Codex attempts to one shot for me but there’s many rounds of refinement. I haven’t used it in the last couple of weeks because it’s disappointing. Over hyped. Gone back to Amp and a little bit of Cursor with Sonnet 4.5
I do look at the backend code it writes, and it seems moderately sane. Sometimes it overcomplicates things, which makes me think that there are a few dragons in the frontend (I haven't looked), but by and large it's been ok.
Oh.
Not good enough for you?
If I skip 5 Pro but still have a large task, I have Codex write a spec file to use as a task list and to review for completeness as it works.
This is how you can use Codex without a plan mode.
I have similar workflow as parent, GPT 5 Pro for aiding with specifications and deep troubleshooting, rely on Codex to ground it in my actual code and project, and to execute the changes.
Yes Codex is still very early. We use it because it's the best model. The client experience will only get better from here. I noticed they onboarded a bunch of devs to the Codex project in GitHub around the time of 5's release.
That hasn't been my experience at all, neither first with the Codex UI since it was available to Pro users, nor since the CLI was available and I first started using that. GPT 5 Pro will (can, to be precise) only read what you give it, Codex goes out searching for what it needs, almost always.
What my quote meant is that once you have the context Codex needs to do its work, if you give it to it, it’ll start the work right away without going and reading all those files again, which can help minimize context use within a Codex session (by having 5 Pro or just another Codex read in a lot of context to identify what is relevant for Codex instead of having Codex waste precious context headroom on discovery in a session that is dedicated to doing the work).
On the web, press the "+" button next to the repo