feat: shell snapshotting

codex-rs/core/src/codex.rs

@@ -109,6 +109,7 @@ use crate::rollout::RolloutRecorder;
 use crate::rollout::RolloutRecorderParams;
 use crate::rollout::map_session_init_error;
 use crate::shell;
+use crate::shell_snapshot::ShellSnapshot;
 use crate::state::ActiveTurn;
 use crate::state::SessionServices;
 use crate::state::SessionState;
@@ -571,7 +572,8 @@ impl Session {
         );
 
         // Create the mutable state for the Session.
-        let state = SessionState::new(session_configuration.clone());
+        let shell_snapshot = ShellSnapshot::try_new(&config.codex_home, &default_shell).await;
+        let state = SessionState::new(session_configuration.clone(), shell_snapshot);
 
         let services = SessionServices {
             mcp_connection_manager: Arc::new(RwLock::new(McpConnectionManager::default())),
@@ -1442,6 +1444,24 @@ impl Session {
         &self.services.user_shell
     }
 
+    /// Add the shell snapshot the command if the snapshot is available.
+    ///
+    /// Returns the new command and `true` if a shell snapshot has been
+    /// applied, `false` otherwise.
+    pub(crate) async fn shell_snapshot(&self) -> Option<ShellSnapshot> {
+        if !self.enabled(Feature::ShellSnapshot) {
+            return None;
+        }
+
+        let state = self.state.lock().await;
+        state.shell_snapshot.clone()
+        // if let Some(path) = snapshot_path {
+        //     (wrap_command_with_snapshot(self.user_shell(), &path, command), true)
+        // } else {
+        //     (command.to_vec(), false)
+        // }
+    }
+
     fn show_raw_agent_reasoning(&self) -> bool {
         self.services.show_raw_agent_reasoning
     }
@@ -2585,7 +2605,7 @@ mod tests {
             session_source: SessionSource::Exec,
         };
 
-        let mut state = SessionState::new(session_configuration);
+        let mut state = SessionState::new(session_configuration, None);
         let initial = RateLimitSnapshot {
             primary: Some(RateLimitWindow {
                 used_percent: 10.0,
@@ -2656,7 +2676,7 @@ mod tests {
             session_source: SessionSource::Exec,
         };
 
-        let mut state = SessionState::new(session_configuration);
+        let mut state = SessionState::new(session_configuration, None);
         let initial = RateLimitSnapshot {
             primary: Some(RateLimitWindow {
                 used_percent: 15.0,
@@ -2863,7 +2883,7 @@ mod tests {
             session_source: SessionSource::Exec,
         };
 
-        let state = SessionState::new(session_configuration.clone());
+        let state = SessionState::new(session_configuration.clone(), None);
 
         let services = SessionServices {
             mcp_connection_manager: Arc::new(RwLock::new(McpConnectionManager::default())),
@@ -2942,7 +2962,7 @@ mod tests {
             session_source: SessionSource::Exec,
         };
 
-        let state = SessionState::new(session_configuration.clone());
+        let state = SessionState::new(session_configuration.clone(), None);
 
         let services = SessionServices {
             mcp_connection_manager: Arc::new(RwLock::new(McpConnectionManager::default())),

codex-rs/core/src/features.rs

@@ -58,6 +58,8 @@ pub enum Feature {
     ParallelToolCalls,
     /// Experimental skills injection (CLI flag-driven).
     Skills,
+    /// Experimental shell snapshotting.
+    ShellSnapshot,
 }
 
 impl Feature {
@@ -345,4 +347,10 @@ pub const FEATURES: &[FeatureSpec] = &[
         stage: Stage::Experimental,
         default_enabled: false,
     },
+    FeatureSpec {
+        id: Feature::ShellSnapshot,
+        key: "shell_snapshot",
+        stage: Stage::Experimental,
+        default_enabled: false,
+    },
 ];

codex-rs/core/src/lib.rs

@@ -73,6 +73,7 @@ mod rollout;
 pub(crate) mod safety;
 pub mod seatbelt;
 pub mod shell;
+pub mod shell_snapshot;
 pub mod skills;
 pub mod spawn;
 pub mod terminal;