credit : https://dev.to/joshmo_dev/using-model-context-protocol-with-rig-m7o

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 tool that adds two numbers and integrates with the RIG agent for LLM prompting.

Clone this repo and run with:

cargo run

In a separate terminal start the MCP Inspector with:

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

You'll see output like:

Starting MCP inspector... 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= Connected to SSE transport Connected MCP client to backing server transport Created web app transport Set up MCP proxy 🔍 MCP Inspector is up and running at http://localhost:5173 🚀 

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

• ✅ Sets up a custom MCP server using ServerSseTransport
• ✅ Connects a MCP client to the server
• ✅ Registers a custom tool: AddTool, which adds two numbers
• ✅ Lists registered tools via MCP
• ✅ Integrates with RIG and prompts an LLM agent using the tool

#[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 defines the Add tool that is registered in the MCP server.

The main function sets up:

• Tracing
• The MCP server and transport (SSE)
• A MCP client that initializes and lists available tools
• A RIG agent with OpenAI backend, which uses the MCP tool

The agent then runs a prompt:

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

When run successfully, you'll see logs like:

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

• 🦀 Rust with tokio
• 📡 SSE transport from mcp_core
• 🔧 MCP server/client architecture
• 🤖 RIG agent with OpenAI model
• 🌐 MCP Inspector web interface

Make sure you have these in your Cargo.toml:

[dependencies] tokio = { version = "1", features = ["full"] } anyhow = "1" serde_json = "1" mcp_core = "..." mcp_core_macros = "..." rig = "..."

Replace ... with the appropriate versions based on your environment.

Visit http://localhost:5173 to view and interact with the MCP Inspector UI.

Query parameters: { transportType: 'sse', url: 'http://localhost:3001/sse' } Connected to SSE transport Connected MCP client to backing server transport Set up MCP proxy Received message for sessionId cdd4a8be-57e2-44e3-9b81-3df300e86f22 

Feel free to open an issue or start a discussion!