Windows desktop: list_threads advertised but returns “No handler registered for tool” #36965

Summary

In the Windows Codex/ChatGPT desktop application, the codex_app__list_threads tool is surfaced as available, but calls consistently fail with:

No handler registered for tool: list_threads

This prevents a safe scheduled rotation of role-based chats: the automation cannot discover the active chat by its exact title before creating a successor and archiving the old one.

Environment

• OS: Windows
• Desktop package: OpenAI.Codex 26.727.6591.0
• Execution environment: local project

Steps to reproduce

1. In the Windows desktop application, invoke codex_app__list_threads with a valid limit (for example 20).
2. Observe the tool response.
3. Fully restart the ChatGPT/Codex desktop application and repeat the call.

Actual result

Both before and after restart, the call returns:

No handler registered for tool: list_threads

Expected result

The tool should either be available and return the accessible thread summaries, or not be surfaced as callable when no handler is registered.

Impact

Automations that must safely rotate persistent role chats cannot verify the active role, successor state, or archival target. They correctly defer rather than risk replacing or archiving the wrong chat.

No project content, secrets, or user data are required to reproduce the issue.