Faithfulness ✅

OPENAI_API_KEY=your_api_key_here

import { openai } from '@ai-sdk/openai';
import { FaithfulnessMetric } from '@kastrax/evals/llm';

const context1 = [
  'The Tesla Model 3 was launched in 2017.',
  'It has a range of up to 358 miles.',
  'The base model accelerates 0-60 mph in 5.8 seconds.',
];
 
const metric1 = new FaithfulnessMetric(openai('gpt-4o-mini'), {
  context: context1,
});
 
const query1 = 'Tell me about the Tesla Model 3.';
const response1 = 'The Tesla Model 3 was introduced in 2017. It can travel up to 358 miles on a single charge and the base version goes from 0 to 60 mph in 5.8 seconds.';
 
console.log('Example 1 - High Faithfulness:');
console.log('Context:', context1);
console.log('Query:', query1);
console.log('Response:', response1);
 
const result1 = await metric1.measure(query1, response1);
console.log('Metric Result:', {
  score: result1.score,
  reason: result1.info.reason,
});
// Example Output:
// Metric Result: { score: 1, reason: 'All claims are supported by the context.' }

const context2 = [
  'Python was created by Guido van Rossum.',
  'The first version was released in 1991.',
  'Python emphasizes code readability.',
];
 
const metric2 = new FaithfulnessMetric(openai('gpt-4o-mini'), {
  context: context2,
});
 
const query2 = 'What can you tell me about Python?';
const response2 = 'Python was created by Guido van Rossum and released in 1991. It is the most popular programming language today and is used by millions of developers worldwide.';
 
console.log('Example 2 - Mixed Faithfulness:');
console.log('Context:', context2);
console.log('Query:', query2);
console.log('Response:', response2);
 
const result2 = await metric2.measure(query2, response2);
console.log('Metric Result:', {
  score: result2.score,
  reason: result2.info.reason,
});
// Example Output:
// Metric Result: { score: 0.5, reason: 'Only half of the claims are supported by the context.' }

const context3 = [
  'Mars is the fourth planet from the Sun.',
  'It has a thin atmosphere of mostly carbon dioxide.',
  'Two small moons orbit Mars: Phobos and Deimos.',
];
 
const metric3 = new FaithfulnessMetric(openai('gpt-4o-mini'), {
  context: context3,
});
 
const query3 = 'What do we know about Mars?';
const response3 = 'Mars is the third planet from the Sun. It has a thick atmosphere rich in oxygen and nitrogen, and is orbited by three large moons.';
 
console.log('Example 3 - Low Faithfulness:');
console.log('Context:', context3);
console.log('Query:', query3);
console.log('Response:', response3);
 
const result3 = await metric3.measure(query3, response3);
console.log('Metric Result:', {
  score: result3.score,
  reason: result3.info.reason,
});
// Example Output:
// Metric Result: { score: 0, reason: 'The response contradicts the context.' }