mcp-handler v2.0、最新 MCP 仕様をサポート

mcp-handler@2.0.0 is now available with support for the 2026-07-28 Model Context Protocol specification and MCP TypeScript SDK v2.

We originally built mcp-handler to make it easier to spin up MCP servers on popular web frameworks including Next, Nuxt, Svelte, and more.

With the new 2.0 release, the handler now supports:

The stateless 2026-07-28 protocol, served natively, including per-request metadata and server/discover

A stateless compatibility layer for clients using 2025-era Streamable HTTP

Both protocols with no Redis dependency or session storage

Existing stateless Streamable HTTP clients can continue connecting to the same /mcp endpoint while servers adopt the latest protocol.

Install the new packages:

Create a Next.js route handler:

MCP clients can connect to /api/mcp.

Get started with the Next.js MCP server template, updated for mcp-handler 2.0.

Before you upgrade

Version 2 requires Node.js 20 or later and zod4, and replaces @modelcontextprotocol/sdk with @modelcontextprotocol/server.

Tool, prompt, and resource definitions now use the SDK v2 registration APIs and Standard Schema inputs, such as registerTool with z.object(...).

The deprecated HTTP+SSE transport has been removed. Requests to /sse and /message return 410 Gone. If your clients still depend on that transport, remain on mcp-handler 1.x while migrating them to Streamable HTTP.

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