Simply MCP

The fastest way to build MCP servers. Tell an AI what you need, or write it yourself.

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Tier 1 Compatible Framework

Simply-MCP is a Tier 1 Compatible Community Framework, providing 100% coverage of the Model Context Protocol specification (2025-11-25) and all active Standards Track SEPs.

• SEP-1865 (MCP Apps): Native support for rich, interactive UIs.
• SEP-1036 (URL Elicitation): Secure out-of-band user interaction.
• SEP-1577 (Sampling): Advanced LLM sampling with tool-use and context support.
• SEP-2339 (Tasks): Durable, asynchronous background operations.

View the full Compliance Report.

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What You Can Build

Real-time dashboards • Interactive maps • Financial modeling • Data visualization

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Two Ways to Build

Path 1: Let AI Build It (Recommended)

With Claude Code or any AI coding tool:

> Build me an MCP server that monitors system resources
  and shows a real-time dashboard

The AI uses Simply-MCP's factory API to generate a complete, production-ready server. Iterate by describing what you want to change.

Path 2: Write It Yourself

import { createServer, createTool } from 'simply-mcp';

export const server = createServer({
  name: 'my-server',
  version: '1.0.0',
});

export const addTool = createTool({
  description: 'Add two numbers',
  params: {
    a: { type: 'number', description: 'First number' },
    b: { type: 'number', description: 'Second number' },
  },
  handler: ({ a, b }) => ({ sum: a + b }),
});

npx simplymcp run server.ts            # Run (stdio for Claude)
npx simplymcp run server.ts --port 3000  # Run (HTTP)

Both paths produce the same thing: a type-safe MCP server with tools, resources, and optional UI.

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Install

npm install simply-mcp

The bare install pulls only the core MCP runtime (SDK, zod, yargs, MCP Apps). Opt-in features are declared as optional peer dependencies — install only the ones your server uses:

Feature you use	Add
HTTP transport	npm install hono @hono/node-server
WebSocket transport	npm install ws
.ts server entries via the CLI	npm install esbuild tsx
Interface API (decorators / IServer)	npm install typescript
OAuth (bcrypt hashing)	npm install bcrypt
OAuth (Redis storage)	npm install ioredis
MCP Apps with React UI	npm install @babel/standalone @remote-dom/core @remote-dom/react
UI minification (production)	npm install postcss cssnano html-minifier-terser terser
HTML input sanitization	npm install dompurify
Code execution sandbox	npm install quickjs-emscripten
File-watch dev mode	npm install chokidar
Resource SQLite backend	npm install better-sqlite3
Express-router OAuth	npm install express

Missing-peer errors point at the exact package to install.

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One Codebase. Multiple Platforms.

Claude Desktop	ChatGPT	Your App
✓	✓	✓

Write once. The OpenAI adapter is built-in.

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Features

Feature	What it does
MCP Apps	Rich UIs with React, Vue, or any framework
OpenAI Compatible	Same code deploys to ChatGPT
Type Inference	Define once, types flow everywhere
Code Execution	Sandboxed QuickJS for AI-generated code
Python Handlers	Mix TypeScript and Python in one server
Multi-Transport	stdio, HTTP, WebSocket — pick any
Bundle Ready	npx simplymcp bundle → single file

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Why Simply-MCP?

// The old way: schema, types, validation, handler — all separate
const schema = { name: 'add', inputSchema: { type: 'object', properties: { a: { type: 'number' } } } };
interface AddParams { a: number; b: number; }
// ...more boilerplate

// Simply-MCP: one definition, fully typed
export const addTool = createTool({
  description: 'Add two numbers',
  params: {
    a: { type: 'number', description: 'First' },
    b: { type: 'number', description: 'Second' },
  },
  handler: ({ a, b }) => ({ sum: a + b }),  // Fully typed!
});

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CLI

npx simplymcp lint server.ts             # Validate before running
npx simplymcp run server.ts              # Run (stdio)
npx simplymcp run server.ts --port 3000  # Run (HTTP)
npx simplymcp dev server.ts --port 3000  # Dev mode with hot reload
npx simplymcp bundle server.ts           # Bundle for production

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Claude Desktop Integration

{
  "mcpServers": {
    "my-server": {
      "command": "npx",
      "args": ["simplymcp", "run", "/path/to/server.ts"]
    }
  }
}

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Documentation

Guide	Description
Quick Start	Get running in 5 minutes
AI Workflow	Building servers with AI assistance
API Reference	createServer, createTool, createResource, createApp
CLI	Full command reference
Transport	stdio, HTTP, WebSocket modes
Code Execution	QuickJS sandbox for tool chaining
Typed Tool Results	Canonical structuredContent + outputSchema parsing contract
Bundling	Production deployment
Examples	Annotated example index
FAQ	Common questions

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Examples

Example	Description
minimal.ts	Absolute minimum (~20 lines)
complete.ts	All core features
code-execution.ts	Sandbox mode

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License

Simply-MCP is free for non-commercial use (research, personal projects, education, evaluation). Commercial use requires a separate license. See LICENSE for details.

For commercial licensing: licensing@cwinnov.com

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NPM · GitHub · Issues

Built with the Model Context Protocol SDK by Anthropic.