Model Context Protocol (MCP) Server - Filesystem Implementation

This is an educational implementation of a Model Context Protocol (MCP) server in Go using the Echo framework. The server provides access to the local filesystem through the MCP protocol.

Overview

The Model Context Protocol (MCP) is an open standard that enables developers to build secure, two-way connections between their data sources and AI-powered tools. This implementation demonstrates how to create an MCP server that provides access to the local filesystem.

Features

• Filesystem Provider: Provides access to the local filesystem through MCP tools and resources
• Tools:
  • filesystem.list: Lists the contents of a directory
  • filesystem.read: Reads the contents of a file
  • filesystem.write: Writes content to a file
  • filesystem.delete: Deletes a file or directory
• Resources:
  • filesystem.file: Represents a file in the filesystem
  • filesystem.directory: Represents a directory in the filesystem

Security Considerations

This implementation includes basic path sanitization to prevent directory traversal attacks, but it is intended for educational purposes only. In a production environment, additional security measures would be necessary, such as:

• User authentication and authorization
• More robust input validation
• Rate limiting
• Audit logging
• Sandboxing

Getting Started

Prerequisites

• Go 1.24 or higher

Installation

1. Clone the repository
2. Install dependencies: go mod tidy
3. Run the server: go run main.go

The server will start on port 8080 by default. You can change the port by setting the PORT environment variable.

API Endpoints

• GET /: Server information
• POST /v1/discover: Discover server capabilities
• POST /v1/call-tool: Call a tool
• POST /v1/load-resource: Load a resource

Example Usage

Discover Server Capabilities

curl -X POST http://localhost:8080/v1/discover

List Directory Contents

curl -X POST http://localhost:8080/v1/call-tool \
  -H "Content-Type: application/json" \
  -d '{
    "tool_id": "filesystem.list",
    "request_id": "req-123",
    "params": {
      "arguments": {
        "path": "."
      }
    }
  }'

Read File Contents

curl -X POST http://localhost:8080/v1/call-tool \
  -H "Content-Type: application/json" \
  -d '{
    "tool_id": "filesystem.read",
    "request_id": "req-123",
    "params": {
      "arguments": {
        "path": "README.md"
      }
    }
  }'

License

This project is licensed under the MIT License - see the LICENSE file for details.

Disclaimer

This implementation is for educational purposes only and should not be used in production environments without proper security review and hardening.