Files
spring-ai/README.md
T
Claude d73620e305 Add mcp-secure module: OAuth2 resource server, per-tool scopes, and MDC audit logging for an MCP server
- JWT bearer authentication via spring-boot-starter-oauth2-resource-server, validated against
  an RSA keypair DemoJwtIssuer generates and signs with locally, so the whole module runs and
  tests deterministically with no external Authorization Server.
- @PreAuthorize on @McpTool methods maps SCOPE_orders:read / SCOPE_orders:write to lookup_order
  and refund_order -- confirmed empirically that method security actually applies to a bean the
  MCP server autoconfiguration invokes via reflection, since it invokes the Spring-proxied bean.
- SecurityFilterChain requires authentication on every request, so tool discovery (initialize/
  tools-list) is rejected before it ever reaches the MCP dispatcher -- no anonymous tool listing.
- ToolAuditAspect logs every tool call through MDC (subject, scopes, tool, outcome), pinned to
  @Order(150) -- between AuthorizationInterceptorsOrder.PRE_FILTER (100) and PRE_AUTHORIZE (200)
  -- so it wraps @PreAuthorize's interceptor and still logs denied calls, not only successful
  ones. Verified with a real Logback ListAppender reading back real MDC contents.

Two real findings worth a note: Spring Boot 4.0 renamed spring-boot-starter-aop to
spring-boot-starter-aspectj (the old artifact stops existing after 4.0.0-M2); and Spring AI's
AbstractSyncMcpToolMethodCallback.createSyncErrorResult concatenates an exception's message with
its root cause's message, which duplicates the text when they're the same exception -- visible
directly in the captured output when @PreAuthorize denies a call ("Access Denied\nAccess Denied").

5/5 tests pass against a real running server over real Streamable HTTP, with real signed JWTs.

Co-Authored-By: Claude Sonnet 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01FtpJvZfg4nvLvtzgJTDWpB
2026-09-23 15:13:36 +00:00

2.3 KiB

spring-ai

Runnable companion code for the Spring AI articles on ankurm.com. One directory per module; each module is one commit and carries its own README, tests and captured output.

Module What it is Article
getting-started/ One ChatClient bean, three endpoints (plain call, templated system prompt, streaming), and a test proving spring.ai.model.chat switches providers with zero code change. Spring Boot 4.1.1, Spring AI 2.0.1, Java 25. Spring AI 2.0 in 10 Minutes: ChatClient on Spring Boot 4.1
rag/ Ingest PDFs, chunk, retrieve from pgvector, rerank, answer, check the answer. Spring Boot 4.1.1, Spring AI 2.0.1, Java 25. Production-grade RAG with Spring AI and the complete example
mcp-server/ An order-lookup service exposed as MCP tools, a resource, and a prompt with @McpTool/@McpResource/@McpPrompt, served over Streamable HTTP (Spring AI 2.0's default MCP server transport). Spring Boot 4.1.1, Spring AI 2.0.1, Java 25. Build an MCP Server with Spring AI 2.0
mcp-client/ ChatClient calling tools from two real external MCP servers (filesystem, git) over stdio via defaultToolCallbacks(ToolCallbackProvider...), contrasted with a local @Tool method, with every call logged through one Micrometer ObservationHandler. Spring Boot 4.1.1, Spring AI 2.0.1, Java 25. Spring AI MCP Client: Calling External MCP Servers from ChatClient
mcp-secure/ The mcp-server article's order-lookup tools behind a real OAuth2 resource server: JWT validation, one scope per tool via @PreAuthorize, unauthenticated tool discovery rejected outright, and every call audit-logged through MDC -- denials included. Spring Boot 4.1.1, Spring AI 2.0.1, Spring Security 7.1.1, Java 25. Securing an MCP Server with Spring Security 7

Upgrading from Spring AI 1.x: migration guide.