| name | tavily-mcp-fix |
| description | Fix Tavily MCP "Client Not Registered" OAuth authentication errors. Use this skill when encountering OAuth failures, invalid client_id errors, or Tavily MCP tools failing to authenticate. Clears cached credentials and triggers fresh OAuth authentication flow. |
Fix Tavily MCP Authentication
When to Use
Use this skill when you encounter:
- "Client Not Registered" error on
mcp.tavily.com/authorize
- Invalid client_id in OAuth flow
- Tavily MCP tools failing to authenticate
- Cached credentials expired or invalidated
Quick Fix
Run the automated fix:
~/.agents/skills/tavily-mcp-fix/scripts/fix-tavily-mcp-auth.sh
Or run manually:
rm -rf ~/.mcp-auth/mcp-remote-*/
rm -rf ~/.cursor/plugins/tavily-cursor-plugin/;
rm -rf ~/.cursor/plugins/cache/cursor-public/tavily/;
npx mcp-remote https://mcp.tavily.com/mcp
Manual Steps
Step 1: Diagnose
Check for invalid cached credentials:
cat ~/.mcp-auth/mcp-remote-*/"*_client_info.json" 2>/dev/null | grep client_id
Step 2: Clear Cache
rm -rf ~/.mcp-auth/mcp-remote-*/
rm -rf ~/.cursor/plugins/tavily-cursor-plugin/
rm -rf ~/.cursor/plugins/cache/cursor-public/tavily/
find ~/.cursor/projects -name "*tavily*" -type d -exec rm -rf {} + 2>/dev/null
Step 3: Install mcp-remote (if needed)
npm install -g mcp-remote
Step 4: Trigger Re-authentication
npx mcp-remote https://mcp.tavily.com/mcp
Step 5: Verify
ls -la ~/.mcp-auth/mcp-remote-*/
cat ~/.mcp-auth/mcp-remote-*/"*_client_info.json" | grep client_id
tvly search "test" --json
Root Cause
Tavily MCP uses OAuth with PKCE. The client generates a client_id that must be registered with Tavily's auth server. The "Client Not Registered" error occurs when:
- Client credentials expire
- Tavily resets their client registry
- Cached credentials become corrupted
Verification Checklist
Common Issues
Browser doesn't open automatically
Manually open the URL shown in terminal.
Port 16735 already in use
Kill the process using that port or wait for the lockfile to expire.
Still getting "Client Not Registered"
rm -rf ~/.mcp-auth/
find ~ -name "mcp*.json" -delete 2>/dev/null
References
