LangChain
Framework for developing applications powered by language models through composability.
Preview
Problem
Building complex applications with Large Language Models requires orchestrating multiple calls, managing state, and integrating with external data sources, which is tedious and repetitive.
Solution
A comprehensive open-source framework providing standardized abstractions for chains, agents, memory, and data retrieval (RAG).
Challenge
Maintaining a stable API surface while the underlying LLM ecosystem evolves at a breakneck pace with new models and paradigms weekly.
Key Features
- Modular components
- Pre-built chains
- Vector store integrations
- Agent orchestration
Tech Choices
Target User
AI Engineers, Data Scientists, and Backend Developers building generative AI apps.
Impact
"Became the industry standard framework for building LLM applications, powering thousands of production AI systems."
How to Use
Install
Run 'pip install langchain' or 'npm install langchain' in your terminal.
Set API Keys
Export your LLM provider API keys (e.g., OPENAI_API_KEY) in your environment variables.
Build a Chain
Import a PromptTemplate and an LLM, create a standard LCEL (LangChain Expression Language) pipeline, and invoke it with your inputs.
Quick Details
- Pricing
- Free
- Platforms
- Python, TypeScript
- Updated
- 8/19/2026