diff --git a/codex-rs/app-server/tests/suite/list_resume.rs b/codex-rs/app-server/tests/suite/list_resume.rs
index 983553e06e..f2b82c6111 100644
--- a/codex-rs/app-server/tests/suite/list_resume.rs
+++ b/codex-rs/app-server/tests/suite/list_resume.rs
@@ -307,6 +307,7 @@ async fn test_list_and_resume_conversations() -> Result<()> {
         content: vec![ContentItem::InputText {
             text: fork_history_text.to_string(),
         }],
+        end_turn: None,
     }];
     let resume_with_history_req_id = mcp
         .send_resume_conversation_request(ResumeConversationParams {
diff --git a/codex-rs/app-server/tests/suite/v2/thread_resume.rs b/codex-rs/app-server/tests/suite/v2/thread_resume.rs
index d2fa72ef14..2865d73649 100644
--- a/codex-rs/app-server/tests/suite/v2/thread_resume.rs
+++ b/codex-rs/app-server/tests/suite/v2/thread_resume.rs
@@ -218,6 +218,7 @@ async fn thread_resume_supports_history_and_overrides() -> Result<()> {
         content: vec![ContentItem::InputText {
             text: history_text.to_string(),
         }],
+        end_turn: None,
     }];
 
     // Resume with explicit history and override the model.
diff --git a/codex-rs/codex-api/src/endpoint/chat.rs b/codex-rs/codex-api/src/endpoint/chat.rs
index 8fe1d2a521..2148a5ad93 100644
--- a/codex-rs/codex-api/src/endpoint/chat.rs
+++ b/codex-rs/codex-api/src/endpoint/chat.rs
@@ -193,6 +193,7 @@ impl Stream for AggregatedStream {
                             content: vec![ContentItem::OutputText {
                                 text: std::mem::take(&mut this.cumulative),
                             }],
+                            end_turn: None,
                         };
                         this.pending
                             .push_back(ResponseEvent::OutputItemDone(aggregated_message));
diff --git a/codex-rs/codex-api/src/requests/chat.rs b/codex-rs/codex-api/src/requests/chat.rs
index 30d8b478d2..5c16a5fb58 100644
--- a/codex-rs/codex-api/src/requests/chat.rs
+++ b/codex-rs/codex-api/src/requests/chat.rs
@@ -386,6 +386,7 @@ mod tests {
             content: vec![ContentItem::InputText {
                 text: "hi".to_string(),
             }],
+            end_turn: None,
         }];
         let req = ChatRequestBuilder::new("gpt-test", "inst", &prompt_input, &[])
             .conversation_id(Some("conv-1".into()))
@@ -412,6 +413,7 @@ mod tests {
                 content: vec![ContentItem::InputText {
                     text: "read these".to_string(),
                 }],
+                end_turn: None,
             },
             ResponseItem::FunctionCall {
                 id: None,
diff --git a/codex-rs/codex-api/src/requests/responses.rs b/codex-rs/codex-api/src/requests/responses.rs
index 65f7dc0243..73a413dd93 100644
--- a/codex-rs/codex-api/src/requests/responses.rs
+++ b/codex-rs/codex-api/src/requests/responses.rs
@@ -223,11 +223,13 @@ mod tests {
                 id: Some("m1".into()),
                 role: "assistant".into(),
                 content: Vec::new(),
+                end_turn: None,
             },
             ResponseItem::Message {
                 id: None,
                 role: "assistant".into(),
                 content: Vec::new(),
+                end_turn: None,
             },
         ];
 
diff --git a/codex-rs/codex-api/src/sse/chat.rs b/codex-rs/codex-api/src/sse/chat.rs
index afd7c8852b..a3effce2e7 100644
--- a/codex-rs/codex-api/src/sse/chat.rs
+++ b/codex-rs/codex-api/src/sse/chat.rs
@@ -330,6 +330,7 @@ async fn append_assistant_text(
             id: None,
             role: "assistant".to_string(),
             content: vec![],
+            end_turn: None,
         };
         *assistant_item = Some(item.clone());
         let _ = tx_event
diff --git a/codex-rs/codex-api/tests/clients.rs b/codex-rs/codex-api/tests/clients.rs
index 1a513bdca4..b71edf3244 100644
--- a/codex-rs/codex-api/tests/clients.rs
+++ b/codex-rs/codex-api/tests/clients.rs
@@ -308,6 +308,7 @@ async fn streaming_client_retries_on_transport_error() -> Result<()> {
             content: vec![ContentItem::InputText {
                 text: "hi".to_string(),
             }],
+            end_turn: None,
         }],
         tools: Vec::<Value>::new(),
         parallel_tool_calls: false,
diff --git a/codex-rs/core/dfa_unless_trusted_5_1.txt b/codex-rs/core/dfa_unless_trusted_5_1.txt
deleted file mode 100644
index 72b7d8ecde..0000000000
--- a/codex-rs/core/dfa_unless_trusted_5_1.txt
+++ /dev/null
@@ -1 +0,0 @@
-danger-unless-trusted
\ No newline at end of file
diff --git a/codex-rs/core/src/codex.rs b/codex-rs/core/src/codex.rs
index cb81c9aa4d..9ca11cd73b 100644
--- a/codex-rs/core/src/codex.rs
+++ b/codex-rs/core/src/codex.rs
@@ -1504,6 +1504,7 @@ impl Session {
             content: vec![ContentItem::InputText {
                 text: format!("Warning: {}", message.into()),
             }],
+            end_turn: None,
         };
 
         self.record_conversation_items(ctx, &[item]).await;
@@ -3613,6 +3614,7 @@ mod tests {
                 content: vec![ContentItem::InputText {
                     text: "turn 1 user".to_string(),
                 }],
+                end_turn: None,
             },
             ResponseItem::Message {
                 id: None,
@@ -3620,6 +3622,7 @@ mod tests {
                 content: vec![ContentItem::OutputText {
                     text: "turn 1 assistant".to_string(),
                 }],
+                end_turn: None,
             },
         ];
         sess.record_into_history(&turn_1, tc.as_ref()).await;
@@ -3631,6 +3634,7 @@ mod tests {
                 content: vec![ContentItem::InputText {
                     text: "turn 2 user".to_string(),
                 }],
+                end_turn: None,
             },
             ResponseItem::Message {
                 id: None,
@@ -3638,6 +3642,7 @@ mod tests {
                 content: vec![ContentItem::OutputText {
                     text: "turn 2 assistant".to_string(),
                 }],
+                end_turn: None,
             },
         ];
         sess.record_into_history(&turn_2, tc.as_ref()).await;
@@ -3669,6 +3674,7 @@ mod tests {
             content: vec![ContentItem::InputText {
                 text: "turn 1 user".to_string(),
             }],
+            end_turn: None,
         }];
         sess.record_into_history(&turn_1, tc.as_ref()).await;
 
@@ -4561,6 +4567,7 @@ mod tests {
             content: vec![ContentItem::InputText {
                 text: "first user".to_string(),
             }],
+            end_turn: None,
         };
         live_history.record_items(std::iter::once(&user1), turn_context.truncation_policy);
         rollout_items.push(RolloutItem::ResponseItem(user1.clone()));
@@ -4571,6 +4578,7 @@ mod tests {
             content: vec![ContentItem::OutputText {
                 text: "assistant reply one".to_string(),
             }],
+            end_turn: None,
         };
         live_history.record_items(std::iter::once(&assistant1), turn_context.truncation_policy);
         rollout_items.push(RolloutItem::ResponseItem(assistant1.clone()));
@@ -4595,6 +4603,7 @@ mod tests {
             content: vec![ContentItem::InputText {
                 text: "second user".to_string(),
             }],
+            end_turn: None,
         };
         live_history.record_items(std::iter::once(&user2), turn_context.truncation_policy);
         rollout_items.push(RolloutItem::ResponseItem(user2.clone()));
@@ -4605,6 +4614,7 @@ mod tests {
             content: vec![ContentItem::OutputText {
                 text: "assistant reply two".to_string(),
             }],
+            end_turn: None,
         };
         live_history.record_items(std::iter::once(&assistant2), turn_context.truncation_policy);
         rollout_items.push(RolloutItem::ResponseItem(assistant2.clone()));
@@ -4629,6 +4639,7 @@ mod tests {
             content: vec![ContentItem::InputText {
                 text: "third user".to_string(),
             }],
+            end_turn: None,
         };
         live_history.record_items(std::iter::once(&user3), turn_context.truncation_policy);
         rollout_items.push(RolloutItem::ResponseItem(user3));
@@ -4639,6 +4650,7 @@ mod tests {
             content: vec![ContentItem::OutputText {
                 text: "assistant reply three".to_string(),
             }],
+            end_turn: None,
         };
         live_history.record_items(std::iter::once(&assistant3), turn_context.truncation_policy);
         rollout_items.push(RolloutItem::ResponseItem(assistant3));
diff --git a/codex-rs/core/src/compact.rs b/codex-rs/core/src/compact.rs
index 958686c149..5c3d56f8d5 100644
--- a/codex-rs/core/src/compact.rs
+++ b/codex-rs/core/src/compact.rs
@@ -305,6 +305,7 @@ fn build_compacted_history_with_limit(
             content: vec![ContentItem::InputText {
                 text: message.clone(),
             }],
+            end_turn: None,
         });
     }
 
@@ -318,6 +319,7 @@ fn build_compacted_history_with_limit(
         id: None,
         role: "user".to_string(),
         content: vec![ContentItem::InputText { text: summary_text }],
+        end_turn: None,
     });
 
     history
@@ -406,6 +408,7 @@ mod tests {
                 content: vec![ContentItem::OutputText {
                     text: "ignored".to_string(),
                 }],
+                end_turn: None,
             },
             ResponseItem::Message {
                 id: Some("user".to_string()),
@@ -413,6 +416,7 @@ mod tests {
                 content: vec![ContentItem::InputText {
                     text: "first".to_string(),
                 }],
+                end_turn: None,
             },
             ResponseItem::Other,
         ];
@@ -432,6 +436,7 @@ mod tests {
                     text: "# AGENTS.md instructions for project\n\n<INSTRUCTIONS>\ndo things\n</INSTRUCTIONS>"
                         .to_string(),
                 }],
+                end_turn: None,
             },
             ResponseItem::Message {
                 id: None,
@@ -439,6 +444,7 @@ mod tests {
                 content: vec![ContentItem::InputText {
                     text: "<ENVIRONMENT_CONTEXT>cwd=/tmp</ENVIRONMENT_CONTEXT>".to_string(),
                 }],
+                end_turn: None,
             },
             ResponseItem::Message {
                 id: None,
@@ -446,6 +452,7 @@ mod tests {
                 content: vec![ContentItem::InputText {
                     text: "real user message".to_string(),
                 }],
+                end_turn: None,
             },
         ];
 
@@ -530,6 +537,7 @@ mod tests {
                 content: vec![ContentItem::InputText {
                     text: marker.clone(),
                 }],
+                end_turn: None,
             },
             ResponseItem::Message {
                 id: None,
@@ -537,6 +545,7 @@ mod tests {
                 content: vec![ContentItem::InputText {
                     text: "real user message".to_string(),
                 }],
+                end_turn: None,
             },
         ];
 
diff --git a/codex-rs/core/src/context_manager/history_tests.rs b/codex-rs/core/src/context_manager/history_tests.rs
index b3d061babf..50ee98e5b6 100644
--- a/codex-rs/core/src/context_manager/history_tests.rs
+++ b/codex-rs/core/src/context_manager/history_tests.rs
@@ -23,6 +23,7 @@ fn assistant_msg(text: &str) -> ResponseItem {
         content: vec![ContentItem::OutputText {
             text: text.to_string(),
         }],
+        end_turn: None,
     }
 }
 
@@ -41,6 +42,7 @@ fn user_msg(text: &str) -> ResponseItem {
         content: vec![ContentItem::OutputText {
             text: text.to_string(),
         }],
+        end_turn: None,
     }
 }
 
@@ -51,6 +53,7 @@ fn user_input_text_msg(text: &str) -> ResponseItem {
         content: vec![ContentItem::InputText {
             text: text.to_string(),
         }],
+        end_turn: None,
     }
 }
 
@@ -93,6 +96,7 @@ fn filters_non_api_messages() {
         content: vec![ContentItem::OutputText {
             text: "ignored".to_string(),
         }],
+        end_turn: None,
     };
     let reasoning = reasoning_msg("thinking...");
     h.record_items([&system, &reasoning, &ResponseItem::Other], policy);
@@ -121,14 +125,16 @@ fn filters_non_api_messages() {
                 role: "user".to_string(),
                 content: vec![ContentItem::OutputText {
                     text: "hi".to_string()
-                }]
+                }],
+                end_turn: None,
             },
             ResponseItem::Message {
                 id: None,
                 role: "assistant".to_string(),
                 content: vec![ContentItem::OutputText {
                     text: "hello".to_string()
-                }]
+                }],
+                end_turn: None,
             }
         ]
     );
@@ -255,6 +261,7 @@ fn replace_last_turn_images_does_not_touch_user_images() {
         content: vec![ContentItem::InputImage {
             image_url: "data:image/png;base64,AAA".to_string(),
         }],
+        end_turn: None,
     }];
     let mut history = create_history_with_items(items.clone());
 
diff --git a/codex-rs/core/src/environment_context.rs b/codex-rs/core/src/environment_context.rs
index 28b5032fac..f0b0877eba 100644
--- a/codex-rs/core/src/environment_context.rs
+++ b/codex-rs/core/src/environment_context.rs
@@ -79,6 +79,7 @@ impl From<EnvironmentContext> for ResponseItem {
             content: vec![ContentItem::InputText {
                 text: ec.serialize_to_xml(),
             }],
+            end_turn: None,
         }
     }
 }
diff --git a/codex-rs/core/src/event_mapping.rs b/codex-rs/core/src/event_mapping.rs
index deee79ae70..55a1037542 100644
--- a/codex-rs/core/src/event_mapping.rs
+++ b/codex-rs/core/src/event_mapping.rs
@@ -89,7 +89,9 @@ fn parse_agent_message(id: Option<&String>, message: &[ContentItem]) -> AgentMes
 
 pub fn parse_turn_item(item: &ResponseItem) -> Option<TurnItem> {
     match item {
-        ResponseItem::Message { role, content, id } => match role.as_str() {
+        ResponseItem::Message {
+            role, content, id, ..
+        } => match role.as_str() {
             "user" => parse_user_message(content).map(TurnItem::UserMessage),
             "assistant" => Some(TurnItem::AgentMessage(parse_agent_message(
                 id.as_ref(),
@@ -169,6 +171,7 @@ mod tests {
                     image_url: img2.clone(),
                 },
             ],
+            end_turn: None,
         };
 
         let turn_item = parse_turn_item(&item).expect("expected user message turn item");
@@ -210,6 +213,7 @@ mod tests {
                     text: user_text.clone(),
                 },
             ],
+            end_turn: None,
         };
 
         let turn_item = parse_turn_item(&item).expect("expected user message turn item");
@@ -250,6 +254,7 @@ mod tests {
                     text: user_text.clone(),
                 },
             ],
+            end_turn: None,
         };
 
         let turn_item = parse_turn_item(&item).expect("expected user message turn item");
@@ -278,6 +283,7 @@ mod tests {
                 content: vec![ContentItem::InputText {
                     text: "<user_instructions>test_text</user_instructions>".to_string(),
                 }],
+                end_turn: None,
             },
             ResponseItem::Message {
                 id: None,
@@ -285,6 +291,7 @@ mod tests {
                 content: vec![ContentItem::InputText {
                     text: "<environment_context>test_text</environment_context>".to_string(),
                 }],
+                end_turn: None,
             },
             ResponseItem::Message {
                 id: None,
@@ -292,6 +299,7 @@ mod tests {
                 content: vec![ContentItem::InputText {
                     text: "# AGENTS.md instructions for test_directory\n\n<INSTRUCTIONS>\ntest_text\n</INSTRUCTIONS>".to_string(),
                 }],
+                end_turn: None,
             },
             ResponseItem::Message {
                 id: None,
@@ -300,6 +308,7 @@ mod tests {
                     text: "<skill>\n<name>demo</name>\n<path>skills/demo/SKILL.md</path>\nbody\n</skill>"
                         .to_string(),
                 }],
+                end_turn: None,
             },
             ResponseItem::Message {
                 id: None,
@@ -307,6 +316,7 @@ mod tests {
                 content: vec![ContentItem::InputText {
                     text: "<user_shell_command>echo 42</user_shell_command>".to_string(),
                 }],
+                end_turn: None,
             },
         ];
 
@@ -324,6 +334,7 @@ mod tests {
             content: vec![ContentItem::OutputText {
                 text: "Hello from Codex".to_string(),
             }],
+            end_turn: None,
         };
 
         let turn_item = parse_turn_item(&item).expect("expected agent message turn item");
diff --git a/codex-rs/core/src/instructions/user_instructions.rs b/codex-rs/core/src/instructions/user_instructions.rs
index 9c563c29c5..611bf4cbf8 100644
--- a/codex-rs/core/src/instructions/user_instructions.rs
+++ b/codex-rs/core/src/instructions/user_instructions.rs
@@ -38,6 +38,7 @@ impl From<UserInstructions> for ResponseItem {
                     contents = ui.text
                 ),
             }],
+            end_turn: None,
         }
     }
 }
@@ -71,6 +72,7 @@ impl From<SkillInstructions> for ResponseItem {
                     si.name, si.path, si.contents
                 ),
             }],
+            end_turn: None,
         }
     }
 }
diff --git a/codex-rs/core/src/rollout/tests.rs b/codex-rs/core/src/rollout/tests.rs
index 08d4a1e2c9..4dcd07ca7c 100644
--- a/codex-rs/core/src/rollout/tests.rs
+++ b/codex-rs/core/src/rollout/tests.rs
@@ -806,6 +806,7 @@ async fn test_updated_at_uses_file_mtime() -> Result<()> {
                 content: vec![ContentItem::OutputText {
                     text: format!("reply-{idx}"),
                 }],
+                end_turn: None,
             }),
         };
         writeln!(file, "{}", serde_json::to_string(&response_line)?)?;
diff --git a/codex-rs/core/src/rollout/truncation.rs b/codex-rs/core/src/rollout/truncation.rs
index 0f72cfc50e..e6a84628fc 100644
--- a/codex-rs/core/src/rollout/truncation.rs
+++ b/codex-rs/core/src/rollout/truncation.rs
@@ -85,6 +85,7 @@ mod tests {
             content: vec![ContentItem::OutputText {
                 text: text.to_string(),
             }],
+            end_turn: None,
         }
     }
 
@@ -95,6 +96,7 @@ mod tests {
             content: vec![ContentItem::OutputText {
                 text: text.to_string(),
             }],
+            end_turn: None,
         }
     }
 
diff --git a/codex-rs/core/src/tasks/mod.rs b/codex-rs/core/src/tasks/mod.rs
index 91303a3bdc..a2f30aa522 100644
--- a/codex-rs/core/src/tasks/mod.rs
+++ b/codex-rs/core/src/tasks/mod.rs
@@ -256,6 +256,7 @@ impl Session {
                         "{TURN_ABORTED_OPEN_TAG}\n  <turn_id>{sub_id}</turn_id>\n  <reason>interrupted</reason>\n  <guidance>{TURN_ABORTED_INTERRUPTED_GUIDANCE}</guidance>\n</turn_aborted>"
                     ),
                 }],
+                end_turn: None,
             };
             self.record_into_history(std::slice::from_ref(&marker), task.turn_context.as_ref())
                 .await;
diff --git a/codex-rs/core/src/tasks/review.rs b/codex-rs/core/src/tasks/review.rs
index 5b0d0bebe9..d156d3e0d5 100644
--- a/codex-rs/core/src/tasks/review.rs
+++ b/codex-rs/core/src/tasks/review.rs
@@ -221,6 +221,7 @@ pub(crate) async fn exit_review_mode(
                 id: Some(REVIEW_USER_MESSAGE_ID.to_string()),
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText { text: user_message }],
+                end_turn: None,
             }],
         )
         .await;
@@ -239,6 +240,7 @@ pub(crate) async fn exit_review_mode(
                 content: vec![ContentItem::OutputText {
                     text: assistant_message,
                 }],
+                end_turn: None,
             },
         )
         .await;
diff --git a/codex-rs/core/src/thread_manager.rs b/codex-rs/core/src/thread_manager.rs
index 6aa4d378d2..70d8cb7900 100644
--- a/codex-rs/core/src/thread_manager.rs
+++ b/codex-rs/core/src/thread_manager.rs
@@ -411,6 +411,7 @@ mod tests {
             content: vec![ContentItem::OutputText {
                 text: text.to_string(),
             }],
+            end_turn: None,
         }
     }
     fn assistant_msg(text: &str) -> ResponseItem {
@@ -420,6 +421,7 @@ mod tests {
             content: vec![ContentItem::OutputText {
                 text: text.to_string(),
             }],
+            end_turn: None,
         }
     }
 
diff --git a/codex-rs/core/src/user_shell_command.rs b/codex-rs/core/src/user_shell_command.rs
index fb8efcc09c..566f39958e 100644
--- a/codex-rs/core/src/user_shell_command.rs
+++ b/codex-rs/core/src/user_shell_command.rs
@@ -62,6 +62,7 @@ pub fn user_shell_command_record_item(
         content: vec![ContentItem::InputText {
             text: format_user_shell_command_record(command, exec_output, turn_context),
         }],
+        end_turn: None,
     }
 }
 
diff --git a/codex-rs/core/tests/chat_completions_payload.rs b/codex-rs/core/tests/chat_completions_payload.rs
index 23b50823f9..cdb92fe672 100644
--- a/codex-rs/core/tests/chat_completions_payload.rs
+++ b/codex-rs/core/tests/chat_completions_payload.rs
@@ -135,6 +135,7 @@ fn user_message(text: &str) -> ResponseItem {
         content: vec![ContentItem::InputText {
             text: text.to_string(),
         }],
+        end_turn: None,
     }
 }
 
@@ -145,6 +146,7 @@ fn assistant_message(text: &str) -> ResponseItem {
         content: vec![ContentItem::OutputText {
             text: text.to_string(),
         }],
+        end_turn: None,
     }
 }
 
diff --git a/codex-rs/core/tests/chat_completions_sse.rs b/codex-rs/core/tests/chat_completions_sse.rs
index f6d7eb24fe..05ef476a05 100644
--- a/codex-rs/core/tests/chat_completions_sse.rs
+++ b/codex-rs/core/tests/chat_completions_sse.rs
@@ -109,6 +109,7 @@ async fn run_stream_with_bytes(sse_body: &[u8]) -> Vec<ResponseEvent> {
         content: vec![ContentItem::InputText {
             text: "hello".to_string(),
         }],
+        end_turn: None,
     }];
 
     let mut stream = match client.stream(&prompt).await {
diff --git a/codex-rs/core/tests/responses_headers.rs b/codex-rs/core/tests/responses_headers.rs
index 8eba3eabe7..22d9fa8b79 100644
--- a/codex-rs/core/tests/responses_headers.rs
+++ b/codex-rs/core/tests/responses_headers.rs
@@ -104,6 +104,7 @@ async fn responses_stream_includes_subagent_header_on_review() {
         content: vec![ContentItem::InputText {
             text: "hello".into(),
         }],
+        end_turn: None,
     }];
 
     let mut stream = client_session.stream(&prompt).await.expect("stream failed");
@@ -200,6 +201,7 @@ async fn responses_stream_includes_subagent_header_on_other() {
         content: vec![ContentItem::InputText {
             text: "hello".into(),
         }],
+        end_turn: None,
     }];
 
     let mut stream = client_session.stream(&prompt).await.expect("stream failed");
@@ -354,6 +356,7 @@ async fn responses_respects_model_info_overrides_from_config() {
         content: vec![ContentItem::InputText {
             text: "hello".into(),
         }],
+        end_turn: None,
     }];
 
     let mut stream = client.stream(&prompt).await.expect("stream failed");
diff --git a/codex-rs/core/tests/suite/client.rs b/codex-rs/core/tests/suite/client.rs
index 1b43f7932f..2231599890 100644
--- a/codex-rs/core/tests/suite/client.rs
+++ b/codex-rs/core/tests/suite/client.rs
@@ -194,6 +194,7 @@ async fn resume_includes_initial_messages_and_sends_prior_items() {
         content: vec![codex_protocol::models::ContentItem::InputText {
             text: "resumed user message".to_string(),
         }],
+        end_turn: None,
     };
     let prior_user_json = serde_json::to_value(&prior_user).unwrap();
     writeln!(
@@ -214,6 +215,7 @@ async fn resume_includes_initial_messages_and_sends_prior_items() {
         content: vec![codex_protocol::models::ContentItem::OutputText {
             text: "resumed system instruction".to_string(),
         }],
+        end_turn: None,
     };
     let prior_system_json = serde_json::to_value(&prior_system).unwrap();
     writeln!(
@@ -234,6 +236,7 @@ async fn resume_includes_initial_messages_and_sends_prior_items() {
         content: vec![codex_protocol::models::ContentItem::OutputText {
             text: "resumed assistant message".to_string(),
         }],
+        end_turn: None,
     };
     let prior_item_json = serde_json::to_value(&prior_item).unwrap();
     writeln!(
@@ -1275,6 +1278,7 @@ async fn azure_responses_request_includes_store_and_reasoning_ids() {
         content: vec![ContentItem::OutputText {
             text: "message".into(),
         }],
+        end_turn: None,
     });
     prompt.input.push(ResponseItem::WebSearchCall {
         id: Some("web-search-id".into()),
diff --git a/codex-rs/core/tests/suite/client_websockets.rs b/codex-rs/core/tests/suite/client_websockets.rs
index 1532ac74d1..d55d71d0d8 100644
--- a/codex-rs/core/tests/suite/client_websockets.rs
+++ b/codex-rs/core/tests/suite/client_websockets.rs
@@ -170,6 +170,7 @@ fn message_item(text: &str) -> ResponseItem {
         id: None,
         role: "user".into(),
         content: vec![ContentItem::InputText { text: text.into() }],
+        end_turn: None,
     }
 }
 
diff --git a/codex-rs/core/tests/suite/compact.rs b/codex-rs/core/tests/suite/compact.rs
index b06f5ef14b..94f768b77f 100644
--- a/codex-rs/core/tests/suite/compact.rs
+++ b/codex-rs/core/tests/suite/compact.rs
@@ -1221,6 +1221,7 @@ async fn auto_compact_runs_after_resume_when_token_usage_is_over_limit() {
             content: vec![codex_protocol::models::ContentItem::OutputText {
                 text: remote_summary.to_string(),
             }],
+            end_turn: None,
         },
         codex_protocol::models::ResponseItem::Compaction {
             encrypted_content: "ENCRYPTED_COMPACTION_SUMMARY".to_string(),
@@ -2071,6 +2072,7 @@ async fn auto_compact_counts_encrypted_reasoning_before_last_user() {
             content: vec![codex_protocol::models::ContentItem::OutputText {
                 text: "REMOTE_COMPACT_SUMMARY".to_string(),
             }],
+            end_turn: None,
         },
         codex_protocol::models::ResponseItem::Compaction {
             encrypted_content: "ENCRYPTED_COMPACTION_SUMMARY".to_string(),
@@ -2190,6 +2192,7 @@ async fn auto_compact_runs_when_reasoning_header_clears_between_turns() {
             content: vec![codex_protocol::models::ContentItem::OutputText {
                 text: "REMOTE_COMPACT_SUMMARY".to_string(),
             }],
+            end_turn: None,
         },
         codex_protocol::models::ResponseItem::Compaction {
             encrypted_content: "ENCRYPTED_COMPACTION_SUMMARY".to_string(),
diff --git a/codex-rs/core/tests/suite/compact_remote.rs b/codex-rs/core/tests/suite/compact_remote.rs
index a18baab540..a2cf73e110 100644
--- a/codex-rs/core/tests/suite/compact_remote.rs
+++ b/codex-rs/core/tests/suite/compact_remote.rs
@@ -58,6 +58,7 @@ async fn remote_compact_replaces_history_for_followups() -> Result<()> {
             content: vec![ContentItem::InputText {
                 text: "REMOTE_COMPACTED_SUMMARY".to_string(),
             }],
+            end_turn: None,
         },
         ResponseItem::Compaction {
             encrypted_content: "ENCRYPTED_COMPACTION_SUMMARY".to_string(),
@@ -179,6 +180,7 @@ async fn remote_compact_runs_automatically() -> Result<()> {
             content: vec![ContentItem::InputText {
                 text: "REMOTE_COMPACTED_SUMMARY".to_string(),
             }],
+            end_turn: None,
         },
         ResponseItem::Compaction {
             encrypted_content: "ENCRYPTED_COMPACTION_SUMMARY".to_string(),
@@ -246,6 +248,7 @@ async fn remote_compact_persists_replacement_history_in_rollout() -> Result<()>
             content: vec![ContentItem::InputText {
                 text: "COMPACTED_USER_SUMMARY".to_string(),
             }],
+            end_turn: None,
         },
         ResponseItem::Compaction {
             encrypted_content: "ENCRYPTED_COMPACTION_SUMMARY".to_string(),
@@ -256,6 +259,7 @@ async fn remote_compact_persists_replacement_history_in_rollout() -> Result<()>
             content: vec![ContentItem::OutputText {
                 text: "COMPACTED_ASSISTANT_NOTE".to_string(),
             }],
+            end_turn: None,
         },
     ];
     let compact_mock = responses::mount_compact_json_once(
diff --git a/codex-rs/core/tests/suite/image_rollout.rs b/codex-rs/core/tests/suite/image_rollout.rs
index 3c3f92ce45..e18f324125 100644
--- a/codex-rs/core/tests/suite/image_rollout.rs
+++ b/codex-rs/core/tests/suite/image_rollout.rs
@@ -156,6 +156,7 @@ async fn copy_paste_local_image_persists_rollout_request_shape() -> anyhow::Resu
                 text: "pasted image".to_string(),
             },
         ],
+        end_turn: None,
     };
 
     assert_eq!(actual, expected);
@@ -235,6 +236,7 @@ async fn drag_drop_image_persists_rollout_request_shape() -> anyhow::Result<()>
                 text: "dropped image".to_string(),
             },
         ],
+        end_turn: None,
     };
 
     assert_eq!(actual, expected);
diff --git a/codex-rs/core/tests/suite/review.rs b/codex-rs/core/tests/suite/review.rs
index e5c980f681..1f0913470b 100644
--- a/codex-rs/core/tests/suite/review.rs
+++ b/codex-rs/core/tests/suite/review.rs
@@ -532,6 +532,7 @@ async fn review_input_isolated_from_parent_history() {
             content: vec![codex_protocol::models::ContentItem::InputText {
                 text: "parent: earlier user message".to_string(),
             }],
+            end_turn: None,
         };
         let user_json = serde_json::to_value(&user).unwrap();
         let user_line = serde_json::json!({
@@ -550,6 +551,7 @@ async fn review_input_isolated_from_parent_history() {
             content: vec![codex_protocol::models::ContentItem::OutputText {
                 text: "parent: assistant reply".to_string(),
             }],
+            end_turn: None,
         };
         let assistant_json = serde_json::to_value(&assistant).unwrap();
         let assistant_line = serde_json::json!({
diff --git a/codex-rs/protocol/src/models.rs b/codex-rs/protocol/src/models.rs
index 1b22fb925f..ff440ac1c8 100644
--- a/codex-rs/protocol/src/models.rs
+++ b/codex-rs/protocol/src/models.rs
@@ -80,6 +80,10 @@ pub enum ResponseItem {
         id: Option<String>,
         role: String,
         content: Vec<ContentItem>,
+        // Do not use directly, no available consistently across all providers.
+        #[serde(default, skip_serializing_if = "Option::is_none")]
+        #[ts(optional)]
+        end_turn: Option<bool>,
     },
     Reasoning {
         #[serde(default, skip_serializing)]
@@ -328,6 +332,7 @@ impl From<DeveloperInstructions> for ResponseItem {
             content: vec![ContentItem::InputText {
                 text: di.into_text(),
             }],
+            end_turn: None,
         }
     }
 }
@@ -497,6 +502,7 @@ impl From<ResponseInputItem> for ResponseItem {
                 role,
                 content,
                 id: None,
+                end_turn: None,
             },
             ResponseInputItem::FunctionCallOutput { call_id, output } => {
                 Self::FunctionCallOutput { call_id, output }
diff --git a/codex-rs/protocol/src/protocol.rs b/codex-rs/protocol/src/protocol.rs
index 0eb5e102a7..70bbf28aca 100644
--- a/codex-rs/protocol/src/protocol.rs
+++ b/codex-rs/protocol/src/protocol.rs
@@ -1607,6 +1607,7 @@ impl From<CompactedItem> for ResponseItem {
             content: vec![ContentItem::OutputText {
                 text: value.message,
             }],
+            end_turn: None,
         }
     }
 }