make codex better at git (#10145)

adds basic git context to the session prefix so the model can anchor git
actions and be a bit more version-aware. structured it in a
multiroot-friendly shape even though we only have one root today

codex-rs/core/src/client.rs

@@ -1,10 +1,13 @@
+use std::path::PathBuf;
 use std::sync::Arc;
 use std::sync::OnceLock;
+use std::sync::RwLock;
 
 use crate::api_bridge::CoreAuthProvider;
 use crate::api_bridge::auth_provider_from_auth;
 use crate::api_bridge::map_api_error;
 use crate::auth::UnauthorizedRecovery;
+use crate::turn_metadata::build_turn_metadata_header;
 use codex_api::AggregateStreamExt;
 use codex_api::ChatClient as ApiChatClient;
 use codex_api::CompactClient as ApiCompactClient;
@@ -72,6 +75,13 @@ use crate::transport_manager::TransportManager;
 
 pub const WEB_SEARCH_ELIGIBLE_HEADER: &str = "x-oai-web-search-eligible";
 pub const X_CODEX_TURN_STATE_HEADER: &str = "x-codex-turn-state";
+pub const X_CODEX_TURN_METADATA_HEADER: &str = "x-codex-turn-metadata";
+
+#[derive(Debug, Default)]
+struct TurnMetadataCache {
+    cwd: Option<PathBuf>,
+    header: Option<HeaderValue>,
+}
 
 #[derive(Debug)]
 struct ModelClientState {
@@ -85,6 +95,7 @@ struct ModelClientState {
     summary: ReasoningSummaryConfig,
     session_source: SessionSource,
     transport_manager: TransportManager,
+    turn_metadata_cache: Arc<RwLock<TurnMetadataCache>>,
 }
 
 #[derive(Debug, Clone)]
@@ -136,11 +147,13 @@ impl ModelClient {
                 summary,
                 session_source,
                 transport_manager,
+                turn_metadata_cache: Arc::new(RwLock::new(TurnMetadataCache::default())),
             }),
         }
     }
 
-    pub fn new_session(&self) -> ModelClientSession {
+    pub fn new_session(&self, turn_metadata_cwd: Option<PathBuf>) -> ModelClientSession {
+        self.prewarm_turn_metadata_header(turn_metadata_cwd);
         ModelClientSession {
             state: Arc::clone(&self.state),
             connection: None,
@@ -149,6 +162,38 @@ impl ModelClient {
             turn_state: Arc::new(OnceLock::new()),
         }
     }
+
+    /// Refresh turn metadata in the background and update a cached header that request
+    /// builders can read without blocking.
+    fn prewarm_turn_metadata_header(&self, turn_metadata_cwd: Option<PathBuf>) {
+        let turn_metadata_cwd =
+            turn_metadata_cwd.map(|cwd| std::fs::canonicalize(&cwd).unwrap_or(cwd));
+
+        if let Ok(mut cache) = self.state.turn_metadata_cache.write()
+            && cache.cwd != turn_metadata_cwd
+        {
+            cache.cwd = turn_metadata_cwd.clone();
+            cache.header = None;
+        }
+
+        let Some(cwd) = turn_metadata_cwd else {
+            return;
+        };
+        let turn_metadata_cache = Arc::clone(&self.state.turn_metadata_cache);
+        if let Ok(handle) = tokio::runtime::Handle::try_current() {
+            let _task = handle.spawn(async move {
+                let header = build_turn_metadata_header(cwd.as_path())
+                    .await
+                    .and_then(|value| HeaderValue::from_str(value.as_str()).ok());
+
+                if let Ok(mut cache) = turn_metadata_cache.write()
+                    && cache.cwd.as_ref() == Some(&cwd)
+                {
+                    cache.header = header;
+                }
+            });
+        }
+    }
 }
 
 impl ModelClient {
@@ -257,6 +302,14 @@ impl ModelClient {
 }
 
 impl ModelClientSession {
+    fn turn_metadata_header(&self) -> Option<HeaderValue> {
+        self.state
+            .turn_metadata_cache
+            .try_read()
+            .ok()
+            .and_then(|cache| cache.header.clone())
+    }
+
     /// Streams a single model turn using either the Responses or Chat
     /// Completions wire API, depending on the configured provider.
     ///
@@ -332,6 +385,7 @@ impl ModelClientSession {
         prompt: &Prompt,
         compression: Compression,
     ) -> ApiResponsesOptions {
+        let turn_metadata_header = self.turn_metadata_header();
         let model_info = &self.state.model_info;
 
         let default_reasoning_effort = model_info.default_reasoning_level;
@@ -380,7 +434,11 @@ impl ModelClientSession {
             store_override: None,
             conversation_id: Some(conversation_id),
             session_source: Some(self.state.session_source.clone()),
-            extra_headers: build_responses_headers(&self.state.config, Some(&self.turn_state)),
+            extra_headers: build_responses_headers(
+                &self.state.config,
+                Some(&self.turn_state),
+                turn_metadata_header.as_ref(),
+            ),
             compression,
             turn_state: Some(Arc::clone(&self.turn_state)),
         }
@@ -713,6 +771,7 @@ fn experimental_feature_headers(config: &Config) -> ApiHeaderMap {
 fn build_responses_headers(
     config: &Config,
     turn_state: Option<&Arc<OnceLock<String>>>,
+    turn_metadata_header: Option<&HeaderValue>,
 ) -> ApiHeaderMap {
     let mut headers = experimental_feature_headers(config);
     headers.insert(
@@ -731,6 +790,9 @@ fn build_responses_headers(
     {
         headers.insert(X_CODEX_TURN_STATE_HEADER, header_value);
     }
+    if let Some(header_value) = turn_metadata_header {
+        headers.insert(X_CODEX_TURN_METADATA_HEADER, header_value.clone());
+    }
     headers
 }
 

codex-rs/core/src/codex.rs

@@ -119,6 +119,7 @@ use crate::error::Result as CodexResult;
 use crate::exec::StreamOutput;
 use crate::exec_policy::ExecPolicyUpdateError;
 use crate::feedback_tags;
+use crate::git_info::get_git_repo_root;
 use crate::instructions::UserInstructions;
 use crate::mcp::CODEX_APPS_MCP_SERVER_NAME;
 use crate::mcp::auth::compute_auth_statuses;
@@ -531,7 +532,6 @@ pub(crate) struct TurnContext {
     pub(crate) truncation_policy: TruncationPolicy,
     pub(crate) dynamic_tools: Vec<DynamicToolSpec>,
 }
-
 impl TurnContext {
     pub(crate) fn resolve_path(&self, path: Option<String>) -> PathBuf {
         path.as_ref()
@@ -3406,7 +3406,9 @@ pub(crate) async fn run_turn(
     // many turns, from the perspective of the user, it is a single turn.
     let turn_diff_tracker = Arc::new(tokio::sync::Mutex::new(TurnDiffTracker::new()));
 
-    let mut client_session = turn_context.client.new_session();
+    let mut client_session = turn_context
+        .client
+        .new_session(Some(turn_context.cwd.clone()));
 
     loop {
         // Note that pending_input would be something like a message the user
@@ -4469,8 +4471,6 @@ pub(super) fn get_last_assistant_message_from_turn(responses: &[ResponseItem]) -
 
 #[cfg(test)]
 pub(crate) use tests::make_session_and_context;
-
-use crate::git_info::get_git_repo_root;
 #[cfg(test)]
 pub(crate) use tests::make_session_and_context_with_rx;
 

codex-rs/core/src/compact.rs

@@ -335,7 +335,9 @@ async fn drain_to_completed(
     turn_context: &TurnContext,
     prompt: &Prompt,
 ) -> CodexResult<()> {
-    let mut client_session = turn_context.client.new_session();
+    let mut client_session = turn_context
+        .client
+        .new_session(Some(turn_context.cwd.clone()));
     let mut stream = client_session.stream(prompt).await?;
     loop {
         let maybe_event = stream.next().await;

codex-rs/core/src/environment_context.rs

@@ -28,6 +28,7 @@ impl EnvironmentContext {
             cwd,
             // should compare all fields except shell
             shell: _,
+            ..
         } = other;
 
         self.cwd == *cwd

codex-rs/core/src/git_info.rs

@@ -1,3 +1,4 @@
+use std::collections::BTreeMap;
 use std::collections::HashSet;
 use std::path::Path;
 use std::path::PathBuf;
@@ -109,6 +110,73 @@ pub async fn collect_git_info(cwd: &Path) -> Option<GitInfo> {
     Some(git_info)
 }
 
+/// Collect fetch remotes in a multi-root-friendly format: {"origin": "https://..."}.
+pub async fn get_git_remote_urls(cwd: &Path) -> Option<BTreeMap<String, String>> {
+    let is_git_repo = run_git_command_with_timeout(&["rev-parse", "--git-dir"], cwd)
+        .await?
+        .status
+        .success();
+    if !is_git_repo {
+        return None;
+    }
+
+    get_git_remote_urls_assume_git_repo(cwd).await
+}
+
+/// Collect fetch remotes without checking whether `cwd` is in a git repo.
+pub async fn get_git_remote_urls_assume_git_repo(cwd: &Path) -> Option<BTreeMap<String, String>> {
+    let output = run_git_command_with_timeout(&["remote", "-v"], cwd).await?;
+    if !output.status.success() {
+        return None;
+    }
+
+    let stdout = String::from_utf8(output.stdout).ok()?;
+    parse_git_remote_urls(stdout.as_str())
+}
+
+/// Return the current HEAD commit hash without checking whether `cwd` is in a git repo.
+pub async fn get_head_commit_hash(cwd: &Path) -> Option<String> {
+    let output = run_git_command_with_timeout(&["rev-parse", "HEAD"], cwd).await?;
+    if !output.status.success() {
+        return None;
+    }
+
+    let stdout = String::from_utf8(output.stdout).ok()?;
+    let hash = stdout.trim();
+    if hash.is_empty() {
+        None
+    } else {
+        Some(hash.to_string())
+    }
+}
+
+fn parse_git_remote_urls(stdout: &str) -> Option<BTreeMap<String, String>> {
+    let mut remotes = BTreeMap::new();
+    for line in stdout.lines() {
+        let Some(fetch_line) = line.strip_suffix(" (fetch)") else {
+            continue;
+        };
+
+        let Some((name, url_part)) = fetch_line
+            .split_once('\t')
+            .or_else(|| fetch_line.split_once(' '))
+        else {
+            continue;
+        };
+
+        let url = url_part.trim_start();
+        if !url.is_empty() {
+            remotes.insert(name.to_string(), url.to_string());
+        }
+    }
+
+    if remotes.is_empty() {
+        None
+    } else {
+        Some(remotes)
+    }
+}
+
 /// A minimal commit summary entry used for pickers (subject + timestamp + sha).
 #[derive(Clone, Debug, Serialize, Deserialize)]
 pub struct CommitLogEntry {
@@ -185,11 +253,9 @@ pub async fn git_diff_to_remote(cwd: &Path) -> Option<GitDiffToRemote> {
 
 /// Run a git command with a timeout to prevent blocking on large repositories
 async fn run_git_command_with_timeout(args: &[&str], cwd: &Path) -> Option<std::process::Output> {
-    let result = timeout(
-        GIT_COMMAND_TIMEOUT,
-        Command::new("git").args(args).current_dir(cwd).output(),
-    )
-    .await;
+    let mut command = Command::new("git");
+    command.args(args).current_dir(cwd).kill_on_drop(true);
+    let result = timeout(GIT_COMMAND_TIMEOUT, command.output()).await;
 
     match result {
         Ok(Ok(output)) => Some(output),

codex-rs/core/src/lib.rs

@@ -101,6 +101,7 @@ pub mod state_db;
 pub mod terminal;
 mod tools;
 pub mod turn_diff_tracker;
+mod turn_metadata;
 pub use rollout::ARCHIVED_SESSIONS_SUBDIR;
 pub use rollout::INTERACTIVE_SESSION_SOURCES;
 pub use rollout::RolloutRecorder;
@@ -131,6 +132,7 @@ pub mod util;
 
 pub use apply_patch::CODEX_APPLY_PATCH_ARG1;
 pub use client::WEB_SEARCH_ELIGIBLE_HEADER;
+pub use client::X_CODEX_TURN_METADATA_HEADER;
 pub use command_safety::is_dangerous_command;
 pub use command_safety::is_safe_command;
 pub use exec_policy::ExecPolicyError;

codex-rs/core/src/turn_metadata.rs

@@ -0,0 +1,43 @@
+use std::collections::BTreeMap;
+use std::path::Path;
+
+use serde::Serialize;
+
+use crate::git_info::get_git_remote_urls_assume_git_repo;
+use crate::git_info::get_git_repo_root;
+use crate::git_info::get_head_commit_hash;
+
+#[derive(Serialize)]
+struct TurnMetadataWorkspace {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    associated_remote_urls: Option<BTreeMap<String, String>>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    latest_git_commit_hash: Option<String>,
+}
+
+#[derive(Serialize)]
+struct TurnMetadata {
+    workspaces: BTreeMap<String, TurnMetadataWorkspace>,
+}
+
+pub(crate) async fn build_turn_metadata_header(cwd: &Path) -> Option<String> {
+    let repo_root = get_git_repo_root(cwd)?;
+
+    let (latest_git_commit_hash, associated_remote_urls) = tokio::join!(
+        get_head_commit_hash(cwd),
+        get_git_remote_urls_assume_git_repo(cwd)
+    );
+    if latest_git_commit_hash.is_none() && associated_remote_urls.is_none() {
+        return None;
+    }
+
+    let mut workspaces = BTreeMap::new();
+    workspaces.insert(
+        repo_root.to_string_lossy().into_owned(),
+        TurnMetadataWorkspace {
+            associated_remote_urls,
+            latest_git_commit_hash,
+        },
+    );
+    serde_json::to_string(&TurnMetadata { workspaces }).ok()
+}