LangChain

LangChain is a popular open-source framework for building applications with large language models. It provides abstractions for chains (sequential LLM calls), tools, memory, retrieval, and output parsing. LangChain supports a wide range of LLM providers and integrations, making it a versatile toolkit for prototyping. While its flexibility makes it easy to get started, its extensive abstraction layers can add complexity and make debugging difficult in production systems. LangChain has a large community and ecosystem, including LangSmith for observability and LangGraph for agent orchestration.