diff --git a/codex-rs/app-server-protocol/src/protocol/thread_history.rs b/codex-rs/app-server-protocol/src/protocol/thread_history.rs
index c126a6f65a..3eb2d184fc 100644
--- a/codex-rs/app-server-protocol/src/protocol/thread_history.rs
+++ b/codex-rs/app-server-protocol/src/protocol/thread_history.rs
@@ -729,8 +729,8 @@ impl ThreadHistoryBuilder {
             sender_thread_id: payload.sender_thread_id.to_string(),
             receiver_thread_ids: vec![receiver_id],
             prompt: None,
-            model: payload.model.clone(),
-            reasoning_effort: payload.reasoning_effort,
+            model: None,
+            reasoning_effort: None,
             agents_states,
         });
     }
@@ -2419,6 +2419,60 @@ mod tests {
         );
     }
 
+    #[test]
+    fn reconstructs_collab_close_end_item_without_model_metadata() {
+        let sender_thread_id = ThreadId::try_from("00000000-0000-0000-0000-000000000001")
+            .expect("valid sender thread id");
+        let receiver_thread_id = ThreadId::try_from("00000000-0000-0000-0000-000000000002")
+            .expect("valid receiver thread id");
+        let events = vec![
+            EventMsg::UserMessage(UserMessageEvent {
+                message: "close agent".into(),
+                images: None,
+                text_elements: Vec::new(),
+                local_images: Vec::new(),
+            }),
+            EventMsg::CollabCloseEnd(codex_protocol::protocol::CollabCloseEndEvent {
+                call_id: "close-1".into(),
+                sender_thread_id,
+                receiver_thread_id,
+                receiver_agent_nickname: Some("Scout".into()),
+                receiver_agent_role: Some("explorer".into()),
+                status: AgentStatus::Completed(None),
+            }),
+        ];
+
+        let items = events
+            .into_iter()
+            .map(RolloutItem::EventMsg)
+            .collect::<Vec<_>>();
+        let turns = build_turns_from_rollout_items(&items);
+        assert_eq!(turns.len(), 1);
+        assert_eq!(turns[0].items.len(), 2);
+        assert_eq!(
+            turns[0].items[1],
+            ThreadItem::CollabAgentToolCall {
+                id: "close-1".into(),
+                tool: CollabAgentTool::CloseAgent,
+                status: CollabAgentToolCallStatus::Completed,
+                sender_thread_id: "00000000-0000-0000-0000-000000000001".into(),
+                receiver_thread_ids: vec!["00000000-0000-0000-0000-000000000002".into()],
+                prompt: None,
+                model: None,
+                reasoning_effort: None,
+                agents_states: [(
+                    "00000000-0000-0000-0000-000000000002".into(),
+                    CollabAgentState {
+                        status: crate::protocol::v2::CollabAgentStatus::Completed,
+                        message: None,
+                    },
+                )]
+                .into_iter()
+                .collect(),
+            }
+        );
+    }
+
     #[test]
     fn rollback_failed_error_does_not_mark_turn_failed() {
         let events = vec![
diff --git a/codex-rs/app-server/src/bespoke_event_handling.rs b/codex-rs/app-server/src/bespoke_event_handling.rs
index 200016b677..19eee2eff8 100644
--- a/codex-rs/app-server/src/bespoke_event_handling.rs
+++ b/codex-rs/app-server/src/bespoke_event_handling.rs
@@ -1078,8 +1078,8 @@ pub(crate) async fn apply_bespoke_event_handling(
                 sender_thread_id: end_event.sender_thread_id.to_string(),
                 receiver_thread_ids: vec![receiver_id],
                 prompt: None,
-                model: end_event.model,
-                reasoning_effort: end_event.reasoning_effort,
+                model: None,
+                reasoning_effort: None,
                 agents_states,
             };
             let notification = ItemCompletedNotification {
diff --git a/codex-rs/core/src/tools/handlers/multi_agents.rs b/codex-rs/core/src/tools/handlers/multi_agents.rs
index 0eb8792c51..6fec8508c0 100644
--- a/codex-rs/core/src/tools/handlers/multi_agents.rs
+++ b/codex-rs/core/src/tools/handlers/multi_agents.rs
@@ -745,25 +745,12 @@ pub mod close_agent {
     ) -> Result<FunctionToolOutput, FunctionCallError> {
         let args: CloseAgentArgs = parse_arguments(&arguments)?;
         let agent_id = agent_id(&args.id)?;
-        let (
-            receiver_agent_nickname,
-            receiver_agent_role,
-            receiver_model,
-            receiver_reasoning_effort,
-        ) = session
+        let (receiver_agent_nickname, receiver_agent_role) = session
             .services
             .agent_control
-            .get_agent_metadata(agent_id)
+            .get_agent_nickname_and_role(agent_id)
             .await
-            .map(|metadata| {
-                (
-                    metadata.nickname,
-                    metadata.role,
-                    Some(metadata.model),
-                    metadata.reasoning_effort,
-                )
-            })
-            .unwrap_or((None, None, None, None));
+            .unwrap_or((None, None));
         session
             .send_event(
                 &turn,
@@ -793,8 +780,6 @@ pub mod close_agent {
                             receiver_thread_id: agent_id,
                             receiver_agent_nickname: receiver_agent_nickname.clone(),
                             receiver_agent_role: receiver_agent_role.clone(),
-                            model: receiver_model.clone(),
-                            reasoning_effort: receiver_reasoning_effort,
                             status,
                         }
                         .into(),
@@ -823,8 +808,6 @@ pub mod close_agent {
                     receiver_thread_id: agent_id,
                     receiver_agent_nickname,
                     receiver_agent_role,
-                    model: receiver_model,
-                    reasoning_effort: receiver_reasoning_effort,
                     status: status.clone(),
                 }
                 .into(),
diff --git a/codex-rs/protocol/src/protocol.rs b/codex-rs/protocol/src/protocol.rs
index 6619188f0f..6cd6ef215f 100644
--- a/codex-rs/protocol/src/protocol.rs
+++ b/codex-rs/protocol/src/protocol.rs
@@ -3269,12 +3269,6 @@ pub struct CollabCloseEndEvent {
     /// Optional role assigned to the receiver agent.
     #[serde(default, skip_serializing_if = "Option::is_none")]
     pub receiver_agent_role: Option<String>,
-    /// Model configured for the receiver agent when available.
-    #[serde(default, skip_serializing_if = "Option::is_none")]
-    pub model: Option<String>,
-    /// Reasoning effort configured for the receiver agent when available.
-    #[serde(default, skip_serializing_if = "Option::is_none")]
-    pub reasoning_effort: Option<ReasoningEffortConfig>,
     /// Last known status of the receiver agent reported to the sender agent before
     /// the close.
     pub status: AgentStatus,