Proxy configured with Github failing on callback

[pragmaticivan]

Version

Latest docker image.

URL:

http://localhost:8080/callback?code=REDACTED&state=REDACTED

Response:

{
  "error": "invalid_grant",
  "error_description": "Failed to exchange authorization code"
}

Logs:

mcp-auth-proxy-1  | 140.82.113.4 - - [17/Sep/2025:16:57:12 +0000] "POST / HTTP/1.1" 401 77
mcp-auth-proxy-1  | 140.82.113.4 - - [17/Sep/2025:16:57:12 +0000] "GET /.well-known/oauth-protected-resource HTTP/1.1" 200 134
mcp-auth-proxy-1  | 140.82.113.4 - - [17/Sep/2025:16:57:12 +0000] "GET /.well-known/oauth-authorization-server HTTP/1.1" 200 638
mcp-auth-proxy-1  | 140.82.113.4 - - [17/Sep/2025:16:57:15 +0000] "GET /authorize?client_id=REDACTED&response_type=code&code_challenge=REDACTED&code_challenge_method=S256&scope=email&resource=http%3A%2F%2Flocalhost%3A8080&redirect_uri=http%3A%2F%2F127.0.0.1%3A33418%2F&state=REDACTED%2BQQ%3D%3D HTTP/1.1" 302 288
mcp-auth-proxy-1  | 2025/09/17 16:57:21 Failed to exchange code for token: oauth2: cannot fetch token: 403 Forbidden
mcp-auth-proxy-1  | Response: Cookies must be enabled to use GitHub.

^ Testing with Copilot/VSCode

Also MCP_SERVER_URL="http://test-mcp:8000" is set. I tried to change this to http://test-mcp:8000/mcp but it fails to boot.