* fix(oauth): client_credentials tokens rejected by MCP bearer auth
Three bugs found in production when connecting Claude Code via Tailscale:
1. Token validation fails with 'Token has no expiration time'
- Root cause: postgres driver with prepare:false returns expires_at as
string, but MCP SDK's bearerAuth middleware checks typeof === 'number'
- Fix: Number(row.expires_at) in verifyAccessToken
2. OAuth metadata missing client_credentials grant type
- Root cause: MCP SDK hardcodes ['authorization_code', 'refresh_token']
in mcpAuthRouter's .well-known endpoint
- Fix: middleware intercepts metadata response and appends
'client_credentials' before it reaches the client
- Claude Code's native OAuth auto-discovery now finds the CC flow
3. Express 5 compatibility fixes
- trust proxy: 'loopback' for reverse proxy deployments (Caddy/Tailscale)
without this, express-rate-limit throws ERR_ERL_UNEXPECTED_X_FORWARDED_FOR
- /admin/* wildcard → /admin/{*path} (Express 5 named param syntax)
* test(oauth): add regression tests for v0.26.1 fixes
Unit test (oauth.test.ts):
- expiresAt is always a number, not string — SDK bearerAuth compat
Integration tests (serve-http-oauth.test.ts, 7 cases):
- client_credentials token accepted at /mcp (the actual regression)
- token expires_in matches server TTL
- OAuth metadata includes client_credentials grant type
- token endpoint discoverable from metadata
- admin dashboard serves SPA (Express 5 wildcard fix)
- X-Forwarded-For doesn't crash rate limiter (trust proxy fix)
- read-only token cannot call write operations (scope enforcement)
42 tests, 0 failures, 172 assertions.
* test(e2e): full E2E suite for serve-http OAuth 2.1 (15 cases)
Spins up a real gbrain serve --http against real Postgres, registers an
OAuth client, mints tokens via client_credentials, and exercises the full
MCP JSON-RPC pipeline end-to-end.
E2E cases (test/e2e/serve-http-oauth.test.ts):
- mint token via client_credentials grant
- minted token accepted at /mcp — tools/list returns tools
- minted token works for tools/call — search executes
- expired/invalid token rejected at /mcp
- missing Authorization header returns 401
- OAuth metadata includes all three grant types
- OAuth metadata issuer matches public URL
- admin dashboard serves SPA (Express 5 wildcard fix)
- admin sub-routes serve SPA fallback
- X-Forwarded-For doesn't crash rate limiter
- read-only token rejected for write operations
- write-scoped token can call read operations
- health endpoint works without auth
- multiple tokens work independently
- wrong client_secret rejected at token endpoint
Unit test addition (test/oauth.test.ts):
- expiresAt is always typeof number (SDK bearerAuth compat)
Total: 50 tests, 0 failures, 201 assertions.
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Co-authored-by: Wintermute <wintermute@garrytan.com>
