: Vec<ResponseItem>, n: usize) -> InitialHistory {
+fn truncate_after_dropping_last_messages(history: InitialHistory, n: usize) -> InitialHistory {
     if n == 0 {
-        return InitialHistory::Resumed(items);
+        return InitialHistory::Forked(history.get_rollout_items());
     }
 
-    // Walk backwards counting only `user` Message items, find cut index.
-    let mut count = 0usize;
-    let mut cut_index = 0usize;
-    for (idx, item) in items.iter().enumerate().rev() {
-        if let ResponseItem::Message { role, .. } = item
+    // Work directly on rollout items, and cut the vector at the nth-from-last user message input.
+    let items: Vec<RolloutItem> = history.get_rollout_items();
+
+    // Find indices of user message inputs in rollout order.
+    let mut user_positions: Vec<usize> = Vec::new();
+    for (idx, item) in items.iter().enumerate() {
+        if let RolloutItem::ResponseItem(ResponseItem::Message { role, .. }) = item
             && role == "user"
         {
-            count += 1;
-            if count == n {
-                // Cut everything from this user message to the end.
-                cut_index = idx;
-                break;
-            }
+            user_positions.push(idx);
         }
     }
-    if cut_index == 0 {
-        // No prefix remains after dropping; start a new conversation.
+
+    // If fewer than n user messages exist, treat as empty.
+    if user_positions.len() < n {
+        return InitialHistory::New;
+    }
+
+    // Cut strictly before the nth-from-last user message (do not keep the nth itself).
+    let cut_idx = user_positions[user_positions.len() - n];
+    let rolled: Vec<RolloutItem> = items.into_iter().take(cut_idx).collect();
+
+    if rolled.is_empty() {
         InitialHistory::New
     } else {
-        InitialHistory::Resumed(items.into_iter().take(cut_index).collect())
+        InitialHistory::Forked(rolled)
     }
 }
 
@@ -249,13 +256,30 @@ mod tests {
             assistant_msg("a4"),
         ];
 
-        let truncated = truncate_after_dropping_last_messages(items.clone(), 1);
+        // Wrap as InitialHistory::Forked with response items only.
+        let initial: Vec<RolloutItem> = items
+            .iter()
+            .cloned()
+            .map(RolloutItem::ResponseItem)
+            .collect();
+        let truncated = truncate_after_dropping_last_messages(InitialHistory::Forked(initial), 1);
+        let got_items = truncated.get_rollout_items();
+        let expected_items = vec![
+            RolloutItem::ResponseItem(items[0].clone()),
+            RolloutItem::ResponseItem(items[1].clone()),
+            RolloutItem::ResponseItem(items[2].clone()),
+        ];
         assert_eq!(
-            truncated,
-            InitialHistory::Resumed(vec![items[0].clone(), items[1].clone(), items[2].clone(),])
+            serde_json::to_value(&got_items).unwrap(),
+            serde_json::to_value(&expected_items).unwrap()
         );
 
-        let truncated2 = truncate_after_dropping_last_messages(items, 2);
-        assert_eq!(truncated2, InitialHistory::New);
+        let initial2: Vec<RolloutItem> = items
+            .iter()
+            .cloned()
+            .map(RolloutItem::ResponseItem)
+            .collect();
+        let truncated2 = truncate_after_dropping_last_messages(InitialHistory::Forked(initial2), 2);
+        assert!(matches!(truncated2, InitialHistory::New));
     }
 }

codex-rs/core/src/default_client.rs

@@ -1,38 +1,123 @@
-pub const DEFAULT_ORIGINATOR: &str = "codex_cli_rs";
+use reqwest::header::HeaderValue;
+use std::sync::LazyLock;
+use std::sync::Mutex;
 
-pub fn get_codex_user_agent(originator: Option<&str>) -> String {
+/// Set this to add a suffix to the User-Agent string.
+///
+/// It is not ideal that we're using a global singleton for this.
+/// This is primarily designed to differentiate MCP clients from each other.
+/// Because there can only be one MCP server per process, it should be safe for this to be a global static.
+/// However, future users of this should use this with caution as a result.
+/// In addition, we want to be confident that this value is used for ALL clients and doing that requires a
+/// lot of wiring and it's easy to miss code paths by doing so.
+/// See https://github.com/openai/codex/pull/3388/files for an example of what that would look like.
+/// Finally, we want to make sure this is set for ALL mcp clients without needing to know a special env var
+/// or having to set data that they already specified in the mcp initialize request somewhere else.
+///
+/// A space is automatically added between the suffix and the rest of the User-Agent string.
+/// The full user agent string is returned from the mcp initialize response.
+/// Parenthesis will be added by Codex. This should only specify what goes inside of the parenthesis.
+pub static USER_AGENT_SUFFIX: LazyLock<Mutex<Option<String>>> = LazyLock::new(|| Mutex::new(None));
+
+pub const CODEX_INTERNAL_ORIGINATOR_OVERRIDE_ENV_VAR: &str = "CODEX_INTERNAL_ORIGINATOR_OVERRIDE";
+
+#[derive(Debug, Clone)]
+pub struct Originator {
+    pub value: String,
+    pub header_value: HeaderValue,
+}
+
+pub static ORIGINATOR: LazyLock<Originator> = LazyLock::new(|| {
+    let default = "codex_cli_rs";
+    let value = std::env::var(CODEX_INTERNAL_ORIGINATOR_OVERRIDE_ENV_VAR)
+        .unwrap_or_else(|_| default.to_string());
+
+    match HeaderValue::from_str(&value) {
+        Ok(header_value) => Originator {
+            value,
+            header_value,
+        },
+        Err(e) => {
+            tracing::error!("Unable to turn originator override {value} into header value: {e}");
+            Originator {
+                value: default.to_string(),
+                header_value: HeaderValue::from_static(default),
+            }
+        }
+    }
+});
+
+pub fn get_codex_user_agent() -> String {
     let build_version = env!("CARGO_PKG_VERSION");
     let os_info = os_info::get();
-    format!(
+    let prefix = format!(
         "{}/{build_version} ({} {}; {}) {}",
-        originator.unwrap_or(DEFAULT_ORIGINATOR),
+        ORIGINATOR.value.as_str(),
         os_info.os_type(),
         os_info.version(),
         os_info.architecture().unwrap_or("unknown"),
         crate::terminal::user_agent()
-    )
+    );
+    let suffix = USER_AGENT_SUFFIX
+        .lock()
+        .ok()
+        .and_then(|guard| guard.clone());
+    let suffix = suffix
+        .as_deref()
+        .map(str::trim)
+        .filter(|value| !value.is_empty())
+        .map_or_else(String::new, |value| format!(" ({value})"));
+
+    let candidate = format!("{prefix}{suffix}");
+    sanitize_user_agent(candidate, &prefix)
+}
+
+/// Sanitize the user agent string.
+///
+/// Invalid characters are replaced with an underscore.
+///
+/// If the user agent fails to parse, it falls back to fallback and then to ORIGINATOR.
+fn sanitize_user_agent(candidate: String, fallback: &str) -> String {
+    if HeaderValue::from_str(candidate.as_str()).is_ok() {
+        return candidate;
+    }
+
+    let sanitized: String = candidate
+        .chars()
+        .map(|ch| if matches!(ch, ' '..='~') { ch } else { '_' })
+        .collect();
+    if !sanitized.is_empty() && HeaderValue::from_str(sanitized.as_str()).is_ok() {
+        tracing::warn!(
+            "Sanitized Codex user agent because provided suffix contained invalid header characters"
+        );
+        sanitized
+    } else if HeaderValue::from_str(fallback).is_ok() {
+        tracing::warn!(
+            "Falling back to base Codex user agent because provided suffix could not be sanitized"
+        );
+        fallback.to_string()
+    } else {
+        tracing::warn!(
+            "Falling back to default Codex originator because base user agent string is invalid"
+        );
+        ORIGINATOR.value.clone()
+    }
 }
 
 /// Create a reqwest client with default `originator` and `User-Agent` headers set.
-pub fn create_client(originator: &str) -> reqwest::Client {
+pub fn create_client() -> reqwest::Client {
     use reqwest::header::HeaderMap;
-    use reqwest::header::HeaderValue;
 
     let mut headers = HeaderMap::new();
-    let originator_value = HeaderValue::from_str(originator)
-        .unwrap_or_else(|_| HeaderValue::from_static(DEFAULT_ORIGINATOR));
-    headers.insert("originator", originator_value);
-    let ua = get_codex_user_agent(Some(originator));
+    headers.insert("originator", ORIGINATOR.header_value.clone());
+    let ua = get_codex_user_agent();
 
-    match reqwest::Client::builder()
+    reqwest::Client::builder()
         // Set UA via dedicated helper to avoid header validation pitfalls
         .user_agent(ua)
         .default_headers(headers)
         .build()
-    {
-        Ok(client) => client,
-        Err(_) => reqwest::Client::new(),
-    }
+        .unwrap_or_else(|_| reqwest::Client::new())
 }
 
 #[cfg(test)]
@@ -41,7 +126,7 @@ mod tests {
 
     #[test]
     fn test_get_codex_user_agent() {
-        let user_agent = get_codex_user_agent(None);
+        let user_agent = get_codex_user_agent();
         assert!(user_agent.starts_with("codex_cli_rs/"));
     }
 
@@ -53,8 +138,7 @@ mod tests {
         use wiremock::matchers::method;
         use wiremock::matchers::path;
 
-        let originator = "test_originator";
-        let client = create_client(originator);
+        let client = create_client();
 
         // Spin up a local mock server and capture a request.
         let server = MockServer::start().await;
@@ -82,21 +166,43 @@ mod tests {
         let originator_header = headers
             .get("originator")
             .expect("originator header missing");
-        assert_eq!(originator_header.to_str().unwrap(), originator);
+        assert_eq!(originator_header.to_str().unwrap(), "codex_cli_rs");
 
         // User-Agent matches the computed Codex UA for that originator
-        let expected_ua = get_codex_user_agent(Some(originator));
+        let expected_ua = get_codex_user_agent();
         let ua_header = headers
             .get("user-agent")
             .expect("user-agent header missing");
         assert_eq!(ua_header.to_str().unwrap(), expected_ua);
     }
 
+    #[test]
+    fn test_invalid_suffix_is_sanitized() {
+        let prefix = "codex_cli_rs/0.0.0";
+        let suffix = "bad\rsuffix";
+
+        assert_eq!(
+            sanitize_user_agent(format!("{prefix} ({suffix})"), prefix),
+            "codex_cli_rs/0.0.0 (bad_suffix)"
+        );
+    }
+
+    #[test]
+    fn test_invalid_suffix_is_sanitized2() {
+        let prefix = "codex_cli_rs/0.0.0";
+        let suffix = "bad\0suffix";
+
+        assert_eq!(
+            sanitize_user_agent(format!("{prefix} ({suffix})"), prefix),
+            "codex_cli_rs/0.0.0 (bad_suffix)"
+        );
+    }
+
     #[test]
     #[cfg(target_os = "macos")]
     fn test_macos() {
         use regex_lite::Regex;
-        let user_agent = get_codex_user_agent(None);
+        let user_agent = get_codex_user_agent();
         let re = Regex::new(
             r"^codex_cli_rs/\d+\.\d+\.\d+ \(Mac OS \d+\.\d+\.\d+; (x86_64|arm64)\) (\S+)$",
         )

codex-rs/core/src/environment_context.rs

@@ -26,6 +26,7 @@ pub(crate) struct EnvironmentContext {
     pub approval_policy: Option<AskForApproval>,
     pub sandbox_mode: Option<SandboxMode>,
     pub network_access: Option<NetworkAccess>,
+    pub writable_roots: Option<Vec<PathBuf>>,
     pub shell: Option<Shell>,
 }
 
@@ -57,6 +58,16 @@ impl EnvironmentContext {
                 }
                 None => None,
             },
+            writable_roots: match sandbox_policy {
+                Some(SandboxPolicy::WorkspaceWrite { writable_roots, .. }) => {
+                    if writable_roots.is_empty() {
+                        None
+                    } else {
+                        Some(writable_roots.clone())
+                    }
+                }
+                _ => None,
+            },
             shell,
         }
     }
@@ -72,6 +83,7 @@ impl EnvironmentContext {
     ///   <cwd>...</cwd>
     ///   <approval_policy>...</approval_policy>
     ///   <sandbox_mode>...</sandbox_mode>
+    ///   <writable_roots>...</writable_roots>
     ///   <network_access>...</network_access>
     ///   <shell>...</shell>
     /// </environment_context>
@@ -94,6 +106,16 @@ impl EnvironmentContext {
                 "  <network_access>{network_access}</network_access>"
             ));
         }
+        if let Some(writable_roots) = self.writable_roots {
+            lines.push("  <writable_roots>".to_string());
+            for writable_root in writable_roots {
+                lines.push(format!(
+                    "    <root>{}</root>",
+                    writable_root.to_string_lossy()
+                ));
+            }
+            lines.push("  </writable_roots>".to_string());
+        }
         if let Some(shell) = self.shell
             && let Some(shell_name) = shell.name()
         {
@@ -115,3 +137,77 @@ impl From<EnvironmentContext> for ResponseItem {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use pretty_assertions::assert_eq;
+
+    fn workspace_write_policy(writable_roots: Vec<&str>, network_access: bool) -> SandboxPolicy {
+        SandboxPolicy::WorkspaceWrite {
+            writable_roots: writable_roots.into_iter().map(PathBuf::from).collect(),
+            network_access,
+            exclude_tmpdir_env_var: false,
+            exclude_slash_tmp: false,
+        }
+    }
+
+    #[test]
+    fn serialize_workspace_write_environment_context() {
+        let context = EnvironmentContext::new(
+            Some(PathBuf::from("/repo")),
+            Some(AskForApproval::OnRequest),
+            Some(workspace_write_policy(vec!["/repo", "/tmp"], false)),
+            None,
+        );
+
+        let expected = r#"<environment_context>
+  <cwd>/repo</cwd>
+  <approval_policy>on-request</approval_policy>
+  <sandbox_mode>workspace-write</sandbox_mode>
+  <network_access>restricted</network_access>
+  <writable_roots>
+    <root>/repo</root>
+    <root>/tmp</root>
+  </writable_roots>
+</environment_context>"#;
+
+        assert_eq!(context.serialize_to_xml(), expected);
+    }
+
+    #[test]
+    fn serialize_read_only_environment_context() {
+        let context = EnvironmentContext::new(
+            None,
+            Some(AskForApproval::Never),
+            Some(SandboxPolicy::ReadOnly),
+            None,
+        );
+
+        let expected = r#"<environment_context>
+  <approval_policy>never</approval_policy>
+  <sandbox_mode>read-only</sandbox_mode>
+  <network_access>restricted</network_access>
+</environment_context>"#;
+
+        assert_eq!(context.serialize_to_xml(), expected);
+    }
+
+    #[test]
+    fn serialize_full_access_environment_context() {
+        let context = EnvironmentContext::new(
+            None,
+            Some(AskForApproval::OnFailure),
+            Some(SandboxPolicy::DangerFullAccess),
+            None,
+        );
+
+        let expected = r#"<environment_context>
+  <approval_policy>on-failure</approval_policy>
+  <sandbox_mode>danger-full-access</sandbox_mode>
+  <network_access>enabled</network_access>
+</environment_context>"#;
+
+        assert_eq!(context.serialize_to_xml(), expected);
+    }
+}

codex-rs/core/src/event_mapping.rs

@@ -25,31 +25,56 @@ pub(crate) fn map_response_item_to_event_messages(
                 return Vec::new();
             }
 
-            let events: Vec<EventMsg> = content
-                .iter()
-                .filter_map(|content_item| match content_item {
-                    ContentItem::OutputText { text } => {
-                        Some(EventMsg::AgentMessage(AgentMessageEvent {
-                            message: text.clone(),
-                        }))
-                    }
+            let mut events: Vec<EventMsg> = Vec::new();
+            let mut message_parts: Vec<String> = Vec::new();
+            let mut images: Vec<String> = Vec::new();
+            let mut kind: Option<InputMessageKind> = None;
+
+            for content_item in content.iter() {
+                match content_item {
                     ContentItem::InputText { text } => {
-                        let trimmed = text.trim_start();
-                        let kind = if trimmed.starts_with("<environment_context>") {
-                            Some(InputMessageKind::EnvironmentContext)
-                        } else if trimmed.starts_with("<user_instructions>") {
-                            Some(InputMessageKind::UserInstructions)
-                        } else {
-                            Some(InputMessageKind::Plain)
-                        };
-                        Some(EventMsg::UserMessage(UserMessageEvent {
-                            message: text.clone(),
-                            kind,
-                        }))
+                        if kind.is_none() {
+                            let trimmed = text.trim_start();
+                            kind = if trimmed.starts_with("<environment_context>") {
+                                Some(InputMessageKind::EnvironmentContext)
+                            } else if trimmed.starts_with("<user_instructions>") {
+                                Some(InputMessageKind::UserInstructions)
+                            } else {
+                                Some(InputMessageKind::Plain)
+                            };
+                        }
+                        message_parts.push(text.clone());
                     }
-                    _ => None,
-                })
-                .collect();
+                    ContentItem::InputImage { image_url } => {
+                        images.push(image_url.clone());
+                    }
+                    ContentItem::OutputText { text } => {
+                        events.push(EventMsg::AgentMessage(AgentMessageEvent {
+                            message: text.clone(),
+                        }));
+                    }
+                }
+            }
+
+            if !message_parts.is_empty() || !images.is_empty() {
+                let message = if message_parts.is_empty() {
+                    String::new()
+                } else {
+                    message_parts.join("")
+                };
+                let images = if images.is_empty() {
+                    None
+                } else {
+                    Some(images)
+                };
+
+                events.push(EventMsg::UserMessage(UserMessageEvent {
+                    message,
+                    kind,
+                    images,
+                }));
+            }
+
             events
         }
 
@@ -96,3 +121,47 @@ pub(crate) fn map_response_item_to_event_messages(
         | ResponseItem::Other => Vec::new(),
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::map_response_item_to_event_messages;
+    use crate::protocol::EventMsg;
+    use crate::protocol::InputMessageKind;
+    use codex_protocol::models::ContentItem;
+    use codex_protocol::models::ResponseItem;
+    use pretty_assertions::assert_eq;
+
+    #[test]
+    fn maps_user_message_with_text_and_two_images() {
+        let img1 = "https://example.com/one.png".to_string();
+        let img2 = "https://example.com/two.jpg".to_string();
+
+        let item = ResponseItem::Message {
+            id: None,
+            role: "user".to_string(),
+            content: vec![
+                ContentItem::InputText {
+                    text: "Hello world".to_string(),
+                },
+                ContentItem::InputImage {
+                    image_url: img1.clone(),
+                },
+                ContentItem::InputImage {
+                    image_url: img2.clone(),
+                },
+            ],
+        };
+
+        let events = map_response_item_to_event_messages(&item, false);
+        assert_eq!(events.len(), 1, "expected a single user message event");
+
+        match &events[0] {
+            EventMsg::UserMessage(user) => {
+                assert_eq!(user.message, "Hello world");
+                assert!(matches!(user.kind, Some(InputMessageKind::Plain)));
+                assert_eq!(user.images, Some(vec![img1.clone(), img2.clone()]));
+            }
+            other => panic!("expected UserMessage, got {other:?}"),
+        }
+    }
+}

codex-rs/core/src/exec_command/exec_command_session.rs

@@ -24,6 +24,9 @@ pub(crate) struct ExecCommandSession {
 
     /// JoinHandle for the child wait task.
     wait_handle: StdMutex<Option<JoinHandle<()>>>,
+
+    /// Tracks whether the underlying process has exited.
+    exit_status: std::sync::Arc<std::sync::atomic::AtomicBool>,
 }
 
 impl ExecCommandSession {
@@ -34,6 +37,7 @@ impl ExecCommandSession {
         reader_handle: JoinHandle<()>,
         writer_handle: JoinHandle<()>,
         wait_handle: JoinHandle<()>,
+        exit_status: std::sync::Arc<std::sync::atomic::AtomicBool>,
     ) -> Self {
         Self {
             writer_tx,
@@ -42,6 +46,7 @@ impl ExecCommandSession {
             reader_handle: StdMutex::new(Some(reader_handle)),
             writer_handle: StdMutex::new(Some(writer_handle)),
             wait_handle: StdMutex::new(Some(wait_handle)),
+            exit_status,
         }
     }
 
@@ -52,6 +57,10 @@ impl ExecCommandSession {
     pub(crate) fn output_receiver(&self) -> broadcast::Receiver<Vec<u8>> {
         self.output_tx.subscribe()
     }
+
+    pub(crate) fn has_exited(&self) -> bool {
+        self.exit_status.load(std::sync::atomic::Ordering::SeqCst)
+    }
 }
 
 impl Drop for ExecCommandSession {

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

@@ -6,6 +6,7 @@ mod session_manager;
 
 pub use exec_command_params::ExecCommandParams;
 pub use exec_command_params::WriteStdinParams;
+pub(crate) use exec_command_session::ExecCommandSession;
 pub use responses_api::EXEC_COMMAND_TOOL_NAME;
 pub use responses_api::WRITE_STDIN_TOOL_NAME;
 pub use responses_api::create_exec_command_tool_for_responses_api;

codex-rs/core/src/exec_command/session_manager.rs

@@ -3,6 +3,7 @@ use std::io::ErrorKind;
 use std::io::Read;
 use std::sync::Arc;
 use std::sync::Mutex as StdMutex;
+use std::sync::atomic::AtomicBool;
 use std::sync::atomic::AtomicU32;
 
 use portable_pty::CommandBuilder;
@@ -19,6 +20,7 @@ use crate::exec_command::exec_command_params::ExecCommandParams;
 use crate::exec_command::exec_command_params::WriteStdinParams;
 use crate::exec_command::exec_command_session::ExecCommandSession;
 use crate::exec_command::session_id::SessionId;
+use crate::truncate::truncate_middle;
 use codex_protocol::models::FunctionCallOutputPayload;
 
 #[derive(Debug, Default)]
@@ -327,11 +329,14 @@ async fn create_exec_command_session(
 
     // Keep the child alive until it exits, then signal exit code.
     let (exit_tx, exit_rx) = oneshot::channel::<i32>();
+    let exit_status = Arc::new(AtomicBool::new(false));
+    let wait_exit_status = exit_status.clone();
     let wait_handle = tokio::task::spawn_blocking(move || {
         let code = match child.wait() {
             Ok(status) => status.exit_code() as i32,
             Err(_) => -1,
         };
+        wait_exit_status.store(true, std::sync::atomic::Ordering::SeqCst);
         let _ = exit_tx.send(code);
     });
 
@@ -343,116 +348,11 @@ async fn create_exec_command_session(
         reader_handle,
         writer_handle,
         wait_handle,
+        exit_status,
     );
     Ok((session, exit_rx))
 }
 
-/// Truncate the middle of a UTF-8 string to at most `max_bytes` bytes,
-/// preserving the beginning and the end. Returns the possibly truncated
-/// string and `Some(original_token_count)` (estimated at 4 bytes/token)
-/// if truncation occurred; otherwise returns the original string and `None`.
-fn truncate_middle(s: &str, max_bytes: usize) -> (String, Option<u64>) {
-    // No truncation needed
-    if s.len() <= max_bytes {
-        return (s.to_string(), None);
-    }
-    let est_tokens = (s.len() as u64).div_ceil(4);
-    if max_bytes == 0 {
-        // Cannot keep any content; still return a full marker (never truncated).
-        return (format!("…{est_tokens} tokens truncated…"), Some(est_tokens));
-    }
-
-    // Helper to truncate a string to a given byte length on a char boundary.
-    fn truncate_on_boundary(input: &str, max_len: usize) -> &str {
-        if input.len() <= max_len {
-            return input;
-        }
-        let mut end = max_len;
-        while end > 0 && !input.is_char_boundary(end) {
-            end -= 1;
-        }
-        &input[..end]
-    }
-
-    // Given a left/right budget, prefer newline boundaries; otherwise fall back
-    // to UTF-8 char boundaries.
-    fn pick_prefix_end(s: &str, left_budget: usize) -> usize {
-        if let Some(head) = s.get(..left_budget)
-            && let Some(i) = head.rfind('\n')
-        {
-            return i + 1; // keep the newline so suffix starts on a fresh line
-        }
-        truncate_on_boundary(s, left_budget).len()
-    }
-
-    fn pick_suffix_start(s: &str, right_budget: usize) -> usize {
-        let start_tail = s.len().saturating_sub(right_budget);
-        if let Some(tail) = s.get(start_tail..)
-            && let Some(i) = tail.find('\n')
-        {
-            return start_tail + i + 1; // start after newline
-        }
-        // Fall back to a char boundary at or after start_tail.
-        let mut idx = start_tail.min(s.len());
-        while idx < s.len() && !s.is_char_boundary(idx) {
-            idx += 1;
-        }
-        idx
-    }
-
-    // Refine marker length and budgets until stable. Marker is never truncated.
-    let mut guess_tokens = est_tokens; // worst-case: everything truncated
-    for _ in 0..4 {
-        let marker = format!("…{guess_tokens} tokens truncated…");
-        let marker_len = marker.len();
-        let keep_budget = max_bytes.saturating_sub(marker_len);
-        if keep_budget == 0 {
-            // No room for any content within the cap; return a full, untruncated marker
-            // that reflects the entire truncated content.
-            return (format!("…{est_tokens} tokens truncated…"), Some(est_tokens));
-        }
-
-        let left_budget = keep_budget / 2;
-        let right_budget = keep_budget - left_budget;
-        let prefix_end = pick_prefix_end(s, left_budget);
-        let mut suffix_start = pick_suffix_start(s, right_budget);
-        if suffix_start < prefix_end {
-            suffix_start = prefix_end;
-        }
-        let kept_content_bytes = prefix_end + (s.len() - suffix_start);
-        let truncated_content_bytes = s.len().saturating_sub(kept_content_bytes);
-        let new_tokens = (truncated_content_bytes as u64).div_ceil(4);
-        if new_tokens == guess_tokens {
-            let mut out = String::with_capacity(marker_len + kept_content_bytes + 1);
-            out.push_str(&s[..prefix_end]);
-            out.push_str(&marker);
-            // Place marker on its own line for symmetry when we keep line boundaries.
-            out.push('\n');
-            out.push_str(&s[suffix_start..]);
-            return (out, Some(est_tokens));
-        }
-        guess_tokens = new_tokens;
-    }
-
-    // Fallback: use last guess to build output.
-    let marker = format!("…{guess_tokens} tokens truncated…");
-    let marker_len = marker.len();
-    let keep_budget = max_bytes.saturating_sub(marker_len);
-    if keep_budget == 0 {
-        return (format!("…{est_tokens} tokens truncated…"), Some(est_tokens));
-    }
-    let left_budget = keep_budget / 2;
-    let right_budget = keep_budget - left_budget;
-    let prefix_end = pick_prefix_end(s, left_budget);
-    let suffix_start = pick_suffix_start(s, right_budget);
-    let mut out = String::with_capacity(marker_len + prefix_end + (s.len() - suffix_start) + 1);
-    out.push_str(&s[..prefix_end]);
-    out.push_str(&marker);
-    out.push('\n');
-    out.push_str(&s[suffix_start..]);
-    (out, Some(est_tokens))
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -616,50 +516,4 @@ Output:
 abc"#;
         assert_eq!(expected, text);
     }
-
-    #[test]
-    fn truncate_middle_no_newlines_fallback() {
-        // A long string with no newlines that exceeds the cap.
-        let s = "abcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
-        let max_bytes = 16; // force truncation
-        let (out, original) = truncate_middle(s, max_bytes);
-        // For very small caps, we return the full, untruncated marker,
-        // even if it exceeds the cap.
-        assert_eq!(out, "…16 tokens truncated…");
-        // Original string length is 62 bytes => ceil(62/4) = 16 tokens.
-        assert_eq!(original, Some(16));
-    }
-
-    #[test]
-    fn truncate_middle_prefers_newline_boundaries() {
-        // Build a multi-line string of 20 numbered lines (each "NNN\n").
-        let mut s = String::new();
-        for i in 1..=20 {
-            s.push_str(&format!("{i:03}\n"));
-        }
-        // Total length: 20 lines * 4 bytes per line = 80 bytes.
-        assert_eq!(s.len(), 80);
-
-        // Choose a cap that forces truncation while leaving room for
-        // a few lines on each side after accounting for the marker.
-        let max_bytes = 64;
-        // Expect exact output: first 4 lines, marker, last 4 lines, and correct token estimate (80/4 = 20).
-        assert_eq!(
-            truncate_middle(&s, max_bytes),
-            (
-                r#"001
-002
-003
-004
-…12 tokens truncated…
-017
-018
-019
-020
-"#
-                .to_string(),
-                Some(20)
-            )
-        );
-    }
 }

codex-rs/core/src/git_info.rs

@@ -3,6 +3,7 @@ use std::path::Path;
 use std::path::PathBuf;
 
 use codex_protocol::mcp_protocol::GitSha;
+use codex_protocol::protocol::GitInfo;
 use futures::future::join_all;
 use serde::Deserialize;
 use serde::Serialize;
@@ -43,19 +44,6 @@ pub fn get_git_repo_root(base_dir: &Path) -> Option<PathBuf> {
 /// Timeout for git commands to prevent freezing on large repositories
 const GIT_COMMAND_TIMEOUT: TokioDuration = TokioDuration::from_secs(5);
 
-#[derive(Serialize, Deserialize, Clone, Debug)]
-pub struct GitInfo {
-    /// Current commit hash (SHA)
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub commit_hash: Option<String>,
-    /// Current branch name
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub branch: Option<String>,
-    /// Repository URL (if available from remote)
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub repository_url: Option<String>,
-}
-
 #[derive(Serialize, Deserialize, Clone, Debug)]
 pub struct GitDiffToRemote {
     pub sha: GitSha,

codex-rs/core/src/lib.rs

@@ -16,6 +16,7 @@ mod codex_conversation;
 pub mod token_data;
 pub use codex_conversation::CodexConversation;
 pub mod config;
+pub mod config_edit;
 pub mod config_profile;
 pub mod config_types;
 mod conversation_history;
@@ -34,6 +35,8 @@ mod mcp_tool_call;
 mod message_history;
 mod model_provider_info;
 pub mod parse_command;
+mod truncate;
+mod unified_exec;
 mod user_instructions;
 pub use model_provider_info::BUILT_IN_OSS_MODEL_PROVIDER_ID;
 pub use model_provider_info::ModelProviderInfo;
@@ -42,6 +45,7 @@ pub use model_provider_info::built_in_model_providers;
 pub use model_provider_info::create_oss_provider_with_base_url;
 mod conversation_manager;
 mod event_mapping;
+pub use codex_protocol::protocol::InitialHistory;
 pub use conversation_manager::ConversationManager;
 pub use conversation_manager::NewConversation;
 // Re-export common auth types for workspace consumers
@@ -61,7 +65,10 @@ pub mod spawn;
 pub mod terminal;
 mod tool_apply_patch;
 pub mod turn_diff_tracker;
+pub use rollout::ARCHIVED_SESSIONS_SUBDIR;
 pub use rollout::RolloutRecorder;
+pub use rollout::SESSIONS_SUBDIR;
+pub use rollout::SessionMeta;
 pub use rollout::list::ConversationItem;
 pub use rollout::list::ConversationsPage;
 pub use rollout::list::Cursor;

codex-rs/core/src/mcp_connection_manager.rs

@@ -163,6 +163,10 @@ impl McpConnectionManager {
                                 name: "codex-mcp-client".to_owned(),
                                 version: env!("CARGO_PKG_VERSION").to_owned(),
                                 title: Some("Codex".into()),
+                                // This field is used by Codex when it is an MCP
+                                // server: it should not be used when Codex is
+                                // an MCP client.
+                                user_agent: None,
                             },
                             protocol_version: mcp_types::MCP_SCHEMA_VERSION.to_owned(),
                         };
@@ -187,7 +191,13 @@ impl McpConnectionManager {
         let mut clients: HashMap<String, ManagedClient> = HashMap::with_capacity(join_set.len());
 
         while let Some(res) = join_set.join_next().await {
-            let (server_name, client_res) = res?; // JoinError propagation
+            let (server_name, client_res) = match res {
+                Ok((server_name, client_res)) => (server_name, client_res),
+                Err(e) => {
+                    warn!("Task panic when starting MCP server: {e:#}");
+                    continue;
+                }
+            };
 
             match client_res {
                 Ok((client, startup_timeout)) => {
@@ -205,7 +215,13 @@ impl McpConnectionManager {
             }
         }
 
-        let all_tools = list_all_tools(&clients).await?;
+        let all_tools = match list_all_tools(&clients).await {
+            Ok(tools) => tools,
+            Err(e) => {
+                warn!("Failed to list tools from some MCP servers: {e:#}");
+                Vec::new()
+            }
+        };
 
         let tools = qualify_tools(all_tools);
 
@@ -270,8 +286,19 @@ async fn list_all_tools(clients: &HashMap<String, ManagedClient>) -> Result<Vec<
     let mut aggregated: Vec<ToolInfo> = Vec::with_capacity(join_set.len());
 
     while let Some(join_res) = join_set.join_next().await {
-        let (server_name, list_result) = join_res?;
-        let list_result = list_result?;
+        let (server_name, list_result) = if let Ok(result) = join_res {
+            result
+        } else {
+            warn!("Task panic when listing tools for MCP server: {join_res:#?}");
+            continue;
+        };
+
+        let list_result = if let Ok(result) = list_result {
+            result
+        } else {
+            warn!("Failed to list tools for MCP server '{server_name}': {list_result:#?}");
+            continue;
+        };
 
         for tool in list_result.tools {
             let tool_info = ToolInfo {

codex-rs/core/src/message_history.rs

@@ -23,7 +23,6 @@ use std::path::PathBuf;
 use serde::Deserialize;
 use serde::Serialize;
 
-use codex_protocol::mcp_protocol::ConversationId;
 use std::time::Duration;
 use tokio::fs;
 use tokio::io::AsyncReadExt;
@@ -31,6 +30,7 @@ use tokio::io::AsyncReadExt;
 use crate::config::Config;
 use crate::config_types::HistoryPersistence;
 
+use codex_protocol::mcp_protocol::ConversationId;
 #[cfg(unix)]
 use std::os::unix::fs::OpenOptionsExt;
 #[cfg(unix)]

codex-rs/core/src/model_family.rs

@@ -103,7 +103,7 @@ pub fn find_family_for_model(slug: &str) -> Option<ModelFamily> {
             slug, "gpt-4.1",
             needs_special_apply_patch_instructions: true,
         )
-    } else if slug.starts_with("gpt-oss") {
+    } else if slug.starts_with("gpt-oss") || slug.starts_with("openai/gpt-oss") {
         model_family!(slug, "gpt-oss", apply_patch_tool_type: Some(ApplyPatchToolType::Function))
     } else if slug.starts_with("gpt-4o") {
         simple_model_family!(slug, "gpt-4o")

codex-rs/core/src/openai_tools.rs

@@ -8,7 +8,6 @@ use std::collections::HashMap;
 use crate::model_family::ModelFamily;
 use crate::plan_tool::PLAN_TOOL;
 use crate::protocol::AskForApproval;
-use crate::protocol::SandboxPolicy;
 use crate::tool_apply_patch::ApplyPatchToolType;
 use crate::tool_apply_patch::create_apply_patch_freeform_tool;
 use crate::tool_apply_patch::create_apply_patch_json_tool;
@@ -58,7 +57,7 @@ pub(crate) enum OpenAiTool {
 #[derive(Debug, Clone)]
 pub enum ConfigShellToolType {
     DefaultShell,
-    ShellWithRequest { sandbox_policy: SandboxPolicy },
+    ShellWithRequest,
     LocalShell,
     StreamableShell,
 }
@@ -70,17 +69,18 @@ pub(crate) struct ToolsConfig {
     pub apply_patch_tool_type: Option<ApplyPatchToolType>,
     pub web_search_request: bool,
     pub include_view_image_tool: bool,
+    pub experimental_unified_exec_tool: bool,
 }
 
 pub(crate) struct ToolsConfigParams<'a> {
     pub(crate) model_family: &'a ModelFamily,
     pub(crate) approval_policy: AskForApproval,
-    pub(crate) sandbox_policy: SandboxPolicy,
     pub(crate) include_plan_tool: bool,
     pub(crate) include_apply_patch_tool: bool,
     pub(crate) include_web_search_request: bool,
     pub(crate) use_streamable_shell_tool: bool,
     pub(crate) include_view_image_tool: bool,
+    pub(crate) experimental_unified_exec_tool: bool,
 }
 
 impl ToolsConfig {
@@ -88,12 +88,12 @@ impl ToolsConfig {
         let ToolsConfigParams {
             model_family,
             approval_policy,
-            sandbox_policy,
             include_plan_tool,
             include_apply_patch_tool,
             include_web_search_request,
             use_streamable_shell_tool,
             include_view_image_tool,
+            experimental_unified_exec_tool,
         } = params;
         let mut shell_type = if *use_streamable_shell_tool {
             ConfigShellToolType::StreamableShell
@@ -103,9 +103,7 @@ impl ToolsConfig {
             ConfigShellToolType::DefaultShell
         };
         if matches!(approval_policy, AskForApproval::OnRequest) && !use_streamable_shell_tool {
-            shell_type = ConfigShellToolType::ShellWithRequest {
-                sandbox_policy: sandbox_policy.clone(),
-            }
+            shell_type = ConfigShellToolType::ShellWithRequest;
         }
 
         let apply_patch_tool_type = match model_family.apply_patch_tool_type {
@@ -126,6 +124,7 @@ impl ToolsConfig {
             apply_patch_tool_type,
             web_search_request: *include_web_search_request,
             include_view_image_tool: *include_view_image_tool,
+            experimental_unified_exec_tool: *experimental_unified_exec_tool,
         }
     }
 }
@@ -200,7 +199,56 @@ fn create_shell_tool() -> OpenAiTool {
     })
 }
 
-fn create_shell_tool_for_sandbox(sandbox_policy: &SandboxPolicy) -> OpenAiTool {
+fn create_unified_exec_tool() -> OpenAiTool {
+    let mut properties = BTreeMap::new();
+    properties.insert(
+        "input".to_string(),
+        JsonSchema::Array {
+            items: Box::new(JsonSchema::String { description: None }),
+            description: Some(
+                "When no session_id is provided, treat the array as the command and arguments \
+                 to launch. When session_id is set, concatenate the strings (in order) and write \
+                 them to the session's stdin."
+                    .to_string(),
+            ),
+        },
+    );
+    properties.insert(
+        "session_id".to_string(),
+        JsonSchema::String {
+            description: Some(
+                "Identifier for an existing interactive session. If omitted, a new command \
+                 is spawned."
+                    .to_string(),
+            ),
+        },
+    );
+    properties.insert(
+        "timeout_ms".to_string(),
+        JsonSchema::Number {
+            description: Some(
+                "Maximum time in milliseconds to wait for output after writing the input."
+                    .to_string(),
+            ),
+        },
+    );
+
+    OpenAiTool::Function(ResponsesApiTool {
+        name: "unified_exec".to_string(),
+        description:
+            "Runs a command in a PTY. Provide a session_id to reuse an existing interactive session.".to_string(),
+        strict: false,
+        parameters: JsonSchema::Object {
+            properties,
+            required: Some(vec!["input".to_string()]),
+            additional_properties: Some(false),
+        },
+    })
+}
+
+const SHELL_TOOL_DESCRIPTION: &str = r#"Runs a shell command and returns its output"#;
+
+fn create_shell_tool_for_sandbox() -> OpenAiTool {
     let mut properties = BTreeMap::new();
     properties.insert(
         "command".to_string(),
@@ -212,82 +260,29 @@ fn create_shell_tool_for_sandbox(sandbox_policy: &SandboxPolicy) -> OpenAiTool {
     properties.insert(
         "workdir".to_string(),
         JsonSchema::String {
-            description: Some("The working directory to execute the command in".to_string()),
+            description: Some("Working directory to execute the command in.".to_string()),
         },
     );
     properties.insert(
         "timeout_ms".to_string(),
         JsonSchema::Number {
-            description: Some("The timeout for the command in milliseconds".to_string()),
+            description: Some("Timeout for the command in milliseconds.".to_string()),
         },
     );
-
-    if matches!(sandbox_policy, SandboxPolicy::WorkspaceWrite { .. }) {
-        properties.insert(
+    properties.insert(
         "with_escalated_permissions".to_string(),
         JsonSchema::Boolean {
-            description: Some("Whether to request escalated permissions. Set to true if command needs to be run without sandbox restrictions".to_string()),
+            description: Some("Request escalated permissions, only for when a command would otherwise be blocked by the sandbox.".to_string()),
         },
     );
-        properties.insert(
+    properties.insert(
         "justification".to_string(),
         JsonSchema::String {
-            description: Some("Only set if with_escalated_permissions is true. 1-sentence explanation of why we want to run this command.".to_string()),
+            description: Some("Required if and only if with_escalated_permissions == true. One sentence explaining why escalation is needed (e.g., write outside CWD, network fetch, git commit).".to_string()),
         },
     );
-    }
 
-    let description = match sandbox_policy {
-        SandboxPolicy::WorkspaceWrite {
-            network_access,
-            writable_roots,
-            ..
-        } => {
-            format!(
-                r#"
-The shell tool is used to execute shell commands.
-- When invoking the shell tool, your call will be running in a sandbox, and some shell commands will require escalated privileges:
-  - Types of actions that require escalated privileges:
-    - Writing files other than those in the writable roots
-      - writable roots:
-{}{}
-  - Examples of commands that require escalated privileges:
-    - git commit
-    - npm install or pnpm install
-    - cargo build
-    - cargo test
-- When invoking a command that will require escalated privileges:
-  - Provide the with_escalated_permissions parameter with the boolean value true
-  - Include a short, 1 sentence explanation for why we need to run with_escalated_permissions in the justification parameter."#,
-                writable_roots.iter().map(|wr| format!("        - {}", wr.to_string_lossy())).collect::<Vec<String>>().join("\n"),
-                if !network_access {
-                    "\n    - Commands that require network access\n"
-                } else {
-                    ""
-                }
-            )
-        }
-        SandboxPolicy::DangerFullAccess => {
-            "Runs a shell command and returns its output.".to_string()
-        }
-        SandboxPolicy::ReadOnly => {
-            r#"
-The shell tool is used to execute shell commands.
-- When invoking the shell tool, your call will be running in a sandbox, and some shell commands (including apply_patch) will require escalated permissions:
-  - Types of actions that require escalated privileges:
-    - Writing files
-    - Applying patches
-  - Examples of commands that require escalated privileges:
-    - apply_patch
-    - git commit
-    - npm install or pnpm install
-    - cargo build
-    - cargo test
-- When invoking a command that will require escalated privileges:
-  - Provide the with_escalated_permissions parameter with the boolean value true
-  - Include a short, 1 sentence explanation for why we need to run with_escalated_permissions in the justification parameter"#.to_string()
-        }
-    };
+    let description = SHELL_TOOL_DESCRIPTION.to_string();
 
     OpenAiTool::Function(ResponsesApiTool {
         name: "shell".to_string(),
@@ -300,7 +295,6 @@ The shell tool is used to execute shell commands.
         },
     })
 }
-
 fn create_view_image_tool() -> OpenAiTool {
     // Support only local filesystem path.
     let mut properties = BTreeMap::new();
@@ -534,23 +528,27 @@ pub(crate) fn get_openai_tools(
 ) -> Vec<OpenAiTool> {
     let mut tools: Vec<OpenAiTool> = Vec::new();
 
-    match &config.shell_type {
-        ConfigShellToolType::DefaultShell => {
-            tools.push(create_shell_tool());
-        }
-        ConfigShellToolType::ShellWithRequest { sandbox_policy } => {
-            tools.push(create_shell_tool_for_sandbox(sandbox_policy));
-        }
-        ConfigShellToolType::LocalShell => {
-            tools.push(OpenAiTool::LocalShell {});
-        }
-        ConfigShellToolType::StreamableShell => {
-            tools.push(OpenAiTool::Function(
-                crate::exec_command::create_exec_command_tool_for_responses_api(),
-            ));
-            tools.push(OpenAiTool::Function(
-                crate::exec_command::create_write_stdin_tool_for_responses_api(),
-            ));
+    if config.experimental_unified_exec_tool {
+        tools.push(create_unified_exec_tool());
+    } else {
+        match &config.shell_type {
+            ConfigShellToolType::DefaultShell => {
+                tools.push(create_shell_tool());
+            }
+            ConfigShellToolType::ShellWithRequest => {
+                tools.push(create_shell_tool_for_sandbox());
+            }
+            ConfigShellToolType::LocalShell => {
+                tools.push(OpenAiTool::LocalShell {});
+            }
+            ConfigShellToolType::StreamableShell => {
+                tools.push(OpenAiTool::Function(
+                    crate::exec_command::create_exec_command_tool_for_responses_api(),
+                ));
+                tools.push(OpenAiTool::Function(
+                    crate::exec_command::create_write_stdin_tool_for_responses_api(),
+                ));
+            }
         }
     }
 
@@ -577,10 +575,8 @@ pub(crate) fn get_openai_tools(
     if config.include_view_image_tool {
         tools.push(create_view_image_tool());
     }
-
     if let Some(mcp_tools) = mcp_tools {
         // Ensure deterministic ordering to maximize prompt cache hits.
-        // HashMap iteration order is non-deterministic, so sort by fully-qualified tool name.
         let mut entries: Vec<(String, mcp_types::Tool)> = mcp_tools.into_iter().collect();
         entries.sort_by(|a, b| a.0.cmp(&b.0));
 
@@ -636,18 +632,18 @@ mod tests {
         let config = ToolsConfig::new(&ToolsConfigParams {
             model_family: &model_family,
             approval_policy: AskForApproval::Never,
-            sandbox_policy: SandboxPolicy::ReadOnly,
             include_plan_tool: true,
             include_apply_patch_tool: false,
             include_web_search_request: true,
             use_streamable_shell_tool: false,
             include_view_image_tool: true,
+            experimental_unified_exec_tool: true,
         });
         let tools = get_openai_tools(&config, Some(HashMap::new()));
 
         assert_eq_tool_names(
             &tools,
-            &["local_shell", "update_plan", "web_search", "view_image"],
+            &["unified_exec", "update_plan", "web_search", "view_image"],
         );
     }
 
@@ -657,18 +653,18 @@ mod tests {
         let config = ToolsConfig::new(&ToolsConfigParams {
             model_family: &model_family,
             approval_policy: AskForApproval::Never,
-            sandbox_policy: SandboxPolicy::ReadOnly,
             include_plan_tool: true,
             include_apply_patch_tool: false,
             include_web_search_request: true,
             use_streamable_shell_tool: false,
             include_view_image_tool: true,
+            experimental_unified_exec_tool: true,
         });
         let tools = get_openai_tools(&config, Some(HashMap::new()));
 
         assert_eq_tool_names(
             &tools,
-            &["shell", "update_plan", "web_search", "view_image"],
+            &["unified_exec", "update_plan", "web_search", "view_image"],
         );
     }
 
@@ -678,12 +674,12 @@ mod tests {
         let config = ToolsConfig::new(&ToolsConfigParams {
             model_family: &model_family,
             approval_policy: AskForApproval::Never,
-            sandbox_policy: SandboxPolicy::ReadOnly,
             include_plan_tool: false,
             include_apply_patch_tool: false,
             include_web_search_request: true,
             use_streamable_shell_tool: false,
             include_view_image_tool: true,
+            experimental_unified_exec_tool: true,
         });
         let tools = get_openai_tools(
             &config,
@@ -726,7 +722,7 @@ mod tests {
         assert_eq_tool_names(
             &tools,
             &[
-                "shell",
+                "unified_exec",
                 "web_search",
                 "view_image",
                 "test_server/do_something_cool",
@@ -783,12 +779,12 @@ mod tests {
         let config = ToolsConfig::new(&ToolsConfigParams {
             model_family: &model_family,
             approval_policy: AskForApproval::Never,
-            sandbox_policy: SandboxPolicy::ReadOnly,
             include_plan_tool: false,
             include_apply_patch_tool: false,
             include_web_search_request: false,
             use_streamable_shell_tool: false,
             include_view_image_tool: true,
+            experimental_unified_exec_tool: true,
         });
 
         // Intentionally construct a map with keys that would sort alphabetically.
@@ -841,11 +837,11 @@ mod tests {
         ]);
 
         let tools = get_openai_tools(&config, Some(tools_map));
-        // Expect shell first, followed by MCP tools sorted by fully-qualified name.
+        // Expect unified_exec first, followed by MCP tools sorted by fully-qualified name.
         assert_eq_tool_names(
             &tools,
             &[
-                "shell",
+                "unified_exec",
                 "view_image",
                 "test_server/cool",
                 "test_server/do",
@@ -860,12 +856,12 @@ mod tests {
         let config = ToolsConfig::new(&ToolsConfigParams {
             model_family: &model_family,
             approval_policy: AskForApproval::Never,
-            sandbox_policy: SandboxPolicy::ReadOnly,
             include_plan_tool: false,
             include_apply_patch_tool: false,
             include_web_search_request: true,
             use_streamable_shell_tool: false,
             include_view_image_tool: true,
+            experimental_unified_exec_tool: true,
         });
 
         let tools = get_openai_tools(
@@ -893,7 +889,7 @@ mod tests {
 
         assert_eq_tool_names(
             &tools,
-            &["shell", "web_search", "view_image", "dash/search"],
+            &["unified_exec", "web_search", "view_image", "dash/search"],
         );
 
         assert_eq!(
@@ -922,12 +918,12 @@ mod tests {
         let config = ToolsConfig::new(&ToolsConfigParams {
             model_family: &model_family,
             approval_policy: AskForApproval::Never,
-            sandbox_policy: SandboxPolicy::ReadOnly,
             include_plan_tool: false,
             include_apply_patch_tool: false,
             include_web_search_request: true,
             use_streamable_shell_tool: false,
             include_view_image_tool: true,
+            experimental_unified_exec_tool: true,
         });
 
         let tools = get_openai_tools(
@@ -953,7 +949,7 @@ mod tests {
 
         assert_eq_tool_names(
             &tools,
-            &["shell", "web_search", "view_image", "dash/paginate"],
+            &["unified_exec", "web_search", "view_image", "dash/paginate"],
         );
         assert_eq!(
             tools[3],
@@ -979,12 +975,12 @@ mod tests {
         let config = ToolsConfig::new(&ToolsConfigParams {
             model_family: &model_family,
             approval_policy: AskForApproval::Never,
-            sandbox_policy: SandboxPolicy::ReadOnly,
             include_plan_tool: false,
             include_apply_patch_tool: false,
             include_web_search_request: true,
             use_streamable_shell_tool: false,
             include_view_image_tool: true,
+            experimental_unified_exec_tool: true,
         });
 
         let tools = get_openai_tools(
@@ -1008,7 +1004,10 @@ mod tests {
             )])),
         );
 
-        assert_eq_tool_names(&tools, &["shell", "web_search", "view_image", "dash/tags"]);
+        assert_eq_tool_names(
+            &tools,
+            &["unified_exec", "web_search", "view_image", "dash/tags"],
+        );
         assert_eq!(
             tools[3],
             OpenAiTool::Function(ResponsesApiTool {
@@ -1036,12 +1035,12 @@ mod tests {
         let config = ToolsConfig::new(&ToolsConfigParams {
             model_family: &model_family,
             approval_policy: AskForApproval::Never,
-            sandbox_policy: SandboxPolicy::ReadOnly,
             include_plan_tool: false,
             include_apply_patch_tool: false,
             include_web_search_request: true,
             use_streamable_shell_tool: false,
             include_view_image_tool: true,
+            experimental_unified_exec_tool: true,
         });
 
         let tools = get_openai_tools(
@@ -1065,7 +1064,10 @@ mod tests {
             )])),
         );
 
-        assert_eq_tool_names(&tools, &["shell", "web_search", "view_image", "dash/value"]);
+        assert_eq_tool_names(
+            &tools,
+            &["unified_exec", "web_search", "view_image", "dash/value"],
+        );
         assert_eq!(
             tools[3],
             OpenAiTool::Function(ResponsesApiTool {
@@ -1086,13 +1088,7 @@ mod tests {
 
     #[test]
     fn test_shell_tool_for_sandbox_workspace_write() {
-        let sandbox_policy = SandboxPolicy::WorkspaceWrite {
-            writable_roots: vec!["workspace".into()],
-            network_access: false,
-            exclude_tmpdir_env_var: false,
-            exclude_slash_tmp: false,
-        };
-        let tool = super::create_shell_tool_for_sandbox(&sandbox_policy);
+        let tool = super::create_shell_tool_for_sandbox();
         let OpenAiTool::Function(ResponsesApiTool {
             description, name, ..
         }) = &tool
@@ -1101,29 +1097,13 @@ mod tests {
         };
         assert_eq!(name, "shell");
 
-        let expected = r#"
-The shell tool is used to execute shell commands.
-- When invoking the shell tool, your call will be running in a sandbox, and some shell commands will require escalated privileges:
-  - Types of actions that require escalated privileges:
-    - Writing files other than those in the writable roots
-      - writable roots:
-        - workspace
-    - Commands that require network access
-
-  - Examples of commands that require escalated privileges:
-    - git commit
-    - npm install or pnpm install
-    - cargo build
-    - cargo test
-- When invoking a command that will require escalated privileges:
-  - Provide the with_escalated_permissions parameter with the boolean value true
-  - Include a short, 1 sentence explanation for why we need to run with_escalated_permissions in the justification parameter."#;
+        let expected = super::SHELL_TOOL_DESCRIPTION;
         assert_eq!(description, expected);
     }
 
     #[test]
     fn test_shell_tool_for_sandbox_readonly() {
-        let tool = super::create_shell_tool_for_sandbox(&SandboxPolicy::ReadOnly);
+        let tool = super::create_shell_tool_for_sandbox();
         let OpenAiTool::Function(ResponsesApiTool {
             description, name, ..
         }) = &tool
@@ -1132,27 +1112,13 @@ The shell tool is used to execute shell commands.
         };
         assert_eq!(name, "shell");
 
-        let expected = r#"
-The shell tool is used to execute shell commands.
-- When invoking the shell tool, your call will be running in a sandbox, and some shell commands (including apply_patch) will require escalated permissions:
-  - Types of actions that require escalated privileges:
-    - Writing files
-    - Applying patches
-  - Examples of commands that require escalated privileges:
-    - apply_patch
-    - git commit
-    - npm install or pnpm install
-    - cargo build
-    - cargo test
-- When invoking a command that will require escalated privileges:
-  - Provide the with_escalated_permissions parameter with the boolean value true
-  - Include a short, 1 sentence explanation for why we need to run with_escalated_permissions in the justification parameter"#;
+        let expected = super::SHELL_TOOL_DESCRIPTION;
         assert_eq!(description, expected);
     }
 
     #[test]
     fn test_shell_tool_for_sandbox_danger_full_access() {
-        let tool = super::create_shell_tool_for_sandbox(&SandboxPolicy::DangerFullAccess);
+        let tool = super::create_shell_tool_for_sandbox();
         let OpenAiTool::Function(ResponsesApiTool {
             description, name, ..
         }) = &tool
@@ -1161,6 +1127,7 @@ The shell tool is used to execute shell commands.
         };
         assert_eq!(name, "shell");
 
-        assert_eq!(description, "Runs a shell command and returns its output.");
+        let expected = super::SHELL_TOOL_DESCRIPTION;
+        assert_eq!(description, expected);
     }
 }

codex-rs/core/src/rollout/list.rs

@@ -10,6 +10,9 @@ use time::macros::format_description;
 use uuid::Uuid;
 
 use super::SESSIONS_SUBDIR;
+use crate::protocol::EventMsg;
+use codex_protocol::protocol::RolloutItem;
+use codex_protocol::protocol::RolloutLine;
 
 /// Returned page of conversation summaries.
 #[derive(Debug, Default, PartialEq)]
@@ -34,7 +37,7 @@ pub struct ConversationItem {
 }
 
 /// Hard cap to bound worst‑case work per request.
-const MAX_SCAN_FILES: usize = 10_000;
+const MAX_SCAN_FILES: usize = 100;
 const HEAD_RECORD_LIMIT: usize = 10;
 
 /// Pagination cursor identifying a file by timestamp and UUID.
@@ -167,10 +170,16 @@ async fn traverse_directories_for_paths(
                     if items.len() == page_size {
                         break 'outer;
                     }
-                    let head = read_first_jsonl_records(&path, HEAD_RECORD_LIMIT)
-                        .await
-                        .unwrap_or_default();
-                    items.push(ConversationItem { path, head });
+                    // Read head and simultaneously detect message events within the same
+                    // first N JSONL records to avoid a second file read.
+                    let (head, saw_session_meta, saw_user_event) =
+                        read_head_and_flags(&path, HEAD_RECORD_LIMIT)
+                            .await
+                            .unwrap_or((Vec::new(), false, false));
+                    // Apply filters: must have session meta and at least one user message event
+                    if saw_session_meta && saw_user_event {
+                        items.push(ConversationItem { path, head });
+                    }
                 }
             }
         }
@@ -273,16 +282,19 @@ fn parse_timestamp_uuid_from_filename(name: &str) -> Option<(OffsetDateTime, Uui
     Some((ts, uuid))
 }
 
-async fn read_first_jsonl_records(
+async fn read_head_and_flags(
     path: &Path,
     max_records: usize,
-) -> io::Result<Vec<serde_json::Value>> {
+) -> io::Result<(Vec<serde_json::Value>, bool, bool)> {
     use tokio::io::AsyncBufReadExt;
 
     let file = tokio::fs::File::open(path).await?;
     let reader = tokio::io::BufReader::new(file);
     let mut lines = reader.lines();
     let mut head: Vec<serde_json::Value> = Vec::new();
+    let mut saw_session_meta = false;
+    let mut saw_user_event = false;
+
     while head.len() < max_records {
         let line_opt = lines.next_line().await?;
         let Some(line) = line_opt else { break };
@@ -290,9 +302,29 @@ async fn read_first_jsonl_records(
         if trimmed.is_empty() {
             continue;
         }
-        if let Ok(v) = serde_json::from_str::<serde_json::Value>(trimmed) {
-            head.push(v);
+
+        let parsed: Result<RolloutLine, _> = serde_json::from_str(trimmed);
+        let Ok(rollout_line) = parsed else { continue };
+
+        match rollout_line.item {
+            RolloutItem::SessionMeta(session_meta_line) => {
+                if let Ok(val) = serde_json::to_value(session_meta_line) {
+                    head.push(val);
+                    saw_session_meta = true;
+                }
+            }
+            RolloutItem::ResponseItem(item) => {
+                if let Ok(val) = serde_json::to_value(item) {
+                    head.push(val);
+                }
+            }
+            RolloutItem::EventMsg(ev) => {
+                if matches!(ev, EventMsg::UserMessage(_)) {
+                    saw_user_event = true;
+                }
+            }
         }
     }
-    Ok(head)
+
+    Ok((head, saw_session_meta, saw_user_event))
 }

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

@@ -1,13 +1,15 @@
 //! Rollout module: persistence and discovery of session rollout files.
 
-pub(crate) const SESSIONS_SUBDIR: &str = "sessions";
+pub const SESSIONS_SUBDIR: &str = "sessions";
+pub const ARCHIVED_SESSIONS_SUBDIR: &str = "archived_sessions";
 
 pub mod list;
 pub(crate) mod policy;
 pub mod recorder;
 
+pub use codex_protocol::protocol::SessionMeta;
 pub use recorder::RolloutRecorder;
-pub use recorder::SessionStateSnapshot;
+pub use recorder::RolloutRecorderParams;
 
 #[cfg(test)]
 pub mod tests;

codex-rs/core/src/rollout/policy.rs

@@ -1,8 +1,21 @@
+use crate::protocol::EventMsg;
+use crate::protocol::RolloutItem;
 use codex_protocol::models::ResponseItem;
 
+/// Whether a rollout `item` should be persisted in rollout files.
+#[inline]
+pub(crate) fn is_persisted_response_item(item: &RolloutItem) -> bool {
+    match item {
+        RolloutItem::ResponseItem(item) => should_persist_response_item(item),
+        RolloutItem::EventMsg(ev) => should_persist_event_msg(ev),
+        // Always persist session meta
+        RolloutItem::SessionMeta(_) => true,
+    }
+}
+
 /// Whether a `ResponseItem` should be persisted in rollout files.
 #[inline]
-pub(crate) fn is_persisted_response_item(item: &ResponseItem) -> bool {
+pub(crate) fn should_persist_response_item(item: &ResponseItem) -> bool {
     match item {
         ResponseItem::Message { .. }
         | ResponseItem::Reasoning { .. }
@@ -14,3 +27,44 @@ pub(crate) fn is_persisted_response_item(item: &ResponseItem) -> bool {
         ResponseItem::WebSearchCall { .. } | ResponseItem::Other => false,
     }
 }
+
+/// Whether an `EventMsg` should be persisted in rollout files.
+#[inline]
+pub(crate) fn should_persist_event_msg(ev: &EventMsg) -> bool {
+    match ev {
+        EventMsg::UserMessage(_)
+        | EventMsg::AgentMessage(_)
+        | EventMsg::AgentReasoning(_)
+        | EventMsg::AgentReasoningRawContent(_)
+        | EventMsg::TokenCount(_) => true,
+        EventMsg::Error(_)
+        | EventMsg::TaskStarted(_)
+        | EventMsg::TaskComplete(_)
+        | EventMsg::AgentMessageDelta(_)
+        | EventMsg::AgentReasoningDelta(_)
+        | EventMsg::AgentReasoningRawContentDelta(_)
+        | EventMsg::AgentReasoningSectionBreak(_)
+        | EventMsg::SessionConfigured(_)
+        | EventMsg::McpToolCallBegin(_)
+        | EventMsg::McpToolCallEnd(_)
+        | EventMsg::WebSearchBegin(_)
+        | EventMsg::WebSearchEnd(_)
+        | EventMsg::ExecCommandBegin(_)
+        | EventMsg::ExecCommandOutputDelta(_)
+        | EventMsg::ExecCommandEnd(_)
+        | EventMsg::ExecApprovalRequest(_)
+        | EventMsg::ApplyPatchApprovalRequest(_)
+        | EventMsg::BackgroundEvent(_)
+        | EventMsg::StreamError(_)
+        | EventMsg::PatchApplyBegin(_)
+        | EventMsg::PatchApplyEnd(_)
+        | EventMsg::TurnDiff(_)
+        | EventMsg::GetHistoryEntryResponse(_)
+        | EventMsg::McpListToolsResponse(_)
+        | EventMsg::ListCustomPromptsResponse(_)
+        | EventMsg::PlanUpdate(_)
+        | EventMsg::TurnAborted(_)
+        | EventMsg::ShutdownComplete
+        | EventMsg::ConversationPath(_) => false,
+    }
+}

codex-rs/core/src/rollout/recorder.rs

@@ -4,6 +4,7 @@ use std::fs::File;
 use std::fs::{self};
 use std::io::Error as IoError;
 use std::path::Path;
+use std::path::PathBuf;
 
 use codex_protocol::mcp_protocol::ConversationId;
 use serde::Deserialize;
@@ -25,25 +26,15 @@ use super::list::Cursor;
 use super::list::get_conversations;
 use super::policy::is_persisted_response_item;
 use crate::config::Config;
-use crate::conversation_manager::InitialHistory;
-use crate::git_info::GitInfo;
+use crate::default_client::ORIGINATOR;
 use crate::git_info::collect_git_info;
 use codex_protocol::models::ResponseItem;
-
-#[derive(Serialize, Deserialize, Clone, Default)]
-pub struct SessionMeta {
-    pub id: ConversationId,
-    pub timestamp: String,
-    pub instructions: Option<String>,
-}
-
-#[derive(Serialize)]
-struct SessionMetaWithGit {
-    #[serde(flatten)]
-    meta: SessionMeta,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    git: Option<GitInfo>,
-}
+use codex_protocol::protocol::InitialHistory;
+use codex_protocol::protocol::ResumedHistory;
+use codex_protocol::protocol::RolloutItem;
+use codex_protocol::protocol::RolloutLine;
+use codex_protocol::protocol::SessionMeta;
+use codex_protocol::protocol::SessionMetaLine;
 
 #[derive(Serialize, Deserialize, Default, Clone)]
 pub struct SessionStateSnapshot {}
@@ -70,16 +61,45 @@ pub struct SavedSession {
 #[derive(Clone)]
 pub struct RolloutRecorder {
     tx: Sender<RolloutCmd>,
+    pub(crate) rollout_path: PathBuf,
+}
+
+#[derive(Clone)]
+pub enum RolloutRecorderParams {
+    Create {
+        conversation_id: ConversationId,
+        instructions: Option<String>,
+    },
+    Resume {
+        path: PathBuf,
+    },
 }
 
 enum RolloutCmd {
-    AddItems(Vec<ResponseItem>),
-    UpdateState(SessionStateSnapshot),
-    Shutdown { ack: oneshot::Sender<()> },
+    AddItems(Vec<RolloutItem>),
+    /// Ensure all prior writes are processed; respond when flushed.
+    Flush {
+        ack: oneshot::Sender<()>,
+    },
+    Shutdown {
+        ack: oneshot::Sender<()>,
+    },
+}
+
+impl RolloutRecorderParams {
+    pub fn new(conversation_id: ConversationId, instructions: Option<String>) -> Self {
+        Self::Create {
+            conversation_id,
+            instructions,
+        }
+    }
+
+    pub fn resume(path: PathBuf) -> Self {
+        Self::Resume { path }
+    }
 }
 
 impl RolloutRecorder {
-    #[allow(dead_code)]
     /// List conversations (rollout files) under the provided Codex home directory.
     pub async fn list_conversations(
         codex_home: &Path,
@@ -92,24 +112,49 @@ impl RolloutRecorder {
     /// Attempt to create a new [`RolloutRecorder`]. If the sessions directory
     /// cannot be created or the rollout file cannot be opened we return the
     /// error so the caller can decide whether to disable persistence.
-    pub async fn new(
-        config: &Config,
-        conversation_id: ConversationId,
-        instructions: Option<String>,
-    ) -> std::io::Result<Self> {
-        let LogFileInfo {
-            file,
-            conversation_id: session_id,
-            timestamp,
-        } = create_log_file(config, conversation_id)?;
+    pub async fn new(config: &Config, params: RolloutRecorderParams) -> std::io::Result<Self> {
+        let (file, rollout_path, meta) = match params {
+            RolloutRecorderParams::Create {
+                conversation_id,
+                instructions,
+            } => {
+                let LogFileInfo {
+                    file,
+                    path,
+                    conversation_id: session_id,
+                    timestamp,
+                } = create_log_file(config, conversation_id)?;
 
-        let timestamp_format: &[FormatItem] = format_description!(
-            "[year]-[month]-[day]T[hour]:[minute]:[second].[subsecond digits:3]Z"
-        );
-        let timestamp = timestamp
-            .to_offset(time::UtcOffset::UTC)
-            .format(timestamp_format)
-            .map_err(|e| IoError::other(format!("failed to format timestamp: {e}")))?;
+                let timestamp_format: &[FormatItem] = format_description!(
+                    "[year]-[month]-[day]T[hour]:[minute]:[second].[subsecond digits:3]Z"
+                );
+                let timestamp = timestamp
+                    .to_offset(time::UtcOffset::UTC)
+                    .format(timestamp_format)
+                    .map_err(|e| IoError::other(format!("failed to format timestamp: {e}")))?;
+
+                (
+                    tokio::fs::File::from_std(file),
+                    path,
+                    Some(SessionMeta {
+                        id: session_id,
+                        timestamp,
+                        cwd: config.cwd.clone(),
+                        originator: ORIGINATOR.value.clone(),
+                        cli_version: env!("CARGO_PKG_VERSION").to_string(),
+                        instructions,
+                    }),
+                )
+            }
+            RolloutRecorderParams::Resume { path } => (
+                tokio::fs::OpenOptions::new()
+                    .append(true)
+                    .open(&path)
+                    .await?,
+                path,
+                None,
+            ),
+        };
 
         // Clone the cwd for the spawned task to collect git info asynchronously
         let cwd = config.cwd.clone();
@@ -122,21 +167,12 @@ impl RolloutRecorder {
         // Spawn a Tokio task that owns the file handle and performs async
         // writes. Using `tokio::fs::File` keeps everything on the async I/O
         // driver instead of blocking the runtime.
-        tokio::task::spawn(rollout_writer(
-            tokio::fs::File::from_std(file),
-            rx,
-            Some(SessionMeta {
-                timestamp,
-                id: session_id,
-                instructions,
-            }),
-            cwd,
-        ));
+        tokio::task::spawn(rollout_writer(file, rx, meta, cwd));
 
-        Ok(Self { tx })
+        Ok(Self { tx, rollout_path })
     }
 
-    pub(crate) async fn record_items(&self, items: &[ResponseItem]) -> std::io::Result<()> {
+    pub(crate) async fn record_items(&self, items: &[RolloutItem]) -> std::io::Result<()> {
         let mut filtered = Vec::new();
         for item in items {
             // Note that function calls may look a bit strange if they are
@@ -155,55 +191,85 @@ impl RolloutRecorder {
             .map_err(|e| IoError::other(format!("failed to queue rollout items: {e}")))
     }
 
-    pub(crate) async fn record_state(&self, state: SessionStateSnapshot) -> std::io::Result<()> {
+    /// Flush all queued writes and wait until they are committed by the writer task.
+    pub async fn flush(&self) -> std::io::Result<()> {
+        let (tx, rx) = oneshot::channel();
         self.tx
-            .send(RolloutCmd::UpdateState(state))
+            .send(RolloutCmd::Flush { ack: tx })
             .await
-            .map_err(|e| IoError::other(format!("failed to queue rollout state: {e}")))
+            .map_err(|e| IoError::other(format!("failed to queue rollout flush: {e}")))?;
+        rx.await
+            .map_err(|e| IoError::other(format!("failed waiting for rollout flush: {e}")))
     }
 
-    pub async fn get_rollout_history(path: &Path) -> std::io::Result<InitialHistory> {
+    pub(crate) async fn get_rollout_history(path: &Path) -> std::io::Result<InitialHistory> {
         info!("Resuming rollout from {path:?}");
+        tracing::error!("Resuming rollout from {path:?}");
         let text = tokio::fs::read_to_string(path).await?;
-        let mut lines = text.lines();
-        let _ = lines
-            .next()
-            .ok_or_else(|| IoError::other("empty session file"))?;
-        let mut items = Vec::new();
+        if text.trim().is_empty() {
+            return Err(IoError::other("empty session file"));
+        }
 
-        for line in lines {
+        let mut items: Vec<RolloutItem> = Vec::new();
+        let mut conversation_id: Option<ConversationId> = None;
+        for line in text.lines() {
             if line.trim().is_empty() {
                 continue;
             }
             let v: Value = match serde_json::from_str(line) {
                 Ok(v) => v,
-                Err(_) => continue,
-            };
-            if v.get("record_type")
-                .and_then(|rt| rt.as_str())
-                .map(|s| s == "state")
-                .unwrap_or(false)
-            {
-                continue;
-            }
-            match serde_json::from_value::<ResponseItem>(v.clone()) {
-                Ok(item) => {
-                    if is_persisted_response_item(&item) {
-                        items.push(item);
-                    }
-                }
                 Err(e) => {
-                    warn!("failed to parse item: {v:?}, error: {e}");
+                    warn!("failed to parse line as JSON: {line:?}, error: {e}");
+                    continue;
+                }
+            };
+
+            // Parse the rollout line structure
+            match serde_json::from_value::<RolloutLine>(v.clone()) {
+                Ok(rollout_line) => match rollout_line.item {
+                    RolloutItem::SessionMeta(session_meta_line) => {
+                        // Use the FIRST SessionMeta encountered in the file as the canonical
+                        // conversation id and main session information. Keep all items intact.
+                        if conversation_id.is_none() {
+                            conversation_id = Some(session_meta_line.meta.id);
+                        }
+                        items.push(RolloutItem::SessionMeta(session_meta_line));
+                    }
+                    RolloutItem::ResponseItem(item) => {
+                        items.push(RolloutItem::ResponseItem(item));
+                    }
+                    RolloutItem::EventMsg(_ev) => {
+                        items.push(RolloutItem::EventMsg(_ev));
+                    }
+                },
+                Err(e) => {
+                    warn!("failed to parse rollout line: {v:?}, error: {e}");
                 }
             }
         }
 
-        info!("Resumed rollout successfully from {path:?}");
+        tracing::error!(
+            "Resumed rollout with {} items, conversation ID: {:?}",
+            items.len(),
+            conversation_id
+        );
+        let conversation_id = conversation_id
+            .ok_or_else(|| IoError::other("failed to parse conversation ID from rollout file"))?;
+
         if items.is_empty() {
-            Ok(InitialHistory::New)
-        } else {
-            Ok(InitialHistory::Resumed(items))
+            return Ok(InitialHistory::New);
         }
+
+        info!("Resumed rollout successfully from {path:?}");
+        Ok(InitialHistory::Resumed(ResumedHistory {
+            conversation_id,
+            history: items,
+            rollout_path: path.to_path_buf(),
+        }))
+    }
+
+    pub(crate) fn get_rollout_path(&self) -> PathBuf {
+        self.rollout_path.clone()
     }
 
     pub async fn shutdown(&self) -> std::io::Result<()> {
@@ -226,6 +292,9 @@ struct LogFileInfo {
     /// Opened file handle to the rollout file.
     file: File,
 
+    /// Full path to the rollout file.
+    path: PathBuf,
+
     /// Session ID (also embedded in filename).
     conversation_id: ConversationId,
 
@@ -265,6 +334,7 @@ fn create_log_file(
 
     Ok(LogFileInfo {
         file,
+        path,
         conversation_id,
         timestamp,
     })
@@ -281,13 +351,15 @@ async fn rollout_writer(
     // 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;
-        let session_meta_with_git = SessionMetaWithGit {
+        let session_meta_line = SessionMetaLine {
             meta: session_meta,
             git: git_info,
         };
 
-        // Write the SessionMeta as the first item in the file
-        writer.write_line(&session_meta_with_git).await?;
+        // Write the SessionMeta as the first item in the file, wrapped in a rollout line
+        writer
+            .write_rollout_item(RolloutItem::SessionMeta(session_meta_line))
+            .await?;
     }
 
     // Process rollout commands
@@ -296,23 +368,17 @@ async fn rollout_writer(
             RolloutCmd::AddItems(items) => {
                 for item in items {
                     if is_persisted_response_item(&item) {
-                        writer.write_line(&item).await?;
+                        writer.write_rollout_item(item).await?;
                     }
                 }
             }
-            RolloutCmd::UpdateState(state) => {
-                #[derive(Serialize)]
-                struct StateLine<'a> {
-                    record_type: &'static str,
-                    #[serde(flatten)]
-                    state: &'a SessionStateSnapshot,
+            RolloutCmd::Flush { ack } => {
+                // Ensure underlying file is flushed and then ack.
+                if let Err(e) = writer.file.flush().await {
+                    let _ = ack.send(());
+                    return Err(e);
                 }
-                writer
-                    .write_line(&StateLine {
-                        record_type: "state",
-                        state: &state,
-                    })
-                    .await?;
+                let _ = ack.send(());
             }
             RolloutCmd::Shutdown { ack } => {
                 let _ = ack.send(());
@@ -328,10 +394,24 @@ struct JsonlWriter {
 }
 
 impl JsonlWriter {
+    async fn write_rollout_item(&mut self, rollout_item: RolloutItem) -> std::io::Result<()> {
+        let timestamp_format: &[FormatItem] = format_description!(
+            "[year]-[month]-[day]T[hour]:[minute]:[second].[subsecond digits:3]Z"
+        );
+        let timestamp = OffsetDateTime::now_utc()
+            .format(timestamp_format)
+            .map_err(|e| IoError::other(format!("failed to format timestamp: {e}")))?;
+
+        let line = RolloutLine {
+            timestamp,
+            item: rollout_item,
+        };
+        self.write_line(&line).await
+    }
     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.write_all(json.as_bytes()).await?;
         self.file.flush().await?;
         Ok(())
     }

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

@@ -42,10 +42,30 @@ fn write_session_file(
 
     let meta = serde_json::json!({
         "timestamp": ts_str,
-        "id": uuid.to_string()
+        "type": "session_meta",
+        "payload": {
+            "id": uuid,
+            "timestamp": ts_str,
+            "instructions": null,
+            "cwd": ".",
+            "originator": "test_originator",
+            "cli_version": "test_version"
+        }
     });
     writeln!(file, "{meta}")?;
 
+    // Include at least one user message event to satisfy listing filters
+    let user_event = serde_json::json!({
+        "timestamp": ts_str,
+        "type": "event_msg",
+        "payload": {
+            "type": "user_message",
+            "message": "Hello from user",
+            "kind": "plain"
+        }
+    });
+    writeln!(file, "{user_event}")?;
+
     for i in 0..num_records {
         let rec = serde_json::json!({
             "record_type": "response",
@@ -93,24 +113,30 @@ async fn test_list_conversations_latest_first() {
         .join("01")
         .join(format!("rollout-2025-01-01T12-00-00-{u1}.jsonl"));
 
-    let head_3 = vec![
-        serde_json::json!({"timestamp": "2025-01-03T12-00-00", "id": u3.to_string()}),
-        serde_json::json!({"record_type": "response", "index": 0}),
-        serde_json::json!({"record_type": "response", "index": 1}),
-        serde_json::json!({"record_type": "response", "index": 2}),
-    ];
-    let head_2 = vec![
-        serde_json::json!({"timestamp": "2025-01-02T12-00-00", "id": u2.to_string()}),
-        serde_json::json!({"record_type": "response", "index": 0}),
-        serde_json::json!({"record_type": "response", "index": 1}),
-        serde_json::json!({"record_type": "response", "index": 2}),
-    ];
-    let head_1 = vec![
-        serde_json::json!({"timestamp": "2025-01-01T12-00-00", "id": u1.to_string()}),
-        serde_json::json!({"record_type": "response", "index": 0}),
-        serde_json::json!({"record_type": "response", "index": 1}),
-        serde_json::json!({"record_type": "response", "index": 2}),
-    ];
+    let head_3 = vec![serde_json::json!({
+        "id": u3,
+        "timestamp": "2025-01-03T12-00-00",
+        "instructions": null,
+        "cwd": ".",
+        "originator": "test_originator",
+        "cli_version": "test_version"
+    })];
+    let head_2 = vec![serde_json::json!({
+        "id": u2,
+        "timestamp": "2025-01-02T12-00-00",
+        "instructions": null,
+        "cwd": ".",
+        "originator": "test_originator",
+        "cli_version": "test_version"
+    })];
+    let head_1 = vec![serde_json::json!({
+        "id": u1,
+        "timestamp": "2025-01-01T12-00-00",
+        "instructions": null,
+        "cwd": ".",
+        "originator": "test_originator",
+        "cli_version": "test_version"
+    })];
 
     let expected_cursor: Cursor =
         serde_json::from_str(&format!("\"2025-01-01T12-00-00|{u1}\"")).unwrap();
@@ -170,14 +196,22 @@ async fn test_pagination_cursor() {
         .join("03")
         .join("04")
         .join(format!("rollout-2025-03-04T09-00-00-{u4}.jsonl"));
-    let head_5 = vec![
-        serde_json::json!({"timestamp": "2025-03-05T09-00-00", "id": u5.to_string()}),
-        serde_json::json!({"record_type": "response", "index": 0}),
-    ];
-    let head_4 = vec![
-        serde_json::json!({"timestamp": "2025-03-04T09-00-00", "id": u4.to_string()}),
-        serde_json::json!({"record_type": "response", "index": 0}),
-    ];
+    let head_5 = vec![serde_json::json!({
+        "id": u5,
+        "timestamp": "2025-03-05T09-00-00",
+        "instructions": null,
+        "cwd": ".",
+        "originator": "test_originator",
+        "cli_version": "test_version"
+    })];
+    let head_4 = vec![serde_json::json!({
+        "id": u4,
+        "timestamp": "2025-03-04T09-00-00",
+        "instructions": null,
+        "cwd": ".",
+        "originator": "test_originator",
+        "cli_version": "test_version"
+    })];
     let expected_cursor1: Cursor =
         serde_json::from_str(&format!("\"2025-03-04T09-00-00|{u4}\"")).unwrap();
     let expected_page1 = ConversationsPage {
@@ -212,14 +246,22 @@ async fn test_pagination_cursor() {
         .join("03")
         .join("02")
         .join(format!("rollout-2025-03-02T09-00-00-{u2}.jsonl"));
-    let head_3 = vec![
-        serde_json::json!({"timestamp": "2025-03-03T09-00-00", "id": u3.to_string()}),
-        serde_json::json!({"record_type": "response", "index": 0}),
-    ];
-    let head_2 = vec![
-        serde_json::json!({"timestamp": "2025-03-02T09-00-00", "id": u2.to_string()}),
-        serde_json::json!({"record_type": "response", "index": 0}),
-    ];
+    let head_3 = vec![serde_json::json!({
+        "id": u3,
+        "timestamp": "2025-03-03T09-00-00",
+        "instructions": null,
+        "cwd": ".",
+        "originator": "test_originator",
+        "cli_version": "test_version"
+    })];
+    let head_2 = vec![serde_json::json!({
+        "id": u2,
+        "timestamp": "2025-03-02T09-00-00",
+        "instructions": null,
+        "cwd": ".",
+        "originator": "test_originator",
+        "cli_version": "test_version"
+    })];
     let expected_cursor2: Cursor =
         serde_json::from_str(&format!("\"2025-03-02T09-00-00|{u2}\"")).unwrap();
     let expected_page2 = ConversationsPage {
@@ -248,10 +290,14 @@ async fn test_pagination_cursor() {
         .join("03")
         .join("01")
         .join(format!("rollout-2025-03-01T09-00-00-{u1}.jsonl"));
-    let head_1 = vec![
-        serde_json::json!({"timestamp": "2025-03-01T09-00-00", "id": u1.to_string()}),
-        serde_json::json!({"record_type": "response", "index": 0}),
-    ];
+    let head_1 = vec![serde_json::json!({
+        "id": u1,
+        "timestamp": "2025-03-01T09-00-00",
+        "instructions": null,
+        "cwd": ".",
+        "originator": "test_originator",
+        "cli_version": "test_version"
+    })];
     let expected_cursor3: Cursor =
         serde_json::from_str(&format!("\"2025-03-01T09-00-00|{u1}\"")).unwrap();
     let expected_page3 = ConversationsPage {
@@ -287,11 +333,14 @@ async fn test_get_conversation_contents() {
         .join("04")
         .join("01")
         .join(format!("rollout-2025-04-01T10-30-00-{uuid}.jsonl"));
-    let expected_head = vec![
-        serde_json::json!({"timestamp": ts, "id": uuid.to_string()}),
-        serde_json::json!({"record_type": "response", "index": 0}),
-        serde_json::json!({"record_type": "response", "index": 1}),
-    ];
+    let expected_head = vec![serde_json::json!({
+        "id": uuid,
+        "timestamp": ts,
+        "instructions": null,
+        "cwd": ".",
+        "originator": "test_originator",
+        "cli_version": "test_version"
+    })];
     let expected_cursor: Cursor = serde_json::from_str(&format!("\"{ts}|{uuid}\"")).unwrap();
     let expected_page = ConversationsPage {
         items: vec![ConversationItem {
@@ -305,10 +354,15 @@ async fn test_get_conversation_contents() {
     assert_eq!(page, expected_page);
 
     // Entire file contents equality
-    let meta = serde_json::json!({"timestamp": ts, "id": uuid.to_string()});
+    let meta = serde_json::json!({"timestamp": ts, "type": "session_meta", "payload": {"id": uuid, "timestamp": ts, "instructions": null, "cwd": ".", "originator": "test_originator", "cli_version": "test_version"}});
+    let user_event = serde_json::json!({
+        "timestamp": ts,
+        "type": "event_msg",
+        "payload": {"type": "user_message", "message": "Hello from user", "kind": "plain"}
+    });
     let rec0 = serde_json::json!({"record_type": "response", "index": 0});
     let rec1 = serde_json::json!({"record_type": "response", "index": 1});
-    let expected_content = format!("{meta}\n{rec0}\n{rec1}\n");
+    let expected_content = format!("{meta}\n{user_event}\n{rec0}\n{rec1}\n");
     assert_eq!(content, expected_content);
 }
 
@@ -341,7 +395,14 @@ async fn test_stable_ordering_same_second_pagination() {
         .join("01")
         .join(format!("rollout-2025-07-01T00-00-00-{u2}.jsonl"));
     let head = |u: Uuid| -> Vec<serde_json::Value> {
-        vec![serde_json::json!({"timestamp": ts, "id": u.to_string()})]
+        vec![serde_json::json!({
+            "id": u,
+            "timestamp": ts,
+            "instructions": null,
+            "cwd": ".",
+            "originator": "test_originator",
+            "cli_version": "test_version"
+        })]
     };
     let expected_cursor1: Cursor = serde_json::from_str(&format!("\"{ts}|{u2}\"")).unwrap();
     let expected_page1 = ConversationsPage {

codex-rs/core/src/seatbelt_base_policy.sbpl

@@ -69,3 +69,8 @@
 ; Added on top of Chrome profile
 ; Needed for python multiprocessing on MacOS for the SemLock
 (allow ipc-posix-sem)
+
+; needed to look up user info, see https://crbug.com/792228
+(allow mach-lookup
+  (global-name "com.apple.system.opendirectoryd.libinfo")
+)

codex-rs/core/src/truncate.rs

@@ -0,0 +1,180 @@
+//! Utilities for truncating large chunks of output while preserving a prefix
+//! and suffix on UTF-8 boundaries.
+
+/// Truncate the middle of a UTF-8 string to at most `max_bytes` bytes,
+/// preserving the beginning and the end. Returns the possibly truncated
+/// string and `Some(original_token_count)` (estimated at 4 bytes/token)
+/// if truncation occurred; otherwise returns the original string and `None`.
+pub(crate) fn truncate_middle(s: &str, max_bytes: usize) -> (String, Option<u64>) {
+    if s.len() <= max_bytes {
+        return (s.to_string(), None);
+    }
+
+    let est_tokens = (s.len() as u64).div_ceil(4);
+    if max_bytes == 0 {
+        return (format!("…{est_tokens} tokens truncated…"), Some(est_tokens));
+    }
+
+    fn truncate_on_boundary(input: &str, max_len: usize) -> &str {
+        if input.len() <= max_len {
+            return input;
+        }
+        let mut end = max_len;
+        while end > 0 && !input.is_char_boundary(end) {
+            end -= 1;
+        }
+        &input[..end]
+    }
+
+    fn pick_prefix_end(s: &str, left_budget: usize) -> usize {
+        if let Some(head) = s.get(..left_budget)
+            && let Some(i) = head.rfind('\n')
+        {
+            return i + 1;
+        }
+        truncate_on_boundary(s, left_budget).len()
+    }
+
+    fn pick_suffix_start(s: &str, right_budget: usize) -> usize {
+        let start_tail = s.len().saturating_sub(right_budget);
+        if let Some(tail) = s.get(start_tail..)
+            && let Some(i) = tail.find('\n')
+        {
+            return start_tail + i + 1;
+        }
+
+        let mut idx = start_tail.min(s.len());
+        while idx < s.len() && !s.is_char_boundary(idx) {
+            idx += 1;
+        }
+        idx
+    }
+
+    let mut guess_tokens = est_tokens;
+    for _ in 0..4 {
+        let marker = format!("…{guess_tokens} tokens truncated…");
+        let marker_len = marker.len();
+        let keep_budget = max_bytes.saturating_sub(marker_len);
+        if keep_budget == 0 {
+            return (format!("…{est_tokens} tokens truncated…"), Some(est_tokens));
+        }
+
+        let left_budget = keep_budget / 2;
+        let right_budget = keep_budget - left_budget;
+        let prefix_end = pick_prefix_end(s, left_budget);
+        let mut suffix_start = pick_suffix_start(s, right_budget);
+        if suffix_start < prefix_end {
+            suffix_start = prefix_end;
+        }
+
+        let kept_content_bytes = prefix_end + (s.len() - suffix_start);
+        let truncated_content_bytes = s.len().saturating_sub(kept_content_bytes);
+        let new_tokens = (truncated_content_bytes as u64).div_ceil(4);
+
+        if new_tokens == guess_tokens {
+            let mut out = String::with_capacity(marker_len + kept_content_bytes + 1);
+            out.push_str(&s[..prefix_end]);
+            out.push_str(&marker);
+            out.push('\n');
+            out.push_str(&s[suffix_start..]);
+            return (out, Some(est_tokens));
+        }
+
+        guess_tokens = new_tokens;
+    }
+
+    let marker = format!("…{guess_tokens} tokens truncated…");
+    let marker_len = marker.len();
+    let keep_budget = max_bytes.saturating_sub(marker_len);
+    if keep_budget == 0 {
+        return (format!("…{est_tokens} tokens truncated…"), Some(est_tokens));
+    }
+
+    let left_budget = keep_budget / 2;
+    let right_budget = keep_budget - left_budget;
+    let prefix_end = pick_prefix_end(s, left_budget);
+    let suffix_start = pick_suffix_start(s, right_budget);
+
+    let mut out = String::with_capacity(marker_len + prefix_end + (s.len() - suffix_start) + 1);
+    out.push_str(&s[..prefix_end]);
+    out.push_str(&marker);
+    out.push('\n');
+    out.push_str(&s[suffix_start..]);
+    (out, Some(est_tokens))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::truncate_middle;
+
+    #[test]
+    fn truncate_middle_no_newlines_fallback() {
+        let s = "abcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ*";
+        let max_bytes = 32;
+        let (out, original) = truncate_middle(s, max_bytes);
+        assert!(out.starts_with("abc"));
+        assert!(out.contains("tokens truncated"));
+        assert!(out.ends_with("XYZ*"));
+        assert_eq!(original, Some((s.len() as u64).div_ceil(4)));
+    }
+
+    #[test]
+    fn truncate_middle_prefers_newline_boundaries() {
+        let mut s = String::new();
+        for i in 1..=20 {
+            s.push_str(&format!("{i:03}\n"));
+        }
+        assert_eq!(s.len(), 80);
+
+        let max_bytes = 64;
+        let (out, tokens) = truncate_middle(&s, max_bytes);
+        assert!(out.starts_with("001\n002\n003\n004\n"));
+        assert!(out.contains("tokens truncated"));
+        assert!(out.ends_with("017\n018\n019\n020\n"));
+        assert_eq!(tokens, Some(20));
+    }
+
+    #[test]
+    fn truncate_middle_handles_utf8_content() {
+        let s = "😀😀😀😀😀😀😀😀😀😀\nsecond line with ascii text\n";
+        let max_bytes = 32;
+        let (out, tokens) = truncate_middle(s, max_bytes);
+
+        assert!(out.contains("tokens truncated"));
+        assert!(!out.contains('\u{fffd}'));
+        assert_eq!(tokens, Some((s.len() as u64).div_ceil(4)));
+    }
+
+    #[test]
+    fn truncate_middle_prefers_newline_boundaries_2() {
+        // Build a multi-line string of 20 numbered lines (each "NNN\n").
+        let mut s = String::new();
+        for i in 1..=20 {
+            s.push_str(&format!("{i:03}\n"));
+        }
+        // Total length: 20 lines * 4 bytes per line = 80 bytes.
+        assert_eq!(s.len(), 80);
+
+        // Choose a cap that forces truncation while leaving room for
+        // a few lines on each side after accounting for the marker.
+        let max_bytes = 64;
+        // Expect exact output: first 4 lines, marker, last 4 lines, and correct token estimate (80/4 = 20).
+        assert_eq!(
+            truncate_middle(&s, max_bytes),
+            (
+                r#"001
+002
+003
+004
+…12 tokens truncated…
+017
+018
+019
+020
+"#
+                .to_string(),
+                Some(20)
+            )
+        );
+    }
+}

codex-rs/core/src/turn_diff_tracker.rs

@@ -1,4 +1,3 @@
-use std::collections::BTreeSet;
 use std::collections::HashMap;
 use std::fs;
 use std::path::Path;
@@ -250,64 +249,6 @@ impl TurnDiffTracker {
         }
     }
 
-    pub fn build_undo_patch(&mut self) -> Result<Option<String>> {
-        let mut delete_paths: BTreeSet<PathBuf> = BTreeSet::new();
-        let mut add_entries: Vec<(PathBuf, String)> = Vec::new();
-
-        let mut baseline_file_names: Vec<String> =
-            self.baseline_file_info.keys().cloned().collect();
-        baseline_file_names.sort();
-
-        for internal in baseline_file_names {
-            let Some(info) = self.baseline_file_info.get(&internal) else {
-                continue;
-            };
-            let current_path = self
-                .get_path_for_internal(&internal)
-                .unwrap_or(info.path.clone());
-            if current_path.exists() {
-                delete_paths.insert(current_path);
-            }
-
-            if info.oid.as_str() != ZERO_OID {
-                let content = String::from_utf8(info.content.clone()).map_err(|_| {
-                    anyhow!(
-                        "undo is not supported for non-UTF8 baseline file {}",
-                        info.path.display()
-                    )
-                })?;
-                add_entries.push((info.path.clone(), content));
-            }
-        }
-
-        if delete_paths.is_empty() && add_entries.is_empty() {
-            return Ok(None);
-        }
-
-        add_entries.sort_by(|(left_path, _), (right_path, _)| left_path.cmp(right_path));
-
-        let mut patch = String::from("*** Begin Patch\n");
-        for path in delete_paths {
-            patch.push_str(&format!("*** Delete File: {}\n", path.display()));
-        }
-
-        for (path, content) in add_entries {
-            patch.push_str(&format!("*** Add File: {}\n", path.display()));
-            if !content.is_empty() {
-                for line in content.split_terminator('\n') {
-                    patch.push('+');
-                    patch.push_str(line);
-                    patch.push('\n');
-                }
-                if !content.ends_with('\n') {
-                    patch.push_str("+\n");
-                }
-            }
-        }
-        patch.push_str("*** End Patch\n");
-        Ok(Some(patch))
-    }
-
     fn get_file_diff(&mut self, internal_file_name: &str) -> String {
         let mut aggregated = String::new();
 
@@ -562,146 +503,6 @@ mod tests {
         out
     }
 
-    fn normalize_patch_for_test(input: &str, root: &Path) -> String {
-        let root_str = root.display().to_string().replace('\\', "/");
-        let mut replaced = input.replace('\\', "/");
-        replaced = replaced.replace(&root_str, "<TMP>");
-
-        if let Some(root_name) = root.file_name().and_then(|name| name.to_str()) {
-            let marker = format!("/{root_name}");
-            let mut normalized = String::with_capacity(replaced.len());
-            let mut search_start = 0;
-
-            while let Some(relative_pos) = replaced[search_start..].find(&marker) {
-                let absolute_pos = search_start + relative_pos;
-
-                let path_start = replaced[..absolute_pos]
-                    .rfind(['\n', ' '])
-                    .map(|idx| idx + 1)
-                    .unwrap_or(0);
-
-                let prefix_end = replaced[path_start..absolute_pos]
-                    .find('/')
-                    .map(|idx| path_start + idx + 1)
-                    .unwrap_or(path_start);
-
-                normalized.push_str(&replaced[search_start..prefix_end]);
-                normalized.push_str("<TMP>");
-
-                let after_marker = absolute_pos + marker.len();
-                let mut rest_start = after_marker;
-                if after_marker < replaced.len() && replaced.as_bytes()[after_marker] == b'/' {
-                    normalized.push('/');
-                    rest_start += 1;
-                }
-
-                search_start = rest_start;
-            }
-
-            normalized.push_str(&replaced[search_start..]);
-            replaced = normalized;
-        }
-
-        if !replaced.ends_with('\n') {
-            replaced.push('\n');
-        }
-        replaced
-    }
-
-    #[test]
-    fn build_undo_patch_returns_none_without_baseline() {
-        let mut tracker = TurnDiffTracker::new();
-        assert_eq!(tracker.build_undo_patch().unwrap(), None);
-    }
-
-    #[test]
-    fn build_undo_patch_restores_updated_file() {
-        let dir = tempdir().unwrap();
-        let path = dir.path().join("undo.txt");
-        fs::write(&path, "before\n").unwrap();
-
-        let mut tracker = TurnDiffTracker::new();
-        let update_changes = HashMap::from([(
-            path.clone(),
-            FileChange::Update {
-                unified_diff: String::new(),
-                move_path: None,
-            },
-        )]);
-        tracker.on_patch_begin(&update_changes);
-
-        fs::write(&path, "after\n").unwrap();
-
-        let patch = tracker
-            .build_undo_patch()
-            .expect("undo patch")
-            .expect("some undo patch");
-        let normalized = normalize_patch_for_test(&patch, dir.path());
-        let expected = concat!(
-            "*** Begin Patch\n",
-            "*** Delete File: <TMP>/undo.txt\n",
-            "*** Add File: <TMP>/undo.txt\n",
-            "+before\n",
-            "*** End Patch\n",
-        );
-        assert_eq!(normalized, expected);
-    }
-
-    #[test]
-    fn build_undo_patch_restores_deleted_file() {
-        let dir = tempdir().unwrap();
-        let path = dir.path().join("gone.txt");
-        fs::write(&path, "gone\n").unwrap();
-
-        let mut tracker = TurnDiffTracker::new();
-        let delete_changes = HashMap::from([(
-            path.clone(),
-            FileChange::Delete {
-                content: "gone\n".to_string(),
-            },
-        )]);
-        tracker.on_patch_begin(&delete_changes);
-
-        fs::remove_file(&path).unwrap();
-
-        let patch = tracker
-            .build_undo_patch()
-            .expect("undo patch")
-            .expect("some undo patch");
-        let normalized = normalize_patch_for_test(&patch, dir.path());
-        let expected = concat!(
-            "*** Begin Patch\n",
-            "*** Add File: <TMP>/gone.txt\n",
-            "+gone\n",
-            "*** End Patch\n",
-        );
-        assert_eq!(normalized, expected);
-    }
-
-    #[test]
-    fn build_undo_patch_rejects_non_utf8_content() {
-        let dir = tempdir().unwrap();
-        let path = dir.path().join("binary.bin");
-        fs::write(&path, [0xff, 0xfe, 0x00]).unwrap();
-
-        let mut tracker = TurnDiffTracker::new();
-        let update_changes = HashMap::from([(
-            path.clone(),
-            FileChange::Update {
-                unified_diff: String::new(),
-                move_path: None,
-            },
-        )]);
-        tracker.on_patch_begin(&update_changes);
-
-        let err = tracker.build_undo_patch().unwrap_err();
-        let message = format!("{err:#}");
-        assert!(
-            message.contains("undo is not supported for non-UTF8 baseline file"),
-            "unexpected error message: {message}"
-        );
-    }
-
     #[test]
     fn accumulates_add_and_update() {
         let mut acc = TurnDiffTracker::new();

codex-rs/core/src/unified_exec/errors.rs

@@ -0,0 +1,22 @@
+use thiserror::Error;
+
+#[derive(Debug, Error)]
+pub(crate) enum UnifiedExecError {
+    #[error("Failed to create unified exec session: {pty_error}")]
+    CreateSession {
+        #[source]
+        pty_error: anyhow::Error,
+    },
+    #[error("Unknown session id {session_id}")]
+    UnknownSessionId { session_id: i32 },
+    #[error("failed to write to stdin")]
+    WriteToStdin,
+    #[error("missing command line for unified exec request")]
+    MissingCommandLine,
+}
+
+impl UnifiedExecError {
+    pub(crate) fn create_session(error: anyhow::Error) -> Self {
+        Self::CreateSession { pty_error: error }
+    }
+}

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

@@ -0,0 +1,653 @@
+use portable_pty::CommandBuilder;
+use portable_pty::PtySize;
+use portable_pty::native_pty_system;
+use std::collections::HashMap;
+use std::collections::VecDeque;
+use std::io::ErrorKind;
+use std::io::Read;
+use std::sync::Arc;
+use std::sync::Mutex as StdMutex;
+use std::sync::atomic::AtomicBool;
+use std::sync::atomic::AtomicI32;
+use std::sync::atomic::Ordering;
+use tokio::sync::Mutex;
+use tokio::sync::Notify;
+use tokio::sync::mpsc;
+use tokio::task::JoinHandle;
+use tokio::time::Duration;
+use tokio::time::Instant;
+
+use crate::exec_command::ExecCommandSession;
+use crate::truncate::truncate_middle;
+
+mod errors;
+
+pub(crate) use errors::UnifiedExecError;
+
+const DEFAULT_TIMEOUT_MS: u64 = 1_000;
+const MAX_TIMEOUT_MS: u64 = 60_000;
+const UNIFIED_EXEC_OUTPUT_MAX_BYTES: usize = 128 * 1024; // 128 KiB
+
+#[derive(Debug)]
+pub(crate) struct UnifiedExecRequest<'a> {
+    pub session_id: Option<i32>,
+    pub input_chunks: &'a [String],
+    pub timeout_ms: Option<u64>,
+}
+
+#[derive(Debug, Clone, PartialEq)]
+pub(crate) struct UnifiedExecResult {
+    pub session_id: Option<i32>,
+    pub output: String,
+}
+
+#[derive(Debug, Default)]
+pub(crate) struct UnifiedExecSessionManager {
+    next_session_id: AtomicI32,
+    sessions: Mutex<HashMap<i32, ManagedUnifiedExecSession>>,
+}
+
+#[derive(Debug)]
+struct ManagedUnifiedExecSession {
+    session: ExecCommandSession,
+    output_buffer: OutputBuffer,
+    /// Notifies waiters whenever new output has been appended to
+    /// `output_buffer`, allowing clients to poll for fresh data.
+    output_notify: Arc<Notify>,
+    output_task: JoinHandle<()>,
+}
+
+#[derive(Debug, Default)]
+struct OutputBufferState {
+    chunks: VecDeque<Vec<u8>>,
+    total_bytes: usize,
+}
+
+impl OutputBufferState {
+    fn push_chunk(&mut self, chunk: Vec<u8>) {
+        self.total_bytes = self.total_bytes.saturating_add(chunk.len());
+        self.chunks.push_back(chunk);
+
+        let mut excess = self
+            .total_bytes
+            .saturating_sub(UNIFIED_EXEC_OUTPUT_MAX_BYTES);
+
+        while excess > 0 {
+            match self.chunks.front_mut() {
+                Some(front) if excess >= front.len() => {
+                    excess -= front.len();
+                    self.total_bytes = self.total_bytes.saturating_sub(front.len());
+                    self.chunks.pop_front();
+                }
+                Some(front) => {
+                    front.drain(..excess);
+                    self.total_bytes = self.total_bytes.saturating_sub(excess);
+                    break;
+                }
+                None => break,
+            }
+        }
+    }
+
+    fn drain(&mut self) -> Vec<Vec<u8>> {
+        let drained: Vec<Vec<u8>> = self.chunks.drain(..).collect();
+        self.total_bytes = 0;
+        drained
+    }
+}
+
+type OutputBuffer = Arc<Mutex<OutputBufferState>>;
+type OutputHandles = (OutputBuffer, Arc<Notify>);
+
+impl ManagedUnifiedExecSession {
+    fn new(session: ExecCommandSession) -> Self {
+        let output_buffer = Arc::new(Mutex::new(OutputBufferState::default()));
+        let output_notify = Arc::new(Notify::new());
+        let mut receiver = session.output_receiver();
+        let buffer_clone = Arc::clone(&output_buffer);
+        let notify_clone = Arc::clone(&output_notify);
+        let output_task = tokio::spawn(async move {
+            while let Ok(chunk) = receiver.recv().await {
+                let mut guard = buffer_clone.lock().await;
+                guard.push_chunk(chunk);
+                drop(guard);
+                notify_clone.notify_waiters();
+            }
+        });
+
+        Self {
+            session,
+            output_buffer,
+            output_notify,
+            output_task,
+        }
+    }
+
+    fn writer_sender(&self) -> mpsc::Sender<Vec<u8>> {
+        self.session.writer_sender()
+    }
+
+    fn output_handles(&self) -> OutputHandles {
+        (
+            Arc::clone(&self.output_buffer),
+            Arc::clone(&self.output_notify),
+        )
+    }
+
+    fn has_exited(&self) -> bool {
+        self.session.has_exited()
+    }
+}
+
+impl Drop for ManagedUnifiedExecSession {
+    fn drop(&mut self) {
+        self.output_task.abort();
+    }
+}
+
+impl UnifiedExecSessionManager {
+    pub async fn handle_request(
+        &self,
+        request: UnifiedExecRequest<'_>,
+    ) -> Result<UnifiedExecResult, UnifiedExecError> {
+        let (timeout_ms, timeout_warning) = match request.timeout_ms {
+            Some(requested) if requested > MAX_TIMEOUT_MS => (
+                MAX_TIMEOUT_MS,
+                Some(format!(
+                    "Warning: requested timeout {requested}ms exceeds maximum of {MAX_TIMEOUT_MS}ms; clamping to {MAX_TIMEOUT_MS}ms.\n"
+                )),
+            ),
+            Some(requested) => (requested, None),
+            None => (DEFAULT_TIMEOUT_MS, None),
+        };
+
+        let mut new_session: Option<ManagedUnifiedExecSession> = None;
+        let session_id;
+        let writer_tx;
+        let output_buffer;
+        let output_notify;
+
+        if let Some(existing_id) = request.session_id {
+            let mut sessions = self.sessions.lock().await;
+            match sessions.get(&existing_id) {
+                Some(session) => {
+                    if session.has_exited() {
+                        sessions.remove(&existing_id);
+                        return Err(UnifiedExecError::UnknownSessionId {
+                            session_id: existing_id,
+                        });
+                    }
+                    let (buffer, notify) = session.output_handles();
+                    session_id = existing_id;
+                    writer_tx = session.writer_sender();
+                    output_buffer = buffer;
+                    output_notify = notify;
+                }
+                None => {
+                    return Err(UnifiedExecError::UnknownSessionId {
+                        session_id: existing_id,
+                    });
+                }
+            }
+            drop(sessions);
+        } else {
+            let command = request.input_chunks.to_vec();
+            let new_id = self.next_session_id.fetch_add(1, Ordering::SeqCst);
+            let session = create_unified_exec_session(&command).await?;
+            let managed_session = ManagedUnifiedExecSession::new(session);
+            let (buffer, notify) = managed_session.output_handles();
+            writer_tx = managed_session.writer_sender();
+            output_buffer = buffer;
+            output_notify = notify;
+            session_id = new_id;
+            new_session = Some(managed_session);
+        };
+
+        if request.session_id.is_some() {
+            let joined_input = request.input_chunks.join(" ");
+            if !joined_input.is_empty() && writer_tx.send(joined_input.into_bytes()).await.is_err()
+            {
+                return Err(UnifiedExecError::WriteToStdin);
+            }
+        }
+
+        let mut collected: Vec<u8> = Vec::with_capacity(4096);
+        let start = Instant::now();
+        let deadline = start + Duration::from_millis(timeout_ms);
+
+        loop {
+            let drained_chunks;
+            let mut wait_for_output = None;
+            {
+                let mut guard = output_buffer.lock().await;
+                drained_chunks = guard.drain();
+                if drained_chunks.is_empty() {
+                    wait_for_output = Some(output_notify.notified());
+                }
+            }
+
+            if drained_chunks.is_empty() {
+                let remaining = deadline.saturating_duration_since(Instant::now());
+                if remaining == Duration::ZERO {
+                    break;
+                }
+
+                let notified = wait_for_output.unwrap_or_else(|| output_notify.notified());
+                tokio::pin!(notified);
+                tokio::select! {
+                    _ = &mut notified => {}
+                    _ = tokio::time::sleep(remaining) => break,
+                }
+                continue;
+            }
+
+            for chunk in drained_chunks {
+                collected.extend_from_slice(&chunk);
+            }
+
+            if Instant::now() >= deadline {
+                break;
+            }
+        }
+
+        let (output, _maybe_tokens) = truncate_middle(
+            &String::from_utf8_lossy(&collected),
+            UNIFIED_EXEC_OUTPUT_MAX_BYTES,
+        );
+        let output = if let Some(warning) = timeout_warning {
+            format!("{warning}{output}")
+        } else {
+            output
+        };
+
+        let should_store_session = if let Some(session) = new_session.as_ref() {
+            !session.has_exited()
+        } else if request.session_id.is_some() {
+            let mut sessions = self.sessions.lock().await;
+            if let Some(existing) = sessions.get(&session_id) {
+                if existing.has_exited() {
+                    sessions.remove(&session_id);
+                    false
+                } else {
+                    true
+                }
+            } else {
+                false
+            }
+        } else {
+            true
+        };
+
+        if should_store_session {
+            if let Some(session) = new_session {
+                self.sessions.lock().await.insert(session_id, session);
+            }
+            Ok(UnifiedExecResult {
+                session_id: Some(session_id),
+                output,
+            })
+        } else {
+            Ok(UnifiedExecResult {
+                session_id: None,
+                output,
+            })
+        }
+    }
+}
+
+async fn create_unified_exec_session(
+    command: &[String],
+) -> Result<ExecCommandSession, UnifiedExecError> {
+    if command.is_empty() {
+        return Err(UnifiedExecError::MissingCommandLine);
+    }
+
+    let pty_system = native_pty_system();
+
+    let pair = pty_system
+        .openpty(PtySize {
+            rows: 24,
+            cols: 80,
+            pixel_width: 0,
+            pixel_height: 0,
+        })
+        .map_err(UnifiedExecError::create_session)?;
+
+    // Safe thanks to the check at the top of the function.
+    let mut command_builder = CommandBuilder::new(command[0].clone());
+    for arg in &command[1..] {
+        command_builder.arg(arg);
+    }
+
+    let mut child = pair
+        .slave
+        .spawn_command(command_builder)
+        .map_err(UnifiedExecError::create_session)?;
+    let killer = child.clone_killer();
+
+    let (writer_tx, mut writer_rx) = mpsc::channel::<Vec<u8>>(128);
+    let (output_tx, _) = tokio::sync::broadcast::channel::<Vec<u8>>(256);
+
+    let mut reader = pair
+        .master
+        .try_clone_reader()
+        .map_err(UnifiedExecError::create_session)?;
+    let output_tx_clone = output_tx.clone();
+    let reader_handle = tokio::task::spawn_blocking(move || {
+        let mut buf = [0u8; 8192];
+        loop {
+            match reader.read(&mut buf) {
+                Ok(0) => break,
+                Ok(n) => {
+                    let _ = output_tx_clone.send(buf[..n].to_vec());
+                }
+                Err(ref e) if e.kind() == ErrorKind::Interrupted => continue,
+                Err(ref e) if e.kind() == ErrorKind::WouldBlock => {
+                    std::thread::sleep(Duration::from_millis(5));
+                    continue;
+                }
+                Err(_) => break,
+            }
+        }
+    });
+
+    let writer = pair
+        .master
+        .take_writer()
+        .map_err(UnifiedExecError::create_session)?;
+    let writer = Arc::new(StdMutex::new(writer));
+    let writer_handle = tokio::spawn({
+        let writer = writer.clone();
+        async move {
+            while let Some(bytes) = writer_rx.recv().await {
+                let writer = writer.clone();
+                let _ = tokio::task::spawn_blocking(move || {
+                    if let Ok(mut guard) = writer.lock() {
+                        use std::io::Write;
+                        let _ = guard.write_all(&bytes);
+                        let _ = guard.flush();
+                    }
+                })
+                .await;
+            }
+        }
+    });
+
+    let exit_status = Arc::new(AtomicBool::new(false));
+    let wait_exit_status = Arc::clone(&exit_status);
+    let wait_handle = tokio::task::spawn_blocking(move || {
+        let _ = child.wait();
+        wait_exit_status.store(true, Ordering::SeqCst);
+    });
+
+    Ok(ExecCommandSession::new(
+        writer_tx,
+        output_tx,
+        killer,
+        reader_handle,
+        writer_handle,
+        wait_handle,
+        exit_status,
+    ))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn push_chunk_trims_only_excess_bytes() {
+        let mut buffer = OutputBufferState::default();
+        buffer.push_chunk(vec![b'a'; UNIFIED_EXEC_OUTPUT_MAX_BYTES]);
+        buffer.push_chunk(vec![b'b']);
+        buffer.push_chunk(vec![b'c']);
+
+        assert_eq!(buffer.total_bytes, UNIFIED_EXEC_OUTPUT_MAX_BYTES);
+        assert_eq!(buffer.chunks.len(), 3);
+        assert_eq!(
+            buffer.chunks.front().unwrap().len(),
+            UNIFIED_EXEC_OUTPUT_MAX_BYTES - 2
+        );
+        assert_eq!(buffer.chunks.pop_back().unwrap(), vec![b'c']);
+        assert_eq!(buffer.chunks.pop_back().unwrap(), vec![b'b']);
+    }
+
+    #[cfg(unix)]
+    #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+    async fn unified_exec_persists_across_requests_jif() -> Result<(), UnifiedExecError> {
+        let manager = UnifiedExecSessionManager::default();
+
+        let open_shell = manager
+            .handle_request(UnifiedExecRequest {
+                session_id: None,
+                input_chunks: &["bash".to_string(), "-i".to_string()],
+                timeout_ms: Some(1_500),
+            })
+            .await?;
+        let session_id = open_shell.session_id.expect("expected session_id");
+
+        manager
+            .handle_request(UnifiedExecRequest {
+                session_id: Some(session_id),
+                input_chunks: &[
+                    "export".to_string(),
+                    "CODEX_INTERACTIVE_SHELL_VAR=codex\n".to_string(),
+                ],
+                timeout_ms: Some(2_500),
+            })
+            .await?;
+
+        let out_2 = manager
+            .handle_request(UnifiedExecRequest {
+                session_id: Some(session_id),
+                input_chunks: &["echo $CODEX_INTERACTIVE_SHELL_VAR\n".to_string()],
+                timeout_ms: Some(1_500),
+            })
+            .await?;
+        assert!(out_2.output.contains("codex"));
+
+        Ok(())
+    }
+
+    #[cfg(unix)]
+    #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+    async fn multi_unified_exec_sessions() -> Result<(), UnifiedExecError> {
+        let manager = UnifiedExecSessionManager::default();
+
+        let shell_a = manager
+            .handle_request(UnifiedExecRequest {
+                session_id: None,
+                input_chunks: &["/bin/bash".to_string(), "-i".to_string()],
+                timeout_ms: Some(1_500),
+            })
+            .await?;
+        let session_a = shell_a.session_id.expect("expected session id");
+
+        manager
+            .handle_request(UnifiedExecRequest {
+                session_id: Some(session_a),
+                input_chunks: &["export CODEX_INTERACTIVE_SHELL_VAR=codex\n".to_string()],
+                timeout_ms: Some(1_500),
+            })
+            .await?;
+
+        let out_2 = manager
+            .handle_request(UnifiedExecRequest {
+                session_id: None,
+                input_chunks: &[
+                    "echo".to_string(),
+                    "$CODEX_INTERACTIVE_SHELL_VAR\n".to_string(),
+                ],
+                timeout_ms: Some(1_500),
+            })
+            .await?;
+        assert!(!out_2.output.contains("codex"));
+
+        let out_3 = manager
+            .handle_request(UnifiedExecRequest {
+                session_id: Some(session_a),
+                input_chunks: &["echo $CODEX_INTERACTIVE_SHELL_VAR\n".to_string()],
+                timeout_ms: Some(1_500),
+            })
+            .await?;
+        assert!(out_3.output.contains("codex"));
+
+        Ok(())
+    }
+
+    #[cfg(unix)]
+    #[tokio::test]
+    async fn unified_exec_timeouts() -> Result<(), UnifiedExecError> {
+        let manager = UnifiedExecSessionManager::default();
+
+        let open_shell = manager
+            .handle_request(UnifiedExecRequest {
+                session_id: None,
+                input_chunks: &["bash".to_string(), "-i".to_string()],
+                timeout_ms: Some(1_500),
+            })
+            .await?;
+        let session_id = open_shell.session_id.expect("expected session id");
+
+        manager
+            .handle_request(UnifiedExecRequest {
+                session_id: Some(session_id),
+                input_chunks: &[
+                    "export".to_string(),
+                    "CODEX_INTERACTIVE_SHELL_VAR=codex\n".to_string(),
+                ],
+                timeout_ms: Some(1_500),
+            })
+            .await?;
+
+        let out_2 = manager
+            .handle_request(UnifiedExecRequest {
+                session_id: Some(session_id),
+                input_chunks: &["sleep 5 && echo $CODEX_INTERACTIVE_SHELL_VAR\n".to_string()],
+                timeout_ms: Some(10),
+            })
+            .await?;
+        assert!(!out_2.output.contains("codex"));
+
+        tokio::time::sleep(Duration::from_secs(7)).await;
+
+        let empty = Vec::new();
+        let out_3 = manager
+            .handle_request(UnifiedExecRequest {
+                session_id: Some(session_id),
+                input_chunks: &empty,
+                timeout_ms: Some(100),
+            })
+            .await?;
+
+        assert!(out_3.output.contains("codex"));
+
+        Ok(())
+    }
+
+    #[cfg(unix)]
+    #[tokio::test]
+    async fn requests_with_large_timeout_are_capped() -> Result<(), UnifiedExecError> {
+        let manager = UnifiedExecSessionManager::default();
+
+        let result = manager
+            .handle_request(UnifiedExecRequest {
+                session_id: None,
+                input_chunks: &["echo".to_string(), "codex".to_string()],
+                timeout_ms: Some(120_000),
+            })
+            .await?;
+
+        assert!(result.output.starts_with(
+            "Warning: requested timeout 120000ms exceeds maximum of 60000ms; clamping to 60000ms.\n"
+        ));
+        assert!(result.output.contains("codex"));
+
+        Ok(())
+    }
+
+    #[cfg(unix)]
+    #[tokio::test]
+    async fn completed_commands_do_not_persist_sessions() -> Result<(), UnifiedExecError> {
+        let manager = UnifiedExecSessionManager::default();
+        let result = manager
+            .handle_request(UnifiedExecRequest {
+                session_id: None,
+                input_chunks: &["/bin/echo".to_string(), "codex".to_string()],
+                timeout_ms: Some(1_500),
+            })
+            .await?;
+
+        assert!(result.session_id.is_none());
+        assert!(result.output.contains("codex"));
+
+        assert!(manager.sessions.lock().await.is_empty());
+
+        Ok(())
+    }
+
+    #[cfg(unix)]
+    #[tokio::test]
+    async fn correct_path_resolution() -> Result<(), UnifiedExecError> {
+        let manager = UnifiedExecSessionManager::default();
+        let result = manager
+            .handle_request(UnifiedExecRequest {
+                session_id: None,
+                input_chunks: &["echo".to_string(), "codex".to_string()],
+                timeout_ms: Some(1_500),
+            })
+            .await?;
+
+        assert!(result.session_id.is_none());
+        assert!(result.output.contains("codex"));
+
+        assert!(manager.sessions.lock().await.is_empty());
+
+        Ok(())
+    }
+
+    #[cfg(unix)]
+    #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+    async fn reusing_completed_session_returns_unknown_session() -> Result<(), UnifiedExecError> {
+        let manager = UnifiedExecSessionManager::default();
+
+        let open_shell = manager
+            .handle_request(UnifiedExecRequest {
+                session_id: None,
+                input_chunks: &["/bin/bash".to_string(), "-i".to_string()],
+                timeout_ms: Some(1_500),
+            })
+            .await?;
+        let session_id = open_shell.session_id.expect("expected session id");
+
+        manager
+            .handle_request(UnifiedExecRequest {
+                session_id: Some(session_id),
+                input_chunks: &["exit\n".to_string()],
+                timeout_ms: Some(1_500),
+            })
+            .await?;
+
+        tokio::time::sleep(Duration::from_millis(200)).await;
+
+        let err = manager
+            .handle_request(UnifiedExecRequest {
+                session_id: Some(session_id),
+                input_chunks: &[],
+                timeout_ms: Some(100),
+            })
+            .await
+            .expect_err("expected unknown session error");
+
+        match err {
+            UnifiedExecError::UnknownSessionId { session_id: err_id } => {
+                assert_eq!(err_id, session_id);
+            }
+            other => panic!("expected UnknownSessionId, got {other:?}"),
+        }
+
+        assert!(!manager.sessions.lock().await.contains_key(&session_id));
+
+        Ok(())
+    }
+}

codex-rs/core/tests/suite/cli_stream.rs

@@ -1,4 +1,6 @@
 use assert_cmd::Command as AssertCommand;
+use codex_core::RolloutRecorder;
+use codex_core::protocol::GitInfo;
 use codex_core::spawn::CODEX_SANDBOX_NETWORK_DISABLED_ENV_VAR;
 use std::time::Duration;
 use std::time::Instant;
@@ -77,6 +79,22 @@ async fn chat_mode_stream_cli() {
     assert_eq!(hi_lines, 1, "Expected exactly one line with 'hi'");
 
     server.verify().await;
+
+    // Verify a new session rollout was created and is discoverable via list_conversations
+    let page = RolloutRecorder::list_conversations(home.path(), 10, None)
+        .await
+        .expect("list conversations");
+    assert!(
+        !page.items.is_empty(),
+        "expected at least one session to be listed"
+    );
+    // First line of head must be the SessionMeta payload (id/timestamp)
+    let head0 = page.items[0].head.first().expect("missing head record");
+    assert!(head0.get("id").is_some(), "head[0] missing id");
+    assert!(
+        head0.get("timestamp").is_some(),
+        "head[0] missing timestamp"
+    );
 }
 
 /// Verify that passing `-c experimental_instructions_file=...` to the CLI
@@ -297,8 +315,10 @@ async fn integration_creates_and_checks_session_file() {
                     Ok(v) => v,
                     Err(_) => continue,
                 };
-                if item.get("type").and_then(|t| t.as_str()) == Some("message")
-                    && let Some(c) = item.get("content")
+                if item.get("type").and_then(|t| t.as_str()) == Some("response_item")
+                    && let Some(payload) = item.get("payload")
+                    && payload.get("type").and_then(|t| t.as_str()) == Some("message")
+                    && let Some(c) = payload.get("content")
                     && c.to_string().contains(&marker)
                 {
                     matching_path = Some(path.to_path_buf());
@@ -361,9 +381,16 @@ async fn integration_creates_and_checks_session_file() {
         .unwrap_or_else(|_| panic!("missing session meta line"));
     let meta: serde_json::Value = serde_json::from_str(meta_line)
         .unwrap_or_else(|_| panic!("Failed to parse session meta line as JSON"));
-    assert!(meta.get("id").is_some(), "SessionMeta missing id");
+    assert_eq!(
+        meta.get("type").and_then(|v| v.as_str()),
+        Some("session_meta")
+    );
+    let payload = meta
+        .get("payload")
+        .unwrap_or_else(|| panic!("Missing payload in meta line"));
+    assert!(payload.get("id").is_some(), "SessionMeta missing id");
     assert!(
-        meta.get("timestamp").is_some(),
+        payload.get("timestamp").is_some(),
         "SessionMeta missing timestamp"
     );
 
@@ -375,8 +402,10 @@ async fn integration_creates_and_checks_session_file() {
         let Ok(item) = serde_json::from_str::<serde_json::Value>(line) else {
             continue;
         };
-        if item.get("type").and_then(|t| t.as_str()) == Some("message")
-            && let Some(c) = item.get("content")
+        if item.get("type").and_then(|t| t.as_str()) == Some("response_item")
+            && let Some(payload) = item.get("payload")
+            && payload.get("type").and_then(|t| t.as_str()) == Some("message")
+            && let Some(c) = payload.get("content")
             && c.to_string().contains(&marker)
         {
             found_message = true;
@@ -388,8 +417,7 @@ async fn integration_creates_and_checks_session_file() {
         "No message found in session file containing the marker"
     );
 
-    // Second run: resume should create a NEW session file that contains both old and new history.
-    let orig_len = content.lines().count();
+    // Second run: resume should update the existing file.
     let marker2 = format!("integration-resume-{}", Uuid::new_v4());
     let prompt2 = format!("echo {marker2}");
     // Cross‑platform safe resume override.  On Windows, backslashes in a TOML string must be escaped
@@ -449,8 +477,8 @@ async fn integration_creates_and_checks_session_file() {
     }
 
     let resumed_path = resumed_path.expect("No resumed session file found containing the marker2");
-    // Resume should have written to a new file, not the original one.
-    assert_ne!(
+    // Resume should write to the existing log file.
+    assert_eq!(
         resumed_path, path,
         "resume should create a new session file"
     );
@@ -464,14 +492,6 @@ async fn integration_creates_and_checks_session_file() {
         resumed_content.contains(&marker2),
         "resumed file missing resumed marker"
     );
-
-    // Original file should remain unchanged.
-    let content_after = std::fs::read_to_string(&path).unwrap();
-    assert_eq!(
-        content_after.lines().count(),
-        orig_len,
-        "original rollout file should not change on resume"
-    );
 }
 
 /// Integration test to verify git info is collected and recorded in session files.
@@ -598,7 +618,7 @@ async fn integration_git_info_unit_test() {
 
     // 5. Test serialization to ensure it works in SessionMeta
     let serialized = serde_json::to_string(&git_info).unwrap();
-    let deserialized: codex_core::git_info::GitInfo = serde_json::from_str(&serialized).unwrap();
+    let deserialized: GitInfo = serde_json::from_str(&serialized).unwrap();
 
     assert_eq!(git_info.commit_hash, deserialized.commit_hash);
     assert_eq!(git_info.branch, deserialized.branch);

codex-rs/core/tests/suite/client.rs

@@ -15,6 +15,7 @@ use core_test_support::wait_for_event;
 use serde_json::json;
 use std::io::Write;
 use tempfile::TempDir;
+use uuid::Uuid;
 use wiremock::Mock;
 use wiremock::MockServer;
 use wiremock::ResponseTemplate;
@@ -122,11 +123,22 @@ async fn resume_includes_initial_messages_and_sends_prior_items() {
     let tmpdir = TempDir::new().unwrap();
     let session_path = tmpdir.path().join("resume-session.jsonl");
     let mut f = std::fs::File::create(&session_path).unwrap();
-    // First line: meta (content not used by reader other than non-empty)
+    let convo_id = Uuid::new_v4();
     writeln!(
         f,
         "{}",
-        serde_json::json!({"meta":"test","instructions":"be nice"})
+        json!({
+            "timestamp": "2024-01-01T00:00:00.000Z",
+            "type": "session_meta",
+            "payload": {
+                "id": convo_id,
+                "timestamp": "2024-01-01T00:00:00Z",
+                "instructions": "be nice",
+                "cwd": ".",
+                "originator": "test_originator",
+                "cli_version": "test_version"
+            }
+        })
     )
     .unwrap();
 
@@ -138,7 +150,17 @@ async fn resume_includes_initial_messages_and_sends_prior_items() {
             text: "resumed user message".to_string(),
         }],
     };
-    writeln!(f, "{}", serde_json::to_string(&prior_user).unwrap()).unwrap();
+    let prior_user_json = serde_json::to_value(&prior_user).unwrap();
+    writeln!(
+        f,
+        "{}",
+        json!({
+            "timestamp": "2024-01-01T00:00:01.000Z",
+            "type": "response_item",
+            "payload": prior_user_json
+        })
+    )
+    .unwrap();
 
     // Prior item: system message (excluded from API history)
     let prior_system = codex_protocol::models::ResponseItem::Message {
@@ -148,7 +170,17 @@ async fn resume_includes_initial_messages_and_sends_prior_items() {
             text: "resumed system instruction".to_string(),
         }],
     };
-    writeln!(f, "{}", serde_json::to_string(&prior_system).unwrap()).unwrap();
+    let prior_system_json = serde_json::to_value(&prior_system).unwrap();
+    writeln!(
+        f,
+        "{}",
+        json!({
+            "timestamp": "2024-01-01T00:00:02.000Z",
+            "type": "response_item",
+            "payload": prior_system_json
+        })
+    )
+    .unwrap();
 
     // Prior item: assistant message
     let prior_item = codex_protocol::models::ResponseItem::Message {
@@ -158,7 +190,17 @@ async fn resume_includes_initial_messages_and_sends_prior_items() {
             text: "resumed assistant message".to_string(),
         }],
     };
-    writeln!(f, "{}", serde_json::to_string(&prior_item).unwrap()).unwrap();
+    let prior_item_json = serde_json::to_value(&prior_item).unwrap();
+    writeln!(
+        f,
+        "{}",
+        json!({
+            "timestamp": "2024-01-01T00:00:03.000Z",
+            "type": "response_item",
+            "payload": prior_item_json
+        })
+    )
+    .unwrap();
     drop(f);
 
     // Mock server that will receive the resumed request
@@ -196,16 +238,13 @@ async fn resume_includes_initial_messages_and_sends_prior_items() {
         .await
         .expect("create new conversation");
 
-    // 1) Assert initial_messages contains the prior user + assistant messages as EventMsg entries
+    // 1) Assert initial_messages only includes existing EventMsg entries; response items are not converted
     let initial_msgs = session_configured
         .initial_messages
         .clone()
-        .expect("expected initial messages for resumed session");
+        .expect("expected initial messages option for resumed session");
     let initial_json = serde_json::to_value(&initial_msgs).unwrap();
-    let expected_initial_json = serde_json::json!([
-        { "type": "user_message", "message": "resumed user message", "kind": "plain" },
-        { "type": "agent_message", "message": "resumed assistant message" }
-    ]);
+    let expected_initial_json = json!([]);
     assert_eq!(initial_json, expected_initial_json);
 
     // 2) Submit new input; the request body must include the prior item followed by the new user input.
@@ -221,7 +260,7 @@ async fn resume_includes_initial_messages_and_sends_prior_items() {
 
     let request = &server.received_requests().await.unwrap()[0];
     let request_body = request.body_json::<serde_json::Value>().unwrap();
-    let expected_input = serde_json::json!([
+    let expected_input = json!([
         {
             "type": "message",
             "role": "user",
@@ -238,7 +277,25 @@ async fn resume_includes_initial_messages_and_sends_prior_items() {
             "content": [{ "type": "input_text", "text": "hello" }]
         }
     ]);
-    assert_eq!(request_body["input"], expected_input);
+    let input_array = request_body
+        .get("input")
+        .and_then(|v| v.as_array())
+        .cloned()
+        .expect("input array in request body");
+    let filtered: Vec<serde_json::Value> = input_array
+        .into_iter()
+        .filter(|item| {
+            let text = item
+                .get("content")
+                .and_then(|c| c.as_array())
+                .and_then(|a| a.first())
+                .and_then(|o| o.get("text"))
+                .and_then(|t| t.as_str())
+                .unwrap_or("");
+            !text.contains("<environment_context>")
+        })
+        .collect();
+    assert_eq!(serde_json::json!(filtered), expected_input);
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
@@ -371,56 +428,6 @@ async fn includes_base_instructions_override_in_request() {
     );
 }
 
-#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-async fn originator_config_override_is_used() {
-    // Mock server
-    let server = MockServer::start().await;
-
-    let first = ResponseTemplate::new(200)
-        .insert_header("content-type", "text/event-stream")
-        .set_body_raw(sse_completed("resp1"), "text/event-stream");
-
-    Mock::given(method("POST"))
-        .and(path("/v1/responses"))
-        .respond_with(first)
-        .expect(1)
-        .mount(&server)
-        .await;
-
-    let model_provider = ModelProviderInfo {
-        base_url: Some(format!("{}/v1", server.uri())),
-        ..built_in_model_providers()["openai"].clone()
-    };
-
-    let codex_home = TempDir::new().unwrap();
-    let mut config = load_default_config_for_test(&codex_home);
-    config.model_provider = model_provider;
-    config.responses_originator_header = "my_override".to_owned();
-
-    let conversation_manager =
-        ConversationManager::with_auth(CodexAuth::from_api_key("Test API Key"));
-    let codex = conversation_manager
-        .new_conversation(config)
-        .await
-        .expect("create new conversation")
-        .conversation;
-
-    codex
-        .submit(Op::UserInput {
-            items: vec![InputItem::Text {
-                text: "hello".into(),
-            }],
-        })
-        .await
-        .unwrap();
-
-    wait_for_event(&codex, |ev| matches!(ev, EventMsg::TaskComplete(_))).await;
-
-    let request = &server.received_requests().await.unwrap()[0];
-    let request_originator = request.headers.get("originator").unwrap();
-    assert_eq!(request_originator.to_str().unwrap(), "my_override");
-}
-
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
 async fn chatgpt_auth_sends_correct_request() {
     if std::env::var(CODEX_SANDBOX_NETWORK_DISABLED_ENV_VAR).is_ok() {
@@ -546,15 +553,12 @@ async fn prefers_chatgpt_token_when_config_prefers_chatgpt() {
     config.model_provider = model_provider;
     config.preferred_auth_method = AuthMode::ChatGPT;
 
-    let auth_manager = match CodexAuth::from_codex_home(
-        codex_home.path(),
-        config.preferred_auth_method,
-        &config.responses_originator_header,
-    ) {
-        Ok(Some(auth)) => codex_core::AuthManager::from_auth_for_testing(auth),
-        Ok(None) => panic!("No CodexAuth found in codex_home"),
-        Err(e) => panic!("Failed to load CodexAuth: {e}"),
-    };
+    let auth_manager =
+        match CodexAuth::from_codex_home(codex_home.path(), config.preferred_auth_method) {
+            Ok(Some(auth)) => codex_core::AuthManager::from_auth_for_testing(auth),
+            Ok(None) => panic!("No CodexAuth found in codex_home"),
+            Err(e) => panic!("Failed to load CodexAuth: {e}"),
+        };
     let conversation_manager = ConversationManager::new(auth_manager);
     let NewConversation {
         conversation: codex,
@@ -622,15 +626,12 @@ async fn prefers_apikey_when_config_prefers_apikey_even_with_chatgpt_tokens() {
     config.model_provider = model_provider;
     config.preferred_auth_method = AuthMode::ApiKey;
 
-    let auth_manager = match CodexAuth::from_codex_home(
-        codex_home.path(),
-        config.preferred_auth_method,
-        &config.responses_originator_header,
-    ) {
-        Ok(Some(auth)) => codex_core::AuthManager::from_auth_for_testing(auth),
-        Ok(None) => panic!("No CodexAuth found in codex_home"),
-        Err(e) => panic!("Failed to load CodexAuth: {e}"),
-    };
+    let auth_manager =
+        match CodexAuth::from_codex_home(codex_home.path(), config.preferred_auth_method) {
+            Ok(Some(auth)) => codex_core::AuthManager::from_auth_for_testing(auth),
+            Ok(None) => panic!("No CodexAuth found in codex_home"),
+            Err(e) => panic!("Failed to load CodexAuth: {e}"),
+        };
     let conversation_manager = ConversationManager::new(auth_manager);
     let NewConversation {
         conversation: codex,
@@ -967,34 +968,6 @@ async fn history_dedupes_streamed_and_final_messages_across_turns() {
     assert_eq!(requests.len(), 3, "expected 3 requests (one per turn)");
 
     // Replace full-array compare with tail-only raw JSON compare using a single hard-coded value.
-    let r3_tail_expected = serde_json::json!([
-        {
-            "type": "message",
-            "role": "user",
-            "content": [{"type":"input_text","text":"U1"}]
-        },
-        {
-            "type": "message",
-            "role": "assistant",
-            "content": [{"type":"output_text","text":"Hey there!\n"}]
-        },
-        {
-            "type": "message",
-            "role": "user",
-            "content": [{"type":"input_text","text":"U2"}]
-        },
-        {
-            "type": "message",
-            "role": "assistant",
-            "content": [{"type":"output_text","text":"Hey there!\n"}]
-        },
-        {
-            "type": "message",
-            "role": "user",
-            "content": [{"type":"input_text","text":"U3"}]
-        }
-    ]);
-
     let r3_input_array = requests[2]
         .body_json::<serde_json::Value>()
         .unwrap()
@@ -1002,12 +975,60 @@ async fn history_dedupes_streamed_and_final_messages_across_turns() {
         .and_then(|v| v.as_array())
         .cloned()
         .expect("r3 missing input array");
-    // skipping earlier context and developer messages
-    let tail_len = r3_tail_expected.as_array().unwrap().len();
-    let actual_tail = &r3_input_array[r3_input_array.len() - tail_len..];
+    // We only assert on the last 5 items of the input history for request 3.
+    // With per-turn environment context injected, the last 5 should be:
+    // [env_ctx, U2, assistant("Hey there!\n"), env_ctx, U3]
+    let actual_tail = &r3_input_array[r3_input_array.len() - 5..];
+
+    // env_ctx 1
+    assert_eq!(actual_tail[0]["type"], serde_json::json!("message"));
+    assert_eq!(actual_tail[0]["role"], serde_json::json!("user"));
+    let env_text_1 = &actual_tail[0]["content"][0]["text"];
+    assert!(
+        env_text_1
+            .as_str()
+            .expect("env text should be string")
+            .contains("<environment_context>")
+    );
+
+    // U2
     assert_eq!(
-        serde_json::Value::Array(actual_tail.to_vec()),
-        r3_tail_expected,
-        "request 3 tail mismatch",
+        actual_tail[1],
+        serde_json::json!({
+            "type": "message",
+            "role": "user",
+            "content": [ { "type": "input_text", "text": "U2" } ]
+        })
+    );
+
+    // assistant response
+    assert_eq!(
+        actual_tail[2],
+        serde_json::json!({
+            "type": "message",
+            "role": "assistant",
+            "content": [ { "type": "output_text", "text": "Hey there!\n" } ]
+        })
+    );
+
+    // env_ctx 2
+    assert_eq!(actual_tail[3]["type"], serde_json::json!("message"));
+    assert_eq!(actual_tail[3]["role"], serde_json::json!("user"));
+    let env_text_2 = &actual_tail[3]["content"][0]["text"];
+    assert!(
+        env_text_2
+            .as_str()
+            .expect("env text should be string")
+            .contains("<environment_context>")
+    );
+
+    // U3
+    assert_eq!(
+        actual_tail[4],
+        serde_json::json!({
+            "type": "message",
+            "role": "user",
+            "content": [ { "type": "input_text", "text": "U3" } ]
+        })
     );
 }

codex-rs/core/tests/suite/fork_conversation.rs

@@ -1,12 +1,16 @@
 use codex_core::CodexAuth;
+use codex_core::ContentItem;
 use codex_core::ConversationManager;
 use codex_core::ModelProviderInfo;
 use codex_core::NewConversation;
+use codex_core::ResponseItem;
 use codex_core::built_in_model_providers;
-use codex_core::protocol::ConversationHistoryResponseEvent;
+use codex_core::protocol::ConversationPathResponseEvent;
 use codex_core::protocol::EventMsg;
 use codex_core::protocol::InputItem;
 use codex_core::protocol::Op;
+use codex_core::protocol::RolloutItem;
+use codex_core::protocol::RolloutLine;
 use core_test_support::load_default_config_for_test;
 use core_test_support::wait_for_event;
 use tempfile::TempDir;
@@ -71,84 +75,121 @@ async fn fork_conversation_twice_drops_to_first_message() {
         let _ = wait_for_event(&codex, |ev| matches!(ev, EventMsg::TaskComplete(_))).await;
     }
 
-    // Request history from the base conversation.
-    codex.submit(Op::GetHistory).await.unwrap();
+    // Request history from the base conversation to obtain rollout path.
+    codex.submit(Op::GetPath).await.unwrap();
     let base_history =
-        wait_for_event(&codex, |ev| matches!(ev, EventMsg::ConversationHistory(_))).await;
-
-    // Capture entries from the base history and compute expected prefixes after each fork.
-    let entries_after_three = match &base_history {
-        EventMsg::ConversationHistory(ConversationHistoryResponseEvent { entries, .. }) => {
-            entries.clone()
-        }
+        wait_for_event(&codex, |ev| matches!(ev, EventMsg::ConversationPath(_))).await;
+    let base_path = match &base_history {
+        EventMsg::ConversationPath(ConversationPathResponseEvent { path, .. }) => path.clone(),
         _ => panic!("expected ConversationHistory event"),
     };
-    // History layout for this test:
-    // [0] user instructions,
-    // [1] environment context,
-    // [2] "first" user message,
-    // [3] "second" user message,
-    // [4] "third" user message.
 
-    // Fork 1: drops the last user message and everything after.
-    let expected_after_first = vec![
-        entries_after_three[0].clone(),
-        entries_after_three[1].clone(),
-        entries_after_three[2].clone(),
-        entries_after_three[3].clone(),
-    ];
+    // GetHistory flushes before returning the path; no wait needed.
 
-    // Fork 2: drops the last user message and everything after.
-    // [0] user instructions,
-    // [1] environment context,
-    // [2] "first" user message,
-    let expected_after_second = vec![
-        entries_after_three[0].clone(),
-        entries_after_three[1].clone(),
-        entries_after_three[2].clone(),
-    ];
+    // Helper: read rollout items (excluding SessionMeta) from a JSONL path.
+    let read_items = |p: &std::path::Path| -> Vec<RolloutItem> {
+        let text = std::fs::read_to_string(p).expect("read rollout file");
+        let mut items: Vec<RolloutItem> = Vec::new();
+        for line in text.lines() {
+            if line.trim().is_empty() {
+                continue;
+            }
+            let v: serde_json::Value = serde_json::from_str(line).expect("jsonl line");
+            let rl: RolloutLine = serde_json::from_value(v).expect("rollout line");
+            match rl.item {
+                RolloutItem::SessionMeta(_) => {}
+                other => items.push(other),
+            }
+        }
+        items
+    };
 
-    // Fork once with n=1 → drops the last user message and everything after.
+    // Compute expected prefixes after each fork by truncating base rollout at nth-from-last user input.
+    let base_items = read_items(&base_path);
+    let find_user_input_positions = |items: &[RolloutItem]| -> Vec<usize> {
+        let mut pos = Vec::new();
+        for (i, it) in items.iter().enumerate() {
+            if let RolloutItem::ResponseItem(ResponseItem::Message { role, content, .. }) = it
+                && role == "user"
+            {
+                // Consider any user message as an input boundary; recorder stores both EventMsg and ResponseItem.
+                // We specifically look for input items, which are represented as ContentItem::InputText.
+                if content
+                    .iter()
+                    .any(|c| matches!(c, ContentItem::InputText { .. }))
+                {
+                    pos.push(i);
+                }
+            }
+        }
+        pos
+    };
+    let user_inputs = find_user_input_positions(&base_items);
+
+    // After dropping last user input (n=1), cut strictly before that input if present, else empty.
+    let cut1 = user_inputs
+        .get(user_inputs.len().saturating_sub(1))
+        .copied()
+        .unwrap_or(0);
+    let expected_after_first: Vec<RolloutItem> = base_items[..cut1].to_vec();
+
+    // After dropping again (n=1 on fork1), compute expected relative to fork1's rollout.
+
+    // Fork once with n=1 → drops the last user input and everything after.
     let NewConversation {
         conversation: codex_fork1,
         ..
     } = conversation_manager
-        .fork_conversation(entries_after_three.clone(), 1, config_for_fork.clone())
+        .fork_conversation(1, config_for_fork.clone(), base_path.clone())
         .await
         .expect("fork 1");
 
-    codex_fork1.submit(Op::GetHistory).await.unwrap();
+    codex_fork1.submit(Op::GetPath).await.unwrap();
     let fork1_history = wait_for_event(&codex_fork1, |ev| {
-        matches!(ev, EventMsg::ConversationHistory(_))
+        matches!(ev, EventMsg::ConversationPath(_))
     })
     .await;
-    let entries_after_first_fork = match &fork1_history {
-        EventMsg::ConversationHistory(ConversationHistoryResponseEvent { entries, .. }) => {
-            assert!(matches!(
-                fork1_history,
-                EventMsg::ConversationHistory(ConversationHistoryResponseEvent { ref entries, .. }) if *entries == expected_after_first
-            ));
-            entries.clone()
-        }
+    let fork1_path = match &fork1_history {
+        EventMsg::ConversationPath(ConversationPathResponseEvent { path, .. }) => path.clone(),
         _ => panic!("expected ConversationHistory event after first fork"),
     };
 
+    // GetHistory on fork1 flushed; the file is ready.
+    let fork1_items = read_items(&fork1_path);
+    pretty_assertions::assert_eq!(
+        serde_json::to_value(&fork1_items).unwrap(),
+        serde_json::to_value(&expected_after_first).unwrap()
+    );
+
     // Fork again with n=1 → drops the (new) last user message, leaving only the first.
     let NewConversation {
         conversation: codex_fork2,
         ..
     } = conversation_manager
-        .fork_conversation(entries_after_first_fork.clone(), 1, config_for_fork.clone())
+        .fork_conversation(1, config_for_fork.clone(), fork1_path.clone())
         .await
         .expect("fork 2");
 
-    codex_fork2.submit(Op::GetHistory).await.unwrap();
+    codex_fork2.submit(Op::GetPath).await.unwrap();
     let fork2_history = wait_for_event(&codex_fork2, |ev| {
-        matches!(ev, EventMsg::ConversationHistory(_))
+        matches!(ev, EventMsg::ConversationPath(_))
     })
     .await;
-    assert!(matches!(
-        fork2_history,
-        EventMsg::ConversationHistory(ConversationHistoryResponseEvent { ref entries, .. }) if *entries == expected_after_second
-    ));
+    let fork2_path = match &fork2_history {
+        EventMsg::ConversationPath(ConversationPathResponseEvent { path, .. }) => path.clone(),
+        _ => panic!("expected ConversationHistory event after second fork"),
+    };
+    // GetHistory on fork2 flushed; the file is ready.
+    let fork1_items = read_items(&fork1_path);
+    let fork1_user_inputs = find_user_input_positions(&fork1_items);
+    let cut_last_on_fork1 = fork1_user_inputs
+        .get(fork1_user_inputs.len().saturating_sub(1))
+        .copied()
+        .unwrap_or(0);
+    let expected_after_second: Vec<RolloutItem> = fork1_items[..cut_last_on_fork1].to_vec();
+    let fork2_items = read_items(&fork2_path);
+    pretty_assertions::assert_eq!(
+        serde_json::to_value(&fork2_items).unwrap(),
+        serde_json::to_value(&expected_after_second).unwrap()
+    );
 }

codex-rs/core/tests/suite/prompt_caching.rs

@@ -191,7 +191,8 @@ async fn prompt_tools_are_consistent_across_requests() {
     let expected_instructions: &str = include_str!("../../prompt.md");
     // our internal implementation is responsible for keeping tools in sync
     // with the OpenAI schema, so we just verify the tool presence here
-    let expected_tools_names: &[&str] = &["shell", "update_plan", "apply_patch", "view_image"];
+    let expected_tools_names: &[&str] =
+        &["unified_exec", "update_plan", "apply_patch", "view_image"];
     let body0 = requests[0].body_json::<serde_json::Value>().unwrap();
     assert_eq!(
         body0["instructions"],
@@ -271,7 +272,7 @@ async fn prefixes_context_and_instructions_once_and_consistently_across_requests
 
     let shell = default_user_shell().await;
 
-    let expected_env_text = format!(
+    let expected_env_text_init = format!(
         r#"<environment_context>
   <cwd>{}</cwd>
   <approval_policy>on-request</approval_policy>
@@ -284,13 +285,28 @@ async fn prefixes_context_and_instructions_once_and_consistently_across_requests
             None => String::new(),
         }
     );
+    // Per-turn environment context omits the shell tag.
+    let expected_env_text_turn = format!(
+        r#"<environment_context>
+  <cwd>{}</cwd>
+  <approval_policy>on-request</approval_policy>
+  <sandbox_mode>read-only</sandbox_mode>
+  <network_access>restricted</network_access>
+</environment_context>"#,
+        cwd.path().to_string_lossy(),
+    );
     let expected_ui_text =
         "<user_instructions>\n\nbe consistent and helpful\n\n</user_instructions>";
 
-    let expected_env_msg = serde_json::json!({
+    let expected_env_msg_init = serde_json::json!({
         "type": "message",
         "role": "user",
-        "content": [ { "type": "input_text", "text": expected_env_text } ]
+        "content": [ { "type": "input_text", "text": expected_env_text_init } ]
+    });
+    let expected_env_msg_turn = serde_json::json!({
+        "type": "message",
+        "role": "user",
+        "content": [ { "type": "input_text", "text": expected_env_text_turn } ]
     });
     let expected_ui_msg = serde_json::json!({
         "type": "message",
@@ -306,7 +322,12 @@ async fn prefixes_context_and_instructions_once_and_consistently_across_requests
     let body1 = requests[0].body_json::<serde_json::Value>().unwrap();
     assert_eq!(
         body1["input"],
-        serde_json::json!([expected_ui_msg, expected_env_msg, expected_user_message_1])
+        serde_json::json!([
+            expected_ui_msg,
+            expected_env_msg_init,
+            expected_env_msg_turn,
+            expected_user_message_1
+        ])
     );
 
     let expected_user_message_2 = serde_json::json!({
@@ -318,7 +339,7 @@ async fn prefixes_context_and_instructions_once_and_consistently_across_requests
     let expected_body2 = serde_json::json!(
         [
             body1["input"].as_array().unwrap().as_slice(),
-            [expected_user_message_2].as_slice(),
+            [expected_env_msg_turn, expected_user_message_2].as_slice(),
         ]
         .concat()
     );
@@ -426,11 +447,17 @@ async fn overrides_turn_context_but_keeps_cached_prefix_and_key_constant() {
     // After overriding the turn context, the environment context should be emitted again
     // reflecting the new approval policy and sandbox settings. Omit cwd because it did
     // not change.
-    let expected_env_text_2 = r#"<environment_context>
+    let expected_env_text_2 = format!(
+        r#"<environment_context>
   <approval_policy>never</approval_policy>
   <sandbox_mode>workspace-write</sandbox_mode>
   <network_access>enabled</network_access>
-</environment_context>"#;
+  <writable_roots>
+    <root>{}</root>
+  </writable_roots>
+</environment_context>"#,
+        writable.path().to_string_lossy()
+    );
     let expected_env_msg_2 = serde_json::json!({
         "type": "message",
         "role": "user",
@@ -540,10 +567,24 @@ async fn per_turn_overrides_keep_cached_prefix_and_key_constant() {
         "role": "user",
         "content": [ { "type": "input_text", "text": "hello 2" } ]
     });
+    let expected_env_text_2 = format!(
+        r#"<environment_context>
+  <cwd>{}</cwd>
+  <approval_policy>never</approval_policy>
+  <sandbox_mode>workspace-write</sandbox_mode>
+  <network_access>enabled</network_access>
+</environment_context>"#,
+        new_cwd.path().to_string_lossy()
+    );
+    let expected_env_msg_2 = serde_json::json!({
+        "type": "message",
+        "role": "user",
+        "content": [ { "type": "input_text", "text": expected_env_text_2 } ]
+    });
     let expected_body2 = serde_json::json!(
         [
             body1["input"].as_array().unwrap().as_slice(),
-            [expected_user_message_2].as_slice(),
+            [expected_env_msg_2, expected_user_message_2].as_slice(),
         ]
         .concat()
     );

codex-rs/core/tests/suite/seatbelt.rs

@@ -159,6 +159,41 @@ async fn read_only_forbids_all_writes() {
         .await;
 }
 
+/// Verify that user lookups via `pwd.getpwuid(os.getuid())` work under the
+/// seatbelt sandbox. Prior to allowing the necessary mach‑lookup for
+/// OpenDirectory libinfo, this would fail with `KeyError: getpwuid(): uid not found`.
+#[tokio::test]
+async fn python_getpwuid_works_under_seatbelt() {
+    if std::env::var(CODEX_SANDBOX_ENV_VAR) == Ok("seatbelt".to_string()) {
+        eprintln!("{CODEX_SANDBOX_ENV_VAR} is set to 'seatbelt', skipping test.");
+        return;
+    }
+
+    // ReadOnly is sufficient here since we are only exercising user lookup.
+    let policy = SandboxPolicy::ReadOnly;
+
+    let mut child = spawn_command_under_seatbelt(
+        vec![
+            "python3".to_string(),
+            "-c".to_string(),
+            // Print the passwd struct; success implies lookup worked.
+            "import pwd, os; print(pwd.getpwuid(os.getuid()))".to_string(),
+        ],
+        &policy,
+        std::env::current_dir().expect("should be able to get current dir"),
+        StdioPolicy::RedirectForShellTool,
+        HashMap::new(),
+    )
+    .await
+    .expect("should be able to spawn python under seatbelt");
+
+    let status = child
+        .wait()
+        .await
+        .expect("should be able to wait for child process");
+    assert!(status.success(), "python exited with {status:?}");
+}
+
 #[expect(clippy::expect_used)]
 fn create_test_scenario(tmp: &TempDir) -> TestScenario {
     let repo_parent = tmp.path().to_path_buf();

codex-rs/exec/Cargo.toml

@@ -25,7 +25,6 @@ codex-common = { path = "../common", features = [
     "sandbox_summary",
 ] }
 codex-core = { path = "../core" }
-codex-login = { path = "../login" }
 codex-ollama = { path = "../ollama" }
 codex-protocol = { path = "../protocol" }
 owo-colors = "4.2.0"

codex-rs/exec/src/event_processor_with_human_output.rs

@@ -26,6 +26,7 @@ use codex_core::protocol::TurnAbortReason;
 use codex_core::protocol::TurnDiffEvent;
 use codex_core::protocol::WebSearchBeginEvent;
 use codex_core::protocol::WebSearchEndEvent;
+use codex_protocol::num_format::format_with_separators;
 use owo_colors::OwoColorize;
 use owo_colors::Style;
 use shlex::try_join;
@@ -194,7 +195,7 @@ impl EventProcessor for EventProcessorWithHumanOutput {
                     ts_println!(
                         self,
                         "tokens used: {}",
-                        usage_info.total_token_usage.blended_total()
+                        format_with_separators(usage_info.total_token_usage.blended_total())
                     );
                 }
             }
@@ -522,6 +523,7 @@ impl EventProcessor for EventProcessorWithHumanOutput {
                     history_log_id: _,
                     history_entry_count: _,
                     initial_messages: _,
+                    rollout_path: _,
                 } = session_configured_event;
 
                 ts_println!(
@@ -557,7 +559,7 @@ impl EventProcessor for EventProcessorWithHumanOutput {
                 }
             },
             EventMsg::ShutdownComplete => return CodexStatus::Shutdown,
-            EventMsg::ConversationHistory(_) => {}
+            EventMsg::ConversationPath(_) => {}
             EventMsg::UserMessage(_) => {}
         }
         CodexStatus::Running

codex-rs/exec/src/lib.rs

@@ -190,7 +190,6 @@ pub async fn run_main(cli: Cli, codex_linux_sandbox_exe: Option<PathBuf>) -> any
     let conversation_manager = ConversationManager::new(AuthManager::shared(
         config.codex_home.clone(),
         config.preferred_auth_method,
-        config.responses_originator_header.clone(),
     ));
     let NewConversation {
         conversation_id: _,

codex-rs/linux-sandbox/Cargo.toml

@@ -15,9 +15,7 @@ path = "src/lib.rs"
 workspace = true
 
 [target.'cfg(target_os = "linux")'.dependencies]
-anyhow = "1"
 clap = { version = "4", features = ["derive"] }
-codex-common = { path = "../common", features = ["cli"] }
 codex-core = { path = "../core" }
 landlock = "0.4.1"
 libc = "0.2.175"

codex-rs/login/Cargo.toml

@@ -17,7 +17,6 @@ serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 sha2 = "0.10"
 tempfile = "3"
-thiserror = "2.0.16"
 tiny_http = "0.12"
 tokio = { version = "1", features = [
     "io-std",
@@ -31,5 +30,4 @@ urlencoding = "2.1"
 webbrowser = "1.0"
 
 [dev-dependencies]
-pretty_assertions = "1.4.1"
 tempfile = "3"

codex-rs/login/src/server.rs

@@ -16,6 +16,7 @@ use base64::Engine;
 use chrono::Utc;
 use codex_core::auth::AuthDotJson;
 use codex_core::auth::get_auth_file;
+use codex_core::default_client::ORIGINATOR;
 use codex_core::token_data::TokenData;
 use codex_core::token_data::parse_id_token;
 use rand::RngCore;
@@ -35,11 +36,10 @@ pub struct ServerOptions {
     pub port: u16,
     pub open_browser: bool,
     pub force_state: Option<String>,
-    pub originator: String,
 }
 
 impl ServerOptions {
-    pub fn new(codex_home: PathBuf, client_id: String, originator: String) -> Self {
+    pub fn new(codex_home: PathBuf, client_id: String) -> Self {
         Self {
             codex_home,
             client_id: client_id.to_string(),
@@ -47,7 +47,6 @@ impl ServerOptions {
             port: DEFAULT_PORT,
             open_browser: true,
             force_state: None,
-            originator,
         }
     }
 }
@@ -103,14 +102,7 @@ pub fn run_login_server(opts: ServerOptions) -> io::Result<LoginServer> {
     let server = Arc::new(server);
 
     let redirect_uri = format!("http://localhost:{actual_port}/auth/callback");
-    let auth_url = build_authorize_url(
-        &opts.issuer,
-        &opts.client_id,
-        &redirect_uri,
-        &pkce,
-        &state,
-        &opts.originator,
-    );
+    let auth_url = build_authorize_url(&opts.issuer, &opts.client_id, &redirect_uri, &pkce, &state);
 
     if opts.open_browser {
         let _ = webbrowser::open(&auth_url);
@@ -311,7 +303,6 @@ fn build_authorize_url(
     redirect_uri: &str,
     pkce: &PkceCodes,
     state: &str,
-    originator: &str,
 ) -> String {
     let query = vec![
         ("response_type", "code"),
@@ -323,7 +314,7 @@ fn build_authorize_url(
         ("id_token_add_organizations", "true"),
         ("codex_cli_simplified_flow", "true"),
         ("state", state),
-        ("originator", originator),
+        ("originator", ORIGINATOR.value.as_str()),
     ];
     let qs = query
         .into_iter()

codex-rs/login/tests/suite/login_server_e2e.rs

@@ -102,7 +102,6 @@ async fn end_to_end_login_flow_persists_auth_json() {
         port: 0,
         open_browser: false,
         force_state: Some(state),
-        originator: "test_originator".to_string(),
     };
     let server = run_login_server(opts).unwrap();
     let login_port = server.actual_port;
@@ -161,7 +160,6 @@ async fn creates_missing_codex_home_dir() {
         port: 0,
         open_browser: false,
         force_state: Some(state),
-        originator: "test_originator".to_string(),
     };
     let server = run_login_server(opts).unwrap();
     let login_port = server.actual_port;
@@ -202,7 +200,6 @@ async fn cancels_previous_login_server_when_port_is_in_use() {
         port: 0,
         open_browser: false,
         force_state: Some("cancel_state".to_string()),
-        originator: "test_originator".to_string(),
     };
 
     let first_server = run_login_server(first_opts).unwrap();
@@ -221,7 +218,6 @@ async fn cancels_previous_login_server_when_port_is_in_use() {
         port: login_port,
         open_browser: false,
         force_state: Some("cancel_state_2".to_string()),
-        originator: "test_originator".to_string(),
     };
 
     let second_server = run_login_server(second_opts).unwrap();

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

@@ -64,6 +64,9 @@ async fn main() -> Result<()> {
             name: "codex-mcp-client".to_owned(),
             version: env!("CARGO_PKG_VERSION").to_owned(),
             title: Some("Codex".to_string()),
+            // This field is used by Codex when it is an MCP server: it should
+            // not be used when Codex is an MCP client.
+            user_agent: None,
         },
         protocol_version: MCP_SCHEMA_VERSION.to_owned(),
     };

codex-rs/mcp-server/Cargo.toml

@@ -26,7 +26,6 @@ schemars = "0.8.22"
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 shlex = "1.3.0"
-strum_macros = "0.27.2"
 tokio = { version = "1", features = [
     "io-std",
     "macros",
@@ -41,8 +40,9 @@ uuid = { version = "1", features = ["serde", "v4"] }
 
 [dev-dependencies]
 assert_cmd = "2"
+base64 = "0.22"
 mcp_test_support = { path = "tests/common" }
+os_info = "3.12.0"
 pretty_assertions = "1.4.1"
 tempfile = "3"
-tokio-test = "0.4"
 wiremock = "0.6"

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

@@ -1,8 +1,3 @@
-use std::collections::HashMap;
-use std::path::PathBuf;
-use std::sync::Arc;
-use std::time::Duration;
-
 use crate::error_code::INTERNAL_ERROR_CODE;
 use crate::error_code::INVALID_REQUEST_ERROR_CODE;
 use crate::json_to_toml::json_to_toml;
@@ -14,11 +9,15 @@ use codex_core::ConversationManager;
 use codex_core::Cursor as RolloutCursor;
 use codex_core::NewConversation;
 use codex_core::RolloutRecorder;
+use codex_core::SessionMeta;
 use codex_core::auth::CLIENT_ID;
+use codex_core::auth::get_auth_file;
+use codex_core::auth::try_read_auth_json;
 use codex_core::config::Config;
 use codex_core::config::ConfigOverrides;
 use codex_core::config::ConfigToml;
 use codex_core::config::load_config_as_toml;
+use codex_core::default_client::get_codex_user_agent;
 use codex_core::exec::ExecParams;
 use codex_core::exec_env::create_env;
 use codex_core::get_platform_sandbox;
@@ -38,6 +37,8 @@ use codex_protocol::mcp_protocol::AddConversationListenerParams;
 use codex_protocol::mcp_protocol::AddConversationSubscriptionResponse;
 use codex_protocol::mcp_protocol::ApplyPatchApprovalParams;
 use codex_protocol::mcp_protocol::ApplyPatchApprovalResponse;
+use codex_protocol::mcp_protocol::ArchiveConversationParams;
+use codex_protocol::mcp_protocol::ArchiveConversationResponse;
 use codex_protocol::mcp_protocol::AuthMode;
 use codex_protocol::mcp_protocol::AuthStatusChangeNotification;
 use codex_protocol::mcp_protocol::ClientRequest;
@@ -48,6 +49,7 @@ use codex_protocol::mcp_protocol::ExecArbitraryCommandResponse;
 use codex_protocol::mcp_protocol::ExecCommandApprovalParams;
 use codex_protocol::mcp_protocol::ExecCommandApprovalResponse;
 use codex_protocol::mcp_protocol::ExecOneOffCommandParams;
+use codex_protocol::mcp_protocol::GetUserAgentResponse;
 use codex_protocol::mcp_protocol::GetUserSavedConfigResponse;
 use codex_protocol::mcp_protocol::GitDiffToRemoteResponse;
 use codex_protocol::mcp_protocol::InputItem as WireInputItem;
@@ -67,12 +69,25 @@ use codex_protocol::mcp_protocol::SendUserMessageResponse;
 use codex_protocol::mcp_protocol::SendUserTurnParams;
 use codex_protocol::mcp_protocol::SendUserTurnResponse;
 use codex_protocol::mcp_protocol::ServerNotification;
+use codex_protocol::mcp_protocol::UserInfoResponse;
 use codex_protocol::mcp_protocol::UserSavedConfig;
+use codex_protocol::models::ContentItem;
+use codex_protocol::models::ResponseItem;
+use codex_protocol::protocol::InputMessageKind;
+use codex_protocol::protocol::USER_MESSAGE_BEGIN;
 use mcp_types::JSONRPCErrorError;
 use mcp_types::RequestId;
+use std::collections::HashMap;
+use std::ffi::OsStr;
+use std::path::PathBuf;
+use std::sync::Arc;
+use std::time::Duration;
+use tokio::select;
 use tokio::sync::Mutex;
 use tokio::sync::oneshot;
 use tracing::error;
+use tracing::info;
+use tracing::warn;
 use uuid::Uuid;
 
 // Duration before a ChatGPT login attempt is abandoned.
@@ -136,6 +151,9 @@ impl CodexMessageProcessor {
             ClientRequest::ResumeConversation { request_id, params } => {
                 self.handle_resume_conversation(request_id, params).await;
             }
+            ClientRequest::ArchiveConversation { request_id, params } => {
+                self.archive_conversation(request_id, params).await;
+            }
             ClientRequest::SendUserMessage { request_id, params } => {
                 self.send_user_message(request_id, params).await;
             }
@@ -169,6 +187,12 @@ impl CodexMessageProcessor {
             ClientRequest::GetUserSavedConfig { request_id } => {
                 self.get_user_saved_config(request_id).await;
             }
+            ClientRequest::GetUserAgent { request_id } => {
+                self.get_user_agent(request_id).await;
+            }
+            ClientRequest::UserInfo { request_id } => {
+                self.get_user_info(request_id).await;
+            }
             ClientRequest::ExecOneOffCommand { request_id, params } => {
                 self.exec_one_off_command(request_id, params).await;
             }
@@ -180,11 +204,7 @@ impl CodexMessageProcessor {
 
         let opts = LoginServerOptions {
             open_browser: false,
-            ..LoginServerOptions::new(
-                config.codex_home.clone(),
-                CLIENT_ID.to_string(),
-                config.responses_originator_header.clone(),
-            )
+            ..LoginServerOptions::new(config.codex_home.clone(), CLIENT_ID.to_string())
         };
 
         enum LoginChatGptReply {
@@ -384,6 +404,12 @@ impl CodexMessageProcessor {
         self.outgoing.send_response(request_id, response).await;
     }
 
+    async fn get_user_agent(&self, request_id: RequestId) {
+        let user_agent = get_codex_user_agent();
+        let response = GetUserAgentResponse { user_agent };
+        self.outgoing.send_response(request_id, response).await;
+    }
+
     async fn get_user_saved_config(&self, request_id: RequestId) {
         let toml_value = match load_config_as_toml(&self.config.codex_home) {
             Ok(val) => val,
@@ -419,6 +445,18 @@ impl CodexMessageProcessor {
         self.outgoing.send_response(request_id, response).await;
     }
 
+    async fn get_user_info(&self, request_id: RequestId) {
+        // Read alleged user email from auth.json (best-effort; not verified).
+        let auth_path = get_auth_file(&self.config.codex_home);
+        let alleged_user_email = match try_read_auth_json(&auth_path) {
+            Ok(auth) => auth.tokens.and_then(|t| t.id_token.email),
+            Err(_) => None,
+        };
+
+        let response = UserInfoResponse { alleged_user_email };
+        self.outgoing.send_response(request_id, response).await;
+    }
+
     async fn exec_one_off_command(&self, request_id: RequestId, params: ExecOneOffCommandParams) {
         tracing::debug!("ExecOneOffCommand params: {params:?}");
 
@@ -513,6 +551,7 @@ impl CodexMessageProcessor {
                 let response = NewConversationResponse {
                     conversation_id,
                     model: session_configured.model,
+                    rollout_path: session_configured.rollout_path,
                 };
                 self.outgoing.send_response(request_id, response).await;
             }
@@ -559,16 +598,11 @@ impl CodexMessageProcessor {
             }
         };
 
-        // Build summaries
-        let mut items: Vec<ConversationSummary> = Vec::new();
-        for it in page.items.into_iter() {
-            let (timestamp, preview) = extract_ts_and_preview(&it.head);
-            items.push(ConversationSummary {
-                path: it.path,
-                preview,
-                timestamp,
-            });
-        }
+        let items = page
+            .items
+            .into_iter()
+            .filter_map(|it| extract_conversation_summary(it.path, &it.head))
+            .collect();
 
         // Encode next_cursor as a plain string
         let next_cursor = match page.next_cursor {
@@ -622,19 +656,29 @@ impl CodexMessageProcessor {
                 session_configured,
                 ..
             }) => {
-                let event = codex_core::protocol::Event {
+                let event = Event {
                     id: "".to_string(),
-                    msg: codex_core::protocol::EventMsg::SessionConfigured(
-                        session_configured.clone(),
-                    ),
+                    msg: EventMsg::SessionConfigured(session_configured.clone()),
                 };
                 self.outgoing.send_event_as_notification(&event, None).await;
+                let initial_messages = session_configured.initial_messages.map(|msgs| {
+                    msgs.into_iter()
+                        .filter(|event| {
+                            // Don't send non-plain user messages (like user instructions
+                            // or environment context) back so they don't get rendered.
+                            if let EventMsg::UserMessage(user_message) = event {
+                                return matches!(user_message.kind, Some(InputMessageKind::Plain));
+                            }
+                            true
+                        })
+                        .collect()
+                });
 
                 // Reply with conversation id + model and initial messages (when present)
                 let response = codex_protocol::mcp_protocol::ResumeConversationResponse {
                     conversation_id,
                     model: session_configured.model.clone(),
-                    initial_messages: session_configured.initial_messages.clone(),
+                    initial_messages,
                 };
                 self.outgoing.send_response(request_id, response).await;
             }
@@ -649,6 +693,141 @@ impl CodexMessageProcessor {
         }
     }
 
+    async fn archive_conversation(&self, request_id: RequestId, params: ArchiveConversationParams) {
+        let ArchiveConversationParams {
+            conversation_id,
+            rollout_path,
+        } = params;
+
+        // Verify that the rollout path is in the sessions directory or else
+        // a malicious client could specify an arbitrary path.
+        let rollout_folder = self.config.codex_home.join(codex_core::SESSIONS_SUBDIR);
+        let canonical_rollout_path = tokio::fs::canonicalize(&rollout_path).await;
+        let canonical_rollout_path = if let Ok(path) = canonical_rollout_path
+            && path.starts_with(&rollout_folder)
+        {
+            path
+        } else {
+            let error = JSONRPCErrorError {
+                code: INVALID_REQUEST_ERROR_CODE,
+                message: format!(
+                    "rollout path `{}` must be in sessions directory",
+                    rollout_path.display()
+                ),
+                data: None,
+            };
+            self.outgoing.send_error(request_id, error).await;
+            return;
+        };
+
+        let required_suffix = format!("{}.jsonl", conversation_id.0);
+        let Some(file_name) = canonical_rollout_path.file_name().map(OsStr::to_owned) else {
+            let error = JSONRPCErrorError {
+                code: INVALID_REQUEST_ERROR_CODE,
+                message: format!(
+                    "rollout path `{}` missing file name",
+                    rollout_path.display()
+                ),
+                data: None,
+            };
+            self.outgoing.send_error(request_id, error).await;
+            return;
+        };
+
+        if !file_name
+            .to_string_lossy()
+            .ends_with(required_suffix.as_str())
+        {
+            let error = JSONRPCErrorError {
+                code: INVALID_REQUEST_ERROR_CODE,
+                message: format!(
+                    "rollout path `{}` does not match conversation id {conversation_id}",
+                    rollout_path.display()
+                ),
+                data: None,
+            };
+            self.outgoing.send_error(request_id, error).await;
+            return;
+        }
+
+        let removed_conversation = self
+            .conversation_manager
+            .remove_conversation(&conversation_id)
+            .await;
+        if let Some(conversation) = removed_conversation {
+            info!("conversation {conversation_id} was active; shutting down");
+            let conversation_clone = conversation.clone();
+            let notify = Arc::new(tokio::sync::Notify::new());
+            let notify_clone = notify.clone();
+
+            // Establish the listener for ShutdownComplete before submitting
+            // Shutdown so it is not missed.
+            let is_shutdown = tokio::spawn(async move {
+                loop {
+                    select! {
+                        _ = notify_clone.notified() => {
+                            break;
+                        }
+                        event = conversation_clone.next_event() => {
+                            if let Ok(event) = event && matches!(event.msg, EventMsg::ShutdownComplete) {
+                                break;
+                            }
+                        }
+                    }
+                }
+            });
+
+            // Request shutdown.
+            match conversation.submit(Op::Shutdown).await {
+                Ok(_) => {
+                    // Successfully submitted Shutdown; wait before proceeding.
+                    select! {
+                        _ = is_shutdown => {
+                            // Normal shutdown: proceed with archive.
+                        }
+                        _ = tokio::time::sleep(Duration::from_secs(10)) => {
+                            warn!("conversation {conversation_id} shutdown timed out; proceeding with archive");
+                            notify.notify_one();
+                        }
+                    }
+                }
+                Err(err) => {
+                    error!("failed to submit Shutdown to conversation {conversation_id}: {err}");
+                    notify.notify_one();
+                    // Perhaps we lost a shutdown race, so let's continue to
+                    // clean up the .jsonl file.
+                }
+            }
+        }
+
+        // Move the .jsonl file to the archived sessions subdir.
+        let result: std::io::Result<()> = async {
+            let archive_folder = self
+                .config
+                .codex_home
+                .join(codex_core::ARCHIVED_SESSIONS_SUBDIR);
+            tokio::fs::create_dir_all(&archive_folder).await?;
+            tokio::fs::rename(&canonical_rollout_path, &archive_folder.join(&file_name)).await?;
+            Ok(())
+        }
+        .await;
+
+        match result {
+            Ok(()) => {
+                let response = ArchiveConversationResponse {};
+                self.outgoing.send_response(request_id, response).await;
+            }
+            Err(err) => {
+                let error = JSONRPCErrorError {
+                    code: INTERNAL_ERROR_CODE,
+                    message: format!("failed to archive conversation: {err}"),
+                    data: None,
+                };
+                self.outgoing.send_error(request_id, error).await;
+            }
+        }
+    }
+
     async fn send_user_message(&self, request_id: RequestId, params: SendUserMessageParams) {
         let SendUserMessageParams {
             conversation_id,
@@ -822,11 +1001,11 @@ impl CodexMessageProcessor {
                         let mut params = match serde_json::to_value(event.clone()) {
                             Ok(serde_json::Value::Object(map)) => map,
                             Ok(_) => {
-                                tracing::error!("event did not serialize to an object");
+                                error!("event did not serialize to an object");
                                 continue;
                             }
                             Err(err) => {
-                                tracing::error!("failed to serialize event: {err}");
+                                error!("failed to serialize event: {err}");
                                 continue;
                             }
                         };
@@ -1009,7 +1188,7 @@ fn derive_config_from_params(
 
 async fn on_patch_approval_response(
     event_id: String,
-    receiver: tokio::sync::oneshot::Receiver<mcp_types::Result>,
+    receiver: oneshot::Receiver<mcp_types::Result>,
     codex: Arc<CodexConversation>,
 ) {
     let response = receiver.await;
@@ -1051,14 +1230,14 @@ async fn on_patch_approval_response(
 
 async fn on_exec_approval_response(
     event_id: String,
-    receiver: tokio::sync::oneshot::Receiver<mcp_types::Result>,
+    receiver: oneshot::Receiver<mcp_types::Result>,
     conversation: Arc<CodexConversation>,
 ) {
     let response = receiver.await;
     let value = match response {
         Ok(value) => value,
         Err(err) => {
-            tracing::error!("request failed: {err:?}");
+            error!("request failed: {err:?}");
             return;
         }
     };
@@ -1085,37 +1264,100 @@ async fn on_exec_approval_response(
     }
 }
 
-fn extract_ts_and_preview(head: &[serde_json::Value]) -> (Option<String>, String) {
-    let ts = head
-        .first()
-        .and_then(|v| v.get("timestamp"))
-        .and_then(|v| v.as_str())
-        .map(|s| s.to_string());
-    let preview = find_first_user_text(head).unwrap_or_default();
-    (ts, preview)
+fn extract_conversation_summary(
+    path: PathBuf,
+    head: &[serde_json::Value],
+) -> Option<ConversationSummary> {
+    let session_meta = match head.first() {
+        Some(first_line) => serde_json::from_value::<SessionMeta>(first_line.clone()).ok()?,
+        None => return None,
+    };
+
+    let preview = head
+        .iter()
+        .filter_map(|value| serde_json::from_value::<ResponseItem>(value.clone()).ok())
+        .find_map(|item| match item {
+            ResponseItem::Message { content, .. } => {
+                content.into_iter().find_map(|content| match content {
+                    ContentItem::InputText { text } => {
+                        match InputMessageKind::from(("user", &text)) {
+                            InputMessageKind::Plain => Some(text),
+                            _ => None,
+                        }
+                    }
+                    _ => None,
+                })
+            }
+            _ => None,
+        })?;
+
+    let preview = match preview.find(USER_MESSAGE_BEGIN) {
+        Some(idx) => preview[idx + USER_MESSAGE_BEGIN.len()..].trim(),
+        None => preview.as_str(),
+    };
+
+    let timestamp = if session_meta.timestamp.is_empty() {
+        None
+    } else {
+        Some(session_meta.timestamp.clone())
+    };
+
+    Some(ConversationSummary {
+        conversation_id: session_meta.id,
+        timestamp,
+        path,
+        preview: preview.to_string(),
+    })
 }
 
-fn find_first_user_text(head: &[serde_json::Value]) -> Option<String> {
-    use codex_core::protocol::InputMessageKind;
-    for v in head.iter() {
-        let t = v.get("type").and_then(|x| x.as_str()).unwrap_or("");
-        if t != "message" {
-            continue;
-        }
-        if v.get("role").and_then(|x| x.as_str()) != Some("user") {
-            continue;
-        }
-        if let Some(arr) = v.get("content").and_then(|c| c.as_array()) {
-            for c in arr.iter() {
-                if let (Some("input_text"), Some(txt)) =
-                    (c.get("type").and_then(|t| t.as_str()), c.get("text"))
-                    && let Some(s) = txt.as_str()
-                    && matches!(InputMessageKind::from(("user", s)), InputMessageKind::Plain)
-                {
-                    return Some(s.to_string());
-                }
-            }
-        }
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use pretty_assertions::assert_eq;
+    use serde_json::json;
+
+    #[test]
+    fn extract_conversation_summary_prefers_plain_user_messages() {
+        let conversation_id =
+            ConversationId(Uuid::parse_str("3f941c35-29b3-493b-b0a4-e25800d9aeb0").unwrap());
+        let timestamp = Some("2025-09-05T16:53:11.850Z".to_string());
+        let path = PathBuf::from("rollout.jsonl");
+
+        let head = vec![
+            json!({
+                "id": conversation_id.0,
+                "timestamp": timestamp,
+                "cwd": "/",
+                "originator": "codex",
+                "cli_version": "0.0.0",
+                "instructions": null
+            }),
+            json!({
+                "type": "message",
+                "role": "user",
+                "content": [{
+                    "type": "input_text",
+                    "text": "<user_instructions>\n<AGENTS.md contents>\n</user_instructions>".to_string(),
+                }],
+            }),
+            json!({
+                "type": "message",
+                "role": "user",
+                "content": [{
+                    "type": "input_text",
+                    "text": format!("<prior context> {USER_MESSAGE_BEGIN}Count to 5"),
+                }],
+            }),
+        ];
+
+        let summary = extract_conversation_summary(path.clone(), &head).expect("summary");
+
+        assert_eq!(summary.conversation_id, conversation_id);
+        assert_eq!(
+            summary.timestamp,
+            Some("2025-09-05T16:53:11.850Z".to_string())
+        );
+        assert_eq!(summary.path, path);
+        assert_eq!(summary.preview, "Count to 5");
     }
-    None
 }

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

@@ -5,6 +5,10 @@
 use std::collections::HashMap;
 use std::sync::Arc;
 
+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;
 use codex_core::CodexConversation;
 use codex_core::ConversationManager;
 use codex_core::NewConversation;
@@ -26,11 +30,6 @@ use mcp_types::TextContent;
 use serde_json::json;
 use tokio::sync::Mutex;
 
-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;
 
 /// Run a complete Codex session and stream events back to the client.
@@ -278,7 +277,7 @@ async fn run_codex_tool_session_inner(
                     | EventMsg::GetHistoryEntryResponse(_)
                     | EventMsg::PlanUpdate(_)
                     | EventMsg::TurnAborted(_)
-                    | EventMsg::ConversationHistory(_)
+                    | EventMsg::ConversationPath(_)
                     | EventMsg::UserMessage(_)
                     | EventMsg::ShutdownComplete => {
                         // For now, we do not do anything extra for these

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

@@ -14,6 +14,8 @@ use codex_protocol::mcp_protocol::ConversationId;
 use codex_core::AuthManager;
 use codex_core::ConversationManager;
 use codex_core::config::Config;
+use codex_core::default_client::USER_AGENT_SUFFIX;
+use codex_core::default_client::get_codex_user_agent;
 use codex_core::protocol::Submission;
 use mcp_types::CallToolRequestParams;
 use mcp_types::CallToolResult;
@@ -54,11 +56,8 @@ impl MessageProcessor {
         config: Arc<Config>,
     ) -> Self {
         let outgoing = Arc::new(outgoing);
-        let auth_manager = AuthManager::shared(
-            config.codex_home.clone(),
-            config.preferred_auth_method,
-            config.responses_originator_header.clone(),
-        );
+        let auth_manager =
+            AuthManager::shared(config.codex_home.clone(), config.preferred_auth_method);
         let conversation_manager = Arc::new(ConversationManager::new(auth_manager.clone()));
         let codex_message_processor = CodexMessageProcessor::new(
             auth_manager,
@@ -211,6 +210,14 @@ impl MessageProcessor {
             return;
         }
 
+        let client_info = params.client_info;
+        let name = client_info.name;
+        let version = client_info.version;
+        let user_agent_suffix = format!("{name}; {version}");
+        if let Ok(mut suffix) = USER_AGENT_SUFFIX.lock() {
+            *suffix = Some(user_agent_suffix);
+        }
+
         self.initialized = true;
 
         // Build a minimal InitializeResult. Fill with placeholders.
@@ -231,6 +238,7 @@ impl MessageProcessor {
                 name: "codex-mcp-server".to_string(),
                 version: env!("CARGO_PKG_VERSION").to_string(),
                 title: Some("Codex".to_string()),
+                user_agent: Some(get_codex_user_agent()),
             },
         };
 

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

@@ -262,6 +262,7 @@ mod tests {
     use codex_protocol::mcp_protocol::LoginChatGptCompleteNotification;
     use pretty_assertions::assert_eq;
     use serde_json::json;
+    use tempfile::NamedTempFile;
     use uuid::Uuid;
 
     use super::*;
@@ -272,6 +273,7 @@ mod tests {
         let outgoing_message_sender = OutgoingMessageSender::new(outgoing_tx);
 
         let conversation_id = ConversationId::new();
+        let rollout_file = NamedTempFile::new().unwrap();
         let event = Event {
             id: "1".to_string(),
             msg: EventMsg::SessionConfigured(SessionConfiguredEvent {
@@ -280,6 +282,7 @@ mod tests {
                 history_log_id: 1,
                 history_entry_count: 1000,
                 initial_messages: None,
+                rollout_path: rollout_file.path().to_path_buf(),
             }),
         };
 
@@ -305,12 +308,14 @@ mod tests {
         let outgoing_message_sender = OutgoingMessageSender::new(outgoing_tx);
 
         let conversation_id = ConversationId::new();
+        let rollout_file = NamedTempFile::new().unwrap();
         let session_configured_event = SessionConfiguredEvent {
             session_id: conversation_id,
             model: "gpt-4o".to_string(),
             history_log_id: 1,
             history_entry_count: 1000,
             initial_messages: None,
+            rollout_path: rollout_file.path().to_path_buf(),
         };
         let event = Event {
             id: "1".to_string(),
@@ -340,6 +345,7 @@ mod tests {
                 "history_log_id": session_configured_event.history_log_id,
                 "history_entry_count": session_configured_event.history_entry_count,
                 "type": "session_configured",
+                "rollout_path": rollout_file.path().to_path_buf(),
             }
         });
         assert_eq!(params.unwrap(), expected_params);

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

@@ -13,16 +13,14 @@ codex-core = { path = "../../../core" }
 codex-mcp-server = { path = "../.." }
 codex-protocol = { path = "../../../protocol" }
 mcp-types = { path = "../../../mcp-types" }
+os_info = "3.12.0"
 pretty_assertions = "1.4.1"
 serde = { version = "1" }
 serde_json = "1"
-shlex = "1.3.0"
-tempfile = "3"
 tokio = { version = "1", features = [
     "io-std",
     "macros",
     "process",
     "rt-multi-thread",
 ] }
-uuid = { version = "1", features = ["serde", "v4"] }
 wiremock = "0.6"

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

@@ -13,6 +13,7 @@ use anyhow::Context;
 use assert_cmd::prelude::*;
 use codex_mcp_server::CodexToolCallParam;
 use codex_protocol::mcp_protocol::AddConversationListenerParams;
+use codex_protocol::mcp_protocol::ArchiveConversationParams;
 use codex_protocol::mcp_protocol::CancelLoginChatGptParams;
 use codex_protocol::mcp_protocol::GetAuthStatusParams;
 use codex_protocol::mcp_protocol::InterruptConversationParams;
@@ -53,6 +54,18 @@ pub struct McpProcess {
 
 impl McpProcess {
     pub async fn new(codex_home: &Path) -> anyhow::Result<Self> {
+        Self::new_with_env(codex_home, &[]).await
+    }
+
+    /// Creates a new MCP process, allowing tests to override or remove
+    /// specific environment variables for the child process only.
+    ///
+    /// Pass a tuple of (key, Some(value)) to set/override, or (key, None) to
+    /// remove a variable from the child's environment.
+    pub async fn new_with_env(
+        codex_home: &Path,
+        env_overrides: &[(&str, Option<&str>)],
+    ) -> anyhow::Result<Self> {
         // Use assert_cmd to locate the binary path and then switch to tokio::process::Command
         let std_cmd = StdCommand::cargo_bin("codex-mcp-server")
             .context("should find binary for codex-mcp-server")?;
@@ -67,6 +80,17 @@ impl McpProcess {
         cmd.env("CODEX_HOME", codex_home);
         cmd.env("RUST_LOG", "debug");
 
+        for (k, v) in env_overrides {
+            match v {
+                Some(val) => {
+                    cmd.env(k, val);
+                }
+                None => {
+                    cmd.env_remove(k);
+                }
+            }
+        }
+
         let mut process = cmd
             .kill_on_drop(true)
             .spawn()
@@ -114,6 +138,7 @@ impl McpProcess {
                 name: "elicitation test".into(),
                 title: Some("Elicitation Test".into()),
                 version: "0.0.0".into(),
+                user_agent: None,
             },
             protocol_version: mcp_types::MCP_SCHEMA_VERSION.into(),
         };
@@ -128,6 +153,14 @@ impl McpProcess {
         .await?;
 
         let initialized = self.read_jsonrpc_message().await?;
+        let os_info = os_info::get();
+        let user_agent = format!(
+            "codex_cli_rs/0.0.0 ({} {}; {}) {} (elicitation test; 0.0.0)",
+            os_info.os_type(),
+            os_info.version(),
+            os_info.architecture().unwrap_or("unknown"),
+            codex_core::terminal::user_agent()
+        );
         assert_eq!(
             JSONRPCMessage::Response(JSONRPCResponse {
                 jsonrpc: JSONRPC_VERSION.into(),
@@ -141,7 +174,8 @@ impl McpProcess {
                     "serverInfo": {
                         "name": "codex-mcp-server",
                         "title": "Codex",
-                        "version": "0.0.0"
+                        "version": "0.0.0",
+                        "user_agent": user_agent
                     },
                     "protocolVersion": mcp_types::MCP_SCHEMA_VERSION
                 })
@@ -186,6 +220,15 @@ impl McpProcess {
         self.send_request("newConversation", params).await
     }
 
+    /// Send an `archiveConversation` JSON-RPC request.
+    pub async fn send_archive_conversation_request(
+        &mut self,
+        params: ArchiveConversationParams,
+    ) -> anyhow::Result<i64> {
+        let params = Some(serde_json::to_value(params)?);
+        self.send_request("archiveConversation", params).await
+    }
+
     /// Send an `addConversationListener` JSON-RPC request.
     pub async fn send_add_conversation_listener_request(
         &mut self,
@@ -247,6 +290,16 @@ impl McpProcess {
         self.send_request("getUserSavedConfig", None).await
     }
 
+    /// Send a `getUserAgent` JSON-RPC request.
+    pub async fn send_get_user_agent_request(&mut self) -> anyhow::Result<i64> {
+        self.send_request("getUserAgent", None).await
+    }
+
+    /// Send a `userInfo` JSON-RPC request.
+    pub async fn send_user_info_request(&mut self) -> anyhow::Result<i64> {
+        self.send_request("userInfo", None).await
+    }
+
     /// Send a `listConversations` JSON-RPC request.
     pub async fn send_list_conversations_request(
         &mut self,

codex-rs/mcp-server/tests/suite/archive_conversation.rs

@@ -0,0 +1,105 @@
+use std::path::Path;
+
+use codex_core::ARCHIVED_SESSIONS_SUBDIR;
+use codex_protocol::mcp_protocol::ArchiveConversationParams;
+use codex_protocol::mcp_protocol::ArchiveConversationResponse;
+use codex_protocol::mcp_protocol::NewConversationParams;
+use codex_protocol::mcp_protocol::NewConversationResponse;
+use mcp_test_support::McpProcess;
+use mcp_test_support::to_response;
+use mcp_types::JSONRPCResponse;
+use mcp_types::RequestId;
+use tempfile::TempDir;
+use tokio::time::timeout;
+
+const DEFAULT_READ_TIMEOUT: std::time::Duration = std::time::Duration::from_secs(10);
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn archive_conversation_moves_rollout_into_archived_directory() {
+    let codex_home = TempDir::new().expect("create temp dir");
+    create_config_toml(codex_home.path()).expect("write config.toml");
+
+    let mut mcp = McpProcess::new(codex_home.path())
+        .await
+        .expect("spawn mcp process");
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize())
+        .await
+        .expect("initialize timeout")
+        .expect("initialize request");
+
+    let new_request_id = mcp
+        .send_new_conversation_request(NewConversationParams {
+            model: Some("mock-model".to_string()),
+            ..Default::default()
+        })
+        .await
+        .expect("send newConversation");
+    let new_response: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(new_request_id)),
+    )
+    .await
+    .expect("newConversation timeout")
+    .expect("newConversation response");
+
+    let NewConversationResponse {
+        conversation_id,
+        rollout_path,
+        ..
+    } = to_response::<NewConversationResponse>(new_response)
+        .expect("deserialize newConversation response");
+
+    assert!(
+        rollout_path.exists(),
+        "expected rollout path {} to exist",
+        rollout_path.display()
+    );
+
+    let archive_request_id = mcp
+        .send_archive_conversation_request(ArchiveConversationParams {
+            conversation_id,
+            rollout_path: rollout_path.clone(),
+        })
+        .await
+        .expect("send archiveConversation");
+    let archive_response: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(archive_request_id)),
+    )
+    .await
+    .expect("archiveConversation timeout")
+    .expect("archiveConversation response");
+
+    let _: ArchiveConversationResponse =
+        to_response::<ArchiveConversationResponse>(archive_response)
+            .expect("deserialize archiveConversation response");
+
+    let archived_directory = codex_home.path().join(ARCHIVED_SESSIONS_SUBDIR);
+    let archived_rollout_path =
+        archived_directory.join(rollout_path.file_name().unwrap_or_else(|| {
+            panic!("rollout path {} missing file name", rollout_path.display())
+        }));
+
+    assert!(
+        !rollout_path.exists(),
+        "expected rollout path {} to be moved",
+        rollout_path.display()
+    );
+    assert!(
+        archived_rollout_path.exists(),
+        "expected archived rollout path {} to exist",
+        archived_rollout_path.display()
+    );
+}
+
+fn create_config_toml(codex_home: &Path) -> std::io::Result<()> {
+    let config_toml = codex_home.join("config.toml");
+    std::fs::write(config_toml, config_contents())
+}
+
+fn config_contents() -> &'static str {
+    r#"model = "mock-model"
+approval_policy = "never"
+sandbox_mode = "read-only"
+"#
+}

codex-rs/mcp-server/tests/suite/auth.rs

@@ -41,7 +41,7 @@ async fn get_auth_status_no_auth() {
     let codex_home = TempDir::new().unwrap_or_else(|e| panic!("create tempdir: {e}"));
     create_config_toml(codex_home.path()).expect("write config.toml");
 
-    let mut mcp = McpProcess::new(codex_home.path())
+    let mut mcp = McpProcess::new_with_env(codex_home.path(), &[("OPENAI_API_KEY", None)])
         .await
         .expect("spawn mcp process");
     timeout(DEFAULT_READ_TIMEOUT, mcp.initialize())

codex-rs/mcp-server/tests/suite/codex_message_processor_flow.rs

@@ -90,6 +90,7 @@ async fn test_codex_jsonrpc_conversation_flow() {
     let NewConversationResponse {
         conversation_id,
         model,
+        rollout_path: _,
     } = new_conv_resp;
     assert_eq!(model, "mock-model");
 

codex-rs/mcp-server/tests/suite/create_conversation.rs

@@ -59,6 +59,7 @@ async fn test_conversation_create_and_send_message_ok() {
     let NewConversationResponse {
         conversation_id,
         model,
+        rollout_path: _,
     } = to_response::<NewConversationResponse>(new_conv_resp)
         .expect("deserialize newConversation response");
     assert_eq!(model, "o3");

codex-rs/mcp-server/tests/suite/list_resume.rs

@@ -156,14 +156,45 @@ fn create_fake_rollout(codex_home: &Path, filename_ts: &str, meta_rfc3339: &str,
 
     let file_path = dir.join(format!("rollout-{filename_ts}-{uuid}.jsonl"));
     let mut lines = Vec::new();
-    // Meta line with timestamp
-    lines.push(json!({"timestamp": meta_rfc3339}).to_string());
-    // Minimal user message entry as a persisted response item
+    // Meta line with timestamp (flattened meta in payload for new schema)
     lines.push(
         json!({
-            "type":"message",
-            "role":"user",
-            "content":[{"type":"input_text","text": preview}]
+            "timestamp": meta_rfc3339,
+            "type": "session_meta",
+            "payload": {
+                "id": uuid,
+                "timestamp": meta_rfc3339,
+                "cwd": "/",
+                "originator": "codex",
+                "cli_version": "0.0.0",
+                "instructions": null
+            }
+        })
+        .to_string(),
+    );
+    // Minimal user message entry as a persisted response item (with envelope timestamp)
+    lines.push(
+        json!({
+            "timestamp": meta_rfc3339,
+            "type":"response_item",
+            "payload": {
+                "type":"message",
+                "role":"user",
+                "content":[{"type":"input_text","text": preview}]
+            }
+        })
+        .to_string(),
+    );
+    // Add a matching user message event line to satisfy filters
+    lines.push(
+        json!({
+            "timestamp": meta_rfc3339,
+            "type":"event_msg",
+            "payload": {
+                "type":"user_message",
+                "message": preview,
+                "kind": "plain"
+            }
         })
         .to_string(),
     );

codex-rs/mcp-server/tests/suite/login.rs

@@ -46,7 +46,7 @@ async fn logout_chatgpt_removes_auth() {
     login_with_api_key(codex_home.path(), "sk-test-key").expect("seed api key");
     assert!(codex_home.path().join("auth.json").exists());
 
-    let mut mcp = McpProcess::new(codex_home.path())
+    let mut mcp = McpProcess::new_with_env(codex_home.path(), &[("OPENAI_API_KEY", None)])
         .await
         .expect("spawn mcp process");
     timeout(DEFAULT_READ_TIMEOUT, mcp.initialize())

codex-rs/mcp-server/tests/suite/mod.rs

@@ -1,4 +1,5 @@
 // Aggregates all former standalone integration tests as modules.
+mod archive_conversation;
 mod auth;
 mod codex_message_processor_flow;
 mod codex_tool;
@@ -8,3 +9,5 @@ mod interrupt;
 mod list_resume;
 mod login;
 mod send_message;
+mod user_agent;
+mod user_info;

codex-rs/mcp-server/tests/suite/user_agent.rs

@@ -0,0 +1,50 @@
+use codex_protocol::mcp_protocol::GetUserAgentResponse;
+use mcp_test_support::McpProcess;
+use mcp_test_support::to_response;
+use mcp_types::JSONRPCResponse;
+use mcp_types::RequestId;
+use pretty_assertions::assert_eq;
+use tempfile::TempDir;
+use tokio::time::timeout;
+
+const DEFAULT_READ_TIMEOUT: std::time::Duration = std::time::Duration::from_secs(10);
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn get_user_agent_returns_current_codex_user_agent() {
+    let codex_home = TempDir::new().unwrap_or_else(|err| panic!("create tempdir: {err}"));
+
+    let mut mcp = McpProcess::new(codex_home.path())
+        .await
+        .expect("spawn mcp process");
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize())
+        .await
+        .expect("initialize timeout")
+        .expect("initialize request");
+
+    let request_id = mcp
+        .send_get_user_agent_request()
+        .await
+        .expect("send getUserAgent");
+    let response: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(request_id)),
+    )
+    .await
+    .expect("getUserAgent timeout")
+    .expect("getUserAgent response");
+
+    let os_info = os_info::get();
+    let user_agent = format!(
+        "codex_cli_rs/0.0.0 ({} {}; {}) {} (elicitation test; 0.0.0)",
+        os_info.os_type(),
+        os_info.version(),
+        os_info.architecture().unwrap_or("unknown"),
+        codex_core::terminal::user_agent()
+    );
+
+    let received: GetUserAgentResponse =
+        to_response(response).expect("deserialize getUserAgent response");
+    let expected = GetUserAgentResponse { user_agent };
+
+    assert_eq!(received, expected);
+}

codex-rs/mcp-server/tests/suite/user_info.rs

@@ -0,0 +1,78 @@
+use std::time::Duration;
+
+use anyhow::Context;
+use base64::Engine;
+use base64::engine::general_purpose::URL_SAFE_NO_PAD;
+use codex_core::auth::AuthDotJson;
+use codex_core::auth::get_auth_file;
+use codex_core::auth::write_auth_json;
+use codex_core::token_data::IdTokenInfo;
+use codex_core::token_data::TokenData;
+use codex_protocol::mcp_protocol::UserInfoResponse;
+use mcp_test_support::McpProcess;
+use mcp_test_support::to_response;
+use mcp_types::JSONRPCResponse;
+use mcp_types::RequestId;
+use pretty_assertions::assert_eq;
+use serde_json::json;
+use tempfile::TempDir;
+use tokio::time::timeout;
+
+const DEFAULT_READ_TIMEOUT: Duration = Duration::from_secs(10);
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn user_info_returns_email_from_auth_json() {
+    let codex_home = TempDir::new().expect("create tempdir");
+
+    let auth_path = get_auth_file(codex_home.path());
+    let mut id_token = IdTokenInfo::default();
+    id_token.email = Some("user@example.com".to_string());
+    id_token.raw_jwt = encode_id_token_with_email("user@example.com").expect("encode id token");
+
+    let auth = AuthDotJson {
+        openai_api_key: None,
+        tokens: Some(TokenData {
+            id_token,
+            access_token: "access".to_string(),
+            refresh_token: "refresh".to_string(),
+            account_id: None,
+        }),
+        last_refresh: None,
+    };
+    write_auth_json(&auth_path, &auth).expect("write auth.json");
+
+    let mut mcp = McpProcess::new(codex_home.path())
+        .await
+        .expect("spawn mcp process");
+    timeout(DEFAULT_READ_TIMEOUT, mcp.initialize())
+        .await
+        .expect("initialize timeout")
+        .expect("initialize request");
+
+    let request_id = mcp.send_user_info_request().await.expect("send userInfo");
+    let response: JSONRPCResponse = timeout(
+        DEFAULT_READ_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(request_id)),
+    )
+    .await
+    .expect("userInfo timeout")
+    .expect("userInfo response");
+
+    let received: UserInfoResponse = to_response(response).expect("deserialize userInfo response");
+    let expected = UserInfoResponse {
+        alleged_user_email: Some("user@example.com".to_string()),
+    };
+
+    assert_eq!(received, expected);
+}
+
+fn encode_id_token_with_email(email: &str) -> anyhow::Result<String> {
+    let header_b64 = URL_SAFE_NO_PAD.encode(
+        serde_json::to_vec(&json!({ "alg": "none", "typ": "JWT" }))
+            .context("serialize jwt header")?,
+    );
+    let payload =
+        serde_json::to_vec(&json!({ "email": email })).context("serialize jwt payload")?;
+    let payload_b64 = URL_SAFE_NO_PAD.encode(payload);
+    Ok(format!("{header_b64}.{payload_b64}.signature"))
+}

codex-rs/mcp-types/Cargo.toml

@@ -9,4 +9,4 @@ workspace = true
 [dependencies]
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
-ts-rs = { version = "11", features = ["serde-json-impl"] }
+ts-rs = { version = "11", features = ["serde-json-impl", "no-serde-warnings"] }

codex-rs/mcp-types/generate_mcp_types.py

@@ -265,8 +265,11 @@ class StructField:
     name: str
     type_name: str
     serde: str | None = None
+    comment: str | None = None
 
     def append(self, out: list[str], supports_const: bool) -> None:
+        if self.comment:
+            out.append(f"    // {self.comment}\n")
         if self.serde:
             out.append(f"    {self.serde}\n")
         if self.viz == "const":
@@ -312,6 +315,18 @@ def define_struct(
         else:
             fields.append(StructField("pub", rs_prop.name, prop_type, rs_prop.serde))
 
+    # Special-case: add Codex-specific user_agent to Implementation
+    if name == "Implementation":
+        fields.append(
+            StructField(
+                "pub",
+                "user_agent",
+                "Option<String>",
+                '#[serde(default, skip_serializing_if = "Option::is_none")]',
+                "This is an extra field that the Codex MCP server sends as part of InitializeResult.",
+            )
+        )
+
     if implements_request_trait(name):
         add_trait_impl(name, "ModelContextProtocolRequest", fields, out)
     elif implements_notification_trait(name):

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

@@ -487,6 +487,9 @@ pub struct Implementation {
     #[serde(default, skip_serializing_if = "Option::is_none")]
     pub title: Option<String>,
     pub version: String,
+    // This is an extra field that the Codex MCP server sends as part of InitializeResult.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub user_agent: Option<String>,
 }
 
 #[derive(Debug, Clone, PartialEq, Deserialize, Serialize, TS)]

codex-rs/mcp-types/tests/suite/initialize.rs

@@ -62,6 +62,7 @@ fn deserialize_initialize_request() {
                 name: "acme-client".into(),
                 title: Some("Acme".to_string()),
                 version: "1.2.3".into(),
+                user_agent: None,
             },
             protocol_version: "2025-06-18".into(),
         }

codex-rs/ollama/Cargo.toml

@@ -24,9 +24,7 @@ tokio = { version = "1", features = [
     "rt-multi-thread",
     "signal",
 ] }
-toml = "0.9.5"
 tracing = { version = "0.1.41", features = ["log"] }
 wiremock = "0.6"
 
 [dev-dependencies]
-tempfile = "3"

codex-rs/protocol-ts/Cargo.toml

@@ -16,6 +16,7 @@ path = "src/main.rs"
 
 [dependencies]
 anyhow = "1"
+mcp-types = { path = "../mcp-types" }
 codex-protocol = { path = "../protocol" }
 ts-rs = "11"
 clap = { version = "4", features = ["derive"] }

codex-rs/protocol-ts/src/lib.rs

@@ -16,37 +16,33 @@ pub fn generate_ts(out_dir: &Path, prettier: Option<&Path>) -> Result<()> {
     ensure_dir(out_dir)?;
 
     // Generate TS bindings
+    mcp_types::InitializeResult::export_all_to(out_dir)?;
     codex_protocol::mcp_protocol::ConversationId::export_all_to(out_dir)?;
     codex_protocol::mcp_protocol::InputItem::export_all_to(out_dir)?;
     codex_protocol::mcp_protocol::ClientRequest::export_all_to(out_dir)?;
     codex_protocol::mcp_protocol::ServerRequest::export_all_to(out_dir)?;
-    codex_protocol::mcp_protocol::NewConversationParams::export_all_to(out_dir)?;
     codex_protocol::mcp_protocol::NewConversationResponse::export_all_to(out_dir)?;
-    codex_protocol::mcp_protocol::AddConversationListenerParams::export_all_to(out_dir)?;
+    codex_protocol::mcp_protocol::ListConversationsResponse::export_all_to(out_dir)?;
+    codex_protocol::mcp_protocol::ResumeConversationResponse::export_all_to(out_dir)?;
+    codex_protocol::mcp_protocol::ArchiveConversationResponse::export_all_to(out_dir)?;
     codex_protocol::mcp_protocol::AddConversationSubscriptionResponse::export_all_to(out_dir)?;
-    codex_protocol::mcp_protocol::RemoveConversationListenerParams::export_all_to(out_dir)?;
     codex_protocol::mcp_protocol::RemoveConversationSubscriptionResponse::export_all_to(out_dir)?;
-    codex_protocol::mcp_protocol::SendUserMessageParams::export_all_to(out_dir)?;
     codex_protocol::mcp_protocol::SendUserMessageResponse::export_all_to(out_dir)?;
-    codex_protocol::mcp_protocol::SendUserTurnParams::export_all_to(out_dir)?;
     codex_protocol::mcp_protocol::SendUserTurnResponse::export_all_to(out_dir)?;
-    codex_protocol::mcp_protocol::InterruptConversationParams::export_all_to(out_dir)?;
     codex_protocol::mcp_protocol::InterruptConversationResponse::export_all_to(out_dir)?;
-    codex_protocol::mcp_protocol::GitDiffToRemoteParams::export_all_to(out_dir)?;
     codex_protocol::mcp_protocol::GitDiffToRemoteResponse::export_all_to(out_dir)?;
     codex_protocol::mcp_protocol::LoginChatGptResponse::export_all_to(out_dir)?;
-    codex_protocol::mcp_protocol::LoginChatGptCompleteNotification::export_all_to(out_dir)?;
-    codex_protocol::mcp_protocol::CancelLoginChatGptParams::export_all_to(out_dir)?;
     codex_protocol::mcp_protocol::CancelLoginChatGptResponse::export_all_to(out_dir)?;
-    codex_protocol::mcp_protocol::LogoutChatGptParams::export_all_to(out_dir)?;
     codex_protocol::mcp_protocol::LogoutChatGptResponse::export_all_to(out_dir)?;
-    codex_protocol::mcp_protocol::GetAuthStatusParams::export_all_to(out_dir)?;
     codex_protocol::mcp_protocol::GetAuthStatusResponse::export_all_to(out_dir)?;
-    codex_protocol::mcp_protocol::ApplyPatchApprovalParams::export_all_to(out_dir)?;
     codex_protocol::mcp_protocol::ApplyPatchApprovalResponse::export_all_to(out_dir)?;
-    codex_protocol::mcp_protocol::ExecCommandApprovalParams::export_all_to(out_dir)?;
     codex_protocol::mcp_protocol::ExecCommandApprovalResponse::export_all_to(out_dir)?;
     codex_protocol::mcp_protocol::GetUserSavedConfigResponse::export_all_to(out_dir)?;
+    codex_protocol::mcp_protocol::GetUserAgentResponse::export_all_to(out_dir)?;
+    codex_protocol::mcp_protocol::UserInfoResponse::export_all_to(out_dir)?;
+
+    // All notification types reachable from this enum will be generated by
+    // induction, so they do not need to be listed individually.
     codex_protocol::mcp_protocol::ServerNotification::export_all_to(out_dir)?;
 
     generate_index_ts(out_dir)?;

codex-rs/protocol/Cargo.toml

@@ -12,17 +12,24 @@ workspace = true
 
 [dependencies]
 base64 = "0.22.1"
+icu_decimal = "2.0.0"
+icu_locale_core = "2.0.0"
 mcp-types = { path = "../mcp-types" }
 mime_guess = "2.0.5"
 serde = { version = "1", features = ["derive"] }
-serde_bytes = "0.11"
 serde_json = "1"
 serde_with = { version = "3.14.0", features = ["macros", "base64"] }
 strum = "0.27.2"
 strum_macros = "0.27.2"
+sys-locale = "0.3.2"
 tracing = "0.1.41"
-ts-rs = { version = "11", features = ["uuid-impl", "serde-json-impl"] }
+ts-rs = { version = "11", features = ["uuid-impl", "serde-json-impl", "no-serde-warnings"] }
 uuid = { version = "1", features = ["serde", "v4"] }
 
 [dev-dependencies]
 pretty_assertions = "1.4.1"
+tempfile = "3"
+
+[package.metadata.cargo-shear]
+# Required because the not imported as strum_macros in non-nightly builds.
+ignored = ["strum"]

codex-rs/protocol/src/custom_prompts.rs

@@ -1,8 +1,9 @@
 use serde::Deserialize;
 use serde::Serialize;
 use std::path::PathBuf;
+use ts_rs::TS;
 
-#[derive(Serialize, Deserialize, Debug, Clone)]
+#[derive(Serialize, Deserialize, Debug, Clone, TS)]
 pub struct CustomPrompt {
     pub name: String,
     pub path: PathBuf,

codex-rs/protocol/src/lib.rs

@@ -3,6 +3,7 @@ pub mod custom_prompts;
 pub mod mcp_protocol;
 pub mod message_history;
 pub mod models;
+pub mod num_format;
 pub mod parse_command;
 pub mod plan_tool;
 pub mod protocol;

codex-rs/protocol/src/mcp_protocol.rs

@@ -19,7 +19,7 @@ use strum_macros::Display;
 use ts_rs::TS;
 use uuid::Uuid;
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize, TS, Hash, Default)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize, TS, Hash)]
 #[ts(type = "string")]
 pub struct ConversationId(pub Uuid);
 
@@ -29,6 +29,12 @@ impl ConversationId {
     }
 }
 
+impl Default for ConversationId {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl Display for ConversationId {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         write!(f, "{}", self.0)
@@ -85,6 +91,11 @@ pub enum ClientRequest {
         request_id: RequestId,
         params: ResumeConversationParams,
     },
+    ArchiveConversation {
+        #[serde(rename = "id")]
+        request_id: RequestId,
+        params: ArchiveConversationParams,
+    },
     SendUserMessage {
         #[serde(rename = "id")]
         request_id: RequestId,
@@ -137,6 +148,14 @@ pub enum ClientRequest {
         #[serde(rename = "id")]
         request_id: RequestId,
     },
+    GetUserAgent {
+        #[serde(rename = "id")]
+        request_id: RequestId,
+    },
+    UserInfo {
+        #[serde(rename = "id")]
+        request_id: RequestId,
+    },
     /// Execute a command (argv vector) under the server's sandbox.
     ExecOneOffCommand {
         #[serde(rename = "id")]
@@ -193,9 +212,10 @@ pub struct NewConversationParams {
 pub struct NewConversationResponse {
     pub conversation_id: ConversationId,
     pub model: String,
+    pub rollout_path: PathBuf,
 }
 
-#[derive(Serialize, Deserialize, Debug, Clone)]
+#[derive(Serialize, Deserialize, Debug, Clone, TS)]
 #[serde(rename_all = "camelCase")]
 pub struct ResumeConversationResponse {
     pub conversation_id: ConversationId,
@@ -218,6 +238,7 @@ pub struct ListConversationsParams {
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, TS)]
 #[serde(rename_all = "camelCase")]
 pub struct ConversationSummary {
+    pub conversation_id: ConversationId,
     pub path: PathBuf,
     pub preview: String,
     /// RFC3339 timestamp string for the session start, if available.
@@ -251,6 +272,18 @@ pub struct AddConversationSubscriptionResponse {
     pub subscription_id: Uuid,
 }
 
+/// The [`ConversationId`] must match the `rollout_path`.
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, TS)]
+#[serde(rename_all = "camelCase")]
+pub struct ArchiveConversationParams {
+    pub conversation_id: ConversationId,
+    pub rollout_path: PathBuf,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, TS)]
+#[serde(rename_all = "camelCase")]
+pub struct ArchiveConversationResponse {}
+
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, TS)]
 #[serde(rename_all = "camelCase")]
 pub struct RemoveConversationSubscriptionResponse {}
@@ -339,6 +372,22 @@ pub struct GetAuthStatusResponse {
     pub auth_token: Option<String>,
 }
 
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, TS)]
+#[serde(rename_all = "camelCase")]
+pub struct GetUserAgentResponse {
+    pub user_agent: String,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, TS)]
+#[serde(rename_all = "camelCase")]
+pub struct UserInfoResponse {
+    /// Note: `alleged_user_email` is not currently verified. We read it from
+    /// the local auth.json, which the user could theoretically modify. In the
+    /// future, we may add logic to verify the email against the server before
+    /// returning it.
+    pub alleged_user_email: Option<String>,
+}
+
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, TS)]
 #[serde(rename_all = "camelCase")]
 pub struct GetUserSavedConfigResponse {
@@ -621,4 +670,10 @@ mod tests {
             serde_json::to_value(&request).unwrap(),
         );
     }
+
+    #[test]
+    fn test_conversation_id_default_is_not_zeroes() {
+        let id = ConversationId::default();
+        assert_ne!(id.0, Uuid::nil());
+    }
 }

codex-rs/protocol/src/message_history.rs

@@ -1,7 +1,8 @@
 use serde::Deserialize;
 use serde::Serialize;
+use ts_rs::TS;
 
-#[derive(Serialize, Deserialize, Debug, Clone)]
+#[derive(Serialize, Deserialize, Debug, Clone, TS)]
 pub struct HistoryEntry {
     pub conversation_id: String,
     pub ts: u64,

codex-rs/protocol/src/models.rs

@@ -6,10 +6,11 @@ use serde::Deserialize;
 use serde::Deserializer;
 use serde::Serialize;
 use serde::ser::Serializer;
+use ts_rs::TS;
 
 use crate::protocol::InputItem;
 
-#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, TS)]
 #[serde(tag = "type", rename_all = "snake_case")]
 pub enum ResponseInputItem {
     Message {
@@ -30,7 +31,7 @@ pub enum ResponseInputItem {
     },
 }
 
-#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, TS)]
 #[serde(tag = "type", rename_all = "snake_case")]
 pub enum ContentItem {
     InputText { text: String },
@@ -38,7 +39,7 @@ pub enum ContentItem {
     OutputText { text: String },
 }
 
-#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, TS)]
 #[serde(tag = "type", rename_all = "snake_case")]
 pub enum ResponseItem {
     Message {
@@ -48,7 +49,7 @@ pub enum ResponseItem {
         content: Vec<ContentItem>,
     },
     Reasoning {
-        #[serde(default)]
+        #[serde(default, skip_serializing)]
         id: String,
         summary: Vec<ReasoningItemReasoningSummary>,
         #[serde(default, skip_serializing_if = "should_serialize_reasoning_content")]
@@ -114,7 +115,6 @@ pub enum ResponseItem {
         status: Option<String>,
         action: WebSearchAction,
     },
-
     #[serde(other)]
     Other,
 }
@@ -159,7 +159,7 @@ impl From<ResponseInputItem> for ResponseItem {
     }
 }
 
-#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, TS)]
 #[serde(rename_all = "snake_case")]
 pub enum LocalShellStatus {
     Completed,
@@ -167,13 +167,13 @@ pub enum LocalShellStatus {
     Incomplete,
 }
 
-#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, TS)]
 #[serde(tag = "type", rename_all = "snake_case")]
 pub enum LocalShellAction {
     Exec(LocalShellExecAction),
 }
 
-#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, TS)]
 pub struct LocalShellExecAction {
     pub command: Vec<String>,
     pub timeout_ms: Option<u64>,
@@ -182,7 +182,7 @@ pub struct LocalShellExecAction {
     pub user: Option<String>,
 }
 
-#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, TS)]
 #[serde(tag = "type", rename_all = "snake_case")]
 pub enum WebSearchAction {
     Search {
@@ -192,13 +192,13 @@ pub enum WebSearchAction {
     Other,
 }
 
-#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, TS)]
 #[serde(tag = "type", rename_all = "snake_case")]
 pub enum ReasoningItemReasoningSummary {
     SummaryText { text: String },
 }
 
-#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, TS)]
 #[serde(tag = "type", rename_all = "snake_case")]
 pub enum ReasoningItemContent {
     ReasoningText { text: String },
@@ -242,7 +242,7 @@ impl From<Vec<InputItem>> for ResponseInputItem {
 
 /// If the `name` of a `ResponseItem::FunctionCall` is either `container.exec`
 /// or shell`, the `arguments` field should deserialize to this struct.
-#[derive(Deserialize, Debug, Clone, PartialEq)]
+#[derive(Deserialize, Debug, Clone, PartialEq, TS)]
 pub struct ShellToolCallParams {
     pub command: Vec<String>,
     pub workdir: Option<String>,
@@ -256,7 +256,7 @@ pub struct ShellToolCallParams {
     pub justification: Option<String>,
 }
 
-#[derive(Debug, Clone, PartialEq)]
+#[derive(Debug, Clone, PartialEq, TS)]
 pub struct FunctionCallOutputPayload {
     pub content: String,
     pub success: Option<bool>,

codex-rs/protocol/src/num_format.rs

@@ -0,0 +1,98 @@
+use std::sync::OnceLock;
+
+use icu_decimal::DecimalFormatter;
+use icu_decimal::input::Decimal;
+use icu_decimal::options::DecimalFormatterOptions;
+use icu_locale_core::Locale;
+
+fn make_local_formatter() -> Option<DecimalFormatter> {
+    let loc: Locale = sys_locale::get_locale()?.parse().ok()?;
+    DecimalFormatter::try_new(loc.into(), DecimalFormatterOptions::default()).ok()
+}
+
+fn make_en_us_formatter() -> DecimalFormatter {
+    #![allow(clippy::expect_used)]
+    let loc: Locale = "en-US".parse().expect("en-US wasn't a valid locale");
+    DecimalFormatter::try_new(loc.into(), DecimalFormatterOptions::default())
+        .expect("en-US wasn't a valid locale")
+}
+
+fn formatter() -> &'static DecimalFormatter {
+    static FORMATTER: OnceLock<DecimalFormatter> = OnceLock::new();
+    FORMATTER.get_or_init(|| make_local_formatter().unwrap_or_else(make_en_us_formatter))
+}
+
+/// Format a u64 with locale-aware digit separators (e.g. "12345" -> "12,345"
+/// for en-US).
+pub fn format_with_separators(n: u64) -> String {
+    formatter().format(&Decimal::from(n)).to_string()
+}
+
+fn format_si_suffix_with_formatter(n: u64, formatter: &DecimalFormatter) -> String {
+    if n < 1000 {
+        return formatter.format(&Decimal::from(n)).to_string();
+    }
+
+    // Format `n / scale` with the requested number of fractional digits.
+    let format_scaled = |n: u64, scale: u64, frac_digits: u32| -> String {
+        let value = n as f64 / scale as f64;
+        let scaled: u64 = (value * 10f64.powi(frac_digits as i32)).round() as u64;
+        let mut dec = Decimal::from(scaled);
+        dec.multiply_pow10(-(frac_digits as i16));
+        formatter.format(&dec).to_string()
+    };
+
+    const UNITS: [(u64, &str); 3] = [(1_000, "K"), (1_000_000, "M"), (1_000_000_000, "G")];
+    let f = n as f64;
+    for &(scale, suffix) in &UNITS {
+        if (100.0 * f / scale as f64).round() < 1000.0 {
+            return format!("{}{}", format_scaled(n, scale, 2), suffix);
+        } else if (10.0 * f / scale as f64).round() < 1000.0 {
+            return format!("{}{}", format_scaled(n, scale, 1), suffix);
+        } else if (f / scale as f64).round() < 1000.0 {
+            return format!("{}{}", format_scaled(n, scale, 0), suffix);
+        }
+    }
+
+    // Above 1000G, keep whole‑G precision.
+    format!(
+        "{}G",
+        format_with_separators(((n as f64) / 1e9).round() as u64)
+    )
+}
+
+/// Format token counts to 3 significant figures, using base-10 SI suffixes.
+///
+/// Examples (en-US):
+///   - 999 -> "999"
+///   - 1200 -> "1.20K"
+///   - 123456789 -> "123M"
+pub fn format_si_suffix(n: u64) -> String {
+    format_si_suffix_with_formatter(n, formatter())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn kmg() {
+        let formatter = make_en_us_formatter();
+        let fmt = |n: u64| format_si_suffix_with_formatter(n, &formatter);
+        assert_eq!(fmt(0), "0");
+        assert_eq!(fmt(999), "999");
+        assert_eq!(fmt(1_000), "1.00K");
+        assert_eq!(fmt(1_200), "1.20K");
+        assert_eq!(fmt(10_000), "10.0K");
+        assert_eq!(fmt(100_000), "100K");
+        assert_eq!(fmt(999_500), "1.00M");
+        assert_eq!(fmt(1_000_000), "1.00M");
+        assert_eq!(fmt(1_234_000), "1.23M");
+        assert_eq!(fmt(12_345_678), "12.3M");
+        assert_eq!(fmt(999_950_000), "1.00G");
+        assert_eq!(fmt(1_000_000_000), "1.00G");
+        assert_eq!(fmt(1_234_000_000), "1.23G");
+        // Above 1000G we keep whole‑G precision (no higher unit supported here).
+        assert_eq!(fmt(1_234_000_000_000), "1,234G");
+    }
+}

codex-rs/protocol/src/parse_command.rs

@@ -1,7 +1,8 @@
 use serde::Deserialize;
 use serde::Serialize;
+use ts_rs::TS;
 
-#[derive(Debug, Clone, PartialEq, Eq, Deserialize, Serialize)]
+#[derive(Debug, Clone, PartialEq, Eq, Deserialize, Serialize, TS)]
 #[serde(tag = "type", rename_all = "snake_case")]
 pub enum ParsedCommand {
     Read {

codex-rs/protocol/src/plan_tool.rs

@@ -1,8 +1,9 @@
 use serde::Deserialize;
 use serde::Serialize;
+use ts_rs::TS;
 
 // Types for the TODO tool arguments matching codex-vscode/todo-mcp/src/main.rs
-#[derive(Debug, Clone, Serialize, Deserialize)]
+#[derive(Debug, Clone, Serialize, Deserialize, TS)]
 #[serde(rename_all = "snake_case")]
 pub enum StepStatus {
     Pending,
@@ -10,14 +11,14 @@ pub enum StepStatus {
     Completed,
 }
 
-#[derive(Debug, Clone, Serialize, Deserialize)]
+#[derive(Debug, Clone, Serialize, Deserialize, TS)]
 #[serde(deny_unknown_fields)]
 pub struct PlanItemArg {
     pub step: String,
     pub status: StepStatus,
 }
 
-#[derive(Debug, Clone, Serialize, Deserialize)]
+#[derive(Debug, Clone, Serialize, Deserialize, TS)]
 #[serde(deny_unknown_fields)]
 pub struct UpdatePlanArgs {
     #[serde(default)]

codex-rs/protocol/src/protocol.rs

@@ -16,6 +16,7 @@ use crate::custom_prompts::CustomPrompt;
 use crate::mcp_protocol::ConversationId;
 use crate::message_history::HistoryEntry;
 use crate::models::ResponseItem;
+use crate::num_format::format_with_separators;
 use crate::parse_command::ParsedCommand;
 use crate::plan_tool::UpdatePlanArgs;
 use mcp_types::CallToolResult;
@@ -32,6 +33,7 @@ pub const USER_INSTRUCTIONS_OPEN_TAG: &str = "<user_instructions>";
 pub const USER_INSTRUCTIONS_CLOSE_TAG: &str = "</user_instructions>";
 pub const ENVIRONMENT_CONTEXT_OPEN_TAG: &str = "<environment_context>";
 pub const ENVIRONMENT_CONTEXT_CLOSE_TAG: &str = "</environment_context>";
+pub const USER_MESSAGE_BEGIN: &str = "## My request for Codex:";
 
 /// Submission Queue Entry - requests from user
 #[derive(Debug, Clone, Deserialize, Serialize)]
@@ -58,9 +60,6 @@ pub enum Op {
         items: Vec<InputItem>,
     },
 
-    /// Undo the most recently applied turn diff using the local git repo.
-    UndoLastTurnDiff,
-
     /// Similar to [`Op::UserInput`], but contains additional context required
     /// for a turn of a [`crate::codex_conversation::CodexConversation`].
     UserTurn {
@@ -150,7 +149,7 @@ pub enum Op {
 
     /// Request the full in-memory conversation transcript for the current session.
     /// Reply is delivered via `EventMsg::ConversationHistory`.
-    GetHistory,
+    GetPath,
 
     /// Request the list of MCP tools available across all configured servers.
     /// Reply is delivered via `EventMsg::McpListToolsResponse`.
@@ -406,7 +405,7 @@ pub struct Event {
 }
 
 /// Response event from the agent
-#[derive(Debug, Clone, Deserialize, Serialize, Display)]
+#[derive(Debug, Clone, Deserialize, Serialize, Display, TS)]
 #[serde(tag = "type", rename_all = "snake_case")]
 #[strum(serialize_all = "snake_case")]
 pub enum EventMsg {
@@ -500,27 +499,27 @@ pub enum EventMsg {
     /// Notification that the agent is shutting down.
     ShutdownComplete,
 
-    ConversationHistory(ConversationHistoryResponseEvent),
+    ConversationPath(ConversationPathResponseEvent),
 }
 
 // Individual event payload types matching each `EventMsg` variant.
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 pub struct ErrorEvent {
     pub message: String,
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 pub struct TaskCompleteEvent {
     pub last_agent_message: Option<String>,
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 pub struct TaskStartedEvent {
     pub model_context_window: Option<u64>,
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize, Default)]
+#[derive(Debug, Clone, Deserialize, Serialize, Default, TS)]
 pub struct TokenUsage {
     pub input_tokens: u64,
     pub cached_input_tokens: u64,
@@ -529,7 +528,7 @@ pub struct TokenUsage {
     pub total_tokens: u64,
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 pub struct TokenUsageInfo {
     pub total_token_usage: TokenUsage,
     pub last_token_usage: TokenUsage,
@@ -566,7 +565,7 @@ impl TokenUsageInfo {
     }
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 pub struct TokenCountEvent {
     pub info: Option<TokenUsageInfo>,
 }
@@ -648,19 +647,26 @@ impl From<TokenUsage> for FinalOutput {
 impl fmt::Display for FinalOutput {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         let token_usage = &self.token_usage;
+
         write!(
             f,
             "Token usage: total={} input={}{} output={}{}",
-            token_usage.blended_total(),
-            token_usage.non_cached_input(),
+            format_with_separators(token_usage.blended_total()),
+            format_with_separators(token_usage.non_cached_input()),
             if token_usage.cached_input() > 0 {
-                format!(" (+ {} cached)", token_usage.cached_input())
+                format!(
+                    " (+ {} cached)",
+                    format_with_separators(token_usage.cached_input())
+                )
             } else {
                 String::new()
             },
-            token_usage.output_tokens,
+            format_with_separators(token_usage.output_tokens),
             if token_usage.reasoning_output_tokens > 0 {
-                format!(" (reasoning {})", token_usage.reasoning_output_tokens)
+                format!(
+                    " (reasoning {})",
+                    format_with_separators(token_usage.reasoning_output_tokens)
+                )
             } else {
                 String::new()
             }
@@ -668,12 +674,12 @@ impl fmt::Display for FinalOutput {
     }
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 pub struct AgentMessageEvent {
     pub message: String,
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 #[serde(rename_all = "snake_case")]
 pub enum InputMessageKind {
     /// Plain user text (default)
@@ -684,11 +690,13 @@ pub enum InputMessageKind {
     EnvironmentContext,
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 pub struct UserMessageEvent {
     pub message: String,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub kind: Option<InputMessageKind>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub images: Option<Vec<String>>,
 }
 
 impl<T, U> From<(T, U)> for InputMessageKind
@@ -714,35 +722,35 @@ where
     }
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 pub struct AgentMessageDeltaEvent {
     pub delta: String,
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 pub struct AgentReasoningEvent {
     pub text: String,
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 pub struct AgentReasoningRawContentEvent {
     pub text: String,
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 pub struct AgentReasoningRawContentDeltaEvent {
     pub delta: String,
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 pub struct AgentReasoningSectionBreakEvent {}
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 pub struct AgentReasoningDeltaEvent {
     pub delta: String,
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 pub struct McpInvocation {
     /// Name of the MCP server as defined in the config.
     pub server: String,
@@ -752,18 +760,19 @@ pub struct McpInvocation {
     pub arguments: Option<serde_json::Value>,
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 pub struct McpToolCallBeginEvent {
     /// Identifier so this can be paired with the McpToolCallEnd event.
     pub call_id: String,
     pub invocation: McpInvocation,
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 pub struct McpToolCallEndEvent {
     /// Identifier for the corresponding McpToolCallBegin that finished.
     pub call_id: String,
     pub invocation: McpInvocation,
+    #[ts(type = "string")]
     pub duration: Duration,
     /// Result of the tool call. Note this could be an error.
     pub result: Result<CallToolResult, String>,
@@ -778,12 +787,12 @@ impl McpToolCallEndEvent {
     }
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 pub struct WebSearchBeginEvent {
     pub call_id: String,
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 pub struct WebSearchEndEvent {
     pub call_id: String,
     pub query: String,
@@ -791,13 +800,127 @@ pub struct WebSearchEndEvent {
 
 /// Response payload for `Op::GetHistory` containing the current session's
 /// in-memory transcript.
-#[derive(Debug, Clone, Deserialize, Serialize)]
-pub struct ConversationHistoryResponseEvent {
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
+pub struct ConversationPathResponseEvent {
     pub conversation_id: ConversationId,
-    pub entries: Vec<ResponseItem>,
+    pub path: PathBuf,
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
+pub struct ResumedHistory {
+    pub conversation_id: ConversationId,
+    pub history: Vec<RolloutItem>,
+    pub rollout_path: PathBuf,
+}
+
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
+pub enum InitialHistory {
+    New,
+    Resumed(ResumedHistory),
+    Forked(Vec<RolloutItem>),
+}
+
+impl InitialHistory {
+    pub fn get_rollout_items(&self) -> Vec<RolloutItem> {
+        match self {
+            InitialHistory::New => Vec::new(),
+            InitialHistory::Resumed(resumed) => resumed.history.clone(),
+            InitialHistory::Forked(items) => items.clone(),
+        }
+    }
+    pub fn get_response_items(&self) -> Vec<ResponseItem> {
+        match self {
+            InitialHistory::New => Vec::new(),
+            InitialHistory::Resumed(resumed) => resumed
+                .history
+                .iter()
+                .filter_map(|ri| match ri {
+                    RolloutItem::ResponseItem(item) => Some(item.clone()),
+                    _ => None,
+                })
+                .collect(),
+            InitialHistory::Forked(items) => items
+                .iter()
+                .filter_map(|ri| match ri {
+                    RolloutItem::ResponseItem(item) => Some(item.clone()),
+                    _ => None,
+                })
+                .collect(),
+        }
+    }
+    pub fn get_event_msgs(&self) -> Option<Vec<EventMsg>> {
+        match self {
+            InitialHistory::New => None,
+            InitialHistory::Resumed(resumed) => Some(
+                resumed
+                    .history
+                    .iter()
+                    .filter_map(|ri| match ri {
+                        RolloutItem::EventMsg(ev) => Some(ev.clone()),
+                        _ => None,
+                    })
+                    .collect(),
+            ),
+            InitialHistory::Forked(items) => Some(
+                items
+                    .iter()
+                    .filter_map(|ri| match ri {
+                        RolloutItem::EventMsg(ev) => Some(ev.clone()),
+                        _ => None,
+                    })
+                    .collect(),
+            ),
+        }
+    }
+}
+
+#[derive(Serialize, Deserialize, Clone, Default, Debug, TS)]
+pub struct SessionMeta {
+    pub id: ConversationId,
+    pub timestamp: String,
+    pub cwd: PathBuf,
+    pub originator: String,
+    pub cli_version: String,
+    pub instructions: Option<String>,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, TS)]
+pub struct SessionMetaLine {
+    #[serde(flatten)]
+    pub meta: SessionMeta,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub git: Option<GitInfo>,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, TS)]
+#[serde(tag = "type", content = "payload", rename_all = "snake_case")]
+pub enum RolloutItem {
+    SessionMeta(SessionMetaLine),
+    ResponseItem(ResponseItem),
+    EventMsg(EventMsg),
+}
+
+#[derive(Serialize, Deserialize, Clone)]
+pub struct RolloutLine {
+    pub timestamp: String,
+    #[serde(flatten)]
+    pub item: RolloutItem,
+}
+
+#[derive(Serialize, Deserialize, Clone, Debug, TS)]
+pub struct GitInfo {
+    /// Current commit hash (SHA)
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub commit_hash: Option<String>,
+    /// Current branch name
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub branch: Option<String>,
+    /// Repository URL (if available from remote)
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub repository_url: Option<String>,
+}
+
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 pub struct ExecCommandBeginEvent {
     /// Identifier so this can be paired with the ExecCommandEnd event.
     pub call_id: String,
@@ -808,7 +931,7 @@ pub struct ExecCommandBeginEvent {
     pub parsed_cmd: Vec<ParsedCommand>,
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 pub struct ExecCommandEndEvent {
     /// Identifier for the ExecCommandBegin that finished.
     pub call_id: String,
@@ -822,12 +945,13 @@ pub struct ExecCommandEndEvent {
     /// The command's exit code.
     pub exit_code: i32,
     /// The duration of the command execution.
+    #[ts(type = "string")]
     pub duration: Duration,
     /// Formatted output from the command, as seen by the model.
     pub formatted_output: String,
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize, PartialEq)]
+#[derive(Debug, Clone, Deserialize, Serialize, PartialEq, TS)]
 #[serde(rename_all = "snake_case")]
 pub enum ExecOutputStream {
     Stdout,
@@ -835,7 +959,7 @@ pub enum ExecOutputStream {
 }
 
 #[serde_as]
-#[derive(Debug, Clone, Deserialize, Serialize, PartialEq)]
+#[derive(Debug, Clone, Deserialize, Serialize, PartialEq, TS)]
 pub struct ExecCommandOutputDeltaEvent {
     /// Identifier for the ExecCommandBegin that produced this chunk.
     pub call_id: String,
@@ -843,10 +967,11 @@ pub struct ExecCommandOutputDeltaEvent {
     pub stream: ExecOutputStream,
     /// Raw bytes from the stream (may not be valid UTF-8).
     #[serde_as(as = "serde_with::base64::Base64")]
+    #[ts(type = "string")]
     pub chunk: Vec<u8>,
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 pub struct ExecApprovalRequestEvent {
     /// Identifier for the associated exec call, if available.
     pub call_id: String,
@@ -859,7 +984,7 @@ pub struct ExecApprovalRequestEvent {
     pub reason: Option<String>,
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 pub struct ApplyPatchApprovalRequestEvent {
     /// Responses API call id for the associated patch apply call, if available.
     pub call_id: String,
@@ -872,17 +997,17 @@ pub struct ApplyPatchApprovalRequestEvent {
     pub grant_root: Option<PathBuf>,
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 pub struct BackgroundEventEvent {
     pub message: String,
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 pub struct StreamErrorEvent {
     pub message: String,
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 pub struct PatchApplyBeginEvent {
     /// Identifier so this can be paired with the PatchApplyEnd event.
     pub call_id: String,
@@ -892,7 +1017,7 @@ pub struct PatchApplyBeginEvent {
     pub changes: HashMap<PathBuf, FileChange>,
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 pub struct PatchApplyEndEvent {
     /// Identifier for the PatchApplyBegin that finished.
     pub call_id: String,
@@ -904,12 +1029,12 @@ pub struct PatchApplyEndEvent {
     pub success: bool,
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 pub struct TurnDiffEvent {
     pub unified_diff: String,
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 pub struct GetHistoryEntryResponseEvent {
     pub offset: usize,
     pub log_id: u64,
@@ -919,19 +1044,19 @@ pub struct GetHistoryEntryResponseEvent {
 }
 
 /// Response payload for `Op::ListMcpTools`.
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 pub struct McpListToolsResponseEvent {
     /// Fully qualified tool name -> tool definition.
     pub tools: std::collections::HashMap<String, McpTool>,
 }
 
 /// Response payload for `Op::ListCustomPrompts`.
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 pub struct ListCustomPromptsResponseEvent {
     pub custom_prompts: Vec<CustomPrompt>,
 }
 
-#[derive(Debug, Default, Clone, Deserialize, Serialize)]
+#[derive(Debug, Default, Clone, Deserialize, Serialize, TS)]
 pub struct SessionConfiguredEvent {
     /// Name left as session_id instead of conversation_id for backwards compatibility.
     pub session_id: ConversationId,
@@ -949,6 +1074,8 @@ pub struct SessionConfiguredEvent {
     /// When present, UIs can use these to seed the history.
     #[serde(skip_serializing_if = "Option::is_none")]
     pub initial_messages: Option<Vec<EventMsg>>,
+
+    pub rollout_path: PathBuf,
 }
 
 /// User's decision in response to an ExecApprovalRequest.
@@ -988,7 +1115,7 @@ pub enum FileChange {
     },
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 pub struct Chunk {
     /// 1-based line index of the first line in the original file
     pub orig_index: u32,
@@ -996,7 +1123,7 @@ pub struct Chunk {
     pub inserted_lines: Vec<String>,
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, TS)]
 pub struct TurnAbortedEvent {
     pub reason: TurnAbortReason,
 }
@@ -1011,13 +1138,15 @@ pub enum TurnAbortReason {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use pretty_assertions::assert_eq;
+    use serde_json::json;
+    use tempfile::NamedTempFile;
 
     /// Serialize Event to verify that its JSON representation has the expected
     /// amount of nesting.
     #[test]
     fn serialize_event() {
         let conversation_id = ConversationId(uuid::uuid!("67e55044-10b1-426f-9247-bb680e5fe0c8"));
+        let rollout_file = NamedTempFile::new().unwrap();
         let event = Event {
             id: "1234".to_string(),
             msg: EventMsg::SessionConfigured(SessionConfiguredEvent {
@@ -1026,13 +1155,22 @@ mod tests {
                 history_log_id: 0,
                 history_entry_count: 0,
                 initial_messages: None,
+                rollout_path: rollout_file.path().to_path_buf(),
             }),
         };
-        let serialized = serde_json::to_string(&event).unwrap();
-        assert_eq!(
-            serialized,
-            r#"{"id":"1234","msg":{"type":"session_configured","session_id":"67e55044-10b1-426f-9247-bb680e5fe0c8","model":"codex-mini-latest","history_log_id":0,"history_entry_count":0}}"#
-        );
+
+        let expected = json!({
+            "id": "1234",
+            "msg": {
+                "type": "session_configured",
+                "session_id": "67e55044-10b1-426f-9247-bb680e5fe0c8",
+                "model": "codex-mini-latest",
+                "history_log_id": 0,
+                "history_entry_count": 0,
+                "rollout_path": format!("{}", rollout_file.path().display()),
+            }
+        });
+        assert_eq!(expected, serde_json::to_value(&event).unwrap());
     }
 
     #[test]

codex-rs/tui/Cargo.toml

@@ -59,9 +59,7 @@ ratatui = { version = "0.29.0", features = [
     "unstable-rendered-line-info",
     "unstable-widget-ref",
 ] }
-ratatui-image = "8.0.0"
 regex-lite = "0.1"
-reqwest = { version = "0.12", features = ["json"] }
 serde = { version = "1", features = ["derive"] }
 serde_json = { version = "1", features = ["preserve_order"] }
 shlex = "1.3.0"
@@ -81,12 +79,10 @@ tokio-stream = "0.1.17"
 tracing = { version = "0.1.41", features = ["log"] }
 tracing-appender = "0.2.3"
 tracing-subscriber = { version = "0.3.19", features = ["env-filter"] }
-tui-input = "0.14.0"
-tui-markdown = "0.3.3"
+pulldown-cmark = "0.10"
 unicode-segmentation = "1.12.0"
 unicode-width = "0.1"
 url = "2"
-uuid = "1"
 pathdiff = "0.2"
 
 [target.'cfg(unix)'.dependencies]

codex-rs/tui/src/app_backtrack.rs

@@ -1,14 +1,17 @@
+use std::path::PathBuf;
+
 use crate::app::App;
 use crate::backtrack_helpers;
 use crate::pager_overlay::Overlay;
 use crate::tui;
 use crate::tui::TuiEvent;
-use codex_core::protocol::ConversationHistoryResponseEvent;
+use codex_core::protocol::ConversationPathResponseEvent;
 use codex_protocol::mcp_protocol::ConversationId;
 use color_eyre::eyre::Result;
 use crossterm::event::KeyCode;
 use crossterm::event::KeyEvent;
 use crossterm::event::KeyEventKind;
+
 /// Aggregates all backtrack-related state used by the App.
 #[derive(Default)]
 pub(crate) struct BacktrackState {
@@ -97,7 +100,7 @@ impl App {
     ) {
         self.backtrack.pending = Some((base_id, drop_last_messages, prefill));
         self.app_event_tx.send(crate::app_event::AppEvent::CodexOp(
-            codex_core::protocol::Op::GetHistory,
+            codex_core::protocol::Op::GetPath,
         ));
     }
 
@@ -264,7 +267,7 @@ impl App {
     pub(crate) async fn on_conversation_history_for_backtrack(
         &mut self,
         tui: &mut tui::Tui,
-        ev: ConversationHistoryResponseEvent,
+        ev: ConversationPathResponseEvent,
     ) -> Result<()> {
         if let Some((base_id, _, _)) = self.backtrack.pending.as_ref()
             && ev.conversation_id == *base_id
@@ -280,14 +283,14 @@ impl App {
     async fn fork_and_switch_to_new_conversation(
         &mut self,
         tui: &mut tui::Tui,
-        ev: ConversationHistoryResponseEvent,
+        ev: ConversationPathResponseEvent,
         drop_count: usize,
         prefill: String,
     ) {
         let cfg = self.chat_widget.config_ref().clone();
         // Perform the fork via a thin wrapper for clarity/testability.
         let result = self
-            .perform_fork(ev.entries.clone(), drop_count, cfg.clone())
+            .perform_fork(ev.path.clone(), drop_count, cfg.clone())
             .await;
         match result {
             Ok(new_conv) => {
@@ -300,13 +303,11 @@ impl App {
     /// Thin wrapper around ConversationManager::fork_conversation.
     async fn perform_fork(
         &self,
-        entries: Vec<codex_protocol::models::ResponseItem>,
+        path: PathBuf,
         drop_count: usize,
         cfg: codex_core::config::Config,
     ) -> codex_core::error::Result<codex_core::NewConversation> {
-        self.server
-            .fork_conversation(entries, drop_count, cfg)
-            .await
+        self.server.fork_conversation(drop_count, cfg, path).await
     }
 
     /// Install a forked conversation into the ChatWidget and update UI to reflect selection.

codex-rs/tui/src/app_event.rs

@@ -1,4 +1,4 @@
-use codex_core::protocol::ConversationHistoryResponseEvent;
+use codex_core::protocol::ConversationPathResponseEvent;
 use codex_core::protocol::Event;
 use codex_file_search::FileMatch;
 
@@ -58,5 +58,5 @@ pub(crate) enum AppEvent {
     UpdateSandboxPolicy(SandboxPolicy),
 
     /// Forwarded conversation history snapshot from the current conversation.
-    ConversationHistory(ConversationHistoryResponseEvent),
+    ConversationHistory(ConversationPathResponseEvent),
 }

codex-rs/tui/src/bin/md-events.rs

@@ -0,0 +1,15 @@
+use std::io::Read;
+use std::io::{self};
+
+fn main() {
+    let mut input = String::new();
+    if let Err(err) = io::stdin().read_to_string(&mut input) {
+        eprintln!("failed to read stdin: {err}");
+        std::process::exit(1);
+    }
+
+    let parser = pulldown_cmark::Parser::new(&input);
+    for event in parser {
+        println!("{event:?}");
+    }
+}

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

@@ -1,4 +1,5 @@
 use codex_core::protocol::TokenUsageInfo;
+use codex_protocol::num_format::format_si_suffix;
 use crossterm::event::KeyCode;
 use crossterm::event::KeyEvent;
 use crossterm::event::KeyEventKind;
@@ -1276,8 +1277,11 @@ impl WidgetRef for ChatComposer {
                     let token_usage = &token_usage_info.total_token_usage;
                     hint.push("   ".into());
                     hint.push(
-                        Span::from(format!("{} tokens used", token_usage.blended_total()))
-                            .style(Style::default().add_modifier(Modifier::DIM)),
+                        Span::from(format!(
+                            "{} tokens used",
+                            format_si_suffix(token_usage.blended_total())
+                        ))
+                        .style(Style::default().add_modifier(Modifier::DIM)),
                     );
                     let last_token_usage = &token_usage_info.last_token_usage;
                     if let Some(context_window) = token_usage_info.model_context_window {

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

@@ -252,6 +252,11 @@ impl TextArea {
                 modifiers: KeyModifiers::CONTROL,
                 ..
             } => self.delete_backward(1),
+            KeyEvent {
+                code: KeyCode::Delete,
+                modifiers: KeyModifiers::ALT,
+                ..
+            }  => self.delete_forward_word(),
             KeyEvent {
                 code: KeyCode::Delete,
                 ..
@@ -435,6 +440,18 @@ impl TextArea {
         self.replace_range(start..self.cursor_pos, "");
     }
 
+    /// Delete text to the right of the cursor using "word" semantics.
+    ///
+    /// Deletes from the current cursor position through the end of the next word as determined
+    /// by `end_of_next_word()`. Any whitespace (including newlines) between the cursor and that
+    /// word is included in the deletion.
+    pub fn delete_forward_word(&mut self) {
+        let end = self.end_of_next_word();
+        if end > self.cursor_pos {
+            self.replace_range(self.cursor_pos..end, "");
+        }
+    }
+
     pub fn kill_to_end_of_line(&mut self) {
         let eol = self.end_of_current_line();
         if self.cursor_pos == eol {
@@ -1104,6 +1121,79 @@ mod tests {
         assert_eq!(t.cursor(), 3);
     }
 
+    #[test]
+    fn delete_forward_word_variants() {
+        let mut t = ta_with("hello   world ");
+        t.set_cursor(0);
+        t.delete_forward_word();
+        assert_eq!(t.text(), "   world ");
+        assert_eq!(t.cursor(), 0);
+
+        let mut t = ta_with("hello   world ");
+        t.set_cursor(1);
+        t.delete_forward_word();
+        assert_eq!(t.text(), "h   world ");
+        assert_eq!(t.cursor(), 1);
+
+        let mut t = ta_with("hello   world");
+        t.set_cursor(t.text().len());
+        t.delete_forward_word();
+        assert_eq!(t.text(), "hello   world");
+        assert_eq!(t.cursor(), t.text().len());
+
+        let mut t = ta_with("foo   \nbar");
+        t.set_cursor(3);
+        t.delete_forward_word();
+        assert_eq!(t.text(), "foo");
+        assert_eq!(t.cursor(), 3);
+
+        let mut t = ta_with("foo\nbar");
+        t.set_cursor(3);
+        t.delete_forward_word();
+        assert_eq!(t.text(), "foo");
+        assert_eq!(t.cursor(), 3);
+
+        let mut t = ta_with("hello   world ");
+        t.set_cursor(t.text().len() + 10);
+        t.delete_forward_word();
+        assert_eq!(t.text(), "hello   world ");
+        assert_eq!(t.cursor(), t.text().len());
+    }
+
+    #[test]
+    fn delete_forward_word_handles_atomic_elements() {
+        let mut t = TextArea::new();
+        t.insert_element("<element>");
+        t.insert_str(" tail");
+
+        t.set_cursor(0);
+        t.delete_forward_word();
+        assert_eq!(t.text(), " tail");
+        assert_eq!(t.cursor(), 0);
+
+        let mut t = TextArea::new();
+        t.insert_str("   ");
+        t.insert_element("<element>");
+        t.insert_str(" tail");
+
+        t.set_cursor(0);
+        t.delete_forward_word();
+        assert_eq!(t.text(), " tail");
+        assert_eq!(t.cursor(), 0);
+
+        let mut t = TextArea::new();
+        t.insert_str("prefix ");
+        t.insert_element("<element>");
+        t.insert_str(" tail");
+
+        // cursor in the middle of the element, delete_forward_word deletes the element
+        let elem_range = t.elements[0].range.clone();
+        t.cursor_pos = elem_range.start + (elem_range.len() / 2);
+        t.delete_forward_word();
+        assert_eq!(t.text(), "prefix  tail");
+        assert_eq!(t.cursor(), elem_range.start);
+    }
+
     #[test]
     fn cursor_left_and_right_handle_graphemes() {
         let mut t = ta_with("a👍b");
@@ -1174,6 +1264,21 @@ mod tests {
         assert_eq!(t.cursor(), 6);
     }
 
+    #[test]
+    fn delete_forward_word_with_without_alt_modifier() {
+        let mut t = ta_with("hello world");
+        t.set_cursor(0);
+        t.input(KeyEvent::new(KeyCode::Delete, KeyModifiers::ALT));
+        assert_eq!(t.text(), " world");
+        assert_eq!(t.cursor(), 0);
+
+        let mut t = ta_with("hello");
+        t.set_cursor(0);
+        t.input(KeyEvent::new(KeyCode::Delete, KeyModifiers::NONE));
+        assert_eq!(t.text(), "ello");
+        assert_eq!(t.cursor(), 0);
+    }
+
     #[test]
     fn control_h_backspace() {
         // Test Ctrl+H as backspace

codex-rs/tui/src/chatwidget.rs

@@ -411,8 +411,6 @@ impl ChatWidget {
 
     fn on_background_event(&mut self, message: String) {
         debug!("BackgroundEvent: {message}");
-        self.add_to_history(history_cell::new_background_event(message));
-        self.request_redraw();
     }
 
     fn on_stream_error(&mut self, message: String) {
@@ -864,9 +862,6 @@ impl ChatWidget {
                     tx.send(AppEvent::DiffResult(text));
                 });
             }
-            SlashCommand::Undo => {
-                self.open_undo_confirmation_popup();
-            }
             SlashCommand::Mention => {
                 self.insert_str("@");
             }
@@ -1088,7 +1083,7 @@ impl ChatWidget {
                     self.on_user_message_event(ev);
                 }
             }
-            EventMsg::ConversationHistory(ev) => {
+            EventMsg::ConversationPath(ev) => {
                 self.app_event_tx
                     .send(crate::app_event::AppEvent::ConversationHistory(ev));
             }
@@ -1258,43 +1253,6 @@ impl ChatWidget {
         );
     }
 
-    fn open_undo_confirmation_popup(&mut self) {
-        let confirm_message = "Undoing the last Codex turn diff.".to_string();
-        let undo_actions: Vec<SelectionAction> = vec![Box::new(move |tx| {
-            tx.send(AppEvent::InsertHistoryCell(Box::new(
-                history_cell::new_background_event(confirm_message.clone()),
-            )));
-            tx.send(AppEvent::CodexOp(Op::UndoLastTurnDiff));
-        })];
-
-        let items = vec![
-            SelectionItem {
-                name: "Undo last turn diff".to_string(),
-                description: Some(
-                    "Revert files that Codex changed during the most recent turn.".to_string(),
-                ),
-                is_current: false,
-                actions: undo_actions,
-            },
-            SelectionItem {
-                name: "Cancel".to_string(),
-                description: Some("Close without undoing any files.".to_string()),
-                is_current: false,
-                actions: Vec::new(),
-            },
-        ];
-
-        self.bottom_pane.show_selection_view(
-            "Undo last Codex turn?".to_string(),
-            Some(
-                "Codex will apply a patch to restore files from before the previous turn."
-                    .to_string(),
-            ),
-            Some("Press Enter to confirm or Esc to cancel".to_string()),
-            items,
-        );
-    }
-
     /// Set the approval policy in the widget's config copy.
     pub(crate) fn set_approval_policy(&mut self, policy: AskForApproval) {
         self.config.approval_policy = policy;

codex-rs/tui/src/chatwidget/snapshots/codex_tui__chatwidget__tests__chatwidget_markdown_code_blocks_vt100_snapshot.snap

@@ -0,0 +1,18 @@
+---
+source: tui/src/chatwidget/tests.rs
+expression: visual
+---
+>     -- Indented code block (4 spaces)
+      SELECT *
+      FROM "users"
+      WHERE "email" LIKE '%@example.com';
+
+  ```sh
+  printf 'fenced within fenced\n'
+  ```
+
+  {
+    // comment allowed in jsonc
+    "path": "C:\\Program Files\\App",
+    "regex": "^foo.*(bar)?$"
+  }

codex-rs/tui/src/chatwidget/tests.rs

@@ -13,7 +13,6 @@ use codex_core::protocol::AgentMessageEvent;
 use codex_core::protocol::AgentReasoningDeltaEvent;
 use codex_core::protocol::AgentReasoningEvent;
 use codex_core::protocol::ApplyPatchApprovalRequestEvent;
-use codex_core::protocol::BackgroundEventEvent;
 use codex_core::protocol::Event;
 use codex_core::protocol::EventMsg;
 use codex_core::protocol::ExecApprovalRequestEvent;
@@ -36,6 +35,7 @@ use std::fs::File;
 use std::io::BufRead;
 use std::io::BufReader;
 use std::path::PathBuf;
+use tempfile::NamedTempFile;
 use tokio::sync::mpsc::unbounded_channel;
 
 fn test_config() -> Config {
@@ -134,7 +134,7 @@ fn resumed_initial_messages_render_history() {
     let (mut chat, mut rx, _ops) = make_chatwidget_manual();
 
     let conversation_id = ConversationId::new();
-
+    let rollout_file = NamedTempFile::new().unwrap();
     let configured = codex_core::protocol::SessionConfiguredEvent {
         session_id: conversation_id,
         model: "test-model".to_string(),
@@ -144,11 +144,13 @@ fn resumed_initial_messages_render_history() {
             EventMsg::UserMessage(UserMessageEvent {
                 message: "hello from user".to_string(),
                 kind: Some(InputMessageKind::Plain),
+                images: None,
             }),
             EventMsg::AgentMessage(AgentMessageEvent {
                 message: "assistant reply".to_string(),
             }),
         ]),
+        rollout_path: rollout_file.path().to_path_buf(),
     };
 
     chat.handle_codex_event(Event {
@@ -178,6 +180,10 @@ fn resumed_initial_messages_render_history() {
     );
 }
 
+#[cfg_attr(
+    target_os = "macos",
+    ignore = "system configuration APIs are blocked under macOS seatbelt"
+)]
 #[tokio::test(flavor = "current_thread")]
 async fn helpers_are_available_and_do_not_panic() {
     let (tx_raw, _rx) = unbounded_channel::<AppEvent>();
@@ -615,58 +621,6 @@ fn disabled_slash_command_while_task_running_snapshot() {
     assert_snapshot!(blob);
 }
 
-#[test]
-fn undo_command_requires_confirmation() {
-    let (mut chat, mut rx, _op_rx) = make_chatwidget_manual();
-
-    chat.dispatch_command(SlashCommand::Undo);
-
-    assert!(rx.try_recv().is_err(), "undo should require confirmation");
-
-    chat.handle_key_event(KeyEvent::new(KeyCode::Enter, KeyModifiers::NONE));
-
-    let mut undo_requested = false;
-    let mut history_lines = Vec::new();
-    while let Ok(event) = rx.try_recv() {
-        match event {
-            AppEvent::InsertHistoryCell(cell) => {
-                history_lines.push(cell.display_lines(80));
-            }
-            AppEvent::CodexOp(Op::UndoLastTurnDiff) => {
-                undo_requested = true;
-            }
-            _ => {}
-        }
-    }
-
-    assert!(undo_requested, "expected undo op after confirmation");
-
-    let combined = history_lines
-        .iter()
-        .map(|lines| lines_to_single_string(lines))
-        .collect::<String>();
-    assert!(combined.contains("Undoing the last Codex turn diff."));
-}
-
-#[test]
-fn background_events_are_rendered_in_history() {
-    let (mut chat, mut rx, _op_rx) = make_chatwidget_manual();
-
-    chat.handle_codex_event(Event {
-        id: "undo".to_string(),
-        msg: EventMsg::BackgroundEvent(BackgroundEventEvent {
-            message: "Reverted last turn diff.".to_string(),
-        }),
-    });
-
-    let history = drain_insert_history(&mut rx);
-    let combined = history
-        .iter()
-        .map(|lines| lines_to_single_string(lines))
-        .collect::<String>();
-    assert!(combined.contains("Reverted last turn diff."));
-}
-
 #[tokio::test(flavor = "current_thread")]
 async fn binary_size_transcript_snapshot() {
     let (mut chat, mut rx, _op_rx) = make_chatwidget_manual();
@@ -1802,3 +1756,123 @@ fn chatwidget_exec_and_status_layout_vt100_snapshot() {
     let visual = vt_lines.join("\n");
     assert_snapshot!(visual);
 }
+
+// E2E vt100 snapshot for complex markdown with indented and nested fenced code blocks
+#[test]
+fn chatwidget_markdown_code_blocks_vt100_snapshot() {
+    let (mut chat, mut rx, _op_rx) = make_chatwidget_manual();
+
+    // Simulate a final agent message via streaming deltas instead of a single message
+
+    chat.handle_codex_event(Event {
+        id: "t1".into(),
+        msg: EventMsg::TaskStarted(TaskStartedEvent {
+            model_context_window: None,
+        }),
+    });
+    // Build a vt100 visual from the history insertions only (no UI overlay)
+    let width: u16 = 80;
+    let height: u16 = 50;
+    let backend = ratatui::backend::TestBackend::new(width, height);
+    let mut term = crate::custom_terminal::Terminal::with_options(backend).expect("terminal");
+    // Place viewport at the last line so that history lines insert above it
+    term.set_viewport_area(Rect::new(0, height - 1, width, 1));
+
+    let mut ansi: Vec<u8> = Vec::new();
+
+    // Simulate streaming via AgentMessageDelta in 2-character chunks (no final AgentMessage).
+    let source: &str = r#"
+
+    -- Indented code block (4 spaces)
+    SELECT *
+    FROM "users"
+    WHERE "email" LIKE '%@example.com';
+
+````markdown
+```sh
+printf 'fenced within fenced\n'
+```
+````
+
+```jsonc
+{
+  // comment allowed in jsonc
+  "path": "C:\\Program Files\\App",
+  "regex": "^foo.*(bar)?$"
+}
+```
+"#;
+
+    let mut it = source.chars();
+    loop {
+        let mut delta = String::new();
+        match it.next() {
+            Some(c) => delta.push(c),
+            None => break,
+        }
+        if let Some(c2) = it.next() {
+            delta.push(c2);
+        }
+
+        chat.handle_codex_event(Event {
+            id: "t1".into(),
+            msg: EventMsg::AgentMessageDelta(AgentMessageDeltaEvent { delta }),
+        });
+        // Drive commit ticks and drain emitted history lines into the vt100 buffer.
+        loop {
+            chat.on_commit_tick();
+            let mut inserted_any = false;
+            while let Ok(app_ev) = rx.try_recv() {
+                if let AppEvent::InsertHistoryCell(cell) = app_ev {
+                    let lines = cell.display_lines(width);
+                    crate::insert_history::insert_history_lines_to_writer(
+                        &mut term, &mut ansi, lines,
+                    );
+                    inserted_any = true;
+                }
+            }
+            if !inserted_any {
+                break;
+            }
+        }
+    }
+
+    // Finalize the stream without sending a final AgentMessage, to flush any tail.
+    chat.handle_codex_event(Event {
+        id: "t1".into(),
+        msg: EventMsg::TaskComplete(TaskCompleteEvent {
+            last_agent_message: None,
+        }),
+    });
+    for lines in drain_insert_history(&mut rx) {
+        crate::insert_history::insert_history_lines_to_writer(&mut term, &mut ansi, lines);
+    }
+
+    let mut parser = vt100::Parser::new(height, width, 0);
+    parser.process(&ansi);
+
+    let mut vt_lines: Vec<String> = (0..height)
+        .map(|row| {
+            let mut s = String::with_capacity(width as usize);
+            for col in 0..width {
+                if let Some(cell) = parser.screen().cell(row, col) {
+                    if let Some(ch) = cell.contents().chars().next() {
+                        s.push(ch);
+                    } else {
+                        s.push(' ');
+                    }
+                } else {
+                    s.push(' ');
+                }
+            }
+            s.trim_end().to_string()
+        })
+        .collect();
+
+    // Compact trailing blank rows for a stable snapshot
+    while matches!(vt_lines.last(), Some(l) if l.trim().is_empty()) {
+        vt_lines.pop();
+    }
+    let visual = vt_lines.join("\n");
+    assert_snapshot!(visual);
+}

codex-rs/tui/src/chatwidget_stream_tests.rs

@@ -1 +0,0 @@
-

codex-rs/tui/src/clipboard_paste.rs

@@ -49,34 +49,60 @@ pub struct PastedImageInfo {
 /// Capture image from system clipboard, encode to PNG, and return bytes + info.
 #[cfg(not(target_os = "android"))]
 pub fn paste_image_as_png() -> Result<(Vec<u8>, PastedImageInfo), PasteImageError> {
+    let _span = tracing::debug_span!("paste_image_as_png").entered();
     tracing::debug!("attempting clipboard image read");
     let mut cb = arboard::Clipboard::new()
         .map_err(|e| PasteImageError::ClipboardUnavailable(e.to_string()))?;
-    let img = cb
-        .get_image()
-        .map_err(|e| PasteImageError::NoImage(e.to_string()))?;
-    let w = img.width as u32;
-    let h = img.height as u32;
+    // Sometimes images on the clipboard come as files (e.g. when copy/pasting from
+    // Finder), sometimes they come as image data (e.g. when pasting from Chrome).
+    // Accept both, and prefer files if both are present.
+    let files = cb
+        .get()
+        .file_list()
+        .map_err(|e| PasteImageError::ClipboardUnavailable(e.to_string()));
+    let dyn_img = if let Some(img) = files
+        .unwrap_or_default()
+        .into_iter()
+        .find_map(|f| image::open(f).ok())
+    {
+        tracing::debug!(
+            "clipboard image opened from file: {}x{}",
+            img.width(),
+            img.height()
+        );
+        img
+    } else {
+        let _span = tracing::debug_span!("get_image").entered();
+        let img = cb
+            .get_image()
+            .map_err(|e| PasteImageError::NoImage(e.to_string()))?;
+        let w = img.width as u32;
+        let h = img.height as u32;
+        tracing::debug!("clipboard image opened from image: {}x{}", w, h);
+
+        let Some(rgba_img) = image::RgbaImage::from_raw(w, h, img.bytes.into_owned()) else {
+            return Err(PasteImageError::EncodeFailed("invalid RGBA buffer".into()));
+        };
+
+        image::DynamicImage::ImageRgba8(rgba_img)
+    };
 
     let mut png: Vec<u8> = Vec::new();
-    let Some(rgba_img) = image::RgbaImage::from_raw(w, h, img.bytes.into_owned()) else {
-        return Err(PasteImageError::EncodeFailed("invalid RGBA buffer".into()));
-    };
-    let dyn_img = image::DynamicImage::ImageRgba8(rgba_img);
-    tracing::debug!("clipboard image decoded RGBA {w}x{h}");
     {
+        let span =
+            tracing::debug_span!("encode_image", byte_length = tracing::field::Empty).entered();
         let mut cursor = std::io::Cursor::new(&mut png);
         dyn_img
             .write_to(&mut cursor, image::ImageFormat::Png)
             .map_err(|e| PasteImageError::EncodeFailed(e.to_string()))?;
+        span.record("byte_length", png.len());
     }
 
-    tracing::debug!("clipboard image encoded to PNG ({}) bytes", png.len());
     Ok((
         png,
         PastedImageInfo {
-            width: w,
-            height: h,
+            width: dyn_img.width(),
+            height: dyn_img.height(),
             encoded_format: EncodedImageFormat::Png,
         },
     ))

codex-rs/tui/src/history_cell.rs

@@ -28,6 +28,7 @@ use codex_core::protocol::SandboxPolicy;
 use codex_core::protocol::SessionConfiguredEvent;
 use codex_core::protocol::TokenUsage;
 use codex_protocol::mcp_protocol::ConversationId;
+use codex_protocol::num_format::format_with_separators;
 use codex_protocol::parse_command::ParsedCommand;
 use image::DynamicImage;
 use image::ImageReader;
@@ -604,6 +605,7 @@ pub(crate) fn new_session_info(
         history_log_id: _,
         history_entry_count: _,
         initial_messages: _,
+        rollout_path: _,
     } = event;
     if is_first_event {
         let cwd_str = match relativize_to_home(&config.cwd) {
@@ -964,7 +966,7 @@ pub(crate) fn new_status_output(
     // Input: <input> [+ <cached> cached]
     let mut input_line_spans: Vec<Span<'static>> = vec![
         "  • Input: ".into(),
-        usage.non_cached_input().to_string().into(),
+        format_with_separators(usage.non_cached_input()).into(),
     ];
     if usage.cached_input_tokens > 0 {
         let cached = usage.cached_input_tokens;
@@ -974,12 +976,12 @@ pub(crate) fn new_status_output(
     // Output: <output>
     lines.push(Line::from(vec![
         "  • Output: ".into(),
-        usage.output_tokens.to_string().into(),
+        format_with_separators(usage.output_tokens).into(),
     ]));
     // Total: <total>
     lines.push(Line::from(vec![
         "  • Total: ".into(),
-        usage.blended_total().to_string().into(),
+        format_with_separators(usage.blended_total()).into(),
     ]));
 
     PlainHistoryCell { lines }
@@ -1064,11 +1066,6 @@ pub(crate) fn new_stream_error_event(message: String) -> PlainHistoryCell {
     PlainHistoryCell { lines }
 }
 
-pub(crate) fn new_background_event(message: String) -> PlainHistoryCell {
-    let lines: Vec<Line<'static>> = vec![vec![padded_emoji("ℹ️").into(), message.into()].into()];
-    PlainHistoryCell { lines }
-}
-
 /// Render a user‑friendly plan update styled like a checkbox todo list.
 pub(crate) fn new_plan_update(update: UpdatePlanArgs) -> PlanUpdateCell {
     let UpdatePlanArgs { explanation, plan } = update;
@@ -1182,13 +1179,14 @@ pub(crate) fn new_proposed_command(command: &[String]) -> PlainHistoryCell {
     let mut lines: Vec<Line<'static>> = Vec::new();
     lines.push(Line::from(vec!["• ".into(), "Proposed Command".bold()]));
 
-    let cmd_lines: Vec<Line<'static>> = cmd
-        .lines()
-        .map(|part| Line::from(part.to_string()))
-        .collect();
+    let highlighted_lines = crate::render::highlight::highlight_bash_to_lines(&cmd);
     let initial_prefix: Span<'static> = "  └ ".dim();
     let subsequent_prefix: Span<'static> = "    ".into();
-    lines.extend(prefix_lines(cmd_lines, initial_prefix, subsequent_prefix));
+    lines.extend(prefix_lines(
+        highlighted_lines,
+        initial_prefix,
+        subsequent_prefix,
+    ));
 
     PlainHistoryCell { lines }
 }

codex-rs/tui/src/insert_history.rs

@@ -97,7 +97,17 @@ pub fn insert_history_lines_to_writer<B, W>(
 
     for line in wrapped {
         queue!(writer, Print("\r\n")).ok();
-        write_spans(writer, &line).ok();
+        // Merge line-level style into each span so that ANSI colors reflect
+        // line styles (e.g., blockquotes with green fg).
+        let merged_spans: Vec<Span> = line
+            .spans
+            .iter()
+            .map(|s| Span {
+                style: s.style.patch(line.style),
+                content: s.content.clone(),
+            })
+            .collect();
+        write_spans(writer, merged_spans.iter()).ok();
     }
 
     queue!(writer, ResetScrollRegion).ok();
@@ -264,6 +274,10 @@ where
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::markdown_render::render_markdown_text;
+    use ratatui::layout::Rect;
+    use ratatui::style::Color;
+    use vt100::Parser;
 
     #[test]
     fn writes_bold_then_regular_spans() {
@@ -292,4 +306,240 @@ mod tests {
             String::from_utf8(expected).unwrap()
         );
     }
+
+    #[test]
+    fn vt100_blockquote_line_emits_green_fg() {
+        // Set up a small off-screen terminal
+        let width: u16 = 40;
+        let height: u16 = 10;
+        let backend = ratatui::backend::TestBackend::new(width, height);
+        let mut term = crate::custom_terminal::Terminal::with_options(backend).expect("terminal");
+        // Place viewport on the last line so history inserts scroll upward
+        let viewport = Rect::new(0, height - 1, width, 1);
+        term.set_viewport_area(viewport);
+
+        // Build a blockquote-like line: apply line-level green style and prefix "> "
+        let mut line: Line<'static> = Line::from(vec!["> ".into(), "Hello world".into()]);
+        line = line.style(Color::Green);
+        let mut ansi: Vec<u8> = Vec::new();
+        insert_history_lines_to_writer(&mut term, &mut ansi, vec![line]);
+
+        // Parse ANSI using vt100 and assert at least one non-default fg color appears
+        let mut parser = Parser::new(height, width, 0);
+        parser.process(&ansi);
+
+        let mut saw_colored = false;
+        'outer: for row in 0..height {
+            for col in 0..width {
+                if let Some(cell) = parser.screen().cell(row, col)
+                    && cell.has_contents()
+                    && cell.fgcolor() != vt100::Color::Default
+                {
+                    saw_colored = true;
+                    break 'outer;
+                }
+            }
+        }
+        assert!(
+            saw_colored,
+            "expected at least one colored cell in vt100 output"
+        );
+    }
+
+    #[test]
+    fn vt100_blockquote_wrap_preserves_color_on_all_wrapped_lines() {
+        // Force wrapping by using a narrow viewport width and a long blockquote line.
+        let width: u16 = 20;
+        let height: u16 = 8;
+        let backend = ratatui::backend::TestBackend::new(width, height);
+        let mut term = crate::custom_terminal::Terminal::with_options(backend).expect("terminal");
+        // Viewport is the last line so history goes directly above it.
+        let viewport = Rect::new(0, height - 1, width, 1);
+        term.set_viewport_area(viewport);
+
+        // Create a long blockquote with a distinct prefix and enough text to wrap.
+        let mut line: Line<'static> = Line::from(vec![
+            "> ".into(),
+            "This is a long quoted line that should wrap".into(),
+        ]);
+        line = line.style(Color::Green);
+
+        let mut ansi: Vec<u8> = Vec::new();
+        insert_history_lines_to_writer(&mut term, &mut ansi, vec![line]);
+
+        // Parse and inspect the final screen buffer.
+        let mut parser = Parser::new(height, width, 0);
+        parser.process(&ansi);
+        let screen = parser.screen();
+
+        // Collect rows that are non-empty; these should correspond to our wrapped lines.
+        let mut non_empty_rows: Vec<u16> = Vec::new();
+        for row in 0..height {
+            let mut any = false;
+            for col in 0..width {
+                if let Some(cell) = screen.cell(row, col)
+                    && cell.has_contents()
+                    && cell.contents() != "\0"
+                    && cell.contents() != " "
+                {
+                    any = true;
+                    break;
+                }
+            }
+            if any {
+                non_empty_rows.push(row);
+            }
+        }
+
+        // Expect at least two rows due to wrapping.
+        assert!(
+            non_empty_rows.len() >= 2,
+            "expected wrapped output to span >=2 rows, got {non_empty_rows:?}",
+        );
+
+        // For each non-empty row, ensure all non-space cells are using a non-default fg color.
+        for row in non_empty_rows {
+            for col in 0..width {
+                if let Some(cell) = screen.cell(row, col) {
+                    let contents = cell.contents();
+                    if !contents.is_empty() && contents != " " {
+                        assert!(
+                            cell.fgcolor() != vt100::Color::Default,
+                            "expected non-default fg on row {row} col {col}, got {:?}",
+                            cell.fgcolor()
+                        );
+                    }
+                }
+            }
+        }
+    }
+
+    #[test]
+    fn vt100_colored_prefix_then_plain_text_resets_color() {
+        let width: u16 = 40;
+        let height: u16 = 6;
+        let backend = ratatui::backend::TestBackend::new(width, height);
+        let mut term = crate::custom_terminal::Terminal::with_options(backend).expect("terminal");
+        let viewport = Rect::new(0, height - 1, width, 1);
+        term.set_viewport_area(viewport);
+
+        // First span colored, rest plain.
+        let line: Line<'static> = Line::from(vec![
+            Span::styled("1. ", ratatui::style::Style::default().fg(Color::LightBlue)),
+            Span::raw("Hello world"),
+        ]);
+
+        let mut ansi: Vec<u8> = Vec::new();
+        insert_history_lines_to_writer(&mut term, &mut ansi, vec![line]);
+
+        let mut parser = Parser::new(height, width, 0);
+        parser.process(&ansi);
+        let screen = parser.screen();
+
+        // Find the first non-empty row; verify first three cells are colored, following cells default.
+        'rows: for row in 0..height {
+            let mut has_text = false;
+            for col in 0..width {
+                if let Some(cell) = screen.cell(row, col)
+                    && cell.has_contents()
+                    && cell.contents() != " "
+                {
+                    has_text = true;
+                    break;
+                }
+            }
+            if !has_text {
+                continue;
+            }
+
+            // Expect "1. Hello world" starting at col 0.
+            for col in 0..3 {
+                let cell = screen.cell(row, col).unwrap();
+                assert!(
+                    cell.fgcolor() != vt100::Color::Default,
+                    "expected colored prefix at col {col}, got {:?}",
+                    cell.fgcolor()
+                );
+            }
+            for col in 3..(3 + "Hello world".len() as u16) {
+                let cell = screen.cell(row, col).unwrap();
+                assert_eq!(
+                    cell.fgcolor(),
+                    vt100::Color::Default,
+                    "expected default color for plain text at col {col}, got {:?}",
+                    cell.fgcolor()
+                );
+            }
+            break 'rows;
+        }
+    }
+
+    #[test]
+    fn vt100_deep_nested_mixed_list_third_level_marker_is_colored() {
+        // Markdown with five levels (ordered → unordered → ordered → unordered → unordered).
+        let md = "1. First\n   - Second level\n     1. Third level (ordered)\n        - Fourth level (bullet)\n          - Fifth level to test indent consistency\n";
+        let text = render_markdown_text(md);
+        let lines: Vec<Line<'static>> = text.lines.clone();
+
+        let width: u16 = 60;
+        let height: u16 = 12;
+        let backend = ratatui::backend::TestBackend::new(width, height);
+        let mut term = crate::custom_terminal::Terminal::with_options(backend).expect("terminal");
+        let viewport = ratatui::layout::Rect::new(0, height - 1, width, 1);
+        term.set_viewport_area(viewport);
+
+        let mut ansi: Vec<u8> = Vec::new();
+        insert_history_lines_to_writer(&mut term, &mut ansi, lines);
+
+        let mut parser = Parser::new(height, width, 0);
+        parser.process(&ansi);
+        let screen = parser.screen();
+
+        // Reconstruct screen rows as strings to locate the 3rd level line.
+        let mut rows: Vec<String> = Vec::with_capacity(height as usize);
+        for row in 0..height {
+            let mut s = String::with_capacity(width as usize);
+            for col in 0..width {
+                if let Some(cell) = screen.cell(row, col) {
+                    if let Some(ch) = cell.contents().chars().next() {
+                        s.push(ch);
+                    } else {
+                        s.push(' ');
+                    }
+                } else {
+                    s.push(' ');
+                }
+            }
+            rows.push(s.trim_end().to_string());
+        }
+
+        let needle = "1. Third level (ordered)";
+        let row_idx = rows
+            .iter()
+            .position(|r| r.contains(needle))
+            .unwrap_or_else(|| {
+                panic!("expected to find row containing {needle:?}, have rows: {rows:?}")
+            });
+        let col_start = rows[row_idx].find(needle).unwrap() as u16; // column where '1' starts
+
+        // Verify that the numeric marker ("1.") at the third level is colored
+        // (non-default fg) and the content after the following space resets to default.
+        for c in [col_start, col_start + 1] {
+            let cell = screen.cell(row_idx as u16, c).unwrap();
+            assert!(
+                cell.fgcolor() != vt100::Color::Default,
+                "expected colored 3rd-level marker at row {row_idx} col {c}, got {:?}",
+                cell.fgcolor()
+            );
+        }
+        let content_col = col_start + 3; // skip '1', '.', and the space
+        if let Some(cell) = screen.cell(row_idx as u16, content_col) {
+            assert_eq!(
+                cell.fgcolor(),
+                vt100::Color::Default,
+                "expected default color for 3rd-level content at row {row_idx} col {content_col}, got {:?}",
+                cell.fgcolor()
+            );
+        }
+    }
 }

codex-rs/tui/src/lib.rs

@@ -45,6 +45,7 @@ pub mod insert_history;
 mod key_hint;
 pub mod live_wrap;
 mod markdown;
+mod markdown_render;
 mod markdown_stream;
 pub mod onboarding;
 mod pager_overlay;
@@ -61,11 +62,6 @@ mod user_approval_widget;
 mod version;
 mod wrapping;
 
-// Internal vt100-based replay tests live as a separate source file to keep them
-// close to the widget code. Include them in unit tests.
-#[cfg(test)]
-mod chatwidget_stream_tests;
-
 #[cfg(not(debug_assertions))]
 mod updates;
 
@@ -217,6 +213,7 @@ pub async fn run_main(
     let file_layer = tracing_subscriber::fmt::layer()
         .with_writer(non_blocking)
         .with_target(false)
+        .with_span_events(tracing_subscriber::fmt::format::FmtSpan::CLOSE)
         .with_filter(env_filter());
 
     if cli.oss {
@@ -311,11 +308,7 @@ async fn run_ratatui_app(
         ..
     } = cli;
 
-    let auth_manager = AuthManager::shared(
-        config.codex_home.clone(),
-        config.preferred_auth_method,
-        config.responses_originator_header.clone(),
-    );
+    let auth_manager = AuthManager::shared(config.codex_home.clone(), config.preferred_auth_method);
     let login_status = get_login_status(&config);
     let should_show_onboarding =
         should_show_onboarding(login_status, &config, should_show_trust_screen);
@@ -399,11 +392,7 @@ fn get_login_status(config: &Config) -> LoginStatus {
         // Reading the OpenAI API key is an async operation because it may need
         // to refresh the token. Block on it.
         let codex_home = config.codex_home.clone();
-        match CodexAuth::from_codex_home(
-            &codex_home,
-            config.preferred_auth_method,
-            &config.responses_originator_header,
-        ) {
+        match CodexAuth::from_codex_home(&codex_home, config.preferred_auth_method) {
             Ok(Some(auth)) => LoginStatus::AuthMode(auth.mode),
             Ok(None) => LoginStatus::NotAuthenticated,
             Err(err) => {