How do I write API tests that capture request and response analytics with TestRelic, using the request fixture — no browser required?

API testing with TestRelic captures analytics about HTTP requests, responses, timing, and test results through the request fixture, without launching a browser.

No browser required

API tests run without launching a browser, making them faster and more lightweight than E2E tests.

Setting up the API fixture

Extend the base Playwright fixture with testRelicApiFixture in your test files:

tests/api/posts.spec.ts

import { test as base } from '@playwright/test';
import { testRelicApiFixture } from '@testrelic/playwright-analytics/api-fixture';
import { expect } from '@testrelic/playwright-analytics/fixture';

const test = base.extend(testRelicApiFixture);

test('fetch posts', { tag: ['@api'] }, async ({ request }) => {
  const response = await request.get('https://jsonplaceholder.typicode.com/posts');
  expect(response.status()).toBe(200);

  const posts = await response.json();
  expect(posts).toBeInstanceOf(Array);
});

Import expect from TestRelic (either .../api-fixture or .../fixture) so assertions are captured — it behaves exactly like Playwright's expect.

When a run opens the API workspace

A run is routed to the API workspace when every test in it is an API test — tagged @api, under an api/ path, in a dedicated API project, or using the API request fixture. Mixed UI + API runs are not reclassified. Request and response cookies are captured with their values masked, shown in the API Cookies tab.

CRUD patterns

tests/api/crud.spec.ts

import { test as base } from '@playwright/test';
import { testRelicApiFixture } from '@testrelic/playwright-analytics/api-fixture';
import { expect } from '@testrelic/playwright-analytics/fixture';

const test = base.extend(testRelicApiFixture);
const BASE_URL = 'https://jsonplaceholder.typicode.com';

test('complete CRUD workflow', { tag: ['@api', '@crud'] }, async ({ request }) => {
  const createRes = await request.post(`${BASE_URL}/posts`, {
    data: { title: 'Test', body: 'Content', userId: 1 },
  });
  expect(createRes.status()).toBe(201);
  const post = await createRes.json();

  const readRes = await request.get(`${BASE_URL}/posts/${post.id}`);
  expect(readRes.status()).toBe(200);

  const updateRes = await request.put(`${BASE_URL}/posts/${post.id}`, {
    data: { ...post, title: 'Updated' },
  });
  expect(updateRes.status()).toBe(200);

  const deleteRes = await request.delete(`${BASE_URL}/posts/${post.id}`);
  expect(deleteRes.status()).toBe(200);
});

Chaining API calls

tests/api/chaining.spec.ts

test('API chaining - user and posts', { tag: ['@api', '@chain'] }, async ({ request }) => {
  const userResponse = await request.get('https://jsonplaceholder.typicode.com/users/1');
  const user = await userResponse.json();

  const postsResponse = await request.get('https://jsonplaceholder.typicode.com/posts', {
    params: { userId: user.id },
  });
  const posts = await postsResponse.json();
  expect(posts.every((post) => post.userId === user.id)).toBe(true);
});

Authentication

tests/api/auth-token.spec.ts

test('bearer token authentication', { tag: ['@api', '@auth'] }, async ({ request }) => {
  const response = await request.get('https://api.example.com/protected', {
    headers: { Authorization: `Bearer ${process.env.API_TOKEN}` },
  });
  expect(response.status()).toBe(200);
});

Sensitive data

Always use environment variables for API keys, tokens, and passwords. Configure redactPatterns (see Configuration) so sensitive values never appear in reports.

Configuration for API-only reporters

playwright.config.ts

export default defineConfig({
  reporter: [
    ['@testrelic/playwright-analytics', {
      outputPath: './test-results/api-analytics.json',
      includeStackTrace: true,
      includeCodeSnippets: true,
      redactPatterns: [/api_key=[^&\s]+/gi, /password=[^&\s]+/gi],
    }],
  ],
});

Running API tests

Terminal

npx playwright test --grep @api
npx playwright test tests/api/posts.spec.ts

Best practices

Keep credentials in environment variables, never hardcoded.
Validate response shape, not just status code.
Test error paths (404s, timeouts) as well as happy paths.
Clean up created test data in a finally block.

API Testing