Summary
Vercel MCP now supports the 2026-07-28 Model Context Protocol specification, giving newer clients a stateless request model and hardened authorization while 2025-protocol clients keep working from the same endpoint through MCP SDK v2 and mcp-handler 2.x.
What changed
Vercel updated its MCP implementation to the 2026-07-28 spec, adopting a stateless protocol core and hardened authorization served from the same endpoint via the official MCP SDK v2 and mcp-handler 2.x, with existing clients needing no changes.
Why it matters
The 2026-07-28 spec removes the session handshake and Mcp-Session-Id header, so a stateless core scales more predictably for concurrent agent connections while hardened authorization tightens the trust boundary as MCP becomes the default tool interface for agents.
Evidence excerpt
Vercel MCP now supports the 2026-07-28 MCP specification, with a stateless protocol core and hardened authorization. Existing clients need no changes. Both protocol versions are served from the same endpoint through the official MCP SDK v2 and mcp-handler 2.x.