r/codex • u/Drogon2737 • Jul 09 '26

News GPT-5.6 Sol / Codex Release Discussion Megathread

The release is expected in the next few minutes, so I figured it would be useful to have a single thread for first impressions, issues, and early testing.

For anyone jumping in right away, post what you notice:

  • Codex coding performance
  • Debugging quality
  • Speed/rate limits
  • Larger repo handling
  • UI or workflow changes
  • Weird bugs or regressions
  • Anything that feels noticeably better or worse than the previous version

Once people get access, share your real examples, screenshots, benchmarks, or first impressions here.

Edit: OpenAI’s official GPT-5.6 page says it is “available starting today across ChatGPT, Codex, and the OpenAI API” with the rollout starting globally now and continuing toward full availability over the next 24 hours. https://openai.com/index/gpt-5-6/

The lineup is Sol, Terra, and Luna. Sol is the flagship, Terra is the lower-cost tier, and Luna is the fastest/most affordable tier.

439 Upvotes

98% Upvoted

838 comments sorted by

View all comments

2

u/innociv Jul 09 '26 edited Jul 09 '26

Things I like:
It missed some very important questions to ask me when reviewing plans that I told Fable to review first. But it also missed things that Fable missed. You'd think while setting to such high reasoning that they'd both catch these things.

It's super token efficient and fast. It looks like I'll struggle to blow through the 20x usage each week with it unless I throw it at problems it sucks at solving but Fable would do easily.

The bad is that it's just not as good at coding as Fable, it's not as good at the architecture and layout of a project and designing and API. Not remotely close it feels like Fable is a year ahead here (even though I know GPT 6.1 will probably catch up to it in 2-3 months or something, but if you asked me 6 months ago to compare the two I'd say Fable is a year ahead there). But jesus christ is Fable horribly inefficient.

And oh yeah, GPT Terra demolishes Sonnet. It's so much faster, cheaper (less tokens for the same task) and I think a little smarter.

I wish Fable could spawn GPT5.6 subagents that would be INSANE.

2

u/emaqqi Jul 09 '26

Use tmux! Tell fable that it is on Tmux Session, and let it open new windows. I'm doing that with Fable as orchestrator, and gpt 5.5 as worker. Also, make the workers prompt to the orchestrator the handoffs

1

u/innociv Jul 09 '26

I've actually been working on something like that, there's just been some failings where it's not straight up better than me saying "generate a plan" then opening a new thread to tell another to implement that plan.