AI connections (MCP)

How it works

/mcp speaks the Model Context Protocol over HTTP. Sign-in uses the Supabase OAuth 2.1 server: an app registers, sends the host to /oauth/consent, and receives a token that Supabase signs with a client_id claim. The database treats any token with that claim as an app token and applies stricter policies and daily ceilings.

Request path

1. The proxy lets /mcp and /.well-known/* through without a cookie round trip (the endpoint uses a bearer token).
2. The route checks the Origin header, then the token, then a per-host rate limit (60 per minute, fails closed).
3. A tool runs through the app's own server code with the host's identity, so Row Level Security still applies.
4. Proposals are written as ai_proposals; the host decides in the app.

Database ceilings for app tokens

Charged in the database so they hold even for a token pointed straight at the API: 10 celebrations a day, 500 guests a day, 50 proposals a day and 20 waiting at once. A first-party session (no client_id) is never charged and cannot insert a proposal at all.

Logging and diagnostics

Activity is written to ai_activity_log. Diagnostic codes explain refusals (for example not an owner or planner, archived event, over a limit). Settings per connection live in ai_connection_settings; usage in ai_quota_usage.

Supabase dashboard steps

1. Authentication → OAuth Server: enable the OAuth server.
2. Set the Authorization Path to /oauth/consent.
3. Allow dynamic client registration (Claude.ai and ChatGPT register themselves; without it they cannot connect).
4. Confirm the Site URL matches NEXT_PUBLIC_APP_URL, which the protected-resource metadata is derived from.
5. Check curl -s <app>/.well-known/oauth-protected-resource returns the metadata and curl -i <app>/mcp returns 401 with a Bearer challenge.

Revoking

A host disconnects an app from Connect your AI. This invalidates its tokens and stops new proposals. Undo of an already-applied proposal is available for 7 days from the approvals desk.