Install and configure LangChain SDK/CLI authentication. Use when setting up a new LangChain integration, configuring API keys, or initializing LangChain in your project. Trigger with phrases like "install langchain", "setup langchain", "langchain auth", "configure langchain API key", "langchain credentials".
Set up LangChain SDK and configure LLM provider authentication credentials.
# Python (recommended)
pip install langchain langchain-core langchain-community
# Or with specific providers
pip install langchain-openai langchain-anthropic langchain-google-genai
# Node.js
npm install langchain @langchain/core @langchain/community
# OpenAI
export OPENAI_API_KEY="your-openai-key"
# Anthropic
export ANTHROPIC_API_KEY="your-anthropic-key"
# Google
export GOOGLE_API_KEY="your-google-key"
# Or create .env file
echo 'OPENAI_API_KEY=your-openai-key' >> .env
from langchain_openai import ChatOpenAI
llm = ChatOpenAI(model="gpt-4o-mini")
response = llm.invoke("Say hello!")
print(response.content)
| Error | Cause | Solution |
|---|---|---|
| Invalid API Key | Incorrect or expired key | Verify key in provider dashboard |
| Rate Limited | Exceeded quota | Check quota limits, implement backoff |
| Network Error | Firewall blocking | Ensure outbound HTTPS allowed |
| Module Not Found | Installation failed | Run pip install again, check Python version |
| Provider Error | Service unavailable | Check provider status page |
import os
from langchain_openai import ChatOpenAI
# Ensure API key is set
assert os.environ.get("OPENAI_API_KEY"), "Set OPENAI_API_KEY"
llm = ChatOpenAI(
model="gpt-4o-mini",
temperature=0.7,
max_tokens=1000
)
from langchain_anthropic import ChatAnthropic
llm = ChatAnthropic(
model="claude-3-5-sonnet-20241022",
temperature=0.7
)
import { ChatOpenAI } from "@langchain/openai";
const llm = new ChatOpenAI({
modelName: "gpt-4o-mini",
temperature: 0.7
});
After successful auth, proceed to langchain-hello-world for your first chain.