44 releases (stable)

new 1.10.2	Feb 6, 2026
1.9.4	Jan 7, 2026
1.9.1	Dec 30, 2025
1.8.6	Nov 29, 2025
0.3.1	Jul 26, 2025

#81 in Network programming

6,809 downloads per month
Used in 14 crates (8 directly)

MIT license

6.5MB
45K SLoC

PMCP - Pragmatic Model Context Protocol

Production-grade Rust implementation of the Model Context Protocol (MCP) - 16x faster than TypeScript, built with Toyota Way quality principles

Overview

PMCP is a complete MCP ecosystem for Rust, providing everything you need to build, test, and deploy production-grade MCP servers:

🦀 pmcp SDK - High-performance Rust crate with full MCP protocol support
⚡ cargo-pmcp - CLI toolkit for scaffolding, testing, and development
📚 pmcp-book - Comprehensive reference guide with 27 chapters
🎓 pmcp-course - Hands-on course with quizzes and exercises
🤖 AI Agents - Kiro and Claude Code configurations for AI-assisted development

Why PMCP?

Performance: 16x faster than TypeScript SDK, 50x lower memory
Safety: Rust's type system + zero unwrap() in production code
Quality: Toyota Way principles - zero technical debt tolerance
Complete: SDK, tooling, documentation, and AI assistance in one ecosystem

Quick Start

Choose your path based on experience and preference:

🚀 Path 1: AI-Assisted (Fastest - Recommended for Rapid Prototyping)

Build production-ready MCP servers with AI assistance in minutes:

Prerequisites:

# Install Rust
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
rustup update

# Install cargo-pmcp
cargo install cargo-pmcp

Install Claude Code AI Agent:

# Install the mcp-developer subagent (user-level - works across all projects)
curl -fsSL https://raw.githubusercontent.com/paiml/rust-mcp-sdk/main/ai-agents/claude-code/mcp-developer.md \
  -o ~/.claude/agents/mcp-developer.md

# Restart Claude Code

Build your server:

You: "Create a weather forecast MCP server with tools for getting current conditions and 5-day forecasts"

Claude Code: [Invokes mcp-developer subagent]

I'll create a production-ready weather MCP server using cargo-pmcp.

$ cargo pmcp new weather-mcp-workspace
$ cd weather-mcp-workspace
$ cargo pmcp add server weather --template minimal

[Implements type-safe tools with validation]
[Adds comprehensive tests and observability]
[Validates quality gates]

✅ Production-ready server complete with 85% test coverage!

What you get: Production-ready code following Toyota Way principles, with comprehensive tests, structured logging, metrics collection, and zero clippy warnings.

Learn more: AI-Assisted Development Course | AI Agents README

⚡ Path 2: cargo-pmcp Toolkit (Recommended for Manual Development)

Scaffold and build servers using the cargo-pmcp CLI:

Installation:

# Install Rust
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
rustup update

# Install cargo-pmcp
cargo install cargo-pmcp

Create a server:

# Create workspace
cargo pmcp new my-mcp-workspace
cd my-mcp-workspace

# Add a server using a template
cargo pmcp add server myserver --template minimal

# Start development server with hot-reload
cargo pmcp dev --server myserver

# Generate and run tests
cargo pmcp test --server myserver --generate-scenarios
cargo pmcp test --server myserver

# Build for production
cargo build --release

Available templates:

minimal - Empty structure for custom servers
calculator - Arithmetic operations (learning)
complete_calculator - Full-featured reference implementation
sqlite_explorer - Database browser pattern

Learn more: cargo-pmcp Guide

🦀 Path 3: pmcp SDK Directly (For Fine-Grained Control)

Use the pmcp crate directly for maximum control:

Installation:

[dependencies]
pmcp = "1.8"
tokio = { version = "1", features = ["full"] }
serde = { version = "1", features = ["derive"] }
schemars = "0.8"  # For type-safe tools

Type-safe server example:

use pmcp::{ServerBuilder, TypedTool, RequestHandlerExtra, Error};
use schemars::JsonSchema;
use serde::{Deserialize, Serialize};

#[derive(Debug, Deserialize, Serialize, JsonSchema)]
#[schemars(deny_unknown_fields)]
struct WeatherArgs {
    #[schemars(description = "City name")]
    city: String,

    #[schemars(description = "Number of days (1-5)")]
    days: Option<u8>,
}

#[derive(Debug, Serialize, JsonSchema)]
struct WeatherOutput {
    temperature: f64,
    conditions: String,
}

async fn get_weather(args: WeatherArgs, _extra: RequestHandlerExtra) -> pmcp::Result<WeatherOutput> {
    // Validate
    if args.city.is_empty() {
        return Err(Error::validation("City cannot be empty"));
    }

    let days = args.days.unwrap_or(1);
    if !(1..=5).contains(&days) {
        return Err(Error::validation("Days must be 1-5"));
    }

    // Call weather API...
    Ok(WeatherOutput {
        temperature: 72.0,
        conditions: "Sunny".to_string(),
    })
}

#[tokio::main]
async fn main() -> pmcp::Result<()> {
    let server = ServerBuilder::new()
        .name("weather-server")
        .version("1.0.0")
        .tool("get-weather", TypedTool::new("get-weather", |args, extra| {
            Box::pin(get_weather(args, extra))
        }).with_description("Get weather forecast for a city"))
        .build()?;

    server.run_stdio().await?;
    Ok(())
}

Learn more: pmcp-book | pmcp-course | API Documentation

PMCP Ecosystem Components

🦀 pmcp SDK (The Crate)

High-performance Rust implementation of the MCP protocol.

Key Features:

Type-Safe Tools: Automatic JSON schema generation from Rust types
Multiple Transports: stdio, HTTP/SSE, WebSocket, WASM
OAuth Support: Full auth context pass-through (v1.8.0+)
Workflows: Multi-step orchestration with array indexing support
Performance: 16x faster than TypeScript, SIMD-accelerated parsing
Quality: Zero unwrap(), comprehensive error handling

Latest Version: pmcp = "1.8.3"

Documentation:

⚡ cargo-pmcp (CLI Toolkit)

Scaffolding and development toolkit for MCP servers.

What it does:

Scaffold servers in seconds with proven patterns
Hot-reload dev server for rapid iteration
Generate test scenarios automatically
Validate quality gates (fmt, clippy, tests)
Deploy to production - AWS Lambda, Google Cloud Run, or Cloudflare Workers
Manage deployments - logs, metrics, secrets, rollback

Commands:

cargo pmcp new <workspace>              # Create workspace
cargo pmcp add server <name>            # Add server
cargo pmcp dev --server <name>          # Start dev server
cargo pmcp test --server <name>         # Run tests
cargo pmcp deploy --target <target>     # Deploy to production
cargo pmcp deploy logs --tail           # Stream logs
cargo pmcp deploy destroy --clean       # Remove deployment

Why use it?

Encodes best practices from 6 production servers
Saves 30-60 minutes vs manual setup
Ensures consistent structure across servers
Integrated testing and quality validation

Learn more: cargo-pmcp Guide

📚 pmcp-book (Reference Guide)

27-chapter comprehensive reference guide to building MCP servers with pmcp.

📖 Read Online

Coverage:

Getting Started: Installation, first server, quick start tutorial
Core Concepts: Tools, resources, prompts, error handling
Advanced Features: Auth, transports, middleware, progress tracking
Real-World: Production servers, testing, deployment, performance
Examples & Patterns: Complete examples and design patterns
TypeScript Migration: Complete compatibility guide
Advanced Topics: Custom transports, AI-assisted development

Local development:

make book-serve    # Serve at http://localhost:3000
make book-open     # Build and open in browser

🎓 pmcp-course (Hands-On Learning)

Interactive course with quizzes, exercises, and real-world projects for mastering MCP development.

🎓 Start the Course

Course Structure:

Part I: Foundations - MCP concepts, first server, typed tools
Part II: Core Concepts - Tools, resources, prompts, validation
Part III: Deployment - AWS Lambda, Cloudflare Workers, Google Cloud Run
Part IV: Testing - Local testing, CI/CD, regression testing
Part V: Security - OAuth 2.0, identity providers, multi-tenant
Part VI: AI-Assisted Dev - Claude Code, feedback loops, collaboration
Part VII: Observability - Middleware, logging, metrics
Part VIII: Advanced - Server composition, MCP Apps (experimental)

Features:

Interactive quizzes after each chapter
Hands-on exercises with solutions
Real-world project examples
Best practices from production servers

Local development:

cd pmcp-course && mdbook serve    # Serve at http://localhost:3000

🤖 ai-agents (AI-Assisted Development)

AI agent configurations that teach Kiro and Claude Code how to build MCP servers.

Supported AI Assistants:

Kiro (Steering Files) - 10,876 lines of persistent MCP expertise

Always-active knowledge in every conversation
Comprehensive testing and observability guidance
Installation Guide

Claude Code (Subagent) - ~750 lines of focused MCP knowledge

On-demand invocation for MCP tasks
Quick scaffolding and implementation
Installation Guide

What AI agents know:

MCP protocol concepts and patterns
cargo-pmcp workflow (never creates files manually)
Type-safe tool implementation
Testing strategies (unit, integration, property, fuzz)
Production observability (logging, metrics)
Toyota Way quality standards

Community implementations welcome:

GitHub Copilot, Cursor, Cline, and others
Contribution Guide

Learn more: AI-Assisted Development Course | ai-agents/

Latest Release: v1.8.3

Highlights:

🔐 OAuth Auth Context: Full token pass-through from transport → middleware → tools
📋 Workflow Array Indexing: Access array elements in workflow templates
🛡️ Spec Compliance: Fixed ClientCapabilities schema for Cursor IDE compatibility
🔧 Type-Safe Tools: Production-ready typed tools with schema generation
⚡ Performance: SIMD-accelerated parsing (10.3x speedup)

Full changelog: CHANGELOG.md

Migration guides:

Core Features

🚀 Transport Layer

stdio: Standard input/output for CLI integration
HTTP/SSE: Streamable HTTP with Server-Sent Events
WebSocket: Full-duplex with auto-reconnection
WASM: Browser and Cloudflare Workers support

🛠️ Type-Safe Development

Automatic Schema Generation: From Rust types using schemars
Compile-Time Validation: Type-checked tool arguments
Runtime Validation: Against generated JSON schemas
Zero Unwraps: Explicit error handling throughout

🔐 Security & Auth

OAuth 2.0: Full auth context pass-through
OIDC Discovery: Automatic provider configuration
Bearer Tokens: Standard authentication
Path Validation: Secure file system access

🧪 Testing & Quality

mcp-tester: Comprehensive server testing tool
Scenario Generation: Auto-generate test cases
Property Testing: Invariant validation
Quality Gates: fmt, clippy, coverage enforcement

⚡ Performance

16x faster than TypeScript SDK
50x lower memory usage
SIMD Parsing: 10.3x SSE speedup with AVX2/SSE4.2
Connection Pooling: Smart load balancing

🏭 Toyota Way Quality

Zero Technical Debt: TDG score 0.76
Jidoka: Stop the line on defects
Genchi Genbutsu: Go and see (evidence-based)
Kaizen: Continuous improvement
No Unwraps: Explicit error handling only

Documentation

📖 Primary Resources

PMCP Documentation Portal - Landing page for all documentation
pmcp-book - Comprehensive reference guide (27 chapters)
pmcp-course - Hands-on course with quizzes and exercises
API Reference - Complete API documentation
cargo-pmcp Guide - CLI toolkit documentation

📚 Additional Resources

Examples - 200+ working examples
CHANGELOG - Version history
Migration Guides - Upgrade instructions
Contributing - How to contribute

🎯 Quick Links

Examples

The SDK includes 60+ comprehensive examples covering all features:

# Basic examples
cargo run --example 01_client_initialize    # Client setup
cargo run --example 02_server_basic         # Basic server
cargo run --example 03_client_tools         # Tool usage

# Type-safe tools (v1.6.0+)
cargo run --example 32_typed_tools --features schema-generation
cargo run --example 33_advanced_typed_tools --features schema-generation

# Advanced features
cargo run --example 09_authentication       # OAuth/Bearer
cargo run --example 13_websocket_transport  # WebSocket
cargo run --example 15_middleware           # Middleware chain

# Testing
cargo run --example 26-server-tester -- test http://localhost:8080

# AI-assisted development
# See ai-agents/README.md for Kiro and Claude Code setup

See examples/README.md for complete list.

MCP Server Tester

Comprehensive testing tool for validating MCP server implementations.

Features:

Protocol compliance validation (JSON-RPC 2.0, MCP spec)
Multi-transport support (HTTP, HTTPS, WebSocket, stdio)
Tool discovery and testing
CI/CD ready with JSON output

Installation:

cargo install mcp-server-tester

# Or download pre-built binaries from releases

Usage:

# Test a server
mcp-tester test http://localhost:8080

# Protocol compliance check
mcp-tester compliance http://localhost:8080 --strict

# Connection diagnostics
mcp-tester diagnose http://localhost:8080

Learn more: examples/26-server-tester/README.md

Quality & Performance

Toyota Way Principles

PMCP is built following Toyota Production System principles:

Jidoka (自働化): Automation with human touch
- Quality gates stop builds on defects
- Zero tolerance for unwrap() in production
- Comprehensive error handling with context
Genchi Genbutsu (現地現物): Go and see
- Evidence-based decisions with metrics
- PMAT quality analysis (TDG score 0.76)
- Comprehensive testing (unit, property, fuzz)
Kaizen (改善): Continuous improvement
- Regular benchmarking and optimization
- Performance regression prevention
- Community-driven enhancements

Quality Metrics

TDG Score: 0.76 (production-ready)
Technical Debt: Minimal (436h across entire codebase)
Complexity: All functions ≤25 complexity
Coverage: 52% line coverage, 100% function coverage
Linting: Zero clippy warnings in production code

Performance Benchmarks

Metric                  PMCP (Rust)     TypeScript SDK    Improvement
────────────────────────────────────────────────────────────────────
Overall Speed           16x             1x                16x faster
Memory Usage            <10 MB          ~500 MB           50x lower
SSE Parsing             336,921 ev/s    32,691 ev/s       10.3x faster
JSON-RPC Parsing        195,181 docs/s  N/A               SIMD-optimized
Round-trip Latency      <100 μs         ~1-2 ms           10-20x faster
Base64 Operations       252+ MB/s       N/A               Optimized

Run benchmarks:

make bench                           # General benchmarks
cargo run --example 32_simd_parsing  # SIMD-specific

WebAssembly Support

Full WASM support for browser and edge deployment:

Targets:

Cloudflare Workers (wasm32-unknown-unknown)
WASI Runtimes (wasm32-wasi)
Browser (wasm-bindgen)

Quick start:

# Build for Cloudflare Workers
cargo build --target wasm32-unknown-unknown --no-default-features --features wasm

# Deploy
make cloudflare-sdk-deploy

Learn more: WASM Guide | WASM Example

Development

Prerequisites

Rust 1.82.0 or later
Git

Setup

git clone https://github.com/paiml/rust-mcp-sdk
cd rust-mcp-sdk

# Install development tools
make setup

# Run quality checks
make quality-gate

Testing

make test-all           # All tests
make test-property      # Property tests
make coverage           # Coverage report
make mutants            # Mutation tests

Contributing

We welcome contributions! Please:

Fork the repository
Create a feature branch (git checkout -b feature/amazing-feature)
Ensure quality gates pass (make quality-gate)
Commit with conventional commits
Push and open a Pull Request

See: CONTRIBUTING.md

Compatibility

Feature	TypeScript SDK	PMCP (Rust)
Protocol Version	2024-10-07+	2024-10-07+
Transports	stdio, SSE, WebSocket	stdio, SSE, WebSocket, WASM
Authentication	OAuth 2.0, Bearer	OAuth 2.0, Bearer, OIDC
Tools	✓	✓ (Type-safe)
Prompts	✓	✓ (Workflows)
Resources	✓	✓ (Subscriptions)
Sampling	✓	✓
Performance	1x	16x faster
Memory	Baseline	50x lower

License

This project is licensed under the MIT License - see the LICENSE file for details.

Acknowledgments

Model Context Protocol specification
TypeScript SDK for reference implementation
PAIML MCP Agent Toolkit for quality standards
Community contributors and early adopters

44 releases (stable)

PMCP - Pragmatic Model Context Protocol

Overview

Quick Start

🚀 Path 1: AI-Assisted (Fastest - Recommended for Rapid Prototyping)

⚡ Path 2: cargo-pmcp Toolkit (Recommended for Manual Development)

🦀 Path 3: pmcp SDK Directly (For Fine-Grained Control)

PMCP Ecosystem Components

🦀 pmcp SDK (The Crate)

⚡ cargo-pmcp (CLI Toolkit)

📚 pmcp-book (Reference Guide)

🎓 pmcp-course (Hands-On Learning)

🤖 ai-agents (AI-Assisted Development)

Latest Release: v1.8.3

Core Features

🚀 Transport Layer

🛠️ Type-Safe Development

🔐 Security & Auth

🧪 Testing & Quality

⚡ Performance

🏭 Toyota Way Quality

Documentation

📖 Primary Resources

📚 Additional Resources

🎯 Quick Links

Examples

MCP Server Tester

Quality & Performance

Toyota Way Principles

Quality Metrics

Performance Benchmarks

WebAssembly Support

Development

Prerequisites

Setup

Testing

Contributing

Compatibility

License

Acknowledgments

Links

Dependencies