VectorMCP

VectorMCP is a Ruby gem implementing the Model Context Protocol (MCP) server-side specification. It provides a framework for creating MCP servers that expose tools, resources, prompts, and roots to LLM clients.

Why VectorMCP?

• 🛡️ Security-First: Built-in input validation and schema checking prevent injection attacks
• ⚡ Production-Ready: Robust error handling, comprehensive test suite, and proven reliability
• 🔌 Multiple Transports: stdio for CLI tools, SSE for web applications
• 📦 Zero Configuration: Works out of the box with sensible defaults
• 🔄 Fully Compatible: Implements the complete MCP specification

Quick Start

gem install vector_mcp

require 'vector_mcp'

# Create a server
server = VectorMCP.new(name: 'MyApp', version: '1.0.0')

# Add a tool
server.register_tool(
  name: 'greet',
  description: 'Says hello to someone',
  input_schema: {
    type: 'object',
    properties: { name: { type: 'string' } },
    required: ['name']
  }
) { |args| "Hello, #{args['name']}!" }

# Start the server
server.run  # Uses stdio transport by default

That's it! Your MCP server is ready to connect with Claude Desktop, custom clients, or any MCP-compatible application.

Transport Options

Command Line Tools (stdio)

Perfect for desktop applications and process-based integrations:

server.run  # Default: stdio transport

Web Applications (HTTP + SSE)

Ideal for web apps and browser-based clients:

server.run(transport: :sse, port: 8080)

Connect via Server-Sent Events at http://localhost:8080/sse

Core Features

Tools (Functions)

Expose functions that LLMs can call:

server.register_tool(
  name: 'calculate',
  description: 'Performs basic math',
  input_schema: {
    type: 'object',
    properties: {
      operation: { type: 'string', enum: ['add', 'subtract', 'multiply'] },
      a: { type: 'number' },
      b: { type: 'number' }
    },
    required: ['operation', 'a', 'b']
  }
) do |args|
  case args['operation']
  when 'add' then args['a'] + args['b']
  when 'subtract' then args['a'] - args['b']
  when 'multiply' then args['a'] * args['b']
  end
end

Resources (Data Sources)

Provide data that LLMs can read:

server.register_resource(
  uri: 'file://config.json',
  name: 'App Configuration',
  description: 'Current application settings'
) { File.read('config.json') }

Prompts (Templates)

Create reusable prompt templates:

server.register_prompt(
  name: 'code_review',
  description: 'Reviews code for best practices',
  arguments: [
    { name: 'language', description: 'Programming language', required: true },
    { name: 'code', description: 'Code to review', required: true }
  ]
) do |args|
  {
    messages: [{
      role: 'user',
      content: {
        type: 'text',
        text: "Review this #{args['language']} code:\n\n#{args['code']}"
      }
    }]
  }
end

Security Features

VectorMCP provides comprehensive, opt-in security for production applications:

Built-in Input Validation

All inputs are automatically validated against your schemas:

# This tool is protected against invalid inputs
server.register_tool(
  name: 'process_user',
  input_schema: {
    type: 'object',
    properties: {
      email: { type: 'stri

... [View full README on GitHub](https://github.com/sergiobayona/vector_mcp#readme)