@ mention search in thread composer hangs when it searches thread history

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

26.623.101652

What subscription do you have?

pro 20x

What platform is your computer?

Darwin 24.6.0 arm64 arm

What issue are you seeing?

In the Codex GUI, when I have any thread open and type @ in the message composer, the mention picker appears to search across all historical threads, given that I have a large number of threads, this causes the app to lag or completely hang for 5-10 seconds. (This has improved in the last week or so)

This happens inside an open thread, not from the app-level search UI.

Actual behavior:

• The app appears to fuzzy-search a large thread history across all threads.
• The UI becomes unresponsive for several seconds.
• This makes using @ mentions inside the composer frustrating, especially when I’m trying to reference files.

What steps can reproduce the bug?

Have several threads/subagent threads etc available locally, while inside a chat, type @ then some letter or start typing out some word as if you were searching for a file and the UI will become unresponsive for several seconds.

What is the expected behavior?

• Typing @ should stay responsive and performant.
• Files should be surfaced before threads.
• There should be an option to disable searching threads from the @ picker.

Additional information

this is on an m4max/64gb, so that can't be the issue