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.
Integration
Works with every stack
# 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 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.