Go MCP

🚀 Go Language MCP Protocol Library

This is a Go language library for implementing the Model Context Protocol (MCP). This protocol defines a standard interface for AI models to interact with the outside world, supporting operations on various content types such as text, images, and audio.

🚀 Quick Start

Create a Server

// Create a service
server, err := mcp.NewServer(service, &types.ServerOptions{
    Address: ":8080",
    Capabilities: &types.ServerCapabilities{
        Prompts: &types.PromptCapabilities{
            ListChanged: true,
        },
        Resources: &types.ResourceCapabilities{
            ListChanged: true,
            Subscribe: true,
            Templates: true,
        },
    },
})

Create a Client

// Create a client
client, err := mcp.NewClient(&types.ClientOptions{
    ServerAddress: "localhost:8080",
    Type: "http",
    UseJSONRPC: true,
    SubscribeToNotifications: true,
})

✨ Features

Why Choose MCP?

• Unified Standard: Developed based on the latest MCP specification of 2025-03-26.
• Rich Functionality: Supports core functions such as prompts, tool calls, and resource operations.
• High Scalability: Built - in support for multiple media types and resource formats.
• Efficient and Reliable: Adopts an asynchronous non - blocking architecture with significant performance optimization.

Protocol Updates

New Features

• Full JSON RPC support
• Multimodal content transmission capability
• Pagination query function
• Resource template system
• Resource subscription notification
• Detailed server declarative capabilities
• Unified response handling mechanism

📦 Installation

go get github.com/your-organization/mcp-go

💻 Usage Examples

Basic Usage

Prompt Operations

prompt := &Prompt{
    Content: "帮我写一首诗",
    Parameters: map[string]string{
        "temperature": "0.7",
    },
}

response, err := client.SendPrompt(prompt)
if err != nil {
    // Handle errors
}

Tool Calls

toolResult, err := client.CallTool("image_generator", map[string]string{
    "prompt": "一片孤帆远影碧空尽",
})
if err != nil {
    // Handle errors
}

📚 Documentation

Interface Definitions

Server Interfaces

The service needs to implement the types.Server interface:

type Server interface {
    MCPService
    Initialize(ctx context.Context, options any) error
    Start() error
    Shutdown(ctx context.Context) error
}

The core functions are defined by the MCPService interface:

type MCPService interface {
    // List all prompts, supporting pagination queries
    ListPrompts(ctx context.Context, cursor string) (*PromptListResult, error)
    
    // Get the content of a specific prompt, with optional parameters
    GetPrompt(ctx context.Context, name string, args map[string]any) (*PromptResult, error)

    // List all tools, supporting pagination queries
    ListTools(ctx context.Context, cursor string) (*ToolListResult, error)

    // Call a specific tool, with optional parameters
    CallTool(ctx context.Context, name string, args map[string]any) (*CallToolResult, error)

    // List all resources, supporting pagination queries
    ListResources(ctx context.Context, cursor string) (*ResourceListResult, error)

    // Read the content of a specific resource
    ReadResource(ctx context.Context, uri string) (*ResourceContent, error)

    // Get the list of resource templates
    ListResourceTemplates(ctx context.Context) ([]ResourceTemplate, error)

    // Subscribe to change notifications for a specific resource
    SubscribeResource(ctx context.Context, resourceID string, callback func(*ResourceUpdateEvent)) error)
}

Client Interfaces

type MCPClient interface {
    // Send a prompt request
    SendPrompt(prompt *Prompt) (*Response, error)

    // Call a tool method
    CallTool(toolName string, args map[string]any) (*Response, error)

    // Subscribe to resource update notifications
    SubscribeResource(resourceID string, callback func(*ResourceUpdateEvent)) error)
}

Error Handling

type MCPError struct {
    Code    int    `json:"code"`
    Message string `json:"message"`
}

func (e *MCPError) Error() string {
    return e.Message
}

🤝 Contribution Guidelines

• Code Style: Follow the Google Go language style guide.
• Unit Testing: Achieve 100% unit test coverage.
• CI Checks: Pass CI checks before submitting a PR.
• Contribution Agreement: Abide by GitHub's contribution agreement.

📄 License

This project uses the MIT license. You are welcome to use and modify it freely.

For more detailed documentation, please refer to Official Documentation.