Spring AI 2.0.0-M6 dropped on May 8, 2026. Buried in the release notes was the thing I had been waiting for since I first wired an MCP server in Java six months ago: native annotations. @McpTool, @McpResource, @McpPrompt, @McpComplete. All in core. All auto-registered.
If you've written an MCP server with the older Spring AI ToolCallback API, you remember the ritual. Build descriptors, register callbacks, wire up the transport manually, handle JSON schema by hand. The annotation API replaces all of it with a single annotation on a method. Spring AI generates the schema. Auto-configuration handles registration. You write the business logic.
This tutorial walks the full path: building a production MCP server, exposing tools and resources, handling async work with progress reporting, picking a transport, registering with Claude Code, and the gotchas I've hit that nobody mentions on the docs.
What changed in Spring AI 2.0 MCP annotations?
Spring AI 2.0 collapses MCP server and client wiring into a small set of annotations that Spring Boot auto-configuration picks up at startup. The annotated beans become the MCP surface for your Spring Boot app.
