MCP C++ SDK - Model Context Protocol Implementation for C++

The most comprehensive C++ implementation of the Model Context Protocol (MCP) for building AI-powered applications. Production-ready SDK with enterprise features including multi-transport support, connection pooling, and multi-language bindings via C API (Python, TypeScript, Go, Rust, Java, C#, Ruby and more).

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Table of Contents

• Architecture Overview
• Cross-Language Support
• What is MCP?
• Features
• Quick Start
• Examples
• Installation
• Documentation
• FAQ
• Contributing
• License

Architecture Overview

┌─────────────────────────────────────────────────────────────────────┐
│                         Application Layer                           │
│  ┌────────────────────────────────────────────────────────────────┐ │
│  │      MCP Server │ MCP Client │ Custom Applications             │ │
│  └────────────────────────────────────────────────────────────────┘ │
├─────────────────────────────────────────────────────────────────────┤
│                    Cross-Language Binding Layer                     │
│  ┌────────────────────────────────────────────────────────────────┐ │
│  │   Python │ TypeScript │ Go │ Rust │ Java │ C# │ Ruby │ Swift   │ │
│  └────────────────────────────────────────────────────────────────┘ │
├─────────────────────────────────────────────────────────────────────┤
│                          C API (FFI Layer)                          │
│  ┌────────────────────────────────────────────────────────────────┐ │
│  │   libgopher_mcp_c: Opaque Handles │ RAII Guards │ Type Safety  │ │
│  └────────────────────────────────────────────────────────────────┘ │
├─────────────────────────────────────────────────────────────────────┤
│                            Protocol Layer                           │
│  ┌──────────────┐ ┌──────────────┐ ┌──────────────┐ ┌────────────┐  │
│  │   JSON-RPC   │ │   Requests   │ │  Responses   │ │   Notify   │  │
│  │   Codec      │ │   Dispatch   │ │   Routing    │ │   Stream   │  │
│  └──────────────┘ └──────────────┘ └──────────────┘ └────────────┘  │
├─────────────────────────────────────────────────────────────────────┤
│                          Filter Chain Layer                         │
│  ┌──────────────┐ ┌──────────────┐ ┌──────────────┐ ┌────────────┐  │
│  │  HTTP / SSE  │ │   Routing    │ │ Rate Limiter │ │   Auth     │  │
│  │    Codecs    │ │   & CORS     │ │ Circuit Brk  │ │  Metrics   │  │
│  └──────────────┘ └──────────────┘ └──────────────┘ └────────────┘  │
├─────────────────────────────────────────────────────────────────────┤
│                           Transport Layer                           │
│  ┌────────────────────────────────────────────────────────────────┐ │
│  │   Stdio │ HTTP(S)+SSE │ Streamable HTTP │ WebSocket │ TCP      │ │
│  └────────────────────────────────────────────────────────────────┘ │
├─────────────────────────────────────────────────────────────────────┤
│                            Network Layer                            │
│  ┌────────────────┐ ┌────────────────┐ ┌────────────────┐           │
│  │   Connection   │ │    Listener    │ │     Socket     │           │
│  │   Management   │ │    & Accept    │ │   Interface    │           │
│  └────────────────┘ └────────────────┘ └────────────────┘           │
├─────────────────────────────────────────────────────────────────────┤
│                       Event Loop & Dispatcher                       │
│  ┌────────────────────────────────────────────────────────────────┐ │
│  │   Libevent │ Timer Management │ I/O Events │ Buffer │ Result   │ │
│  └────────────────────────────────────────────────────────────────┘ │
└─────────────────────────────────────────────────────────────────────┘

Design Principles

1. Thread-Safe Dispatcher Model - All I/O in dispatcher threads, no complex synchronization
2. Filter Chain Architecture - Modular, composable request processing
3. Production Patterns - Connection pooling, circuit breaker, graceful shutdown

Cross-Language Support

Use MCP C++ SDK from any programming language via the stable C API (libgopher_mcp_c):

Language	Binding Type	Features
Python	ctypes/cffi	Async support, type hints
TypeScript/Node.js	N-API	High performance, native async
Go	CGO	Goroutine-safe wrappers
Rust	FFI	Safe wrappers, ownership guarantees
Java	JNI	Automatic resource management
C#/.NET	P/Invoke	Async/await support
Ruby	Native extension	GC integration

# Installation paths
Headers: /usr/local/include/gopher-mcp/mcp/c_api/
Library: /usr/local/lib/libgopher_mcp_c.{so,dylib,dll}

What is MCP?

Model Context Protocol (MCP) is an open protocol that enables AI models (like Claude, GPT, etc.) to securely interact with external tools, data sources, and services. MCP provides a standardized way for:

• AI assistants to access files, databases, and APIs
• Developers to expose tools and resources to AI models
• Applications to integrate AI capabilities with enterprise systems

This MCP C++ SDK implements the official MCP specification in high-performance C++, suitable for:

• Embedded systems and IoT devices
• High-frequency trading and real-time applications
• Game engines and graphics applications
• Native desktop and mobile applications
• Backend services requiring low latency

Features

Category	Features
Protocol	Full MCP 2025-06-18 specification, JSON-RPC 2.0, resources, tools, prompts
Transports	stdio, HTTP+SSE, HTTPS+SSE, WebSocket, TCP
Performance	Zero-copy buffers, lock-free operations, connection pooling
Reliability	Circuit breaker, rate limiting, retry with backoff, graceful shutdown
Security	TLS/SSL, authentication middleware, request validation
Observability	Structured logging, metrics, health endpoints
Cross-Language	C API for Python, Node.js, Go, Rust, Java, C#, Ruby bindings

Quick Start

Build and Install

# Show all available commands
make help

# Build
make

# Install (auto-prompts for sudo if needed)
make install

# Run tests
make test

Create an MCP Server

#include "mcp/server/mcp_server.h"

int main() {
    mcp::server::McpServerConfig config;
    config.server_name = "my-mcp-server";

    auto server = mcp::server::createMcpServer(config);

    // Register a tool
    mcp::Tool calculator;
    calculator.name = "add";
    calculator.description = "Add two numbers";

    server->registerTool(calculator, [](const std::string& name,
                                         const mcp::optional<mcp::Metadata>& arguments,
                                         mcp::server::SessionContext& ctx) {
        mcp::CallToolResult result;
        auto args = arguments.value();
        auto a_it = args.find("a");
        auto b_it = args.find("b");

        double a = mcp::holds_alternative<double>(a_it->second)
                       ? mcp::get<double>(a_it->second) : 0.0;
        double b = mcp::holds_alternative<double>(b_it->second)
                       ? mcp::get<double>(b_it->second) : 0.0;

        result.content.push_back(mcp::TextContent{"Result: " + std::to_string(a + b)});
        return result;
    });

    server->listen("http://0.0.0.0:3000");
    server->run();
}

Create an MCP Client

#include "mcp/client/mcp_client.h"

int main() {
    mcp::client::McpClientConfig config;
    config.client_name = "my-mcp-client";

    auto client = mcp::client::createMcpClient(config);
    client->connect("http://localhost:3000");

    // Initialize protocol
    auto init = client->initializeProtocol().get();

    // Call a tool
    auto args = mcp::make<mcp::Metadata>()
                    .add("a", 10.0)
                    .add("b", 5.0)
                    .build();

    auto result = client->callTool("add", mcp::make_optional(args)).get();
}

Examples

See examples/mcp/README.md for complete working examples:

# Terminal 1: Start server
./build/examples/mcp/mcp_example_server --verbose

# Terminal 2: Run client with demo
./build/examples/mcp/mcp_example_client --demo --verbose

The example server includes:

• Resource registration and subscriptions
• Tool execution (calculator, database query, system info)
• Prompt templates
• Session management
• HTTP/SSE endpoints

Installation

Prerequisites

• C++14 compiler (GCC 8+, Clang 10+, MSVC 2019+)
• CMake 3.10+
• libevent 2.1+
• OpenSSL 1.1+ (optional, for TLS)

Build Options

# Debug build
make debug

# Release build
make release

# Static libraries only
cmake -B build -DBUILD_SHARED_LIBS=OFF

# Without C API
cmake -B build -DBUILD_C_API=OFF

# Custom install prefix
cmake -B build -DCMAKE_INSTALL_PREFIX=~/.local

Windows (Cygwin + MinGW)

Building on Windows requires Cygwin with MinGW-w64 toolchain:

Prerequisites

Install Cygwin with these packages:

• make, cmake - Build tools
• mingw64-x86_64-gcc-g++ - MinGW C++ compiler
• mingw64-x86_64-libevent - Event library
• mingw64-x86_64-openssl - SSL/TLS library

Build Commands

# From Cygwin bash shell
./build-mingw.sh           # Release build (default)
./build-mingw.sh debug     # Debug build
./build-mingw.sh release   # Release build
./build-mingw.sh clean     # Clean build directory

Output

• Build directory: build-mingw/
• Executable: build-mingw/examples/mcp/mcp_example_server.exe

Documentation

MCP C++ Documentation

• Examples Guide - Working server and client examples

MCP CPP Core Components

• MCP Protocol in C++ - Model Context Protocol implementation details
• Filter Chain - Processing pipeline architecture
• Transport Layer - Transport implementations
• Network Layer - Connection management and socket abstraction

Design Documents

• Event Loop Design - Event-driven architecture and dispatcher design
• Filter Usage Guide - Comprehensive guide for using and creating filters
• CTAD Alternatives - Class Template Argument Deduction alternatives for C++14
• MCP Serialization Coverage - JSON serialization implementation details

FAQ

What is the Model Context Protocol?

MCP is an open protocol by Anthropic that standardizes how AI models interact with external tools and data. It defines JSON-RPC methods for resources (data), tools (actions), and prompts (templates).

Why use C++ for MCP?

C++ provides maximum performance and portability. This SDK is ideal for embedded systems, real-time applications, game engines, and any environment where Python/Node.js overhead is unacceptable.

Does this work with Claude, GPT, and other AI models?

Yes. MCP is model-agnostic. Any AI system that supports MCP can use servers built with this SDK.

How do I integrate with my Python/Node.js application?

Use the C API bindings. The SDK provides a stable C interface that can be called from any language with FFI support.

Is this production-ready?

Yes. The SDK includes connection pooling, circuit breakers, rate limiting, TLS support, and comprehensive error handling suitable for enterprise deployments.

What transports are supported?

• stdio - Standard input/output (CLI tools)
• HTTP+SSE - HTTP with Server-Sent Events (web applications)
• HTTPS+SSE - Secure HTTP+SSE
• WebSocket - Bidirectional real-time
• TCP - Raw TCP sockets

How do I contribute?

See CONTRIBUTING.md for guidelines. Issues and pull requests welcome!

Keywords & Search Terms

MCP C++, MCP CPP, Model Context Protocol C++, MCP SDK, C++ MCP, CPP MCP, Model Context Protocol CPP, MCP implementation, AI model integration C++, LLM integration C++, MCP server C++, MCP client C++, Model Context Protocol SDK, C++ AI SDK, Enterprise MCP, Production MCP C++

Contributing

Contributions are welcome! Please read our contributing guidelines before submitting pull requests.

License

Apache License 2.0 - see LICENSE for details.

Related Projects

• Model Context Protocol Specification
• MCP TypeScript SDK
• MCP Python SDK