npm install mcp-toolkit-ts

import { MCPServer, ToolDefinition } from 'mcp-toolkit-ts';

const server = new MCPServer('my-agent-tools', '1.0.0');

// Register a custom typed tool
server.registry.register({
  name: 'calculate_growth',
  description: 'Calculate compounded interest rate for financial simulations',
  parameters: {
    principal: { type: 'number', description: 'Initial balance', required: true },
    rate: { type: 'number', description: 'Annual interest rate percentage', required: true },
    years: { type: 'number', description: 'Simulation duration in years', required: true },
  },
  handler: async ({ principal, rate, years }) => {
    return principal * Math.pow(1 + rate / 100, years);
  },
});

// Handle incoming MCP JSON-RPC call
const response = await server.handleRequest({
  method: 'tools/call',
  params: {
    name: 'calculate_growth',
    arguments: { principal: 1000, rate: 5, years: 3 }
  }
});

console.log('Result:', response); // 1157.625