Generate a Mock API from JSON

Frontend developers often need to prototype against an API that doesn't exist yet. DataLensia's Mock API Generator lets you create a live endpoint in seconds — no server, no deployment, no sign-up.

🚩 The Scenario

You're building a dashboard and the backend team hasn't shipped the /api/users endpoint yet. You have a sample response:

[
  {"id": 1, "name": "Alice", "role": "admin", "lastLogin": "2025-01-15"},
  {"id": 2, "name": "Bob", "role": "editor", "lastLogin": "2025-01-14"}
]

🛠️ Step-by-Step

1. Open the Mock API Tool.
2. Paste your JSON into the editor or upload a file.
3. Configure the endpoint:
   • Status Code: 200 OK (or any other code for testing error handling).
   • HTTP Method: GET (restrict to specific methods if needed).
   • Delay: Add 500ms of artificial latency to simulate real network conditions.
   • Content-Type: Defaults to application/json.
4. Click Generate Link.
5. Copy the generated URL and use it in your frontend code:

const response = await fetch("https://datalensia.com/api/mock/m1.eJy...");
const users = await response.json();

🎲 Dynamic Values with Faker.js

Make your mock responses dynamic! Use placeholders that generate new data on every request:

{
  "id": "{{faker.string.uuid()}}",
  "name": "{{faker.person.fullName()}}",
  "email": "{{faker.internet.email()}}",
  "createdAt": "{{faker.date.recent()}}"
}

Every time the endpoint is called, fresh data is generated using Faker.js.

🔗 Path-Based Sub-Resources

The Mock API supports nested paths. If you generate a mock at https://datalensia.com/api/mock/<data>, you can also access:

• https://datalensia.com/api/mock/<data>/users — returns the users key from your JSON.
• https://datalensia.com/api/mock/<data>/users/0 — returns the first user.

🧪 Simulation Panel

The Mock API tool includes a built-in Simulation tab where you can:

• Send test requests to your endpoint.
• See the exact response headers, body, and timing.
• Verify that your status codes and delays work as expected.

📄 Auto-Generated Documentation

The Docs tab automatically generates API documentation for your mock endpoint, including:

• Endpoint URL.
• Expected response format.
• TypeScript type definitions for the response.

🚀 Try it now

Create your first mock endpoint in the Mock API Generator.