typescript-sdk

# MCP TypeScript SDK

<!-- prettier-ignore -->
> [!IMPORTANT]
> **This is the `main` branch: v2 of the SDK** (`@modelcontextprotocol/server`, `@modelcontextprotocol/client`), the stable release line, implementing the [2026-07-28 MCP spec](https://modelcontextprotocol.io/specification/2026-07-28). Start with the [v2 documentation](https://ts.sdk.modelcontextprotocol.io/v2/); coming from v1, see the [migration guide](https://ts.sdk.modelcontextprotocol.io/v2/migration/upgrade-to-v2).
>
> **v1.x** (`@modelcontextprotocol/sdk`) lives on the [`v1.x` branch](https://github.com/modelcontextprotocol/typescript-sdk/tree/v1.x) and continues to receive bug fixes and security updates for at least six months after the v2 release (2026-07-27). Its documentation is at [ts.sdk.modelcontextprotocol.io](https://ts.sdk.modelcontextprotocol.io/).
>
> Found a problem in v2? [Open an issue](https://github.com/modelcontextprotocol/typescript-sdk/issues/new?template=v2-feedback.yml).

<!-- prettier-ignore -->
> [!NOTE]
> **Contributors without write access can have one open pull request at a time.** Draft pull requests don't count toward the limit. For a feature or a larger change, please [open an issue](https://github.com/modelcontextprotocol/typescript-sdk/issues/new/choose) first; see [CONTRIBUTING.md](CONTRIBUTING.md).

[![NPM Version - Server](https://img.shields.io/npm/v/%40modelcontextprotocol%2Fserver?label=%40modelcontextprotocol%2Fserver)](https://www.npmjs.com/package/@modelcontextprotocol/server)
[![NPM Version - Client](https://img.shields.io/npm/v/%40modelcontextprotocol%2Fclient?label=%40modelcontextprotocol%2Fclient)](https://www.npmjs.com/package/@modelcontextprotocol/client) ![Apache-2.0 licensed](https://img.shields.io/npm/l/%40modelcontextprotocol%2Fserver)

<details>
<summary>Table of Contents</summary>

- [Overview](#overview)
- [Packages](#packages)
- [Installation](#installation)
- [Getting Started](#getting-started)
- [Documentation](#documentation)
- [Contributing](#contributing)
- [License](#license)

</details>

## Overview

The Model Context Protocol (MCP) allows applications to provide context for LLMs in a standardized way, separating the concerns of providing context from the actual LLM interaction.

This repository contains the TypeScript SDK implementation of the MCP specification. It runs on **Node.js**, **Bun**, and **Deno**, and ships:

- MCP **server** libraries (tools/resources/prompts, Streamable HTTP, stdio, auth helpers)
- MCP **client** libraries (transports, high-level helpers, OAuth helpers)
- Optional **middleware packages** for specific runtimes/frameworks (Express, Fastify, Hono, Node.js HTTP)
- Runnable **examples** (under [`examples/`](https://github.com/modelcontextprotocol/typescript-sdk/tree/main/examples))

## Packages

This monorepo publishes split packages:

- **`@modelcontextprotocol/server`**: build MCP servers
- **`@modelcontextprotocol/client`**: build MCP clients

Tool and prompt schemas use [Standard Schema](