langchain4j
LangChain4j is an open-source Java library for building large language model (LLM)-based applications on the JVM.
- Region
- Overseas
- Pricing
- Free
- Open source
- Yes
- GitHub Stars
- ★ 12.2k
- Source
- GitHub
- Added
- 2026-06-05
- Last verified
- 2026-06-05
Overview
LangChain4j is an open-source Java library designed to simplify integrating large language models (LLMs) into applications running on the JVM. It provides a unified API to access popular LLM providers and vector storage services, making it easy to implement tool calling, agents, and retrieval-augmented generation. Additionally, it seamlessly integrates with enterprise-grade Java frameworks like Quarkus and Spring Boot, making it ideal for developers who want to leverage LLM capabilities without diving into the intricacies of specific APIs.
Key features
- ▪Supports 20+ LLM providers
- ▪Compatible with 30+ vector storage options
- ▪Easy switching between different LLMs or storage backends
- ▪Built-in collection of practical toolkits
- ▪Seamless integration with mainstream Java frameworks
Use cases
Pros
- ＋Unified and easy-to-use API
- ＋Rich set of example resources
- ＋Follows Java programming conventions
- ＋Strong community support
Limitations / notes
- －Limited to JVM environments
- －Requires basic Java knowledge
Who it's for
This overview was compiled by AI from public sources and may contain inaccuracies — please refer to the official site.
FAQ
Is LangChain4j a port of the Python version of LangChain?
No, it is a standalone library specifically designed for Java.
Something wrong? Let us know on the About page and we'll fix it.