You can run this example with:

npx promptfoo@latest init --example config-node-package
cd config-node-package

This example demonstrates using promptfoo from a Node.js script.

• Node.js ^20.20.0 or >=22.22.0 (Node.js 20 support ends July 30, 2026; Node.js 24 LTS recommended)
• API keys for LLM providers set as environment variables:
  • OPENAI_API_KEY - Get from OpenAI API keys page
  • ANTHROPIC_API_KEY - Get from Anthropic Console (optional)

You can set these in a .env file:

OPENAI_API_KEY=sk-your-key-here
ANTHROPIC_API_KEY=sk-ant-your-key-here

1. Install dependencies:

npm install

2. Execute the script:

node full-eval.js

The script will:

• Run evaluations programmatically using the promptfoo Node.js API
• Save results to output.json
• Display evaluation metrics in the console
• Allow you to view detailed results with promptfoo view