LangChain
The most popular framework for building LLM-powered agents
🤖 Agent-friendly⭐ Featured
Pricing
freeCategory
FrameworkAPI Available
✓ YesOpen Source
✓ YesDescription
Agent 开发最主流的框架。提供工具调用、记忆管理、RAG、多步骤推理等核心能力，生态极丰富，支持几乎所有 LLM 和外部服务集成。配套 LangGraph 可构建复杂的有状态 Agent 工作流。
💰 框架本身开源免费，LangSmith 观测平台有付费套餐
🤖 Quick Start for Agents
# Get tool info via AgentDex API
curl https://www.agentdex.top/api/tools/langchain# Build a simple agent with LangChain
from langchain.agents import initialize_agent
from langchain.tools import Tool
tools = [Tool(name="calc", func=lambda x: eval(x))]
agent = initialize_agent(tools, llm, agent="zero-shot-react-description")# Get this tool via AgentDex API
curl https://www.agentdex.top/api/tools/langchain