MCP Robot - Go Server Library for Model Context Protocol

A Go server library for implementing Model Context Protocol (MCP) servers, built following Go conventions and inspired by the standard net/http package.

⚠️ Work in Progress: This library currently supports tools only. Resources, prompts, and other MCP features are planned for future releases.

🚀 Features

• Type-Safe Tool Definitions: Leverage Go generics for compile-time type safety
• Fluent Builder API: Intuitive schema building with method chaining
• Automatic Input Validation: Input arguments are automatically validated against input schemas
• Multiple Server Types: HTTP and Stdio transport support
• Rich Result Types: Support for text, media, structured data, and resource links
• Go Conventions: Follows standard Go patterns, inspired by `net/http

📦 Installation

go get github.com/makarski/mcp-robot

🔧 Quick Start

package main

import (
    "github.com/makarski/mcp-robot/server"
    "github.com/makarski/mcp-robot/tools"
)

func main() {
    // Define a tool with input/output schemas
    weatherTool := tools.NewTool("get_weather").
        Title("Weather Information").
        Description("Get current weather for a location").
        Input().
            WithString("location", "City name or coordinates", true).
            WithBoolean("celsius", "Use celsius temperature", false).
            Done().
        Output().
            WithString("status", "Response status", true).
            WithNumber("temperature", "Temperature value", true).
            WithString("conditions", "Weather conditions", true).
            Done().
        MarkReadOnly(true).
        Build()

    // Create tool function
    weatherFunc := tools.ToolFunc[tools.ToolResultStructured](func(params map[string]any) (tools.ToolResultStructured, error) {
        location := params["location"].(string)
        return tools.ToolResultStructured{
            "status": "success",
            "temperature": 22.5,
            "conditions": "Sunny",
            "location": location,
        }, nil
    })

    // Build and start server
    server := server.NewServerBuilder("weather-server", "1.0.0").
        WithTool(weatherTool, weatherFunc).
        BuildHTTPServer()

    server.ListenAndServe("mcp")(":8080", nil)
}

Stdio Server

server := server.NewServerBuilder("weather-server", "1.0.0").
    WithTool(weatherTool, weatherFunc).
    BuildStdioServer()

// Start server
server.ListenAndServe()

🏗️ Tool Definition Builder

The library provides validation for both input and output schemas

Basic Types

tool := tools.NewTool("example").
    Input().
        WithString("name", "User name", true).           // required
        WithNumber("age", "User age", false).            // optional
        WithBoolean("active", "Is active", true).
        Done().
    Build()

Arrays

tool := tools.NewTool("process_data").
    Input().
        WithArray("items", "List of items to process", true).
            Of("object", "Individual item").
                WithString("id", "Item ID", true).
                WithString("name", "Item name", true).
                Done().
        Done().
    Build()

Nested Objects

Arrays

tool := tools.NewTool("process_data").
    Input().
        WithArray("items", "List of items to process", true).
            Of("object", "Individual item").
                WithString("id", "Item ID", true).
                WithString("name", "Item name", true).
                Done().
        Done().
    Build()

🎯 Tool Result Types

Text Results

func textTool(params map[string]any) (tools.ToolResultText, error) {
    return tools.NewToolResultText("Hello, World!"), nil
}

Structured Results

func structuredTool(params map[string]any) (tools.ToolResultStructured, error) {
    return tools.ToolResultStru

... [View full README on GitHub](https://github.com/makarski/mcp-robot#readme)