Stop Using Fake Data in Your API Tests

#cypress #playwright #testing #webdev

If you're still testing APIs with fake payloads copied from documentation, you're probably missing the bugs that actually happen in production.

One of the biggest mistakes developers make is building tests around "perfect" data instead of real-world traffic.

Here's a workflow that has saved me hours when working with webhooks, email verification, and end-to-end testing.

Step 1 — Capture Real Data

Instead of inventing JSON payloads, capture a real request.

A webhook inspector lets you see exactly what Stripe, GitHub, Clerk, or another provider sends, including:

Once you have that payload, save it as a fixture for future tests.

Many signup systems rely on OTP emails or verification links.

Using your personal inbox quickly becomes messy.

A disposable inbox lets you create clean test accounts every time without polluting your real email.

Once you have:

You can replay the entire flow inside Cypress or Playwright instead of relying on mocked data.

Your tests become much closer to production behavior.

I've been collecting practical examples for these workflows here:

The examples are completely public.

If you're building internal tools, SaaS products, or API integrations, I'd love to know:

What's the most annoying part of your current testing workflow?