Codex desktop: update_plan unavailable and no replacement exposed

What version of the Codex App are you using (From “About Codex” dialog)?

26.901.51231

What subscription do you have?

Pro

What platform is your computer?

macOS 26.6.2 (25G83), Apple Silicon Darwin 25.6.0 arm64 arm

What issue are you seeing?

The assistant cannot update the native task-progress plan because update_plan is unavailable in its exposed tool set.

Searching the available tool registry found neither update_plan nor an equivalent planning/progress API. Checking typeof tools.update_plan returned "undefined".

The assistant falls back to textual progress updates. No failed update_plan invocation or UI error was observed.

What steps can reproduce the bug?

Fresh-session reproduction has not been verified. To check the behavior observed in the affected desktop task:

1. In a local task using Default mode, ask: "Show a native task-progress plan with two steps."
2. If the assistant reports that update_plan is unavailable, ask it to inspect the exposed tools for alternative planning/progress APIs.
3. Observe whether the assistant finds an applicable API or falls back to textual progress updates.

The absence was observed in the original task and checked again in a side conversation.

Feedback ID: 01a07dea-f90e-7ed1-9bab-627a7a23fb8f
Token limit usage: Not recorded.
Context window usage: Not recorded.

What is the expected behavior?

The assistant can create and update the native task-progress plan through update_plan or a documented replacement. If this surface intentionally does not support it, that limitation should be explicit.

Additional information

Observed on September 7, 2026.

A locally installed show-task-progress skill still instructs the assistant to call update_plan. This does not establish whether the tool is currently supported.

Restart behavior and reproduction in an unrelated fresh task have not been tested. A regression or API rename has not been established.

Start by reproducing the behavior in a fresh Codex desktop Default-mode task and inspect the exposed tool registry for update_plan or a replacement. The issue is done when native task-progress updates work through an available API, or the unsupported surface is explicitly documented.