Fast Mode has disappeared from Codex App

Resolved 💬 5 comments Opened Apr 14, 2026 by miraclebakelaser Closed Apr 20, 2026

💡 Likely answer: A maintainer (github-actions[bot], contributor) responded on this thread — see the highlighted reply below.

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

Version 26.409.20454 (1462)

What subscription do you have?

Pro

What platform is your computer?

Darwin 25.4.0 arm64 arm

What issue are you seeing?

There seems to be no way to enable fast mode within Codex App.
<img width="293" height="234" alt="Image" src="https://github.com/user-attachments/assets/1a2b97ee-449a-46f5-ba16-1ea01a46ea3e" />

service_tier = "fast" in config.toml seems to only affect Codex CLI.

What steps can reproduce the bug?

Open Codex app. Try to enable fast mode via / command and + menu. Option to enable fast mode is no longer available.

What is the expected behavior?

_No response_

Additional information

_No response_

View original on GitHub ↗

5 Comments

github-actions[bot] contributor · 4 months ago

Potential duplicates detected. Please review them and close your issue if it is a duplicate.

#14689

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miraclebakelaser contributor · 4 months ago

Not a dupe.

conacts · 4 months ago

Not a dupe.

Was the removal of fast mode a bug or done on purpose?

qiutao20 · 4 months ago

same problem on win 26.409.61251

miraclebakelaser contributor · 4 months ago

I figured it out. It's because I'm using a custom models.json file to clean up my model picker (https://github.com/openai/codex/issues/13736#issuecomment-4020871332).

Looks like codex app now picks up fast capability from additional_speed_tiers (https://github.com/openai/codex/commit/80ebc80be5dbe61b300279c0123918275fc145a5).

Adding this to my models.json brings back fast mode to codex app:
https://github.com/openai/codex/blob/d0047de7cbd0d8ffd03804d3736478594f0742c8/codex-rs/models-manager/models.json#L119-L121