[wahnfrieden]

If I'm doing a large task, I use GPT 5 Pro to write a spec first (with advice for Codex, broken down task list, snippets etc). I may also supply entire files/repos as context for 5 Pro to produce this.

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.

[stavros]

I still wish it would do all that on its own, without me having to switch models and make sure it won't make code changes.

[embedding-shape]

Well, when you use GPT 5 Pro Mode it can't make any code changes, so not really a problem :)

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.

[wahnfrieden]

Codex won't read as much of your code as 5 Pro will (if you give it the context), and Codex will skip over reading in context that you give it (5 Pro can decide what's relevant after reading it all).

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.

[embedding-shape]

> and Codex will skip over reading in context that you give it

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.

[wahnfrieden]

That’s what I’m saying. Codex will search but then won’t read full files and is stingy with ingesting context. 5 Pro will take in a lot more context (quality up to about 60k input tokens) but you must give it. So sometimes you can even use Codex first to find what full files you should give to 5 Pro to create the spec/task list.

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).

[nl]

I've noted it elsewhere, but Codex has a plan mode.

On the web, press the "+" button next to the repo

[wahnfrieden]

I can’t use web because I do iOS dev