feat(app-server): thread/turns/items/list -> thread/items/list (#29705)

## Description

Rename the experimental app-server item pagination API from
`thread/turns/items/list` to `thread/items/list` and make `turnId`
optional. Clients can now page persisted items across a thread, or still
filter to one turn when needed.

## What changed

- Rename the request/response protocol types and JSON-RPC method to
`ThreadItemsList*` / `thread/items/list`.
- Pass optional `turnId` through to `ThreadStore::list_items`.
- Update app-server docs and focused protocol/app-server tests.

## Validation

- `just test -p codex-app-server-protocol thread_items_list_round_trips`
- `just test -p codex-app-server thread_items_list_returns_unsupported`

codex-rs/app-server/README.md

@@ -145,7 +145,7 @@ Example with notification opt-out:
 - `thread/loaded/list` — list the thread ids currently loaded in memory.
 - `thread/read` — read a stored thread by id without resuming it; optionally include turns via `includeTurns`. The returned `thread` includes `status` (`ThreadStatus`), defaulting to `notLoaded` when the thread is not currently loaded.
 - `thread/turns/list` — experimental; page through a stored thread’s turn history without resuming it; supports cursor-based pagination with `sortDirection`, `itemsView`, `nextCursor`, and `backwardsCursor`.
-- `thread/turns/items/list` — experimental; reserved for paging full items for one turn. The API shape is present, but app-server currently returns an unsupported-method JSON-RPC error.
+- `thread/items/list` — experimental; page through persisted thread items without resuming the thread. Pass `turnId` to restrict results to one turn, or omit it to page items across the thread. The active thread store must support item pagination.
 - `thread/metadata/update` — patch stored thread metadata in sqlite; currently supports updating persisted `gitInfo` fields and returns the refreshed `thread`.
 - `thread/settings/update` — experimental; queue a partial update to a loaded thread’s next-turn settings without starting a turn or adding transcript items. Omitted fields leave settings unchanged; `serviceTier: null` clears the tier; `multiAgentMode` selects `none`, `explicitRequestOnly`, or `proactive` for subsequent turns; `sandboxPolicy` and `permissions` cannot be combined. Returns `{}` when the update is accepted and emits `thread/settings/updated` with the full effective settings only if they actually change. `turn/start` settings overrides emit the same notification when they change the stored settings.
 - `thread/memoryMode/set` — experimental; set a thread’s persisted memory eligibility to `"enabled"` or `"disabled"` for either a loaded thread or a stored rollout; returns `{}` on success.
@@ -514,10 +514,10 @@ Every returned `Turn` includes `itemsView`, which tells clients whether the `ite
 } }
 ```
 
-`thread/turns/items/list` is the planned hydration API for fetching full items for one turn:
+`thread/items/list` pages full persisted items across a thread, optionally filtered to one turn:
 
 ```json
-{ "method": "thread/turns/items/list", "id": 25, "params": {
+{ "method": "thread/items/list", "id": 25, "params": {
     "threadId": "thr_123",
     "turnId": "turn_456",
     "limit": 100,
@@ -525,7 +525,7 @@ Every returned `Turn` includes `itemsView`, which tells clients whether the `ite
 } }
 ```
 
-This method currently returns JSON-RPC `-32601` with message `thread/turns/items/list is not supported yet`.
+Omit `turnId` or pass `null` to page items across the thread. Thread stores that do not implement item pagination return JSON-RPC `-32601` with message `thread/items/list is not supported yet`.
 
 ### Example: Update stored thread metadata
 

codex-rs/app-server/src/message_processor.rs

@@ -1223,8 +1223,8 @@ impl MessageProcessor {
             ClientRequest::ThreadTurnsList { params, .. } => {
                 self.thread_processor.thread_turns_list(params).await
             }
-            ClientRequest::ThreadTurnsItemsList { params, .. } => {
-                self.thread_processor.thread_turns_items_list(params).await
+            ClientRequest::ThreadItemsList { params, .. } => {
+                self.thread_processor.thread_items_list(params).await
             }
             ClientRequest::ThreadShellCommand { params, .. } => {
                 self.thread_processor

codex-rs/app-server/src/request_processors.rs

@@ -211,6 +211,8 @@ use codex_app_server_protocol::ThreadIncrementElicitationResponse;
 use codex_app_server_protocol::ThreadInjectItemsParams;
 use codex_app_server_protocol::ThreadInjectItemsResponse;
 use codex_app_server_protocol::ThreadItem;
+use codex_app_server_protocol::ThreadItemsListParams;
+use codex_app_server_protocol::ThreadItemsListResponse;
 use codex_app_server_protocol::ThreadListCwdFilter;
 use codex_app_server_protocol::ThreadListParams;
 use codex_app_server_protocol::ThreadListResponse;
@@ -256,7 +258,6 @@ use codex_app_server_protocol::ThreadStartParams;
 use codex_app_server_protocol::ThreadStartResponse;
 use codex_app_server_protocol::ThreadStartedNotification;
 use codex_app_server_protocol::ThreadStatus;
-use codex_app_server_protocol::ThreadTurnsItemsListParams;
 use codex_app_server_protocol::ThreadTurnsListParams;
 use codex_app_server_protocol::ThreadTurnsListResponse;
 use codex_app_server_protocol::ThreadUnarchiveParams;
@@ -436,6 +437,7 @@ use codex_state::log_db::LogDbLayer;
 use codex_thread_store::ArchiveThreadParams as StoreArchiveThreadParams;
 use codex_thread_store::DeleteThreadParams as StoreDeleteThreadParams;
 use codex_thread_store::GitInfoPatch as StoreGitInfoPatch;
+use codex_thread_store::ListItemsParams as StoreListItemsParams;
 use codex_thread_store::ListThreadsParams as StoreListThreadsParams;
 use codex_thread_store::LocalThreadStore;
 use codex_thread_store::ReadThreadByRolloutPathParams as StoreReadThreadByRolloutPathParams;

codex-rs/app-server/src/request_processors/thread_processor.rs

@@ -683,13 +683,13 @@ impl ThreadRequestProcessor {
             .map(|response| Some(response.into()))
     }
 
-    pub(crate) async fn thread_turns_items_list(
+    pub(crate) async fn thread_items_list(
         &self,
-        _params: ThreadTurnsItemsListParams,
+        params: ThreadItemsListParams,
     ) -> Result<Option<ClientResponsePayload>, JSONRPCErrorError> {
-        Err(method_not_found(
-            "thread/turns/items/list is not supported yet",
-        ))
+        self.thread_items_list_response_inner(params)
+            .await
+            .map(|response| Some(response.into()))
     }
 
     pub(crate) async fn thread_shell_command(
@@ -2388,6 +2388,68 @@ impl ThreadRequestProcessor {
         )
     }
 
+    async fn thread_items_list_response_inner(
+        &self,
+        params: ThreadItemsListParams,
+    ) -> Result<ThreadItemsListResponse, JSONRPCErrorError> {
+        let ThreadItemsListParams {
+            thread_id,
+            turn_id,
+            cursor,
+            limit,
+            sort_direction,
+        } = params;
+        let thread_id = ThreadId::from_string(&thread_id)
+            .map_err(|err| invalid_request(format!("invalid thread id: {err}")))?;
+        let page_size = limit
+            .map(|value| value as usize)
+            .unwrap_or(THREAD_ITEMS_DEFAULT_LIMIT)
+            .clamp(1, THREAD_ITEMS_MAX_LIMIT);
+        let page = self
+            .thread_store
+            .list_items(StoreListItemsParams {
+                thread_id,
+                turn_id,
+                include_archived: true,
+                cursor,
+                page_size,
+                sort_direction: match sort_direction.unwrap_or(SortDirection::Asc) {
+                    SortDirection::Asc => StoreSortDirection::Asc,
+                    SortDirection::Desc => StoreSortDirection::Desc,
+                },
+            })
+            .await
+            .map_err(|err| match err {
+                ThreadStoreError::InvalidRequest { message } => invalid_request(message),
+                ThreadStoreError::Unsupported { .. } => {
+                    method_not_found("thread/items/list is not supported yet")
+                }
+                ThreadStoreError::ThreadNotFound { thread_id } => {
+                    invalid_request(format!("no rollout found for thread id {thread_id}"))
+                }
+                err => internal_error(format!("failed to list thread items: {err}")),
+            })?;
+        let data =
+            page.items
+                .into_iter()
+                .map(|item| {
+                    serde_json::from_slice::<ThreadItem>(&item.materialized_thread_item_json)
+                        .map_err(|err| {
+                            internal_error(format!(
+                                "failed to deserialize stored thread item {}: {err}",
+                                item.item_key
+                            ))
+                        })
+                })
+                .collect::<Result<Vec<_>, _>>()?;
+
+        Ok(ThreadItemsListResponse {
+            data,
+            next_cursor: page.next_cursor,
+            backwards_cursor: page.backwards_cursor,
+        })
+    }
+
     async fn load_thread_turns_list_history(
         &self,
         thread_id: ThreadId,
@@ -3714,6 +3776,8 @@ fn xcode_26_4_mcp_elicitations_auto_deny(
 
 const THREAD_TURNS_DEFAULT_LIMIT: usize = 25;
 const THREAD_TURNS_MAX_LIMIT: usize = 100;
+const THREAD_ITEMS_DEFAULT_LIMIT: usize = 25;
+const THREAD_ITEMS_MAX_LIMIT: usize = 100;
 
 fn thread_backwards_cursor_for_sort_key(
     thread: &StoredThread,

codex-rs/app-server/tests/common/test_app_server.rs

@@ -84,6 +84,7 @@ use codex_app_server_protocol::ThreadCompactStartParams;
 use codex_app_server_protocol::ThreadDeleteParams;
 use codex_app_server_protocol::ThreadForkParams;
 use codex_app_server_protocol::ThreadInjectItemsParams;
+use codex_app_server_protocol::ThreadItemsListParams;
 use codex_app_server_protocol::ThreadListParams;
 use codex_app_server_protocol::ThreadLoadedListParams;
 use codex_app_server_protocol::ThreadMemoryModeSetParams;
@@ -102,7 +103,6 @@ use codex_app_server_protocol::ThreadSetNameParams;
 use codex_app_server_protocol::ThreadSettingsUpdateParams;
 use codex_app_server_protocol::ThreadShellCommandParams;
 use codex_app_server_protocol::ThreadStartParams;
-use codex_app_server_protocol::ThreadTurnsItemsListParams;
 use codex_app_server_protocol::ThreadTurnsListParams;
 use codex_app_server_protocol::ThreadUnarchiveParams;
 use codex_app_server_protocol::ThreadUnsubscribeParams;
@@ -602,13 +602,13 @@ impl TestAppServer {
         self.send_request("thread/turns/list", params).await
     }
 
-    /// Send a `thread/turns/items/list` JSON-RPC request.
-    pub async fn send_thread_turns_items_list_request(
+    /// Send a `thread/items/list` JSON-RPC request.
+    pub async fn send_thread_items_list_request(
         &mut self,
-        params: ThreadTurnsItemsListParams,
+        params: ThreadItemsListParams,
     ) -> anyhow::Result<i64> {
         let params = Some(serde_json::to_value(params)?);
-        self.send_request("thread/turns/items/list", params).await
+        self.send_request("thread/items/list", params).await
     }
 
     /// Send a `model/list` JSON-RPC request.

codex-rs/app-server/tests/suite/v2/thread_read.rs

@@ -19,6 +19,7 @@ use codex_app_server_protocol::SortDirection;
 use codex_app_server_protocol::ThreadForkParams;
 use codex_app_server_protocol::ThreadForkResponse;
 use codex_app_server_protocol::ThreadItem;
+use codex_app_server_protocol::ThreadItemsListParams;
 use codex_app_server_protocol::ThreadListParams;
 use codex_app_server_protocol::ThreadListResponse;
 use codex_app_server_protocol::ThreadNameUpdatedNotification;
@@ -32,7 +33,6 @@ use codex_app_server_protocol::ThreadSetNameResponse;
 use codex_app_server_protocol::ThreadStartParams;
 use codex_app_server_protocol::ThreadStartResponse;
 use codex_app_server_protocol::ThreadStatus;
-use codex_app_server_protocol::ThreadTurnsItemsListParams;
 use codex_app_server_protocol::ThreadTurnsListParams;
 use codex_app_server_protocol::ThreadTurnsListResponse;
 use codex_app_server_protocol::TurnItemsView;
@@ -1137,7 +1137,7 @@ async fn thread_turns_list_rejects_unmaterialized_loaded_thread() -> Result<()>
 }
 
 #[tokio::test]
-async fn thread_turns_items_list_returns_unsupported() -> Result<()> {
+async fn thread_items_list_returns_unsupported() -> Result<()> {
     let server = create_mock_responses_server_repeating_assistant("Done").await;
     let codex_home = TempDir::new()?;
     create_config_toml(codex_home.path(), &server.uri())?;
@@ -1146,9 +1146,9 @@ async fn thread_turns_items_list_returns_unsupported() -> Result<()> {
     timeout(DEFAULT_READ_TIMEOUT, mcp.initialize()).await??;
 
     let read_id = mcp
-        .send_thread_turns_items_list_request(ThreadTurnsItemsListParams {
-            thread_id: "thr_123".to_string(),
-            turn_id: "turn_456".to_string(),
+        .send_thread_items_list_request(ThreadItemsListParams {
+            thread_id: "00000000-0000-4000-8000-000000000123".to_string(),
+            turn_id: None,
             cursor: None,
             limit: None,
             sort_direction: None,
@@ -1163,7 +1163,7 @@ async fn thread_turns_items_list_returns_unsupported() -> Result<()> {
     assert_eq!(read_err.error.code, -32601);
     assert_eq!(
         read_err.error.message,
-        "thread/turns/items/list is not supported yet"
+        "thread/items/list is not supported yet"
     );
 
     Ok(())