LangChain

An open-source framework for building context-aware reasoning applications powered by large language models (LLMs).

LangChain interface

Overview

LangChain provides developers with modular components and tools to create sophisticated AI applications. It simplifies integrating LLMs with external data sources, enabling tasks like question answering over documents, chatbot creation, and agentic workflows. LangChain supports various LLMs, data loaders, and vector stores, making it a versatile choice for building robust AI systems.

Key Features

Modular Components: Chains, Agents, Memory

Provides building blocks like Chains (sequences of calls), Agents (LLMs using tools), and Memory (persisting state) for complex applications.

Data Integration & Retrieval

Connects LLMs to external data sources (files, APIs, databases) using Document Loaders and Retrievers for context-aware responses.

Ecosystem & Tooling (LangSmith)

Offers a rich ecosystem, integrations with numerous LLMs/tools, and LangSmith for debugging, testing, and monitoring LLM applications.

Use Cases

  • Building RAG (Retrieval-Augmented Generation) systems
  • Creating AI agents and chatbots
  • Developing LLM-powered applications

Pricing

The core LangChain framework is open-source and free; LangSmith (observability platform) offers free and paid subscription tiers.

For the most current details, please visit the official pricing page .