Codex Desktop/App no longer exposes a thread pinning tool to assistants

Summary

Codex Desktop/App previously exposed a background thread pinning capability to assistants through tool discovery, under codex_app.set_thread_pinned. In current Codex Desktop/App sessions on codex-cli 0.136.0, that tool is no longer discoverable, and I could not find a documented replacement in the Codex App Server API.

This makes it impossible for an assistant to satisfy a direct user request such as "pin this chat" or a repository boot instruction that asks new Codex threads to pin themselves.

Expected behavior

When a user asks Codex Desktop/App to pin the current chat/thread, the assistant should have a callable, discoverable capability to do that, for example the old shape:

codex_app.set_thread_pinned({ threadId: CODEX_THREAD_ID, pinned: true })

If this capability was intentionally replaced, the replacement should be documented and discoverable by the assistant.

Actual behavior

• codex --version: codex-cli 0.136.0
• Searching for set_thread_pinned, codex_app, pin, and pinned thread through tool discovery returns no thread-pinning tool.
• The public Codex App Server API documents thread methods such as thread/name/set, thread/archive, thread/unarchive, and thread/metadata/update, but I do not see a pin/unpin endpoint.
• Generated App Server bindings for this version also do not appear to contain a pinned, favorite, bookmark, or equivalent thread property/method.

Repro steps

1. Start a Codex Desktop/App thread.
2. Ask the assistant to pin the current thread, or provide a repo instruction that asks the assistant to pin new threads during boot.
3. Have the assistant search available tools for thread pinning.
4. Observe that there is no callable codex_app.set_thread_pinned tool and no obvious documented replacement.

Impact

Users cannot automate pinning important Codex Desktop/App threads from chat or from persistent repo instructions. The assistant has to report that pinning is pending instead of completing the request.

Proposed fix

Please restore a discoverable assistant-callable thread pinning capability in Codex Desktop/App, or expose an equivalent App Server method such as thread/pin/set. The method should accept a real thread id and a boolean pin state, and it should be reachable from the assistant when operating inside the current Codex Desktop/App thread.