'Invalid origin' error when attempting to verify setup

[capellini]

OS: Fedora 41
Browser: Chrome (Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/137.0.0.0 Safari/537.36)
Node: v22.16.0 (npm v10.9.2)

When I attempt to verify my setup using the instructions provided, after running npm start, the MCP server and client seem to start ok:

[05.02.solution:7042] Starting MCP inspector...
[05.02.solution:7042]
[05.02.solution:7042] ⚙️ Proxy server listening on 127.0.0.1:10000
[05.02.solution:7042]
[05.02.solution:7042] 🔑 Session token: ...
[05.02.solution:7042] Use this token to authenticate requests or set DANGEROUSLY_OMIT_AUTH=true to disable auth
[05.02.solution:7042]
[05.02.solution:7042] 🔗 Open inspector with token pre-filled:
[05.02.solution:7042]    http://localhost:9000/?MCP_PROXY_AUTH_TOKEN=...
[05.02.solution:7042]    (Auto-open is disabled when authentication is enabled)
[05.02.solution:7042]
[05.02.solution:7042]
[05.02.solution:7042] 🐨 Proxy server running: http://localhost:7042
[05.02.solution:7042]
[05.02.solution:7042] - Client port: 9000
[05.02.solution:7042] - Server port: 10000

However, I cannot connect to the MCP server via the window provided in the final exercise. The logs printed on the console have this line, indicating that the proxy server's origin is not allowed:

[05.02.solution:7042] Invalid origin: http://localhost:7042

It looks like the origins allowed by the MCP server are only the MCP client's origin (no sign of the proxy server's port 7042):

allowedOrigins [ 'http://localhost:9000', 'http://127.0.0.1:9000' ]

If I open another tab and navigate to the MCP playground on port 9000, everything works, as expected.

[kentcdodds]

Thank you so much for reporting this! There was a change in the inspector I missed. I've fixed it now. Please let me know if it's not fixed for you.