I'm trying to use Codex via the Xcode interface, and I can not find a way to set the reasoning level. There are no settings to be found anywhere. What am I missing?
I mean, I can continue to use Codex's own app, but I was hoping to use Xcode's new agentic interface, which seems superior to v26 and somewhat more useful. But if it's going to default to medium and I have no control over it, of course, I would continue using Codex's app rather than Xcode.
What's weird, I get responses like this when I ask about:
What's your current reasoning level and how can I adjust it?
This session appears to be using the default reasoning level: medium.
You generally adjust it outside my reply, in the model/session settings for Codex or the API request. Typical options are:
• low: faster, cheaper, best for simple edits or direct questions
• medium: default balance
• high: better for complex debugging, architecture, tricky code changes
• xhigh: deepest reasoning, slower, useful for hard multi-step work
Inside this chat, I can’t change my own base reasoning level mid-response. You can still tell me “use high reasoning for this” and I’ll treat the task more deliberately, but the actual runtime setting has to be changed in the client/session configuration.
So, it doesn't even know the level it's using or how to adjust.