Vercel's mcp-handler 2.0.0 adopts 2026-07-28, answers /sse with 410 Gone, and drops its Redis dependency

Vercel announced mcp-handler 2.0.0 on July 30, a day after the package itself hit npm. The framework adapter, which spins up MCP servers on Next.js and other web frameworks, now serves the stateless 2026-07-28 protocol natively, including per-request metadata and server/discover, alongside a stateless compatibility layer for 2025-era Streamable HTTP clients. Both protocols run with no Redis dependency or session storage, and existing stateless clients keep connecting to the same /mcp endpoint.

The legacy HTTP+SSE transport is removed outright rather than aliased: requests to /sse and /message return 410 Gone, with Vercel's guidance to stay on 1.x while migrating clients that still depend on it. That is a deliberately different retirement shape from Cloudflare's same-week choice to keep /sse URLs resolving as aliases, and server operators will encounter both.

The 2.x line has breaking dependency changes: @modelcontextprotocol/server ^2.0.0 replaces the old @modelcontextprotocol/sdk peer dependency, zod moves to ^4, and Node.js 20 or later is required. Registration follows SDK v2 (registerTool with Standard Schema inputs), and the GitHub release notes describe the release as the "CIMD era", with Dynamic Client Registration deprecated by the spec in favor of Client ID Metadata Documents. The redis dependency and the redisUrl, maxDuration, and sessionIdGenerator options became deprecated no-ops in 2.0.0, and v2.1.0, published July 30 and now npm's latest, removed the 1.x compatibility shims entirely.

One naming caution: mcp-handler is the framework adapter, distinct from Vercel MCP, the hosted first-party server at mcp.vercel.com, which announced its own 2026-07-28 support on July 31 and is built on this handler.