Codex app thread-management tools not exposed despite thread creation being available

Summary

In a Codex desktop session, the user asked the assistant to open another Codex thread and send an execution prompt there. The app context says thread-management tools should be available through tool search, including create_thread, send_message_to_thread, fork_thread, list_threads, and related tools.

However, repeated tool searches did not expose any of those tools.

What happened

The assistant searched for:

• create_thread
• send_message_to_thread
• fork_thread
• list_threads read_thread set_thread_title
• broader queries such as create thread Codex thread title message

No real thread-management tools were returned.

Because the real thread tool was unavailable, the assistant incorrectly fell back to spawning a multi_agent worker. The user then had to stop the worker, because they wanted a real sidebar Codex thread, not a background subagent.

Expected behaviour

If the Codex app supports user-owned thread creation, the thread tools should be discoverable and callable when the user explicitly asks to create/open/fork/send work to another thread.

At minimum, if thread tools are unavailable in a session, the assistant should have a reliable way to know that and report it clearly, instead of only discovering this through failed tool search.

Actual behaviour

Thread-management tools were not exposed through tool search, even though the app instructions referenced them and the user reports having used this capability many times.

Impact

This creates a confusing and potentially harmful fallback path:

• the assistant cannot perform the requested thread workflow;
• the assistant may confuse background subagents with user-owned Codex threads;
• the user loses control over where long-running work is happening;
• the assistant may start work in the wrong execution surface.

Suggested fix

Ensure thread-management tools are exposed when the Codex desktop app supports them, especially:

• create_thread
• send_message_to_thread
• fork_thread
• list_threads
• read_thread
• set_thread_title

Alternatively, provide an explicit unavailable state so the assistant can say: “I cannot create a real Codex thread from this session.”

Search performed before filing

Searched existing openai/codex issues for:

• thread create_thread send_message_to_thread tool_search
• create thread tools unavailable
• tool_search missing tools
• thread management tools
• multi_agent thread

No close match was found.

Session details

Date: 2026-06-26
Context: Codex desktop app
Observed available fallback: multi_agent_v1.spawn_agent, which is not equivalent to creating a user-owned Codex thread.