Fast mode activates on its own
Resolved 💬 4 comments Opened May 17, 2026 by kgaspard Closed May 18, 2026
💡 Likely answer: A maintainer (etraut-openai, contributor)
responded on this thread — see the highlighted reply below.
What version of Codex CLI is running?
codex-cli 0.130.0
What subscription do you have?
Business
Which model were you using?
gpt-5.5
What platform is your computer?
Darwin 25.3.0 arm64 arm
What terminal emulator and version are you using (if applicable)?
iTerm2
Codex doctor report
Not working (`error: unexpected argument '--json' found`)What issue are you seeing?
Codex seems to automatically activate fast mode, despite me neither explicitly (with the slash command) nor implicitly asking for it. I can deactivate it with /fast, and I can see it get deactivated (fast disappears from the bottom of the CLI as expected), but after a few messages it comes back on its own.
What steps can reproduce the bug?
See above
What is the expected behavior?
_No response_
Additional information
_No response_
4 Comments
If this happens again, please use
/feedbackto upload your logs and post the session ID here.When you disable fast mode using
/fast, you should seefast_default_opt_out = truewritten to your config file. If you open~/.codex/config.toml, do you see this config key?I just found a repro of the problem. It required me to use
/agentto switch to a subagent thread or/sideto switch to a side conversation. When I returned to the main thread, fast mode was reported as on. It was actually off still, but the TUI reported a stale state. Do you remember using/agentor/side?@etraut-openai apologies, I never received the notification for your replies. It seems the issue is closed but on the off chance it's still helpful:
/feedback, will do/agentnor/side. I frequently use/modelto change the model and/or effort.