authenticate

name	authenticate
description	Authenticate Gmail and Google Calendar MCP servers. Use after first install, after codespace rebuild, or when MCP authentication fails. Runs OAuth flow for both Gmail and Calendar services.

Google Workspace Authentication

Authenticate the Gmail and Google Calendar MCP servers via OAuth 2.0.

Prerequisites

1. A Google Cloud Platform project with a Desktop-type OAuth 2.0 Client ID
2. Download the OAuth JSON and place it in BOTH locations:
   • ~/.gmail-mcp/gcp-oauth.keys.json
   • ~/.calendar-mcp/gcp-oauth.keys.json
3. Enable these APIs in the GCP project:
   • Gmail API
   • Google Calendar API
   • People API (for contact lookup)

Procedure

1. Verify OAuth keys exist:

   ls ~/.gmail-mcp/gcp-oauth.keys.json ~/.calendar-mcp/gcp-oauth.keys.json
   

2. Create config directories if missing:

   mkdir -p ~/.gmail-mcp ~/.calendar-mcp
   

3. Authenticate Gmail server (opens browser for OAuth consent):

   node ${CLAUDE_PLUGIN_ROOT}/servers/gmail/index.js auth
   

4. Authenticate Calendar server:

   node ${CLAUDE_PLUGIN_ROOT}/servers/calendar/index.js auth
   

5. Verify credentials were created:

   ls ~/.gmail-mcp/credentials.json ~/.calendar-mcp/credentials.json
   

6. Test connectivity by running /mcp to reconnect both servers.

7. Report success/failure to user.

Troubleshooting

• Port 3000 conflict: lsof -ti:3000 | xargs kill -9 then retry
• Browser doesn't open: Copy the auth URL from terminal output manually
• People API error: Ensure People API is enabled in GCP console
• Token expired: Re-run this authentication flow. Tokens auto-refresh during normal use but may expire after prolonged inactivity.