diff --git a/codex-rs/core/src/codex.rs b/codex-rs/core/src/codex.rs
index a05521e80..a3b3aba9a 100644
--- a/codex-rs/core/src/codex.rs
+++ b/codex-rs/core/src/codex.rs
@@ -1061,6 +1061,11 @@ impl Session {
             .await
     }
 
+    pub(crate) async fn current_collaboration_mode(&self) -> CollaborationMode {
+        let state = self.state.lock().await;
+        state.session_configuration.collaboration_mode.clone()
+    }
+
     fn build_environment_update_item(
         &self,
         previous: Option<&Arc<TurnContext>>,
@@ -3096,11 +3101,17 @@ async fn try_run_sampling_request(
     prompt: &Prompt,
     cancellation_token: CancellationToken,
 ) -> CodexResult<SamplingRequestResult> {
+    // TODO: If we need to guarantee the persisted mode always matches the prompt used for this
+    // turn, capture it in TurnContext at creation time. Using SessionConfiguration here avoids
+    // duplicating model settings on TurnContext, but a later Op could update the session config
+    // before this write occurs.
+    let collaboration_mode = sess.current_collaboration_mode().await;
     let rollout_item = RolloutItem::TurnContext(TurnContextItem {
         cwd: turn_context.cwd.clone(),
         approval_policy: turn_context.approval_policy,
         sandbox_policy: turn_context.sandbox_policy.clone(),
         model: turn_context.client.get_model(),
+        collaboration_mode: Some(collaboration_mode),
         effort: turn_context.client.get_reasoning_effort(),
         summary: turn_context.client.get_reasoning_summary(),
         user_instructions: turn_context.user_instructions.clone(),
diff --git a/codex-rs/core/src/compact.rs b/codex-rs/core/src/compact.rs
index 970eb0054..958686c14 100644
--- a/codex-rs/core/src/compact.rs
+++ b/codex-rs/core/src/compact.rs
@@ -84,11 +84,17 @@ async fn run_compact_task_inner(
     let max_retries = turn_context.client.get_provider().stream_max_retries();
     let mut retries = 0;
 
+    // TODO: If we need to guarantee the persisted mode always matches the prompt used for this
+    // turn, capture it in TurnContext at creation time. Using SessionConfiguration here avoids
+    // duplicating model settings on TurnContext, but an Op after turn start could update the
+    // session config before this write occurs.
+    let collaboration_mode = sess.current_collaboration_mode().await;
     let rollout_item = RolloutItem::TurnContext(TurnContextItem {
         cwd: turn_context.cwd.clone(),
         approval_policy: turn_context.approval_policy,
         sandbox_policy: turn_context.sandbox_policy.clone(),
         model: turn_context.client.get_model(),
+        collaboration_mode: Some(collaboration_mode),
         effort: turn_context.client.get_reasoning_effort(),
         summary: turn_context.client.get_reasoning_summary(),
         user_instructions: turn_context.user_instructions.clone(),
diff --git a/codex-rs/core/tests/suite/resume_warning.rs b/codex-rs/core/tests/suite/resume_warning.rs
index 8c3ecf7af..162e0e26e 100644
--- a/codex-rs/core/tests/suite/resume_warning.rs
+++ b/codex-rs/core/tests/suite/resume_warning.rs
@@ -26,6 +26,7 @@ fn resume_history(
         approval_policy: config.approval_policy.value(),
         sandbox_policy: config.sandbox_policy.get().clone(),
         model: previous_model.to_string(),
+        collaboration_mode: None,
         effort: config.model_reasoning_effort,
         summary: config.model_reasoning_summary,
         user_instructions: None,
diff --git a/codex-rs/protocol/src/protocol.rs b/codex-rs/protocol/src/protocol.rs
index 533fe04d8..1a9029f27 100644
--- a/codex-rs/protocol/src/protocol.rs
+++ b/codex-rs/protocol/src/protocol.rs
@@ -1602,6 +1602,8 @@ pub struct TurnContextItem {
     pub approval_policy: AskForApproval,
     pub sandbox_policy: SandboxPolicy,
     pub model: String,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub collaboration_mode: Option<CollaborationMode>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub effort: Option<ReasoningEffortConfig>,
     pub summary: ReasoningSummaryConfig,