langfuse-install-auth

# Langfuse Install & Auth ## Overview Set up Langfuse SDK and configure authentication for LLM observability and tracing. ## Prerequisites - Node.js 18+ or Python 3.9+ - Package manager (npm, pnpm, or pip) - Langfuse account (cloud or self-hosted) - Public and Secret keys from Langfuse dashboard ## Instructions ### Step 1: Install SDK ```bash # Node.js / TypeScript npm install langfuse # or pnpm add langfuse # Python pip install langfuse ``` ### Step 2: Get API Keys 1. Go to Langfuse dashboard (https://cloud.langfuse.com or your self-hosted instance) 2. Navigate to Settings -> API Keys 3. Create new API key pair (Public Key + Secret Key) 4. Note your host URL (cloud: `https://cloud.langfuse.com`) ### Step 3: Configure Authentication ```bash # Set environment variables export LANGFUSE_PUBLIC_KEY="pk-lf-..." export LANGFUSE_SECRET_KEY="sk-lf-..." export LANGFUSE_HOST="https://cloud.langfuse.com" # or self-hosted URL # Or create .env file cat >> .env << 'EOF' LANGFUSE_PUBLIC_KEY=pk-lf-your-public-key LANGFUSE_SECRET_KEY=sk-lf-your-secret-key LANGFUSE_HOST=https://cloud.langfuse.com EOF ``` ### Step 4: Verify Connection ```typescript // TypeScript verification import { Langfuse } from "langfuse"; const langfuse = new Langfuse({ publicKey: process.env.LANGFUSE_PUBLIC_KEY, secretKey: process.env.LANGFUSE_SECRET_KEY, baseUrl: process.env.LANGFUSE_HOST, }); // Create a test trace const trace = langfuse.trace({ name: "connection-test", metadata: { test: true }, }); // Flush to ensure data is sent await langfuse.flushAsync(); console.log("Langfuse connection successful! Check dashboard for trace."); ``` ```python # Python verification from langfuse import Langfuse import os langfuse = Langfuse( public_key=os.environ.get("LANGFUSE_PUBLIC_KEY"), secret_key=os.environ.get("LANGFUSE_SECRET_KEY"), host=os.environ.get("LANGFUSE_HOST"), ) # Create a test trace trace = langfuse.trace(name="connection-test", metadata={"test": True}) # Flush to ensure data is sent langfuse.flush() print("Langfuse connection successful! Check dashboard for trace.") ``` ## Output - Installed SDK package in node_modules or site-packages - Environment variables or .env file with API credentials - Successful connection verification trace visible in dashboard ## Error Handling | Error | Cause | Solution | |-------|-------|----------| | Invalid API Key | Incorrect or revoked key | Verify keys in Langfuse dashboard | | Connection Refused | Wrong host URL | Check LANGFUSE_HOST is correct | | Network Error | Firewall blocking | Ensure outbound HTTPS to Langfuse host | | Module Not Found | Installation failed | Run `npm install` or `pip install` again | | 401 Unauthorized | Keys don't match project | Ensure keys are from same project | ## Examples ### TypeScript Initialization with Options ```typescript import { Langfuse } from "langfuse"; const langfuse = new Langfuse({ publicKey: process.env.LANGFUSE_PUBLIC_KEY!, secretKey: process.env.LANGFUSE_SECRET_KEY!, baseUrl: process.env.LANGFUSE_HOST, // Optional configuration flushAt: 15, // Flush after 15 events (default: 15) flushInterval: 10000, // Flush every 10 seconds (default: 10000ms) requestTimeout: 10000, // Request timeout (default: 10000ms) enabled: process.env.NODE_ENV === "production", // Disable in dev }); // Ensure clean shutdown process.on("beforeExit", async () => { await langfuse.shutdownAsync(); }); ``` ### Python Initialization with Options ```python from langfuse import Langfuse import os langfuse = Langfuse( public_key=os.environ.get("LANGFUSE_PUBLIC_KEY"), secret_key=os.environ.get("LANGFUSE_SECRET_KEY"), host=os.environ.get("LANGFUSE_HOST"), # Optional configuration flush_at=15, # Flush after 15 events flush_interval=10.0, # Flush every 10 seconds enabled=os.environ.get("NODE_ENV") == "production", ) # Register shutdown handler import atexit atexit.register(langfuse.flush) ``` ### OpenAI Integration (Automatic Tracing) ```typescript import { observeOpenAI } from "langfuse"; import OpenAI from "openai"; const openai = observeOpenAI(new OpenAI(), { clientInitParams: { publicKey: process.env.LANGFUSE_PUBLIC_KEY, secretKey: process.env.LANGFUSE_SECRET_KEY, baseUrl: process.env.LANGFUSE_HOST, }, }); // All OpenAI calls are now automatically traced const response = await openai.chat.completions.create({ model: "gpt-4", messages: [{ role: "user", content: "Hello!" }], }); ``` ## Resources - [Langfuse Documentation](https://langfuse.com/docs) - [Langfuse SDK Reference](https://langfuse.com/docs/sdk) - [Langfuse Cloud Dashboard](https://cloud.langfuse.com) - [Self-Hosting Guide](https://langfuse.com/docs/deployment/self-host) ## Next Steps After successful auth, proceed to `langfuse-hello-world` for your first trace.