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Troubleshooting

Common problems and how to fix them.

AI client shows no tools​

Symptoms: You connected your client, but asking "what tools do you have?" returns nothing or says "no tools available."

Check these in order:

  1. Did you authorize? When you first connected, a browser window should have opened asking you to confirm. If you closed it without clicking Authorize, the connection was never authenticated. Re-connect and complete the authorization.

  2. Is the MCP server enabled? In Willow, click MCP Servers. If the server you want is showing Enable (not Disable), it's been deactivated. Click Enable.

  3. Did you restart your client? Many AI clients (especially Cursor) need a full restart to pick up new MCP configurations. Close and reopen your client.

  4. Is the URL correct? In your client's config, check the URL matches what Willow showed you. A typo in the organization name or server name will cause a silent failure.

"Unauthorized" or 401 error​

Your session has expired or the authorization was never completed.

Fix: Disconnect and reconnect from scratch. In the Connect MCP modal, copy a fresh URL and add it to your client again. When the auth prompt appears, click Authorize.

Connection refused / can't reach server​

Fix:

  1. Verify your internet connection
  2. Check that the URL uses https:// (not http://)
  3. Confirm with your admin that your gateway domain is deployed and active

Cursor: tools don't appear after configuration​

This is usually caused by a missing "type": "http" field in the config file.

Open ~/.cursor/mcp.json and verify your entry looks like this:

{
  "mcpServers": {
    "willow": {
      "type": "http",
      "url": "https://yourorg.mcp-s.com/mcp?mcp=servername"
    }
  }
}

The "type": "http" field is required. Cursor silently ignores entries that are missing it.

Claude Code: MCP server shows as disconnected​

Run /mcp in a Claude Code session to see the status of connected MCP servers. If Willow shows as "disconnected," re-run the add command:

claude mcp add --transport http willow https://yourorg.mcp-s.com/mcp

404 error on localhost during MCP authentication​

When setting up an MCP server in your AI client, the browser shows a 404 error on localhost after you complete authentication.

Fix:

  1. Go back to your AI client
  2. Trigger re-authentication (restart the session, or re-run the MCP setup flow)
  3. Try again. The connection usually succeeds after 1–2 retry attempts

Something else is wrong​

Check the FAQ for more common questions, or contact support.

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