KingBuilds MCP Server

Production-ready reference MCP server with 4 tools:

• file_ops — Sandboxed file read/write/list within allowed directory

• web_scraper — Clean HTML extraction (title, text, links, CSS selectors)

• data_transform — JSON↔CSV conversion + aggregation (sum/avg/count/min/max/filter/sort)

• http_request — Authenticated HTTP requests with SSRF protection

Quickstart

# Install
pip install -e .

# Run stdio transport (for Claude Desktop)
mcp-server-stdio

# Run HTTP/SSE server
mcp-server-http

Related MCP server: Enhanced Fetch MCP

Configuration

Environment variables:

• ALLOWED_DIR — Sandbox directory for file operations (default: ./data)

• MCP_TRANSPORT — stdio or streamable-http (default: streamable-http)

• MCP_HOST — Host to bind (default: 0.0.0.0)

• MCP_PORT — Port for HTTP transport (default: 8080)

• MAX_FILE_BYTES — Max file size for read/write (default: 1048576)

• REQUEST_TIMEOUT — HTTP request timeout seconds (default: 30)

Tools

file_ops

• read_file(path: str) — Read UTF-8 text file

• write_file(path: str, content: str, overwrite: bool) — Write file

• list_directory(path: str) — List directory contents

web_scraper

• fetch_page(url: str, selector: str = None) — Fetch and extract HTML content

data_transform

• transform_data(data: list, operation: str, **kwargs) — Transform data

http_request

• http_request(method: str, url: str, headers: dict, body: dict, auth: dict) — Make HTTP requests

Claude Desktop Config

{
  "mcpServers": {
    "kingbuilds-mcp": {
      "command": "mcp-server-stdio",
      "env": {
        "ALLOWED_DIR": "/home/user/data"
      }
    }
  }
}

Deployment

# Docker
docker-compose up -d

# Systemd
sudo cp deploy/systemd/claude-mcp-server.service /etc/systemd/system/
sudo systemctl enable --now claude-mcp-server

Security

• File operations sandboxed to ALLOWED_DIR with path traversal protection

• SSRF protection: private/loopback/link-local IPs blocked by default

• Request size/timeouts enforced

• Input validation on all tool inputs

License

MIT