LangChain4j

LangChain4j is the Java library for building LLM-powered applications: unified API, easy RAG implementation, and declarative AI Services.

LangChain4j is the definitive, open-source Java library for integrating Large Language Models (LLMs) into enterprise applications. It provides a unified API, abstracting away the specifics of over 20 LLM providers (OpenAI, Gemini, Ollama) and 30+ vector stores (Pinecone, Milvus). The library's core strength is simplifying complex patterns like Retrieval-Augmented Generation (RAG), tool calling, and agent creation. Developers leverage the `AiServices` abstraction to declaratively define AI behavior, allowing for rapid development of robust, production-ready systems that integrate seamlessly with frameworks like Spring Boot and Quarkus.

https://github.com/langchain4j/langchain4j