DigiBugCat/simple-rust-mcp-server

MCP Server

A simple Model Context Protocol (MCP) server implementation in Rust with streamable-http transport. This server provides example tools and can be easily deployed using Docker.

Features

• 🚀 Lightweight MCP server with streamable-http transport
• 🛠️ Four example tools included:
  • get_time - Get the current time
  • increment_counter - Increment a counter
  • get_counter - Get the current counter value
  • system_info - Get system information
• 🐳 Docker support with multi-platform builds (amd64/arm64)
• 🔄 Automatic GitHub Actions for Docker image publishing
• 📦 Minimal dependencies and small image size

Quick Start

Using Docker (Recommended)

Pull and run the latest image:

docker run -p 8080:8080 ghcr.io/digibugcat/simple-rust-mcp-server:latest

Using Docker Compose

docker-compose up

Building from Source

Requirements:

• Rust 1.75 or later

# Clone the repository
git clone https://github.com/DigiBugCat/simple-rust-mcp-server.git
cd simple-rust-mcp-server

# Build and run
cargo run --release

Endpoints

• Streamable HTTP Endpoint: http://localhost:8080/message - JSON-RPC endpoint for MCP protocol

Environment Variables

• HOST - Server host (default: 0.0.0.0)
• PORT - Server port (default: 8080)
• RUST_LOG - Log level (default: mcp_server=info)

Docker Image

The Docker image is automatically built and published to GitHub Container Registry on every push to the main branch.

Available Tags

• latest - Latest build from main branch
• vX.Y.Z - Specific version releases
• main - Latest main branch build

Testing with MCP Inspector

You can test the server using MCP Inspector:

1. Start the server: docker run -p 8080:8080 ghcr.io/digibugcat/simple-rust-mcp-server:latest
2. Open MCP Inspector
3. Select transport: streamable-http
4. Enter URL: http://localhost:8080/message
5. Connect and test the tools

Example Usage with MCP Client

// Example using the MCP SDK with streamable-http transport
import { Client } from '@modelcontextprotocol/sdk/client/index.js';
import { StreamableHttpClientTransport } from '@modelcontextprotocol/sdk/client/streamable-http.js';

const transport = new StreamableHttpClientTransport(
  new URL('http://localhost:8080/message')
);

const client = new Client({
  name: 'example-client',
  version: '1.0.0',
}, {
  capabilities: {}
});

await client.connect(transport);

// Call a tool
const result = await client.callTool({
  name: 'get_time',
  arguments: {}
});

console.log(result);

Development

Project Structure

.
├── src/
│   ├── main.rs         # Main server entry point
│   └── mcp/
│       ├── mod.rs      # MCP module
│       └── tools.rs    # Tool implementations
├── Cargo.toml          # Rust dependencies
├── Dockerfile          # Multi-stage Docker build
├── docker-compose.yml  # Local development setup
└── .github/
    └── workflows/
        └── docker-publish.yml  # CI/CD pipeline

Adding New Tools

To add new tools, edit src/mcp/tools.rs and add your tool implementation using the #[tool] macro:

#[tool(description = "Your tool description")]
async fn your_tool_name(&self, param: String) -> Result<CallToolResult, McpError> {
    // Tool implementation
    Ok(CallToolResult::success(vec![
        Content::text("Tool result")
    ]))
}

License

MIT