Two rolling windows, not a monthly quota
ChatGPT meters Codex on a 5-hour window and a weekly one. The time in the message is the end of whichever window you filled, which is why the same account is free again within the hour on one day and blocked for days on another.
Nothing on your machine caused it
Codex CLI is relaying what the backend answered. Reinstalling the CLI, clearing $CODEX_HOME or starting a fresh session changes nothing, because the counter lives on the account rather than on the box.
A reset credit may be sitting unused
ChatGPT grants rate-limit reset credits to some accounts. They are separate from the usage windows and from purchased credits, and spending one lifts the current limit at once. The app-server returns them as rateLimitResetCredits beside the windows, so reading only the windows is how a granted credit stays invisible.
The weekly window does not always arrive where you expect
Codex ships the two windows in a primary and a secondary slot, and it now sends the weekly one as primary with secondary empty. Anything that reads the slot rather than the window length can label a weekly block as a 5-hour one, which turns a four-day wait into a promise of forty minutes. It also means some accounts report only a weekly window, which is why /status is a better source than any rule of thumb.
ChatGPT Work spends the same allowance
OpenAI's Codex pricing page says ChatGPT Work and Codex share usage, and that ChatGPT Work inside ChatGPT uses the same pricing, credits and usage limits as Codex. Work you did in the ChatGPT app can therefore be what filled the window your terminal just hit.
Some models burn it faster than others
The window counts usage, not prompts, and models cost it at different rates. Codex itself describes GPT-6 Luna as significantly more efficient, so your usage limits go even further, and flags some options with Consumes usage limits faster. Long agentic turns at high reasoning effort on a frontier model empty a window far sooner than short ones on a light model.
The message changes with your plan
Codex prints different endings for the same limit depending on the account. One suggests upgrading to Plus, one offers Pro and https://chatgpt.com/settings/usage to purchase more credits, one offers only the credits link, and one says To get more access now, send a request to your admin, because on a managed workspace the admin, not you, controls the credits. The ending tells you which levers your account actually has.
An API key does not use these windows at all
Signed in with an API key, Codex bills through your OpenAI Platform account at API prices. The pricing page puts it as pay for Codex usage based on API pricing. The ChatGPT 5-hour and weekly windows belong to a ChatGPT sign-in only, so this message means the CLI is signed in with ChatGPT.