LangChain

framework
https://langchain.com

LangChain is the most widely adopted framework for building applications powered by language models. It provides abstractions for chains (sequential LLM calls), agents (autonomous tool-using systems), RAG (retrieval-augmented generation), and memory.

LangGraph, LangChain's agent orchestration layer, enables building stateful, multi-step agent workflows as graphs. LangSmith provides observability and tracing for debugging agent behavior in production.

The framework supports 700+ integrations with tools, vector stores, LLM providers, and data sources. While it adds abstraction overhead, it significantly speeds up development for complex LLM applications.

Key Features

  • LangGraph for stateful agent workflows
  • LangSmith for tracing and observability
  • 700+ integrations
  • Built-in RAG and memory patterns
  • Multi-language (Python, JavaScript/TypeScript)

Pros

  • +Largest ecosystem and community
  • +Comprehensive documentation
  • +Rapid prototyping
  • +Production-ready with LangSmith

Cons

  • Heavy abstraction layer
  • Frequent breaking changes
  • Can be over-engineered for simple use cases