Supabase MCP OAuth reconnection fails: 'OAuth authorization request does not exist'

Description

After the Supabase MCP OAuth token was revoked (possibly during the Mar 25 claude.ai outage), reconnecting Supabase MCP consistently fails with:

Failed to fetch details for API authorization request Please retry your authorization request from the requesting app Error: OAuth authorization request does not exist

Steps to reproduce

1. Supabase MCP was previously connected and working
2. OAuth token got revoked (unclear if due to expiry or the Mar 25 outage)
3. Go to Claude Code settings → Integrations → Supabase → "..." → Disconnect
4. Click "Configure" to reconnect
5. Supabase authorization page opens → click "Authorize Claude"
6. Supabase side succeeds — receive "OAuth Application Approval" email confirming access was granted
7. Claude side fails — redirects to error page with "OAuth authorization request does not exist"

Key observation

Supabase successfully processes the authorization (confirmed via email notification), but Claude's server fails to match it back to the original authorization request. This suggests the issue is on Claude/Anthropic's side — the OAuth state/request is not being persisted or retrieved correctly.

Environment

• Claude Code VS Code extension
• Claude Opus 4.6 (1M context)
• macOS (Darwin 25.3.0)
• Supabase project region: ap-southeast-1

Timeline

• Mar 25, 15:04 UTC — claude.ai status page reported "Elevated errors on Claude Opus 4.6" and "Elevated connection reset errors in Cowork" (Major Outage)
• Mar 25 — Supabase MCP stopped working with "OAuth token has been revoked"
• Mar 26 — Multiple reconnection attempts all fail with the same error, despite Supabase confirming authorization each time

Expected behavior

Disconnecting and reconnecting Supabase MCP should start a fresh OAuth flow and restore the integration.

Workaround

Querying Supabase directly via the service role key + @supabase/supabase-js in a Node script works fine. Only the MCP OAuth integration is broken.