API Assertion Generator

Generate Playwright, Postman, Cypress, Jest, and checklist-style API assertions from JSON responses.

Aruvix API Assertion Generator helps QA engineers create test assertions from API responses while keeping response content local to the browser.

API assertion generator workspace The interactive tool loads here immediately.

What is API Assertion Generator

An API assertion generator analyzes a JSON response and produces ready-to-use test assertions for Playwright, Postman, Cypress, Jest, or a plain checklist — checking status codes, field existence, data types, arrays, and response timing.

Why use API Assertion Generator

Use it when you receive a new API response and need to quickly generate assertions for an automated test suite without manually writing each type check, field check, or status assertion.

Features

  • Generate Playwright, Postman, Cypress, Jest, or checklist assertions
  • Detect field types, arrays, and nested objects
  • Include status code and response time assertions
  • Flag nullable fields with warnings
  • Response body stays in your browser

How to use

  1. Paste a JSON object with a 'response' field.
  2. Set the framework in Settings.
  3. Click Run Tool to generate assertions.
  4. Copy the assertion code.

FAQ

Which test frameworks are supported?

Playwright, Postman test scripts, Cypress, Jest, and a generic assertion checklist.

Does my API response get sent to a server?

No. All assertion generation happens locally in your browser.

Can it handle nested JSON?

Yes. The generator checks root-level fields and reports nested objects and arrays for deeper manual assertions.