retrieve documents from the search index. • Query keywords are extracted from the whole chat conversation with additional call to Open AI. • Retrieval mode: text, vectors, hybrid. • OpenAI embedding API to convert the user's query text to an embeddings vector ( vector or hybrid) • Hybrid search improve search results mixing text search and vector search. • Can be further simplified with SK VectorStore abstraction and AzureAISearchVectoreStore implementation. No need to create an explicit database search plugin, provides features for performing similarity searches over databases https://github.com/Azure-Samples/azure-search-openai-demo-java/blob/main/app/backend/src/main/java/com/microsoft/openai/samples/rag/retrieval/AzureAISearchRetriever.java https://github.com/Azure-Samples/azure-search-openai-demo- java/blob/main/app/backend/src/main/java/com/microsoft/openai/samples/rag/retrieval/AzureAISearc hRetriever.java