Crate rs_fast_mcp 

Rs Fast MCP

High-performance, async-first Rust implementation of the Model Context Protocol (MCP).

Rs Fast MCP provides a complete framework for building MCP servers and clients using modern Rust practices. Built on tokio and actix-web, it offers non-blocking I/O, type-safe interfaces, and a rich middleware pipeline out of the box.

Key Features

• Flexible transports — Stdio (pipe) and HTTP/SSE with session management.
• Authentication — Pluggable server::auth::AuthProvider trait with built-in providers for Google, GitHub, Azure, AWS Cognito, Auth0, and more.
• Middleware — Composable request pipeline with rate-limiting, caching, and logging.
• Component managers — First-class registration, validation, and execution for tools, resources, and prompts.
• Client SDK — Async client with transport auto-detection, sampling, and roots support.

Quick Start

use rs_fast_mcp::server::app::Server;
use rs_fast_mcp::tools::tool::{Tool, ToolResult};
use rs_fast_mcp::mcp::types::ContentBlock;

#[tokio::main]
async fn main() {
    // Build the server (creates an internal FastMCPServer engine)
    let server = Server::builder("my-server", "0.1.0")
        .stdio()
        .build();

    // Register a tool on the running engine
    let tool = Tool::new("greet", "Say hello to a name")
        .add_parameter("name", "string", "The name to greet");
    server.core.add_tool(tool).unwrap();

    // Run until EOF or SIGINT
    server.run().await.unwrap();
}

Module Overview

Module	Purpose
mcp	Protocol types, JSON-RPC messages, and configuration
server	Server core, transports, auth, and middleware
client	Async MCP client SDK
tools	Tool registration, validation, and execution
resources	Resource management and URI templates
prompts	Prompt templates and execution
cli	Command-line interface (serve, client, inspect)
settings	Environment-driven configuration
error	Error types used across the crate
util	JSON Schema helpers and shared utilities

Modules

cli

Command-line interface for rs-fast-mcp.

client

error

Crate-wide error types.

mcp

Model Context Protocol (MCP) type definitions and wire-format utilities.

prompts

Prompt template registration and execution.

resources

Resource management, URI templates, and subscriptions.

server

MCP server implementation.

settings

Environment-driven application settings.

shared

tools

Tool registration, validation, and execution.

util

Shared utility modules.