warningBreaking change
mcp-handler 2.0 breaks pre-2.0 setups
- Announced
- 30 Jul 2026
- Effective
- no date announced
- Version
- 2.0.0
- Source
- the vendor’s own page · last checked 2 Oct 2026
What breaks
Upgrading to mcp-handler 2.0.0 changes requirements and removes an old transport.
- Requires Node.js 20 or later
- Requires zod4
- Replaces @modelcontextprotocol/sdk with @modelcontextprotocol/server
- Tool, prompt, and resource definitions must use SDK v2 registration APIs (e.g. registerTool with z.object(...)) and Standard Schema inputs
- The HTTP+SSE transport is removed; requests to /sse and /message return 410 Gone
What to do
Move to mcp-handler 2.0.0 once your setup meets the new requirements.
- Upgrade to Node.js 20 or later
- Upgrade to zod4
- Switch from @modelcontextprotocol/sdk to @modelcontextprotocol/server
- Rewrite tool, prompt, and resource definitions using SDK v2 registration APIs
- If clients still depend on HTTP+SSE, stay on mcp-handler 1.x while migrating them to Streamable HTTP
What the vendor said
mcp-handler 2.0.0 adds support for the 2026-07-28 MCP spec and MCP TypeScript SDK v2, while still allowing stateless Streamable HTTP clients to keep connecting to the same /mcp endpoint. The release changes runtime requirements, the SDK package, and the registration APIs used to define tools, prompts, and resources.