Rust MCP SDK

What is Rust MCP SDK?

A high-performance, asynchronous Rust toolkit for building MCP servers and clients. It implements the latest MCP protocol version (2025-11-25) and passes 100% of official MCP conformance tests, letting developers focus on application logic while the SDK handles protocol, transports, and authentication.

How to use Rust MCP SDK?

Add rust-mcp-sdk = "0.9.0" to your Cargo.toml, then define tools using the mcp_tool macro and implement the ServerHandler trait. Quick-start examples show a minimal stdio server, a Streamable HTTP server with Axum or Actix backends, and a BYO-server mode for embedding MCP in existing apps.

Key features of Rust MCP SDK

• Implements MCP protocol 2025-11-25
• Passes 100% of official conformance tests (client and server)
• Supports Stdio, Streamable HTTP, and SSE transports
• Framework-agnostic: native Axum, Actix, and BYO-server integrations
• Multi-client concurrency and DNS rebinding protection
• OAuth authentication for servers and clients (multiple providers)

Use cases of Rust MCP SDK

• Build a minimal MCP server using standard input/output transport
• Deploy a Streamable HTTP MCP server with Axum or Actix for multi-client access
• Embed MCP endpoints into an existing web application via BYO-server mode
• Implement custom tools, resources, and templates with procedural macros
• Add OAuth-based authentication to MCP servers or clients

FAQ from Rust MCP SDK

What MCP protocol version does the SDK support?

It supports protocol version 2025-11-25.

Does the SDK pass official MCP conformance tests?

Yes, it passes 100% of the official client (254/254) and server (40/40) conformance tests.

What transports are available?

Stdio, Streamable HTTP, and backward-compatible SSE transport are supported.

Can I use the SDK with a different HTTP framework?

Yes, through the BYO-server (Bring Your Own Server) mode you can mount MCP routes onto your existing Axum or Actix router. For other frameworks (e.g., Rocket, Salto, Warp), a custom integration guide is provided.

Does the SDK support OAuth authentication?

Yes, it provides OAuth authentication for both MCP servers (with remote providers like Keycloak, WorkOS, Scalekit) and clients (metadata discovery, DCR, PKCE, token refresh).