Local MCP Servers

Local MCP servers run on your machine, providing tools and capabilities without network latency or external dependencies.

📸 SCREENSHOT: local-mcp-config.png

Local MCP server configuration

Overview

Local MCP servers offer:

Zero network latency
Full data privacy
Offline operation
Custom tool integration
Direct system access

Configuration

Basic Setup

{
  "mcp": {
    "servers": {
      "my-tools": {
        "command": "node",
        "args": ["./mcp-server/index.js"]
      }
    }
  }
}

Project-Level Configuration

{
  "mcp": {
    "servers": {
      "project-tools": {
        "command": "python",
        "args": ["-m", "project_mcp"]
      }
    }
  }
}

Server Types

Node.js Servers

{
  "mcp": {
    "servers": {
      "node-tools": {
        "command": "npx",
        "args": ["-y", "@modelcontextprotocol/server-filesystem"]
      }
    }
  }
}

Python Servers

{
  "mcp": {
    "servers": {
      "python-tools": {
        "command": "python",
        "args": ["-m", "mcp_server"]
      }
    }
  }
}

Binary Executables

{
  "mcp": {
    "servers": {
      "binary-tools": {
        "command": "/usr/local/bin/mcp-scanner"
      }
    }
  }
}

Docker Containers

{
  "mcp": {
    "servers": {
      "docker-tools": {
        "command": "docker",
        "args": ["run", "-i", "--rm", "mcp-tools:latest"]
      }
    }
  }
}

Environment Variables

Pass to Server

{
  "mcp": {
    "servers": {
      "api-tools": {
        "command": "node",
        "args": ["server.js"],
        "env": {
          "API_KEY": "{env:MY_API_KEY}",
          "DEBUG": "true"
        }
      }
    }
  }
}

Inherit Environment

{
  "mcp": {
    "servers": {
      "tools": {
        "command": "python",
        "args": ["server.py"],
        "inheritEnv": true
      }
    }
  }
}

Working Directory

Set Working Directory

{
  "mcp": {
    "servers": {
      "project-tools": {
        "command": "node",
        "args": ["server.js"],
        "cwd": "/path/to/project"
      }
    }
  }
}

Relative Paths

{
  "mcp": {
    "servers": {
      "local-tools": {
        "command": "./scripts/mcp-server.sh"
      }
    }
  }
}

Popular Local Servers

Filesystem Server

Access files and directories:

{
  "mcp": {
    "servers": {
      "filesystem": {
        "command": "npx",
        "args": ["-y", "@modelcontextprotocol/server-filesystem", "/path/to/allow"]
      }
    }
  }
}

SQLite Server

Query local databases:

{
  "mcp": {
    "servers": {
      "sqlite": {
        "command": "npx",
        "args": ["-y", "@modelcontextprotocol/server-sqlite", "--db", "data.db"]
      }
    }
  }
}

Git Server

Git operations:

{
  "mcp": {
    "servers": {
      "git": {
        "command": "npx",
        "args": ["-y", "@modelcontextprotocol/server-git"]
      }
    }
  }
}

Server Lifecycle

Startup

Servers start when:

Cyberstrike launches (if configured)
First tool from server is used (lazy start)

Auto-Start

{
  "mcp": {
    "servers": {
      "tools": {
        "command": "node",
        "args": ["server.js"],
        "autoStart": true
      }
    }
  }
}

Lazy Start

{
  "mcp": {
    "servers": {
      "tools": {
        "command": "node",
        "args": ["server.js"],
        "autoStart": false
      }
    }
  }
}

Restart on Failure

{
  "mcp": {
    "servers": {
      "tools": {
        "command": "node",
        "args": ["server.js"],
        "restart": {
          "enabled": true,
          "maxRetries": 3,
          "delay": 1000
        }
      }
    }
  }
}

Health Checks

Timeout Configuration

{
  "mcp": {
    "servers": {
      "tools": {
        "command": "node",
        "args": ["server.js"],
        "timeout": 30000
      }
    }
  }
}

Connection Verification

> Check MCP server status

Output:

MCP Server Status:
- my-tools: connected (5 tools)
- filesystem: connected (3 tools)
- sqlite: disconnected (starting...)

Resource Limits

Memory Limits

{
  "mcp": {
    "servers": {
      "tools": {
        "command": "node",
        "args": ["--max-old-space-size=512", "server.js"]
      }
    }
  }
}

CPU Priority

{
  "mcp": {
    "servers": {
      "tools": {
        "command": "nice",
        "args": ["-n", "10", "node", "server.js"]
      }
    }
  }
}

Security Considerations

Sandboxing

{
  "mcp": {
    "servers": {
      "untrusted": {
        "command": "docker",
        "args": ["run", "--rm", "-i", "--network=none", "mcp-server"]
      }
    }
  }
}

Permission Restrictions

{
  "mcp": {
    "servers": {
      "readonly": {
        "command": "node",
        "args": ["server.js"],
        "permissions": {
          "filesystem": "read",
          "network": false
        }
      }
    }
  }
}

Debugging

Enable Logging

{
  "mcp": {
    "servers": {
      "tools": {
        "command": "node",
        "args": ["server.js"],
        "env": {
          "DEBUG": "mcp:*"
        }
      }
    }
  }
}

View Logs

# Server logs location
tail -f ~/.cyberstrike/logs/mcp-my-tools.log

Manual Testing

# Test server directly
echo '{"jsonrpc":"2.0","method":"tools/list","id":1}' | node server.js

Troubleshooting

Server Not Starting

Error: Failed to start MCP server: my-tools

Check:

Command exists and is executable
Working directory is correct
Dependencies are installed

Connection Timeout

Error: MCP server connection timeout

Solutions:

Increase timeout value
Check server startup time
Verify server is responding

Tool Not Found

Error: Tool not found: my-tools/scanner

Verify:

Server is running
Tool is exported by server
Tool name is correct

Tip

Use lazy start for servers with slow startup times to avoid slowing down Cyberstrike launch.

MCP Overview - MCP basics
Remote Servers - Remote MCP
Creating Servers - Build custom servers