Cursor MCP Not Working

Config file location in Cursor

Cursor MCP uses a different config file from Claude Desktop. There are two locations:

• Global (all projects): ~/.cursor/mcp.json
• Project-level (one project): .cursor/mcp.json in your project root

The project-level config takes precedence over the global one. If you have both, Cursor will use the project config for that project and ignore the global one.

Create the global config if it does not exist:

# macOS/Linux
mkdir -p ~/.cursor
touch ~/.cursor/mcp.json

# Windows
New-Item -ItemType Directory -Force "$env:USERPROFILE\.cursor"
New-Item -ItemType File "$env:USERPROFILE\.cursor\mcp.json"

Correct config format

Cursor's mcp.json uses the same mcpServers format as Claude Desktop:

{
  "mcpServers": {
    "filesystem": {
      "command": "/usr/local/bin/npx",
      "args": ["-y", "@modelcontextprotocol/server-filesystem", "/Users/you/projects"]
    },
    "github": {
      "command": "/usr/local/bin/npx",
      "args": ["-y", "@modelcontextprotocol/server-github"],
      "env": {
        "GITHUB_PERSONAL_ACCESS_TOKEN": "ghp_yourtoken"
      }
    }
  }
}

Tools not showing up in Cursor

Work through this checklist:

1. Confirm the config file path

# Check if global config exists and has content
cat ~/.cursor/mcp.json

# Check if project config exists
cat .cursor/mcp.json

2. Validate the JSON

# macOS/Linux
cat ~/.cursor/mcp.json | python3 -m json.tool

# Windows
Get-Content "$env:USERPROFILE\.cursor\mcp.json" | ConvertFrom-Json

3. Use absolute paths

Replace bare npx or uvx with the full path from which npx.

4. Check Cursor version

MCP support in Cursor has improved significantly over time. Open Cursor → Help → About and confirm you are on a recent version. Versions from mid-2024 onwards have more reliable MCP support.

5. Enable MCP in Cursor settings

In some Cursor versions, MCP must be enabled in settings. Open Cursor Settings (Cmd+, / Ctrl+,) and search for "MCP" — confirm it is toggled on.

How to reload MCP in Cursor

After editing mcp.json, Cursor may not auto-detect the change. Options:

1. Open the Cursor MCP settings panel (Settings → search "MCP") and click the reload/refresh button if available
2. Use the command palette (Cmd+Shift+P / Ctrl+Shift+P) and search for "MCP" to find reload options
3. Fully restart Cursor: close all windows and reopen

Debugging Cursor MCP errors

Cursor logs MCP server output. To find them:

• Open the Output panel: View → Output (or Cmd+Shift+U)
• In the dropdown, look for "MCP" or the server name
• Check for the same error patterns: spawn ENOENT, tracebacks, 401/403 errors

You can also run the server command directly in Cursor's integrated terminal to see its output without any MCP layer:

/usr/local/bin/npx -y @modelcontextprotocol/server-filesystem /Users/you/projects

If it errors there, fix the error. If it runs fine, the issue is in how Cursor is invoking it (path, env, args).

Cursor vs Claude Desktop MCP differences

• Config file path: Cursor uses ~/.cursor/mcp.json; Claude Desktop uses ~/Library/Application Support/Claude/claude_desktop_config.json
• Project-level config: Cursor supports per-project .cursor/mcp.json; Claude Desktop has only a global config
• Log location: Cursor logs are in the Output panel; Claude Desktop logs are in ~/Library/Logs/Claude/
• Reload mechanism: Cursor has an in-IDE reload; Claude Desktop requires a full quit and restart
• Server format: the mcpServers entry format is identical between the two

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