Use case · API Mocking

Stop hardcoding
test JSON

Describe your API response structure in plain English — Hadarac generates hundreds of realistic, varied fixtures instantly. Pipe directly into your mock server, test suite, or Postman collection.

< 2s
from schema to fixture
12+
output formats
100%
deterministic with seed
0
hardcoded values

Integration

Works with every stack

REST — generate fixtures on demand
# Generate 500 mock user API responses
curl -X POST https://api.hadarac.com/v1/generate \
  -H "Authorization: Bearer hdr_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "prompt": "User API response: id (UUID), name, email, avatar_url,
               subscription (free/pro/enterprise), created_at, last_login,
               usage_this_month (0-500 integer)",
    "rows": 500,
    "format": "json"
  }'

# Pipe into your mock server
| jq '.' > fixtures/users.json
vitest / jest — fixture factory
import expect from "vitest";

let users: User[];

beforeAll(async () =>  {
  const res = await fetch("https://api.hadarac.com/v1/generate",  {
    method: "POST",
    headers:  { Authorization: `Bearer ${process.env.HADARAC_KEY}` },
    body: JSON.stringify( {
      prompt: "Users: id (UUID), name, email, role (admin/member/viewer), active (bool)",
      rows: 200,
      seed: 42,   // deterministic — same data every CI run
      format: "json"
    }),
  });
  users = await res.json();
});

it("admin users have correct role", () =>  {
  const admins = users.filter(u => u.role === "admin");
  admins.forEach(u => expect(u.active).toBe(true));
});

Use cases

Every mocking workflow covered

Generate response fixtures from any schema

Describe your API response structure in plain English — Hadarac returns hundreds of realistic, varied JSON records instantly. No more hand-crafting test JSON.

OpenAPI / Swagger schema to mock data

Paste your OpenAPI spec into the prompt. Hadarac reads the object structure and generates realistic mock payloads that match your types, enums, and constraints.

Consistent mocks across all test environments

Use the seed parameter for deterministic output — same fixture data in CI, staging, and local dev. No more test flakiness caused by random mock values.

Stress test with edge-case payloads

Describe adversarial inputs: nulls in unexpected fields, max-length strings, deeply nested arrays, conflicting status codes. Find the bugs before your users do.

Compatible with

Works with every API tool

Postman

Insomnia

MSW

WireMock

Prism

Mirage JS

JSON Server

Nock

Better mocks. Better tests.

Free plan: 15 generations/month, 100k records each. No credit card. Add to any pipeline in minutes.