🐍 Python 安装
# 要求 Python 3.10+
pip install langchain
# 安装模型提供商
pip install langchain-openai # OpenAI
pip install langchain-anthropic # Anthropic
pip install langchain-google-genai # Google
pip install langchain-community # 社区集成虚拟环境(推荐)
python -m venv .venv
source .venv/bin/activate # Linux/macOS
.venv\Scripts\activate # Windows
pip install langchain📜 JavaScript 安装
# npm
npm install langchain @langchain/openai
# yarn
yarn add langchain @langchain/openai
# pnpm
pnpm add langchain @langchain/openai🔑 环境变量配置
# .env 文件
OPENAI_API_KEY=sk-...
ANTHROPIC_API_KEY=sk-ant-...
GOOGLE_API_KEY=AIza...使用 python-dotenv 自动加载:
pip install python-dotenv
📦 可选依赖
✅ 验证安装
python -c "import langchain; print(langchain.__version__)"