Cursor MCP Server Not Connecting
Quick Answer
Missing or malformed .cursor/mcp.json file, or Node.js version too old for the MCP server. Start with "Check .cursor/mcp.json" before making broader code changes.
You're in the right place if...
- !MCP tools not appearing in Cursor
- !Connection error in MCP settings
- !Timeout when trying to use MCP
Why this happens
Missing or malformed .cursor/mcp.json file, or Node.js version too old for the MCP server.
Fix
Check .cursor/mcp.json
Verify the file exists and is valid JSON:
{
"mcpServers": {
"supabase": {
"command": "npx",
"args": [
"-y",
"@supabase/mcp-server-supabase@latest",
"--supabase-url", "YOUR_URL",
"--supabase-key", "YOUR_KEY"
]
}
}
}Refresh MCP
Cursor Settings → MCP → click the refresh button. If still failing, check that Node.js 18+ is installed.
Prevent this next time
Test MCP connections immediately after setup. Don't wait until you need them.
Frequently Asked Questions
Model Context Protocol. It lets Cursor connect to external tools like Supabase, GitHub, or databases directly.
Not required, but very useful. MCP lets Cursor read your actual database schema instead of guessing.
Related fixes
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