Codex BYOK

Codex BYOK means running the Codex coding agent on the ChatGPT Plus / Pro subscription you already pay for. Sign in with your ChatGPT account via Codex OAuth — no OpenAI API key, no per-token bill, no VibeKit markup. The agent draws on your existing subscription quota, hosted at <name>.vibekit.bot.

Run Codex on the ChatGPT subscription you already have

If you pay for ChatGPT Plus or Pro, you already have everything you need to run a real coding agent. Codex OAuth lets you authenticate with that same ChatGPT account, and the Codex agent runs against your subscription quota — the same allowance you use in ChatGPT, now powering a hosted agent that lives on the web, in the iOS app, and on Telegram.

There's no second AI bill. You're not buying tokens. You're not topping up VibeKit credits for AI. You're using the subscription that's already on your card — VibeKit just gives the Codex agent somewhere to run.

How Codex OAuth works (no API key)

• Sign in, don't paste a key. Instead of generating an OpenAI API key (sk-…), you tap "Sign in with ChatGPT" and authorize via Codex OAuth. VibeKit stores the OAuth credential, not a raw key.
• It's a real OpenAI-family BYOK route. Under the hood, Codex OAuth lives in your OpenAI credential slot and routes to the codex/* models. It's your own subscription, your own account, your own bill.
• The agent runs against your quota. Every Codex request the agent makes counts against your existing ChatGPT Plus / Pro allowance — exactly as if you'd asked Codex yourself.
• No per-token reconciliation. There's no metered charge stacked on top. What your ChatGPT plan covers is what you get.

Zero markup — it's your subscription

Codex OAuth is a BYOK route, and BYOK on VibeKit never carries a markup. The Codex agent runs on your ChatGPT subscription, the cost is whatever your plan already covers, and VibeKit doesn't sit in the billing path. Nothing is deducted from VibeKit credits, and there's no per-token re-bill.

Compare that to platforms that charge a flat monthly "AI" fee while quietly routing prompts to a cheap model — that's pure margin in their pocket. With Codex BYOK, the meter isn't ours, so we can't pad it.

What you get free

With Codex BYOK, VibeKit's free tier is genuinely free — your ChatGPT subscription covers the AI, and everything else is included at no extra cost:

• Hosting. Every app runs on AWS Fargate at <name>.vibekit.bot, live and persistent.
• iOS app. Drive the Codex agent from your phone.
• Telegram bot. Chat the agent into building and shipping from anywhere.
• Agent runtime. The Codex coding agent, hosted and ready — no local setup.
• GitHub integration. Connect a repo and let the agent commit and push.
• Custom domains. Map your own domain to a hosted app.

API key instead? Use /byok-openai

This page is specifically about the ChatGPT subscription route via Codex OAuth. If you'd rather use a raw OpenAI API key (sk-…) and pay per token — for example because you want GPT-5 / GPT-4o through the API, or you don't have a ChatGPT subscription — that's the API-key path. See the OpenAI API key BYOK page → for that route.

Either way you're on a BYOK route with zero VibeKit markup. The difference is just subscription quota (this page) vs per-token API key (/byok-openai). For the full picture across Anthropic and OpenAI, see the BYOK hub →.

Token security

Your Codex OAuth token is encrypted at rest with AES-GCM, decrypted in memory only when a request fires, and never logged. It's scoped per-app — a token connected for one app isn't shared with another. You can revoke it at any time from Settings, and the next request switches over. Server-side, the only thing that ever sees the plaintext token is the proxy that forwards the model request to OpenAI. Tokens never appear in any chat transcript, log, or telemetry stream we keep.

No ChatGPT subscription?

You can still use the agent through VibeKit's platform fallback. It routes OpenAI, Anthropic, or DeepSeek via OpenRouter at list price plus a flat 20% platform markup, or the free tier on OpenRouter's pool at $0 — genuinely free, no key required. But if you already pay for ChatGPT Plus or Pro, Codex OAuth is the better deal: your subscription quota covers the AI and VibeKit stays free on top.

Setup

1. Profile → AI Provider
2. Tap "Sign in with ChatGPT" (Codex OAuth)
3. Pick Codex as the provider for an app
4. Send a message — the Codex agent runs on
   your ChatGPT subscription quota

Per-app: different apps can use different providers, so you can run Codex on one project and a BYOK key elsewhere. New to the wider BYOK setup? See the BYOK hub → or the OpenAI API key route →.

FAQ