Fake API docs

Introduction

Fake API helps you quickly create mock APIs for developing and testing applications without needing a real backend. It's useful when you want to develop the frontend independently, test different scenarios (success, error, delay), demo an app with simulated data, or quickly experiment with an idea without setting up a server.

Each project you create gets a unique public projectId. You attach this to a path and define the JSON body, HTTP status code, and delay for each endpoint, and decide whether that body is served exactly as written or regenerated by AI on every call. The final URL format is:

https://www.fake-api.dev/{projectId}{your_created_path}

Getting started: account & login

You need an account before you can create projects and endpoints.

You need to verify your email before you can use all features.

Create a project

After logging in, you'll land on the Project management page, this is where all your mock APIs are organized.

The project list shows each project's Name and its public_id, that's the projectId you'll use in mock API URLs.

Endpoint groups

Endpoint groups help you organize endpoints by functionality or module, for example users, orders, or products. On desktop, groups appear in the left panel of the project page, on mobile, use the dropdown menu instead. Select a group to view and configure its endpoints.

• Create: click Create new in the Endpoint Group section, enter a name, and Save.
• Edit or delete: use the ⋮ menu on a group to rename it, or delete it along with all endpoints inside.

Create endpoints

Endpoints define how the mock API responds when it's called. Select an Endpoint Group, click Create new, and fill in:

Example endpoint configuration:

{
  "method": "GET",
  "path": "/api/users/1",
  "response_body": {
    "id": 1,
    "name": "John Doe",
    "email": "johndoe@example.com"
  },
  "delay_ms": 500,
  "status_code": 200,
  "ai_enabled": true,
  "ai_fields": ["name", "email"],
  "ai_prompt": "keep the email domain example.com"
}

Click Save, the endpoint list updates right away with the new endpoint.

Dynamic routes

Prefix a path segment with to turn it into a dynamic parameter that matches any value, for example . That single endpoint responds to , , and any other value in that position, so you don't need a separate endpoint per id.

Edit, delete, and copy URL

• Edit: click an endpoint to open the edit form, change the method, path, body, delay, or status, then Save.
• Delete: use the trash icon on an endpoint, or Delete all to clear every endpoint in the group.
• Copy URL: click the copy icon to copy the full https://www.fake-api.dev/{projectId}{path} URL, ready to paste into your code.

AI response variants

An endpoint can answer with the same JSON every time, or with different values on every call. Tick Enable, choose which values are allowed to change, and each request comes back with a fresh version of your body. The shape stays put, only the values you picked move, so a list of users is still a list of users and your app keeps working against the same structure. Every call is different, so a screen that pages through a hundred records shows a hundred different records.

Call the mock API

Use the projectId shown in the API Endpoint card on your project's detail page:

curl -X GET https://www.fake-api.dev/QGONEwKEqJg/api/user/1

fetch('https://www.fake-api.dev/QGONEwKEqJg/api/users/1')
  .then(response => response.json())
  .then(data => console.log(data))
  .catch(error => console.error('Error:', error));

axios.get('https://www.fake-api.dev/QGONEwKEqJg/api/users/1')
  .then(response => console.log(response.data))
  .catch(error => console.error('Error:', error));

When you call the API, it will:

1. Find the endpoint matching the method and path
2. Apply the configured delay_ms, if any
3. Return the response_body with the configured status_code, or a varied version of it if AI variants are on

Headers and CORS

Your mock endpoints answer a browser from any origin, so a page on localhost can call them straight away with no setup. Responses come back as JSON and are never cached, so an edit to a body shows up on the very next call.

Headers of your own

The Headers tab in the endpoint form is where you add anything else the response should carry. A page count next to a list is the common one, and your app reads it back the way it reads any header:

const response = await fetch('https://www.fake-api.dev/QGONEwKEqJg/api/users');
const total = response.headers.get('X-Total-Count');

You can set up to 20 of them per endpoint, and setting Content-Type or Cache-Control replaces what the response would have used. A handful of names, cookies among them, belong to Fake API itself and are refused with a message saying so.

When you want a call blocked

Create or edit a project, open its Advanced tab, and the Browser access group holds one switch. Turn it off and browsers stop being able to reach that project's endpoints, which is how you check what your app does when that happens. curl and anything server-side still get an answer, so the mock keeps working while you test.

More options under it lets you limit which origins are allowed, and once you name at least one you can let the browser send cookies along too. Most projects never need either: naming origins only changes what a browser permits, so it keeps nothing private.

Tips for using Fake API

• Follow RESTful naming: plural resources (/api/users), details (/api/users/123), sub-resources (/api/users/123/orders).
• Group related endpoints into the same Endpoint Group so they're easy to find and manage.
• Keep response JSON concise, only include fields you actually need, with realistic sample data.
• Create multiple endpoints for different data states, e.g. an active user and an inactive user.