| name | langchain-install-auth |
|---|---|
| description | 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". |
| allowed-tools | Read, Write, Edit, Bash(npm:*), Bash(pip:*), Grep |
| version | 1.0.0 |
| license | MIT |
| author | Jeremy Longshore <[email protected]> |
LangChain Install & Auth
Overview
Set up LangChain SDK and configure LLM provider authentication credentials.
Prerequisites
- Python 3.9+ or Node.js 18+
- Package manager (pip, poetry, or npm)
- LLM provider account (OpenAI, Anthropic, Google, etc.)
- API key from your LLM provider dashboard
Instructions
Step 1: Install LangChain Core
# 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
Step 2: Configure Authentication
# 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
Step 3: Verify Connection
from langchain_openai import ChatOpenAI
llm = ChatOpenAI(model="gpt-4o-mini")
response = llm.invoke("Say hello!")
print(response.content)
Output
- Installed LangChain packages in virtual environment
- Environment variables or .env file with API keys
- Successful connection verification output
Error Handling
| 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 |
Examples
Python Setup (OpenAI)
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
)
Python Setup (Anthropic)
from langchain_anthropic import ChatAnthropic
llm = ChatAnthropic(
model="claude-3-5-sonnet-20241022",
temperature=0.7
)
TypeScript Setup
import { ChatOpenAI } from "@langchain/openai";
const llm = new ChatOpenAI({
modelName: "gpt-4o-mini",
temperature: 0.7
});
Resources
Next Steps
After successful auth, proceed to langchain-hello-world for your first chain.