Run AI tools on your ChatGPT plan instead of an API key
OpenAI's Codex tools let you sign in with your ChatGPT account. Some other apps can reuse that same sign-in, so their AI runs on your subscription instead of a pay-per-use API key.
How I set it up
Install the Codex command-line tool and run codex login. Choose "Sign in with ChatGPT".
In my AI bot app (Hermes Agent), I imported that login, so its bots use my plan.
I picked the model per bot. My main assistant runs gpt-5.6-luna.
What I run on it
My main assistant, Jarvis
The summaries that keep long chats short
The illustrations in my carousels
Know the limits
It shares your plan's usage limits with everything else you use ChatGPT for.
Not every app supports this sign-in. Look for "Sign in with ChatGPT" or a Codex login option.
The login file is your account. Never paste it anywhere or share it.