LangChain
LangChain
The default open-source framework for composing LLM apps.
Python + TypeScript framework for chaining prompts, tools, retrievers, and memory into LLM applications. Ubiquitous in the ecosystem; pairs with LangGraph for agent orchestration and LangSmith for tracing.
Worth knowing
Started Oct 2022 as Harrison Chase's side project while at Robust Intelligence; became a unicorn at $1.25B in 2025.
- framework
- python
- typescript
- rag
- +1