Troubleshooting

Sign-in fails with "not an approved MCP client callback URL"

{"error": "invalid_redirect_uri", "error_description": "The redirect_uri `…` is not an approved MCP client callback URL."}

Your client asked Whippy to send the sign-in result to a callback that isn't on the allow-list. Whippy accepts Claude, ChatGPT, Cursor, Devin, Grok, VS Code, Windsurf, and http://localhost:8787/callback (see How sign-in works).

• Claude Code: add the server with --callback-port 8787. See Connect Claude Code.
• Other local clients: configure the OAuth callback as exactly http://localhost:8787/callback if the client allows it.
• Clients that can't change their callback aren't supported yet. Contact [email protected] with the client's name and the callback URL from the error.

The client says it needs an API key or header

Don't add an Authorization or X-WHIPPY-KEY header. Remove any header you added, then reconnect so the client starts the OAuth sign-in. API keys are rejected on /mcp with 401.

401 Unauthorized after it was working

The token was revoked or has expired and couldn't be refreshed. This happens after you disconnect the app in Connected apps, when your user is disabled, or if the client lost its refresh token. Reconnect or re-authenticate the server in your client.

"You do not belong to the selected workspace"

You picked a workspace you are not a member of, or your access was removed. Sign in again and pick a workspace you belong to.

"Token does not have the required scope for this action"

The token is missing the scope this tool needs. Usually the client requested no scopes. Disconnect the app in Connected apps and sign in again. If it keeps happening, see OAuth scopes.

403 or "permission" errors on a tool

Your Whippy role doesn't allow that action. The assistant has exactly your permissions. Ask a workspace admin to update your role, or have someone with access do it.

429 Too Many Requests

You went over 10 requests per second for your user in this workspace. Wait a second and retry. See Rate limits.

The assistant can't see some tools, or warns about too many tools

Your client caps how many tools it loads. See Tool limits.

The assistant works in the wrong workspace

Each connection is tied to the workspace you picked at sign-in. Disconnect the app and sign in again, choosing the right workspace. To use two workspaces, add the server twice under different names.

Still stuck

Email [email protected] with your client name and version, the time of the failure, and the exact error text.