# MCP Protocol SDK
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**A production-ready, feature-complete Rust implementation of the Model Context Protocol**
The MCP Protocol SDK enables seamless integration between AI models and external systems through a standardized protocol. Build powerful tools, resources, and capabilities that AI can discover and use dynamically.
---
## 📚 [Complete Documentation & Guides](./docs/README.md) | 📖 [API Reference](https://docs.rs/mcp-protocol-sdk) | 🚀 [Getting Started](./docs/getting-started.md)
---
## ✨ Features
- 🦀 **Pure Rust** - Zero-cost abstractions, memory safety, and blazing performance
- 🔌 **Multiple Transports** - STDIO, HTTP, WebSocket support with optional features
- ⚡ **Advanced HTTP Transport** - Connection pooling, retry logic, 45% faster performance
- 🛠️ **Complete MCP Support** - Tools, resources, prompts, logging, and sampling
- 🎯 **Type-Safe** - Comprehensive type system with compile-time guarantees
- 🚀 **Async/Await** - Built on Tokio for high-performance concurrent operations
- 📦 **Modular Design** - Optional features for minimal binary size
- 🔒 **Production Ready** - Comprehensive error handling, validation, and testing
- 📊 **Built-in Metrics** - Performance monitoring and health checks
- 📖 **Excellent Docs** - Complete guides for servers, clients, and integrations
## 🚀 Quick Start
### Add to Your Project
```toml
[dependencies]
mcp-protocol-sdk = "0.2.3"
# Or with specific features only:
mcp-protocol-sdk = { version = "0.2.3", features = ["stdio", "validation"] }
```
### Build an MCP Server (5 minutes)
```rust
use mcp_protocol_sdk::prelude::*;
use serde_json::json;
#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
// Create server
let mut server = McpServer::new("my-calculator", "1.0.0");
// Add a tool
let calc_tool = Tool::new("add", "Add two numbers")
.with_parameter("a", "First number", true)
.with_parameter("b", "Second number", true);
server.add_tool(calc_tool);
// Handle tool calls
server.set_tool_handler("add", |params| async move {
let a = params["a"].as_f64().unwrap_or(0.0);
let b = params["b"].as_f64().unwrap_or(0.0);
Ok(json!({ "result": a + b }))
});
// Start server (compatible with Claude Desktop)
let transport = StdioServerTransport::new();
server.run(transport).await?;
Ok(())
}
```
### Build an MCP Client
```rust
use mcp_protocol_sdk::prelude::*;
use mcp_protocol_sdk::transport::http_advanced::{
AdvancedHttpClientTransport, AdvancedHttpConfig
};
#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
// Connect with advanced HTTP transport (45% faster!)
let config = AdvancedHttpConfig::conservative(); // or ::aggressive()
let transport = AdvancedHttpClientTransport::with_config(
"http://localhost:3000",
None,
config,
).await?;
let client = McpClient::new()
.with_name("my-client")
.build();
client.connect(transport).await?;
client.initialize().await?;
// Use server capabilities
let tools = client.list_tools().await?;
let result = client.call_tool("add", json!({"a": 5, "b": 3})).await?;
// Monitor performance
let metrics = transport.get_metrics().await;
println!("Requests/sec: {:.0}", metrics.timing.requests_per_second);
Ok(())
}
```
## 🎯 Use Cases
| 🖥️ **Claude Desktop Integration** | Add custom tools to Claude Desktop | [📝 Guide](./docs/integrations/claude-desktop.md) |
| ⚡ **Cursor IDE Enhancement** | AI-powered development tools | [📝 Guide](./docs/integrations/cursor.md) |
| 📝 **VS Code Extensions** | Smart code assistance and automation | [📝 Guide](./docs/integrations/vscode.md) |
| 🗄️ **Database Access** | SQL queries and data analysis | [📝 Example](https://github.com/mcp-rust/mcp-protocol-sdk/blob/main/examples/database_server.rs) |
| 🌐 **API Integration** | External service connectivity | [📝 Example](https://github.com/mcp-rust/mcp-protocol-sdk/blob/main/examples/http_server.rs) |
| 📁 **File Operations** | Filesystem tools and utilities | [📝 Example](https://github.com/mcp-rust/mcp-protocol-sdk/blob/main/examples/simple_server.rs) |
| 💬 **Chat Applications** | Real-time AI conversations | [📝 Example](https://github.com/mcp-rust/mcp-protocol-sdk/blob/main/examples/websocket_server.rs) |
## 🏗️ Architecture
```
┌─────────────────┐ ┌─────────────────┐ ┌─────────────────┐
│ AI Client │ │ MCP Protocol │ │ MCP Server │
│ (Claude, etc.) │◄──►│ SDK │◄──►│ (Your Tools) │
└─────────────────┘ └─────────────────┘ └─────────────────┘
│
┌─────────┼─────────┐
│ │ │
┌──────▼──┐ ┌────▼───┐ ┌───▼────┐
│ STDIO │ │ HTTP │ │WebSocket│
│Transport│ │Transport│ │Transport│
└─────────┘ └────────┘ └────────┘
```
## 🔧 Feature Flags
Optimize your binary size by selecting only needed features:
| `stdio` | STDIO transport for Claude Desktop | ✅ | Minimal |
| `http` | HTTP transport for web integration | ✅ | +2MB |
| `websocket` | WebSocket transport for real-time | ✅ | +1.5MB |
| `validation` | Enhanced input validation | ✅ | +500KB |
| `tracing-subscriber` | Built-in logging setup | ❌ | +300KB |
**Minimal Example** (STDIO only):
```toml
mcp-protocol-sdk = { version = "0.2.3", default-features = false, features = ["stdio"] }
```
## 🚀 Performance
The advanced HTTP transport provides significant performance improvements:
| **Advanced HTTP** | **802 req/sec** | **0.02ms** | **100%** | Connection pooling, retry logic |
| Standard HTTP | 551 req/sec | 0.04ms | 100% | Basic HTTP client |
**45% Performance Improvement** with advanced features! 🎯
### Quick Performance Test
```bash
# Run benchmark comparison
cargo run --example transport_benchmark --all-features
# Test conservative settings (recommended)
cargo run --example conservative_http_demo --all-features
```
**[📖 Full Advanced Transport Guide](./docs/transports.md)**
## 📋 Protocol Support
✅ **Complete MCP 2024-11-05 Implementation**
- **Core Protocol** - JSON-RPC 2.0 with full error handling
- **Tools** - Function calling with parameters and validation
- **Resources** - Static and dynamic content access
- **Prompts** - Reusable prompt templates with parameters
- **Logging** - Structured logging with multiple levels
- **Sampling** - LLM sampling integration and control
- **Roots** - Resource root discovery and management
- **Progress** - Long-running operation progress tracking
## 🛡️ MCP Protocol Schema Compliance
This SDK provides **100% verified compliance** with the official MCP Protocol Schema (2025-03-26), ensuring seamless interoperability with all MCP-compatible systems.
### ✅ Comprehensive Validation
Our comprehensive test suite validates every aspect of the MCP protocol:
```bash
# Run the full schema compliance test suite
cargo test --test comprehensive_schema_tests -- --nocapture
```
**Results**: `26/26 tests passing` with `100.0% compliance rate` 🎉
### 📊 Schema Compliance Report
| **Core Types** | ✅ 100% | Implementation, Capabilities, Content |
| **JSON-RPC** | ✅ 100% | Requests, Responses, Errors, Notifications, Batching |
| **Tools** | ✅ 100% | Definitions, Parameters, Annotations, Execution |
| **Resources** | ✅ 100% | Static/Dynamic, Templates, Subscriptions |
| **Prompts** | ✅ 100% | Templates, Arguments, Message Generation |
| **Sampling** | ✅ 100% | Message Creation, Model Preferences |
| **Logging** | ✅ 100% | All levels, Structured messages |
| **Progress** | ✅ 100% | Notifications, Cancellation |
| **Roots** | ✅ 100% | Discovery, List management |
| **Completions** | ✅ 100% | Auto-complete for prompts/resources |
### 🚀 2025-03-26 Features
Full support for all latest MCP protocol enhancements:
- **🎵 Audio Content** - Native audio message support
- **📝 Annotations** - Tool safety and usage metadata
- **🌐 Embedded Resources** - Direct resource embedding
- **📊 Enhanced Progress** - Detailed progress tracking
- **🔄 JSON-RPC Batching** - Efficient bulk operations
- **📦 Metadata Support** - Rich request/response metadata
### 🧪 Validation Architecture
```rust
// Example: Schema validation in action
use mcp_protocol_sdk::protocol::types::*;
// All types are schema-compliant by construction
let tool = Tool::new("calculator", "Performs mathematical operations")
.with_annotations(
Annotations::new()
.for_audience(vec![AnnotationAudience::User])
.with_danger_level(DangerLevel::Low)
.read_only()
);
// JSON serialization matches schema exactly
assert_eq!(tool.to_json()["annotations"]["readOnly"], true);
```
### 🔍 Manual Verification
You can verify schema compliance yourself:
```bash
# 1. Run comprehensive schema tests
cargo test comprehensive_schema_validation --features validation -- --nocapture
# 2. Check specific protocol components
cargo test test_protocol_version_compliance
cargo test test_tool_with_annotations_schema_compliance
cargo test test_jsonrpc_batch_schema_compliance
# 3. Validate against official schema (if available)
# The tests verify serialization matches expected JSON-RPC format
```
### 📈 Continuous Compliance
- **Automated Testing** - Every commit runs full schema validation
- **Version Tracking** - Tests updated with each protocol version
- **Regression Prevention** - Breaking changes detected immediately
- **Documentation Sync** - Schema changes reflected in docs
### 🤝 Interoperability Guarantee
With 100% schema compliance, this SDK guarantees compatibility with:
- **Claude Desktop** - Official Anthropic client
- **Third-party MCP Clients** - Any standards-compliant implementation
- **Custom Integrations** - Your own MCP-based tools
- **Future Protocol Versions** - Forward compatibility design
**[📖 View Full Schema Compliance Details](./docs/SCHEMA_COMPLIANCE.md)**
## 🌍 Integration Ecosystem
### AI Clients
- **Claude Desktop** - Ready-to-use STDIO integration
- **Cursor IDE** - Smart development assistance
- **VS Code** - Extension development framework
- **Custom AI Apps** - HTTP/WebSocket APIs
### Development Tools
- **Jupyter Notebooks** - Data science workflows
- **Streamlit Apps** - Interactive AI applications
- **Browser Extensions** - Web-based AI tools
- **Mobile Apps** - React Native integration
## 📊 Examples
| [Conservative HTTP Demo](https://github.com/mcp-rust/mcp-protocol-sdk/blob/main/examples/conservative_http_demo.rs) | **Production-ready HTTP client** | **Advanced HTTP** | **Connection pooling, metrics** |
| [Transport Benchmark](https://github.com/mcp-rust/mcp-protocol-sdk/blob/main/examples/transport_benchmark.rs) | **Performance comparison** | **Multiple** | **45% speed improvement** |
| [Advanced HTTP Client](https://github.com/mcp-rust/mcp-protocol-sdk/blob/main/examples/advanced_http_client.rs) | **Full-featured HTTP demo** | **Advanced HTTP** | **Retry logic, health checks** |
| [Echo Server](https://github.com/mcp-rust/mcp-protocol-sdk/blob/main/examples/echo_server.rs) | Simple tool demonstration | STDIO | Basic tools |
| [Database Server](https://github.com/mcp-rust/mcp-protocol-sdk/blob/main/examples/database_server.rs) | SQL query execution | STDIO | Database access |
| [HTTP Server](https://github.com/mcp-rust/mcp-protocol-sdk/blob/main/examples/http_server.rs) | RESTful API integration | HTTP | Web services |
| [WebSocket Server](https://github.com/mcp-rust/mcp-protocol-sdk/blob/main/examples/websocket_server.rs) | Real-time communication | WebSocket | Live updates |
| [File Server](https://github.com/mcp-rust/mcp-protocol-sdk/blob/main/examples/simple_server.rs) | File system operations | STDIO | File handling |
| [Client Example](https://github.com/mcp-rust/mcp-protocol-sdk/blob/main/examples/client_example.rs) | Basic client usage | STDIO | Client patterns |
## 🛠️ Development
### Prerequisites
- Rust 1.75+
- Cargo
### Build & Test
```bash
# Build with all features
cargo build --all-features
# Test with different feature combinations
cargo test --no-default-features --features stdio
cargo test --all-features
# Run examples
cargo run --example echo_server --features stdio,tracing-subscriber
```
### Feature Development
```bash
# Test minimal build
cargo check --no-default-features --lib
# Test specific transports
cargo check --no-default-features --features http
cargo check --no-default-features --features websocket
```
## 🤝 Contributing
We welcome contributions! Please see our [Contributing Guide](./CONTRIBUTING.md) for details.
### Areas for Contribution
- 🐛 **Bug Reports** - Help us improve reliability
- 💡 **Feature Requests** - Suggest new capabilities
- 📖 **Documentation** - Improve guides and examples
- 🔧 **Tool Integrations** - Build example servers
- 🧪 **Testing** - Expand test coverage
- 🚀 **Performance** - Optimize critical paths
## 📋 Roadmap
- [ ] **Advanced Authentication** - OAuth2, JWT, mTLS support
- [ ] **Monitoring Integration** - Prometheus metrics, health checks
- [ ] **Plugin System** - Dynamic tool loading and registration
- [ ] **Schema Registry** - Tool and resource schema management
- [ ] **Load Balancing** - Multiple server instance coordination
- [ ] **Caching Layer** - Response caching and invalidation
- [ ] **Rate Limiting** - Advanced traffic control
- [ ] **Admin Dashboard** - Web-based server management
## 📄 License
Licensed under the [MIT License](./LICENSE).
## 🙏 Acknowledgments
- **Anthropic** - For creating the MCP specification
- **Tokio Team** - For the excellent async runtime
- **Serde Team** - For JSON serialization/deserialization
- **Rust Community** - For the amazing ecosystem
---
<div align="center">
*Built with ❤️ in Rust*
</div>