Latest MCP spec now supported in mcp-handler

[email protected] 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:

npm install mcp-handler@^2 @modelcontextprotocol/server@^2 zod@^4

Create a Next.js route handler:

import { createMcpHandler } from "mcp-handler";
import { z } from "zod";
const handler = createMcpHandler((server) => {
  server.registerTool(
    "roll_dice",
    {
      description: "Roll an N-sided die",
      inputSchema: z.object({
        sides: z.number().int().min(2),
      }),
    },
    async ({ sides }) => {
      const value = 1 + Math.floor(Math.random() * sides);
      return {
        content: [
          {
            type: "text",
            text: `🎲 You rolled a ${value}!`,
          },
        ],
      };
    },
  );
});

MCP clients can connect to /api/mcp.

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

Copy link to headingBefore 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.