Support ChatGPT subscription (Codex OAuth) as a model provider — pi-ai already ships the client

[kei-tenkawa]

The "Add Model" flow currently requires an API key for every provider. Many users already pay for a ChatGPT subscription, and OpenAI now openly tolerates third-party use of Codex OAuth (they open-sourced a plugin calling Codex from Claude Code, and enabled OAuth for OpenClaw). Platforms like exe.dev already offer "connect your ChatGPT subscription" as a first-class model source.

Notably, @earendil-works/pi-ai 0.83.0 — already vendored here — ships everything needed: api/openai-codex-responses (speaks to chatgpt.com/backend-api, WebSocket + SSE fallback, auth via access token + chatgpt-account-id) and the openai-codex model catalog. The wiring in ai-models.ts (API_STREAMS / catalogModel / a direct-path handle) looks thin.

The design questions would be: (1) the "Sign in with ChatGPT" OAuth flow and refresh-token custody — presumably a DO, following the same pattern as the Cloudflare gatekeeper's OAuth; (2) subscription traffic bypassing AI Gateway cost accounting.

Would love to see this in-tree someday!

[manojitballav]

Would this design be generalized for other subscription providers ?