# Helixdevelopment Helixagent Langchain Install Auth

> LangChain Install & Auth

- Skill: `tomevault-io/helixdevelopment-helixagent-langchain-install-auth` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add tomevault-io/helixdevelopment-helixagent-langchain-install-auth`
- Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/helixdevelopment-helixagent-langchain-install-auth/raw
- Safety review: pending (external: skill-scanner PASS, skillspector CAUTION)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: tomevault-io (https://skillmd.com/u/tomevault-io)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/tomevault-io/helixdevelopment-helixagent-langchain-install-auth

---


# 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
```bash
# 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
```bash
# 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
```python
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)
```python
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)
```python
from langchain_anthropic import ChatAnthropic

llm = ChatAnthropic(
    model="claude-3-5-sonnet-20241022",
    temperature=0.7
)
```

### TypeScript Setup
```typescript
import { ChatOpenAI } from "@langchain/openai";

const llm = new ChatOpenAI({
  modelName: "gpt-4o-mini",
  temperature: 0.7
});
```

## Resources
- [LangChain Documentation](https://python.langchain.com/docs/)
- [LangChain JS/TS](https://js.langchain.com/docs/)
- [OpenAI API Keys](https://platform.openai.com/api-keys)
- [Anthropic Console](https://console.anthropic.com/)

## Next Steps
After successful auth, proceed to `langchain-hello-world` for your first chain.

---
> Source: [HelixDevelopment/HelixAgent](https://github.com/HelixDevelopment/HelixAgent) — distributed by [TomeVault](https://tomevault.io).
<!-- tomevault:4.0:skill_md:2026-06-16 -->