Codex OAuth is the authentication flow OpenAI's official Codex CLI uses to let ChatGPT Plus and Pro subscribers run a coding agent against their existing subscription quota — no API key, no per-token billing. VibeKit supports the same OAuth flow: sign in with your ChatGPT account in Settings → AI Provider and your coding agent runs against your existing $20 (Plus) or $200 (Pro) per month subscription.

Does this mean I get unlimited coding for $20/mo?

It means you get the same usage allowance OpenAI gives Plus subscribers on Codex — which is generous but not unlimited. Pro ($200/mo) has dramatically higher limits. Either way, you don't pay anything extra to VibeKit on the AI side; we run zero markup on BYOK. Our paid plans cover hosting + multiple apps + custom domains.

How does this compare to using an OpenAI API key (sk-)?

API key is pay-per-token. Codex OAuth is flat-rate subscription. For a developer doing 10+ agent tasks a day, Codex OAuth via ChatGPT Plus often comes out cheaper than the equivalent in API tokens. For light usage or bursty work, the API key might be cheaper. VibeKit lets you switch between them per-app.

Does it work the same as Claude Pro OAuth?

Yes — same idea, different provider. Claude Pro / Max OAuth uses your Anthropic subscription quota; ChatGPT Plus / Pro Codex OAuth uses your OpenAI subscription quota. Both are zero-markup BYOK paths on VibeKit. Pick whichever subscription you already have, or use both on different apps.

Use ChatGPT Plus / Pro as a Coding Agent

If you're already paying $20/mo (Plus) or $200/mo (Pro) for ChatGPT, that subscription can power a real coding agent on VibeKit — via the same Codex OAuth flow OpenAI's official Codex CLI uses. No second AI subscription. No per-token charges on top.

The math

Buying OpenAI API tokens for ChatGPT-tier usage gets expensive fast: a typical coding session of 10–20 agent prompts can run $1–$5 in API tokens. ChatGPT Plus ($20/mo) covers that volume daily as part of the flat subscription, with substantial quota left over. ChatGPT Pro ($200/mo) is effectively unlimited for individual use.

OpenAI made Codex OAuth specifically so subscribers can use their plan for coding-style automation without spinning up a separate Developer-account billing relationship. VibeKit supports the same auth path.

What you actually get

Same model OpenAI uses for Codex — currently the GPT-5 family. Same quality, same context window.
Same usage caps as ChatGPT Plus / Pro directly — not a separate per-token meter on top.
Zero VibeKit markup. BYOK is BYOK. We don't bill anything on the AI side.
Real container hosting included. Free tier covers 1 app on Fargate.

Setup

Install VibeKit (App Store) or visit app.vibekit.bot
Settings → AI Provider → Sign in with ChatGPT
OpenAI's OAuth screen confirms your Plus / Pro subscription
Pick a template or connect a GitHub repo
Start chatting — agent calls now run against your existing subscription

How this stacks against the alternatives

Option	Monthly cost	Best for
ChatGPT Plus + Codex OAuth (VibeKit)	$20 (existing sub)	You already pay for Plus
ChatGPT Pro + Codex OAuth (VibeKit)	$200 (existing sub)	Heavy daily coding
OpenAI `sk-` API key	Pay per token	Light or bursty usage
Platform fallback (no BYOK)	OpenRouter price + 20%	Trying VibeKit out
Free Qwen on VibeKit	$0	Everyday tasks, prototypes

You can mix Claude and ChatGPT per-app

Different apps can use different providers. Run your marketing site on Codex OAuth, your serious DeFi app on Claude Pro OAuth, and a throwaway prototype on free Qwen. Switch in Settings → AI Provider at any time — different apps remember different choices.

Your $20 ChatGPT sub → a coding agent

Codex OAuth · No second sub · Real hosting · iPhone + web

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