Free Stateful Fake REST API for Prototyping & Testing

Playground API is a zero-configuration, JSONPlaceholder-compatible mock REST API with instant, per-visitor session sandbox overlays. Prototype frontend applications, test HTTP clients, and execute realistic CRUD operations without breaking shared global seed data.

🔄 Virtual Merging Engine

GET requests dynamically construct a virtual list merging global database records with your session's creates (on top), updates (in-place), and deletes.

🛡️ 30-Record Quota Cap

Each identity session is allowed up to 30 self-created sandbox records per resource. Local sandbox records receive local-<uuid> string IDs.

🔒 Cookie-Based Identity

Identity is securely tied to the pg_identity HTTP cookie. IP addresses are hashed using SHA-256 strictly for rate limiting backstop (60 req/min).

Why Choose Playground API? (Feature Comparison)

Feature Playground API JSONPlaceholder DummyJSON / ReqRes
Per-Session Stateful Mutations ✅ Yes (`pg_identity` Sandbox) ❌ Stateless (Fake Response) ❌ Stateless / Static Mock
Interactive Live Request Tester ✅ Built-in per endpoint ⚠️ Basic code examples ⚠️ Static snippets
Zero Configuration / Registration ✅ 100% Free & Open ✅ Free ✅ Free
Pagination & Field Filtering ✅ `page`, `limit`, virtual ID slice ✅ Supported ✅ Supported

Quickstart Integration Snippets

JavaScript (Fetch API)

// Send GET request with credentials to include pg_identity sandbox cookie
fetch('http://localhost:3000/users?page=1&limit=10', {
  method: 'GET',
  credentials: 'include'
})
  .then(res => res.json())
  .then(data => console.log(data));

cURL Command

curl -i -b "pg_identity=local-sandbox" \
  -H "Content-Type: application/json" \
  -X POST -d '{"name":"Leanne Graham","username":"Bret","email":"Sincere@april.biz"}' \
  http://localhost:3000/users

Available Mock API Resources

/users REST

Interactive mock endpoints, JSON schemas, and live request runner for /users.

/posts REST

Interactive mock endpoints, JSON schemas, and live request runner for /posts.

/comments REST

Interactive mock endpoints, JSON schemas, and live request runner for /comments.

/todos REST

Interactive mock endpoints, JSON schemas, and live request runner for /todos.

Frequently Asked Questions (FAQ)

What makes Playground API different from JSONPlaceholder?

While standard mock APIs like JSONPlaceholder return fake responses when you send a POST, PUT, or DELETE request without saving your changes, Playground API saves your mutations into a per-session sandbox overlay tied to your HTTP cookie. When you perform subsequent GET requests, your created, updated, or deleted items persist specifically for you without altering global seed data for other developers.

Do I need an API key or registration to use Playground API?

No. Playground API is 100% free and open. No API keys, sign-ups, or authentication headers are required. Simply make standard HTTP requests using fetch, axios, cURL, or Postman.

How long do sandbox session mutations persist?

Your session overlay data persists via the pg_identity cookie and is maintained in our database for up to 10 days of inactivity. An automated daily cron job cleans up inactive identity sessions automatically.

What are the rate limits on Playground API?

General read requests are limited to 60 requests per minute per salted IP hash. Mutation requests (POST, PUT, DELETE) are limited to 15 requests per hour per IP hash with a quota cap of 30 custom sandbox records per identity session.