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mcp/harbor
Cursor

MCP Sidecar for Cursor

io.github.lsequeiraa/mcp-sidecar

Cross-platform MCP server for managing long-lived background processes from any MCP client

client:Cursor transport:stdio runtime:npm

Install MCP Sidecar in Cursor

~/.cursor/mcp.json · windows: %USERPROFILE%\.cursor\mcp.json

Held in this page only — never stored, logged, or sent anywhere but back to your screen. 

{
  "mcpServers": {
    "mcp-sidecar": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "mcp-sidecar"
      ],
      "env": {
        "SIDECAR_MAX_PROCESSES": "<SIDECAR_MAX_PROCESSES>",
        "SIDECAR_BUFFER_SIZE": "<SIDECAR_BUFFER_SIZE>",
        "SIDECAR_KILL_TIMEOUT": "<SIDECAR_KILL_TIMEOUT>",
        "SIDECAR_CLEANUP_AFTER": "<SIDECAR_CLEANUP_AFTER>",
        "SIDECAR_MAX_OUTPUT_SIZE": "<SIDECAR_MAX_OUTPUT_SIZE>",
        "SIDECAR_ALLOWED_EXECUTABLES": "<SIDECAR_ALLOWED_EXECUTABLES>",
        "SIDECAR_BLOCKED_PATTERNS": "<SIDECAR_BLOCKED_PATTERNS>",
        "SIDECAR_AUDIT_LOG": "<SIDECAR_AUDIT_LOG>"
      }
    }
  }
}

Use .cursor/mcp.json in a project root instead to scope it to that project. Cursor merges both. Cursor docs

MCP Sidecar in other clients

MCP Sidecar MCP server