mcpcraft

A lightweight and elegant SDK for building Model Context Protocol (MCP) servers fast.

Why mcpcraft?

The official MCP SDK is powerful but requires significant JSON-RPC boilerplate and manual schema definitions. mcpcraft wraps it to provide a streamlined, zero-config API with automatic TypeScript type inference and Zod runtime schema validation.

Related MCP server: TypeScript MCP Server Boilerplate

Install

npm install mcpcraft zod

Quick Start

import { createServer, tool } from "mcpcraft";

const server = createServer({ name: "my-mcp-server" });

server.add(tool({
  name: "get_weather",
  description: "Get the current weather for a location",
  input: {
    location: { type: "string", description: "City name" }
  },
  run: async ({ location }) => {
    return { temp: 22, condition: "Sunny", city: location };
  }
}));

server.start();

API Reference

createServer(options)

Creates a new server instance.

• options:

  • name: string (required) - Name of the server.

  • version?: string (optional) - Version of the server (default: 0.1.0).

  • description?: string (optional) - Description of the server.

Returns: A server instance with:

• add(item: Tool | Resource): Register a tool or a resource (chainable).

• start(): Starts the server listening on the standard input/output (stdio) transport.

• server: Access the underlying official Server instance if low-level control is needed.

tool(options)

Defines an MCP tool with schema validation.

• options:

  • name: string - The name of the tool (alphanumeric and underscores).

  • description: string - A description explaining what the tool does (used by the LLM).

  • input?: Record<string, { type: "string" | "number" | "boolean"; description?: string; required?: boolean }> - Parameter schemas.

  • run: (args) => Promise<any> | any - The execution logic. The args parameter is fully typed and inferred automatically based on input.

resource(options)

Defines an MCP resource or resource template.

• options:

  • name: string - The name of the resource.

  • description: string - Description of the resource.

  • uri: string - The URI (e.g. info://system) or URI Template (e.g. users://{userId}/profile).

  • mimeType?: string - The MIME type (e.g., application/json, text/plain).

  • fetch: (params) => Promise<any> | any - Handler that returns the resource content. If the URI is a template, params is populated with parsed dynamic variables.

Built on top of the official MCP SDK

mcpcraft is designed to play nicely with the official ecosystem. It runs directly on top of @modelcontextprotocol/sdk and uses the standard stdio transport, meaning it works out-of-the-box with Cursor, Claude Desktop, and all other MCP hosts.

License

MIT