ref: state 3 (#4165)

codex-rs/core/src/codex.rs

@@ -1,6 +1,5 @@
 use std::borrow::Cow;
 use std::collections::HashMap;
-use std::collections::HashSet;
 use std::path::Path;
 use std::path::PathBuf;
 use std::sync::Arc;
@@ -110,7 +109,6 @@ use crate::protocol::Submission;
 use crate::protocol::TaskCompleteEvent;
 use crate::protocol::TokenCountEvent;
 use crate::protocol::TokenUsage;
-use crate::protocol::TokenUsageInfo;
 use crate::protocol::TurnDiffEvent;
 use crate::protocol::WebSearchBeginEvent;
 use crate::rollout::RolloutRecorder;
@@ -118,6 +116,7 @@ use crate::rollout::RolloutRecorderParams;
 use crate::safety::SafetyCheck;
 use crate::safety::assess_command_safety;
 use crate::safety::assess_safety_for_untrusted_command;
+use crate::services::SessionServices;
 use crate::shell;
 use crate::turn_diff_tracker::TurnDiffTracker;
 use crate::unified_exec::UnifiedExecSessionManager;
@@ -252,17 +251,7 @@ impl Codex {
     }
 }
 
-/// Mutable state of the agent
-#[derive(Default)]
-struct State {
-    approved_commands: HashSet<Vec<String>>,
-    current_task: Option<AgentTask>,
-    pending_approvals: HashMap<String, oneshot::Sender<ReviewDecision>>,
-    pending_input: Vec<ResponseInputItem>,
-    history: ConversationHistory,
-    token_info: Option<TokenUsageInfo>,
-    latest_rate_limits: Option<RateLimitSnapshot>,
-}
+use crate::state::SessionState;
 
 /// Context for an initialized model agent
 ///
@@ -270,21 +259,8 @@ struct State {
 pub(crate) struct Session {
     conversation_id: ConversationId,
     tx_event: Sender<Event>,
-
-    /// Manager for external MCP servers/tools.
-    mcp_connection_manager: McpConnectionManager,
-    session_manager: ExecSessionManager,
-    unified_exec_manager: UnifiedExecSessionManager,
-
-    notifier: UserNotifier,
-
-    /// Optional rollout recorder for persisting the conversation transcript so
-    /// sessions can be replayed or inspected later.
-    rollout: Mutex<Option<RolloutRecorder>>,
-    state: Mutex<State>,
-    codex_linux_sandbox_exe: Option<PathBuf>,
-    user_shell: shell::Shell,
-    show_raw_agent_reasoning: bool,
+    state: Mutex<SessionState>,
+    services: SessionServices,
     next_internal_sub_id: AtomicU64,
 }
 
@@ -412,10 +388,7 @@ impl Session {
         })?;
         let rollout_path = rollout_recorder.rollout_path.clone();
         // Create the mutable state for the Session.
-        let state = State {
-            history: ConversationHistory::new(),
-            ..Default::default()
-        };
+        let state = SessionState::new();
 
         // Handle MCP manager result and record any startup failures.
         let (mcp_connection_manager, failed_clients) = match mcp_res {
@@ -473,18 +446,22 @@ impl Session {
             is_review_mode: false,
             final_output_json_schema: None,
         };
-        let sess = Arc::new(Session {
-            conversation_id,
-            tx_event: tx_event.clone(),
+        let services = SessionServices {
             mcp_connection_manager,
             session_manager: ExecSessionManager::default(),
             unified_exec_manager: UnifiedExecSessionManager::default(),
             notifier: notify,
-            state: Mutex::new(state),
             rollout: Mutex::new(Some(rollout_recorder)),
             codex_linux_sandbox_exe: config.codex_linux_sandbox_exe.clone(),
             user_shell: default_shell,
             show_raw_agent_reasoning: config.show_raw_agent_reasoning,
+        };
+
+        let sess = Arc::new(Session {
+            conversation_id,
+            tx_event: tx_event.clone(),
+            state: Mutex::new(state),
+            services,
             next_internal_sub_id: AtomicU64::new(0),
         });
 
@@ -591,7 +568,7 @@ impl Session {
         let event_id = sub_id.clone();
         let prev_entry = {
             let mut state = self.state.lock().await;
-            state.pending_approvals.insert(sub_id, tx_approve)
+            state.insert_pending_approval(sub_id, tx_approve)
         };
         if prev_entry.is_some() {
             warn!("Overwriting existing pending approval for sub_id: {event_id}");
@@ -623,7 +600,7 @@ impl Session {
         let event_id = sub_id.clone();
         let prev_entry = {
             let mut state = self.state.lock().await;
-            state.pending_approvals.insert(sub_id, tx_approve)
+            state.insert_pending_approval(sub_id, tx_approve)
         };
         if prev_entry.is_some() {
             warn!("Overwriting existing pending approval for sub_id: {event_id}");
@@ -645,7 +622,7 @@ impl Session {
     pub async fn notify_approval(&self, sub_id: &str, decision: ReviewDecision) {
         let entry = {
             let mut state = self.state.lock().await;
-            state.pending_approvals.remove(sub_id)
+            state.remove_pending_approval(sub_id)
         };
         match entry {
             Some(tx_approve) => {
@@ -659,7 +636,7 @@ impl Session {
 
     pub async fn add_approved_command(&self, cmd: Vec<String>) {
         let mut state = self.state.lock().await;
-        state.approved_commands.insert(cmd);
+        state.add_approved_command(cmd);
     }
 
     /// Records input items: always append to conversation history and
@@ -699,7 +676,7 @@ impl Session {
     /// Append ResponseItems to the in-memory conversation history only.
     async fn record_into_history(&self, items: &[ResponseItem]) {
         let mut state = self.state.lock().await;
-        state.history.record_items(items.iter());
+        state.record_items(items.iter());
     }
 
     async fn persist_rollout_response_items(&self, items: &[ResponseItem]) {
@@ -720,14 +697,14 @@ impl Session {
             Some(turn_context.cwd.clone()),
             Some(turn_context.approval_policy),
             Some(turn_context.sandbox_policy.clone()),
-            Some(self.user_shell.clone()),
+            Some(self.services.user_shell.clone()),
         )));
         items
     }
 
     async fn persist_rollout_items(&self, items: &[RolloutItem]) {
         let recorder = {
-            let guard = self.rollout.lock().await;
+            let guard = self.services.rollout.lock().await;
             guard.clone()
         };
         if let Some(rec) = recorder
@@ -746,12 +723,10 @@ impl Session {
         {
             let mut state = self.state.lock().await;
             if let Some(token_usage) = token_usage {
-                let info = TokenUsageInfo::new_or_append(
-                    &state.token_info,
-                    &Some(token_usage.clone()),
+                state.update_token_info_from_usage(
+                    token_usage,
                     turn_context.client.get_model_context_window(),
                 );
-                state.token_info = info;
             }
         }
         self.send_token_count_event(sub_id).await;
@@ -760,7 +735,7 @@ impl Session {
     async fn update_rate_limits(&self, sub_id: &str, new_rate_limits: RateLimitSnapshot) {
         {
             let mut state = self.state.lock().await;
-            state.latest_rate_limits = Some(new_rate_limits);
+            state.set_rate_limits(new_rate_limits);
         }
         self.send_token_count_event(sub_id).await;
     }
@@ -768,7 +743,7 @@ impl Session {
     async fn send_token_count_event(&self, sub_id: &str) {
         let (info, rate_limits) = {
             let state = self.state.lock().await;
-            (state.token_info.clone(), state.latest_rate_limits.clone())
+            state.token_info_and_rate_limits()
         };
         let event = Event {
             id: sub_id.to_string(),
@@ -786,8 +761,10 @@ impl Session {
             .await;
 
         // Derive user message events and persist only UserMessage to rollout
-        let msgs =
-            map_response_item_to_event_messages(&response_item, self.show_raw_agent_reasoning);
+        let msgs = map_response_item_to_event_messages(
+            &response_item,
+            self.services.show_raw_agent_reasoning,
+        );
         let user_msgs: Vec<RolloutItem> = msgs
             .into_iter()
             .filter_map(|m| match m {
@@ -986,7 +963,7 @@ impl Session {
     pub async fn turn_input_with_history(&self, extra: Vec<ResponseItem>) -> Vec<ResponseItem> {
         let history = {
             let state = self.state.lock().await;
-            state.history.contents()
+            state.history_snapshot()
         };
         [history, extra].concat()
     }
@@ -995,7 +972,7 @@ impl Session {
     pub async fn inject_input(&self, input: Vec<InputItem>) -> Result<(), Vec<InputItem>> {
         let mut state = self.state.lock().await;
         if state.current_task.is_some() {
-            state.pending_input.push(input.into());
+            state.push_pending_input(input.into());
             Ok(())
         } else {
             Err(input)
@@ -1004,13 +981,7 @@ impl Session {
 
     pub async fn get_pending_input(&self) -> Vec<ResponseInputItem> {
         let mut state = self.state.lock().await;
-        if state.pending_input.is_empty() {
-            Vec::with_capacity(0)
-        } else {
-            let mut ret = Vec::new();
-            std::mem::swap(&mut ret, &mut state.pending_input);
-            ret
-        }
+        state.take_pending_input()
     }
 
     pub async fn call_tool(
@@ -1019,7 +990,8 @@ impl Session {
         tool: &str,
         arguments: Option<serde_json::Value>,
     ) -> anyhow::Result<CallToolResult> {
-        self.mcp_connection_manager
+        self.services
+            .mcp_connection_manager
             .call_tool(server, tool, arguments)
             .await
     }
@@ -1027,8 +999,7 @@ impl Session {
     pub async fn interrupt_task(&self) {
         info!("interrupt received: abort current task, if any");
         let mut state = self.state.lock().await;
-        state.pending_approvals.clear();
-        state.pending_input.clear();
+        state.clear_pending();
         if let Some(task) = state.current_task.take() {
             task.abort(TurnAbortReason::Interrupted);
         }
@@ -1036,8 +1007,7 @@ impl Session {
 
     fn interrupt_task_sync(&self) {
         if let Ok(mut state) = self.state.try_lock() {
-            state.pending_approvals.clear();
-            state.pending_input.clear();
+            state.clear_pending();
             if let Some(task) = state.current_task.take() {
                 task.abort(TurnAbortReason::Interrupted);
             }
@@ -1045,7 +1015,7 @@ impl Session {
     }
 
     pub(crate) fn notifier(&self) -> &UserNotifier {
-        &self.notifier
+        &self.services.notifier
     }
 }
 
@@ -1417,7 +1387,7 @@ async fn submission_loop(
                 let sub_id = sub.id.clone();
 
                 // This is a cheap lookup from the connection manager's cache.
-                let tools = sess.mcp_connection_manager.list_all_tools();
+                let tools = sess.services.mcp_connection_manager.list_all_tools();
                 let event = Event {
                     id: sub_id,
                     msg: EventMsg::McpListToolsResponse(
@@ -1467,7 +1437,7 @@ async fn submission_loop(
                 // Gracefully flush and shutdown rollout recorder on session end so tests
                 // that inspect the rollout file do not race with the background writer.
                 let recorder_opt = {
-                    let mut guard = sess.rollout.lock().await;
+                    let mut guard = sess.services.rollout.lock().await;
                     guard.take()
                 };
                 if let Some(rec) = recorder_opt
@@ -1494,7 +1464,7 @@ async fn submission_loop(
                 let sub_id = sub.id.clone();
                 // Flush rollout writes before returning the path so readers observe a consistent file.
                 let (path, rec_opt) = {
-                    let guard = sess.rollout.lock().await;
+                    let guard = sess.services.rollout.lock().await;
                     match guard.as_ref() {
                         Some(rec) => (rec.get_rollout_path(), Some(rec.clone())),
                         None => {
@@ -1952,7 +1922,7 @@ async fn run_turn(
 ) -> CodexResult<TurnRunResult> {
     let tools = get_openai_tools(
         &turn_context.tools_config,
-        Some(sess.mcp_connection_manager.list_all_tools()),
+        Some(sess.services.mcp_connection_manager.list_all_tools()),
     );
 
     let prompt = Prompt {
@@ -2202,7 +2172,7 @@ async fn try_run_turn(
                 sess.send_event(event).await;
             }
             ResponseEvent::ReasoningContentDelta(delta) => {
-                if sess.show_raw_agent_reasoning {
+                if sess.services.show_raw_agent_reasoning {
                     let event = Event {
                         id: sub_id.to_string(),
                         msg: EventMsg::AgentReasoningRawContentDelta(
@@ -2324,7 +2294,10 @@ async fn handle_response_item(
                     trace!("suppressing assistant Message in review mode");
                     Vec::new()
                 }
-                _ => map_response_item_to_event_messages(&item, sess.show_raw_agent_reasoning),
+                _ => map_response_item_to_event_messages(
+                    &item,
+                    sess.services.show_raw_agent_reasoning,
+                ),
             };
             for msg in msgs {
                 let event = Event {
@@ -2370,7 +2343,11 @@ async fn handle_unified_exec_tool_call(
         timeout_ms,
     };
 
-    let result = sess.unified_exec_manager.handle_request(request).await;
+    let result = sess
+        .services
+        .unified_exec_manager
+        .handle_request(request)
+        .await;
 
     let output_payload = match result {
         Ok(value) => {
@@ -2545,6 +2522,7 @@ async fn handle_function_call(
                 }
             };
             let result = sess
+                .services
                 .session_manager
                 .handle_exec_command_request(exec_params)
                 .await;
@@ -2568,6 +2546,7 @@ async fn handle_function_call(
                 }
             };
             let result = sess
+                .services
                 .session_manager
                 .handle_write_stdin_request(write_stdin_params)
                 .await;
@@ -2579,7 +2558,7 @@ async fn handle_function_call(
             }
         }
         _ => {
-            match sess.mcp_connection_manager.parse_tool_name(&name) {
+            match sess.services.mcp_connection_manager.parse_tool_name(&name) {
                 Some((server, tool_name)) => {
                     handle_mcp_tool_call(sess, &sub_id, call_id, server, tool_name, arguments).await
                 }
@@ -2697,11 +2676,12 @@ fn maybe_translate_shell_command(
     sess: &Session,
     turn_context: &TurnContext,
 ) -> ExecParams {
-    let should_translate = matches!(sess.user_shell, crate::shell::Shell::PowerShell(_))
+    let should_translate = matches!(sess.services.user_shell, crate::shell::Shell::PowerShell(_))
         || turn_context.shell_environment_policy.use_profile;
 
     if should_translate
         && let Some(command) = sess
+            .services
             .user_shell
             .format_default_shell_invocation(params.command.clone())
     {
@@ -2816,7 +2796,7 @@ async fn handle_container_exec_with_params(
                     &params.command,
                     turn_context.approval_policy,
                     &turn_context.sandbox_policy,
-                    &state.approved_commands,
+                    state.approved_commands_ref(),
                     params.with_escalated_permissions.unwrap_or(false),
                 )
             };
@@ -2895,7 +2875,7 @@ async fn handle_container_exec_with_params(
                 sandbox_type,
                 sandbox_policy: &turn_context.sandbox_policy,
                 sandbox_cwd: &turn_context.cwd,
-                codex_linux_sandbox_exe: &sess.codex_linux_sandbox_exe,
+                codex_linux_sandbox_exe: &sess.services.codex_linux_sandbox_exe,
                 stdout_stream: if exec_command_context.apply_patch.is_some() {
                     None
                 } else {
@@ -3030,7 +3010,7 @@ async fn handle_sandbox_error(
                         sandbox_type: SandboxType::None,
                         sandbox_policy: &turn_context.sandbox_policy,
                         sandbox_cwd: &turn_context.cwd,
-                        codex_linux_sandbox_exe: &sess.codex_linux_sandbox_exe,
+                        codex_linux_sandbox_exe: &sess.services.codex_linux_sandbox_exe,
                         stdout_stream: if exec_command_context.apply_patch.is_some() {
                             None
                         } else {
@@ -3384,7 +3364,7 @@ mod tests {
             }),
         ));
 
-        let actual = tokio_test::block_on(async { session.state.lock().await.history.contents() });
+        let actual = tokio_test::block_on(async { session.state.lock().await.history_snapshot() });
         assert_eq!(expected, actual);
     }
 
@@ -3397,7 +3377,7 @@ mod tests {
             session.record_initial_history(&turn_context, InitialHistory::Forked(rollout_items)),
         );
 
-        let actual = tokio_test::block_on(async { session.state.lock().await.history.contents() });
+        let actual = tokio_test::block_on(async { session.state.lock().await.history_snapshot() });
         assert_eq!(expected, actual);
     }
 
@@ -3623,21 +3603,21 @@ mod tests {
             is_review_mode: false,
             final_output_json_schema: None,
         };
-        let session = Session {
-            conversation_id,
-            tx_event,
+        let services = SessionServices {
             mcp_connection_manager: McpConnectionManager::default(),
             session_manager: ExecSessionManager::default(),
             unified_exec_manager: UnifiedExecSessionManager::default(),
             notifier: UserNotifier::default(),
             rollout: Mutex::new(None),
-            state: Mutex::new(State {
-                history: ConversationHistory::new(),
-                ..Default::default()
-            }),
             codex_linux_sandbox_exe: None,
             user_shell: shell::Shell::Unknown,
             show_raw_agent_reasoning: config.show_raw_agent_reasoning,
+        };
+        let session = Session {
+            conversation_id,
+            tx_event,
+            state: Mutex::new(SessionState::new()),
+            services,
             next_internal_sub_id: AtomicU64::new(0),
         };
         (session, turn_context)

codex-rs/core/src/codex/compact.rs

@@ -153,7 +153,7 @@ async fn run_compact_task_inner(
     }
     let history_snapshot = {
         let state = sess.state.lock().await;
-        state.history.contents()
+        state.history_snapshot()
     };
     let summary_text = get_last_assistant_message_from_turn(&history_snapshot).unwrap_or_default();
     let user_messages = collect_user_messages(&history_snapshot);
@@ -161,7 +161,7 @@ async fn run_compact_task_inner(
     let new_history = build_compacted_history(initial_context, &user_messages, &summary_text);
     {
         let mut state = sess.state.lock().await;
-        state.history.replace(new_history);
+        state.replace_history(new_history);
     }
 
     let rollout_item = RolloutItem::Compacted(CompactedItem {
@@ -271,7 +271,7 @@ async fn drain_to_completed(
         match event {
             Ok(ResponseEvent::OutputItemDone(item)) => {
                 let mut state = sess.state.lock().await;
-                state.history.record_items(std::slice::from_ref(&item));
+                state.record_items(std::slice::from_ref(&item));
             }
             Ok(ResponseEvent::Completed { .. }) => {
                 return Ok(());

codex-rs/core/src/lib.rs

@@ -47,6 +47,7 @@ pub use model_provider_info::create_oss_provider_with_base_url;
 mod conversation_manager;
 mod event_mapping;
 pub mod review_format;
+mod services;
 pub use codex_protocol::protocol::InitialHistory;
 pub use conversation_manager::ConversationManager;
 pub use conversation_manager::NewConversation;
@@ -75,6 +76,7 @@ pub use rollout::find_conversation_path_by_id_str;
 pub use rollout::list::ConversationItem;
 pub use rollout::list::ConversationsPage;
 pub use rollout::list::Cursor;
+mod state;
 mod user_notification;
 pub mod util;
 

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

@@ -0,0 +1,23 @@
+//! Group long‑lived helpers/managers for a session.
+
+use std::path::PathBuf;
+
+use tokio::sync::Mutex;
+
+use crate::exec_command::ExecSessionManager;
+use crate::mcp_connection_manager::McpConnectionManager;
+use crate::rollout::RolloutRecorder;
+use crate::unified_exec::UnifiedExecSessionManager;
+use crate::user_notification::UserNotifier;
+
+/// Container for side‑effectful services and helpers used by `Session`.
+pub(crate) struct SessionServices {
+    pub(crate) mcp_connection_manager: McpConnectionManager,
+    pub(crate) session_manager: ExecSessionManager,
+    pub(crate) unified_exec_manager: UnifiedExecSessionManager,
+    pub(crate) notifier: UserNotifier,
+    pub(crate) rollout: Mutex<Option<RolloutRecorder>>,
+    pub(crate) codex_linux_sandbox_exe: Option<PathBuf>,
+    pub(crate) user_shell: crate::shell::Shell,
+    pub(crate) show_raw_agent_reasoning: bool,
+}

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

@@ -0,0 +1,10 @@
+//! Session/turn state module scaffolding.
+//!
+//! This module will encapsulate all mutable state for a Codex session.
+//! It starts with lightweight placeholders to enable incremental refactors
+//! without changing behaviour.
+
+mod session;
+mod turn;
+
+pub(crate) use session::SessionState;

codex-rs/core/src/state/session.rs

@@ -0,0 +1,121 @@
+//! Session-wide mutable state.
+
+use std::collections::HashMap;
+use std::collections::HashSet;
+
+use codex_protocol::models::ResponseInputItem;
+use codex_protocol::models::ResponseItem;
+use tokio::sync::oneshot;
+
+use crate::codex::AgentTask;
+use crate::conversation_history::ConversationHistory;
+use crate::protocol::RateLimitSnapshot;
+use crate::protocol::ReviewDecision;
+use crate::protocol::TokenUsage;
+use crate::protocol::TokenUsageInfo;
+
+/// Persistent, session-scoped state previously stored directly on `Session`.
+#[derive(Default)]
+pub(crate) struct SessionState {
+    pub(crate) approved_commands: HashSet<Vec<String>>,
+    pub(crate) current_task: Option<AgentTask>,
+    pub(crate) pending_approvals: HashMap<String, oneshot::Sender<ReviewDecision>>,
+    pub(crate) pending_input: Vec<ResponseInputItem>,
+    pub(crate) history: ConversationHistory,
+    pub(crate) token_info: Option<TokenUsageInfo>,
+    pub(crate) latest_rate_limits: Option<RateLimitSnapshot>,
+}
+
+impl SessionState {
+    /// Create a new session state mirroring previous `State::default()` semantics.
+    pub(crate) fn new() -> Self {
+        Self {
+            history: ConversationHistory::new(),
+            ..Default::default()
+        }
+    }
+
+    // History helpers
+    pub(crate) fn record_items<I>(&mut self, items: I)
+    where
+        I: IntoIterator,
+        I::Item: std::ops::Deref<Target = ResponseItem>,
+    {
+        self.history.record_items(items)
+    }
+
+    pub(crate) fn history_snapshot(&self) -> Vec<ResponseItem> {
+        self.history.contents()
+    }
+
+    pub(crate) fn replace_history(&mut self, items: Vec<ResponseItem>) {
+        self.history.replace(items);
+    }
+
+    // Approved command helpers
+    pub(crate) fn add_approved_command(&mut self, cmd: Vec<String>) {
+        self.approved_commands.insert(cmd);
+    }
+
+    pub(crate) fn approved_commands_ref(&self) -> &HashSet<Vec<String>> {
+        &self.approved_commands
+    }
+
+    // Token/rate limit helpers
+    pub(crate) fn update_token_info_from_usage(
+        &mut self,
+        usage: &TokenUsage,
+        model_context_window: Option<u64>,
+    ) {
+        self.token_info = TokenUsageInfo::new_or_append(
+            &self.token_info,
+            &Some(usage.clone()),
+            model_context_window,
+        );
+    }
+
+    pub(crate) fn set_rate_limits(&mut self, snapshot: RateLimitSnapshot) {
+        self.latest_rate_limits = Some(snapshot);
+    }
+
+    pub(crate) fn token_info_and_rate_limits(
+        &self,
+    ) -> (Option<TokenUsageInfo>, Option<RateLimitSnapshot>) {
+        (self.token_info.clone(), self.latest_rate_limits.clone())
+    }
+
+    // Pending input/approval helpers
+    pub(crate) fn insert_pending_approval(
+        &mut self,
+        key: String,
+        tx: oneshot::Sender<ReviewDecision>,
+    ) -> Option<oneshot::Sender<ReviewDecision>> {
+        self.pending_approvals.insert(key, tx)
+    }
+
+    pub(crate) fn remove_pending_approval(
+        &mut self,
+        key: &str,
+    ) -> Option<oneshot::Sender<ReviewDecision>> {
+        self.pending_approvals.remove(key)
+    }
+
+    pub(crate) fn clear_pending(&mut self) {
+        self.pending_approvals.clear();
+        self.pending_input.clear();
+    }
+
+    pub(crate) fn push_pending_input(&mut self, input: ResponseInputItem) {
+        self.pending_input.push(input);
+    }
+
+    pub(crate) fn take_pending_input(&mut self) -> Vec<ResponseInputItem> {
+        if self.pending_input.is_empty() {
+            Vec::with_capacity(0)
+        } else {
+            let mut ret = Vec::new();
+            std::mem::swap(&mut ret, &mut self.pending_input);
+            ret
+        }
+    }
+}

codex-rs/core/src/state/turn.rs

@@ -0,0 +1,9 @@
+//! Turn-scoped state and active turn metadata scaffolding.
+
+/// Metadata about the currently running turn.
+#[derive(Debug, Default)]
+pub(crate) struct ActiveTurn;
+
+/// Mutable state for a single turn.
+#[derive(Debug, Default)]
+pub(crate) struct TurnState;