Add rag module: Spring AI 2.0 RAG with pgvector, chunking, reranking and a faithfulness check

Co-Authored-By: Claude Sonnet 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01B38FGKKam5SCGgwgduVAh3
2026-09-21 18:52:48 +00:00
commit 2d89b99652
62 changed files with 3686 additions and 0 deletions
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+spring:
+  application:
+    name: spring-ai-rag
+  threads:
+    virtual:
+      enabled: true
+  datasource:
+    url: ${RAG_PG_URL:jdbc:postgresql://localhost:5432/ragdb}
+    username: ${RAG_PG_USER:raguser}
+    password: ${RAG_PG_PASSWORD:ragpass}
+  ai:
+    openai:
+      api-key: ${OPENAI_API_KEY}
+      # In 2.0.1 the "options" level (chat.options.model) is marked deprecated in the jars' metadata; the
+      # settings now sit directly under chat: and embedding:. Spring Boot ignores keys it does not know,
+      # so a misspelt key fails nothing: ConfigKeysTest checks every spring.ai key against the jars.
+      chat:
+        model: gpt-4o
+        temperature: 0.1
+      embedding:
+        model: text-embedding-3-small
+    vectorstore:
+      pgvector:
+        schema-name: rag
+        table-name: document_chunks
+        index-type: HNSW
+        distance-type: COSINE_DISTANCE
+        dimensions: 1536
+        # false: the schema comes from init.sql, not from the application.
+        initialize-schema: false
+
+rag:
+  retrieval:
+    top-k: 20
+    similarity-threshold: 0.0
+  rerank:
+    top-n: 5
+  chunking:
+    chunk-size: 512
+    min-chunk-size-chars: 350
+
+management:
+  endpoints:
+    web:
+      exposure:
+        include: health, prometheus