Skip to main content
If you already pay for Claude Max, a ChatGPT plan that includes Codex, Google Antigravity, or xAI Grok, you can point CORE at your subscription instead of buying separate API credits. The CoreBrain Gateway ships a subscription proxy that exposes an OpenAI-compatible API and translates to each provider under the hood.
Subscription plans are licensed for interactive use. Providers can rate-limit or revoke tokens if they detect headless usage. Fine for personal self-host; risky if you’re serving other users. When in doubt, use real API keys.

​
Four steps

​
1. Deploy the gateway

The LLM proxy ships with the container image, so pick one of the container deployments: Both paths end with a Base URL and a gwk_... security key. Keep both handy — you’ll paste them into the UI in step 2 and reuse the same security key as the BYOK API key in step 4.

​
2. Add the gateway in the UI

In the CORE webapp: Sidebar → Gateways → + New gateway. Pick the deployment kind you used in step 1 (Docker or Railway), then paste the URL and security key.

​
3. Log in to your subscription

Pick the gateway you just added when prompted. Follow the printed OAuth URL — for Claude / Codex / Antigravity the browser redirect is caught automatically; for xAI you’ll type a short device code shown in the terminal. Repeat with --login codex, --login antigravity, or --login xai for other providers.

​
4. Wire it into CORE

In the webapp: Settings → Models → + New API key. Choose OpenAI and fill in:
  • Base URL — https://<your-gateway-host>/llmproxy/v1
  • API key — the same security key from step 1
Then pick a model with the openai/ prefix. Examples: Get the exact list of available models by hitting the proxy’s model endpoint:

​
When a token expires

Just re-run the same login command:
The proxy auto-rotates access tokens as long as the refresh token stays valid; when it doesn’t, re-login. Tokens live on the gateway’s persistent volume, so container restarts never blow them away.

​
Under the hood

The gateway embeds CLIProxyAPI, which handles the OAuth flow for each subscription and re-shapes the requests into each provider’s native protocol behind a single OpenAI-compatible surface at /llmproxy/v1. That’s why one Base URL + one API key covers Claude, Codex, Antigravity, and xAI. Other proxies exposing the same OpenAI-compatible shape work with the same wire-up if you’d rather run them yourself:
  • Vercel AI Gateway — first-party pass-through for Claude Max via ANTHROPIC_BASE_URL. No self-hosting.
  • ai-cli-proxy-api — variant that supports Factory and Amp CLIs alongside ChatGPT Plus/Pro and Claude Pro/Max.