VibeKit
Enter App
BYOK in AI Coding Tools
Almost every AI coding tool takes a bring-your-own-key (BYOK) now — Codex, Claude Code, Cursor, and GitHub Copilot all let you plug in your own OpenAI or Anthropic key. So the real question isn't who supports BYOK, it's what BYOK actually saves you: is there a markup on your key, do you still pay a seat, and does anyone host the app for you? Here's the 2026 lay of the land.
BYOK support, side by side (2026)
| Tool | BYOK? | Keys you can bring | Markup on your key | Seat on top | Hosts the app? |
|---|---|---|---|---|---|
| OpenAI Codex (CLI) | Yes | OpenAI API key, or ChatGPT Plus/Pro via OAuth | None | No (uses your OpenAI/ChatGPT plan) | No — local |
| Claude Code (CLI) | Yes | Anthropic API key, or Claude Pro/Max | None | No (uses your Anthropic plan) | No — local |
| Cursor | Yes | OpenAI, Anthropic, Google | None | ~$20/mo seat still applies | No — editor |
| GitHub Copilot | Yes (2026) | OpenAI, Anthropic, Azure, Bedrock, Google, xAI, Ollama… | None | Copilot seat still applies | No — editor |
| VibeKit | Yes | Anthropic, OpenAI, or ChatGPT via Codex OAuth | Zero markup | None — free tier | Yes — <name>.vibekit.bot |
Replit and Perplexity are omitted from the table on purpose — see the note below. Details change fast; each tool's own docs are the source of truth.
What BYOK actually saves you
The reason to bring your own key is cost and control. Without BYOK, a tool buys tokens wholesale and resells them to you — bundled into a subscription or marked up per message. With BYOK, your model calls bill straight to OpenAI or Anthropic at list price, on your own account, and you see exactly what each task cost on the provider's own dashboard. No middle meter.
But "supports BYOK" hides two very different deals:
- BYOK that removes the whole bill. The local CLIs (Codex, Claude Code) and VibeKit never sit in the billing path — your provider is the only thing you pay. VibeKit adds a genuinely free tier and hosting on top, so your key is the only bill.
- BYOK that only swaps the model. Cursor and Copilot let you bring a key so calls run on your account, but you still pay their monthly seat. BYOK there is about control and picking your model — not about paying less overall.
Per tool
Codex BYOK
The Codex CLI takes BYOK two ways: an OpenAI API key (sk-… / sk-proj-…) billed to your account, or a ChatGPT Plus/Pro subscription via OAuth that runs against the quota you already pay for. It's a local tool, so you supply the machine and there's no hosting. Want the same Codex BYOK on a hosted agent you drive from your phone? See Codex BYOK on VibeKit and the OpenAI key format.
Claude Code BYOK
Claude Code runs on your Anthropic API key (sk-ant-api03-…) or your Claude Pro/Max subscription — the bill is between you and Anthropic. Also local, also no hosting. The hosted-agent equivalent is Claude BYOK on VibeKit; new to the key shape, see the sk-ant-api03 format.
Cursor BYOK
Cursor lets you add your own OpenAI, Anthropic, or Google key and bypass its bundled model pool, so calls bill to your provider. The ~$20/mo seat still applies, and some agentic features route through Cursor's backend — so BYOK removes the model markup, not the subscription.
GitHub Copilot BYOK
New in 2026: in VS Code, add a provider under Settings → Model Providers with your own key — OpenAI, Anthropic, Azure OpenAI, Microsoft Foundry, AWS Bedrock, Google, xAI, Ollama, or any OpenAI-compatible endpoint — and its models show up in the picker next to Copilot's. Keys live in the OS keychain. Your Copilot subscription still applies; BYOK changes which model answers, not the seat.
Replit & Perplexity
Both come up in BYOK searches, but neither is really a bring-your-own-key coding tool. Replit's AI runs on its own model access and credits; Perplexity is an answer engine with its own API. As of this writing, neither offers a first-class path to bring your own Claude/OpenAI key into their product the way the tools above do. Treat their docs as the live source — this space moves monthly.
Where VibeKit fits
VibeKit is the BYOK option that's also hosted and free. Bring your Anthropic or OpenAI key — or sign in with ChatGPT via Codex OAuth — and the model bill goes straight to the provider at zero markup. Everything around it is included at no cost: the persistent agent, hosting at <name>.vibekit.bot, the iOS app, GitHub, custom domains. No seat, no per-message markup — your provider key is the only thing you pay, and if you have no key at all, the free-model pool runs at $0.
- Zero markup on your OpenAI/Anthropic key — VibeKit is never in the billing path.
- Hosted, not local — the agent keeps working (and keeps your app live) when your laptop's off.
- Free tier — hosting, iOS, GitHub, domains included; bring a key or run the $0 pool.
- Per-app keys — different apps can use different keys, encrypted at rest, revocable any time.
FAQ
Does OpenAI Codex support BYOK?
Yes. The Codex CLI runs two BYOK ways: paste an OpenAI API key (sk-… / sk-proj-…) and OpenAI bills your account directly, or sign in with a ChatGPT Plus / Pro subscription via OAuth and Codex runs against that quota with no per-token charge on top. Codex is a local CLI, so there's no hosting — you run it on your own machine. VibeKit exposes the same Codex BYOK (API key or ChatGPT OAuth) but on a hosted agent you drive from your phone or CLI.
Does Claude Code support bring your own key?
Yes. Claude Code uses your own Anthropic API key (sk-ant-api03-…) or your Claude Pro / Max subscription — the token bill or quota is between you and Anthropic. Like Codex it's a local tool with no hosting. If you want that same Anthropic BYOK on a persistent hosted agent, that's VibeKit's Claude BYOK path.
Does Cursor support BYOK?
Yes — Cursor lets you add your own OpenAI, Anthropic, or Google API key and bypass its included model pool, so model calls bill to your provider account. The catch is that the Cursor seat (about $20/mo) still applies on top, and some agentic features route through Cursor's backend. So BYOK removes the model markup but not the subscription.
Does GitHub Copilot support BYOK?
Yes, as of 2026. In VS Code you add a provider under Settings → Model Providers with your own key — OpenAI, Anthropic, Azure OpenAI, Microsoft Foundry, AWS Bedrock, Google, xAI, Ollama, or any OpenAI-compatible endpoint — and those models appear in the picker alongside Copilot's. Keys sit in the OS keychain. As with Cursor, your Copilot subscription still applies; BYOK changes which model runs, not the seat.
What about Replit and Perplexity BYOK?
Both center on their own hosted models rather than your key. Replit's AI features run on Replit's own model access and credits, and Perplexity is an answer engine with its own API — neither offers a first-class path to bring your own Claude or OpenAI key into their coding/agent product the way Codex, Claude Code, Cursor, Copilot, or VibeKit do, as of this writing. Check their current docs, since this space moves fast.
Which AI coding tool adds no markup to your own API key?
The tools that never sit in the billing path add no markup: Codex and Claude Code (local CLIs) and VibeKit (hosted) all send your model calls straight to OpenAI or Anthropic on your own key, so you pay provider list price and nothing on top. Cursor and Copilot also don't mark up your key, but they still charge a monthly seat. VibeKit is the one that combines zero markup with hosting and a genuinely free tier, so on BYOK your provider bill is the only bill.
Is there a free BYOK AI coding tool?
VibeKit is free on BYOK: bring your own Anthropic or OpenAI key (or a ChatGPT subscription via Codex OAuth) and hosting, the iOS app, GitHub integration, custom domains, and the agent runtime are all included at no cost — you only pay your model provider. There's also a $0 free-model pool if you have no key at all. Local CLIs like Codex and Claude Code are free to run but you supply your own machine and they don't host the app for you.