Rig MCP Server

🚀 [Example of MCP Server + Inspector Tool Using Rust: SSE Transport with Addition Tool]

This project demonstrates how to set up an MCP (Model Context Protocol) server and client using Server-Sent Events (SSE) for communication. It includes a simple addition tool and integrates with the RIG proxy for LLM prompting.

🚀 Quick Start

Clone this repository and run:

cargo run

Start the MCP inspector tool in another terminal:

npx @modelcontextprotocol/inspector sse http://127.0.0.1:3001/sse

You will see output similar to the following:

Starting MCP inspector tool...
Proxy server listening on port 3000
New SSE connection
Query parameters: { transportType: 'sse', url: 'http://localhost:3001/sse' }
SSE transport: url=http://localhost:3001/sse, headers=
Connecting to SSE transport
Connecting MCP client to backend server transport
Creating web app transport
Setting up MCP proxy
🔍 MCP inspector tool is up and running at http://localhost:5173 🚀

You can view the web interface at http://localhost:5173

✨ Features

• ✅ Set up a custom MCP server using ServerSseTransport
• ✅ Connect an MCP client to the server
• ✅ Register a custom tool: AddTool for addition operations
• ✅ List registered tools
• ✅ Integrate with RIG and use tools to prompt the LLM agent

💻 Usage Examples

Basic Usage

#[tool(
    name = "Add",
    description = "Adds two numbers together.",
    params(a = "The first number to add", b = "The second number to add")
)]
async fn add_tool(a: f64, b: f64) -> Result<ToolResponseContent> {
    Ok(tool_text_content!((a + b).to_string()))
}

This code defines the Add tool, which is registered in the MCP server.

Advanced Usage

The main function sets up:

• Tracing
• MCP server and transport (SSE)
• Connection to the MCP client and listing available tools
• RIG proxy with an OpenAI backend, using MCP tools

Then the proxy runs a prompt:

let response = agent.prompt("Add 10 + 10").await;

🧪 Example Output

When running successfully, you will see logs similar to the following:

Initialization completed: Ok(...)
Tools: Ok([...])
Building RIG agent
Prompting RIG agent
Agent response: Some("20")

🔧 Technical Details

Technology Stack

• 🦀 Rust using tokio
• 📡 SSE transport from mcp_core
• 🔧 MCP server/client architecture
• 🤖 RIG proxy with an OpenAI model
• 🌐 MCP inspector tool web interface

Dependencies

The project requires the following dependencies:

[dependencies]
mcp = "0.1"
tokio = { version = "1.0", features = ["full"] }

These can be found in the Cargo.toml file.

📚 Documentation

Inspector Tool Interface

After starting the inspector tool, you will access a web interface that displays the registered MCP tools and their responses. You can test and interact with the tools through this interface.

Diagram

The following is a brief schematic diagram of the project structure and functionality:

📄 License

No license information provided in the original document, so this section is skipped.

📢 Feedback

Feel free to open an issue or start a discussion!