Json-server

A rapid tool to expose JSON data as a RESTful API

When developing a Front-end or testing a Client, you often need a working API before the actual Back-end is ready. Waiting for the full database and server logic to be implemented can stall your progress.

To solve this, we use json-server. It is a lightweight tool that turns a simple JSON file into a fully functional REST API in seconds, supporting all standard HTTP methods.

Installation

First, ensure you have Node.js and npm installed on your system. Then, install json-server globally.

sudo apt update
sudo apt install nodejs npm
npm install -g json-server

Setting Up the Mock Data

The behavior of the API is entirely determined by a local JSON file. This file acts as your “database.”

• In directory data, create a file named db.json

data/db.json

{
  "games": [
    {
      "id": "1",
      "players_list": ["Alice", "Bob"],
      "winner_name": "Alice",
      "location_name": "Arena 1",
      "duration_seconds": 120,
      "mode_type": "coinflip"
    },
    {
      "id": "2",
      "players_list": ["Eve", "Frank"],
      "winner_name": "Eve",
      "location_name": "Secret Cave",
      "duration_seconds": 300,
      "mode_type": "dice"
    }
  ],
  "$schema": "./node_modules/json-server/schema.json"
}

NoneGames data

{
  "games": [
    {
      "id": "1",
      "players_list": [
        "Alice",
        "Bob"
      ],
      "winner_name": "Alice",
      "location_name": "Arena 1",
      "duration_seconds": 120,
      "mode_type": "coinflip"
    },
    {
      "id": "2",
      "players_list": [
        "Eve",
        "Frank"
      ],
      "winner_name": "Eve",
      "location_name": "Secret Cave",
      "duration_seconds": 300,
      "mode_type": "dice"
    },
    {
      "id": "3",
      "players_list": [
        "Eve",
        "Boris"
      ],
      "winner_name": "Eve",
      "location_name": "Secret Cave",
      "duration_seconds": 300,
      "mode_type": "dice"
    },
    {
      "id": "4",
      "players_list": [
        "Eve",
        "Boris"
      ],
      "winner_name": "Eve",
      "location_name": "Secret Cave",
      "duration_seconds": 300,
      "mode_type": "dice"
    },
    {
      "uuid_match": 103,
      "players_list": [
        "Eve",
        "Boris"
      ],
      "winner_name": "Eve",
      "location_name": "Secret Cave",
      "duration_seconds": 300,
      "mode_type": "dice",
      "id": "FIWBuFDQqUQ"
    },
    {
      "uuid_match": 103,
      "players_list": [
        "Eve",
        "Boris"
      ],
      "winner_name": "Eve",
      "location_name": "Secret Cave",
      "duration_seconds": 300,
      "mode_type": "dice",
      "id": "jSIh2DO8Be4"
    }
  ],
  "$schema": "./node_modules/json-server/schema.json"
}

Launching the Server

To start the API, run the following command in your terminal. The --watch flag ensures that any changes you make to db.json are immediately reflected in the API.

json-server --watch data/db.json --port 5000

NoteEndpoint URL

Your API is now live at http://localhost:5000. The keys in your JSON file (e.g., "games") become the resource endpoints (e.g., /games).

Testing the API

You can interact with your new server using cURL or any professional API client like Bruno or Insomnia.

READ Operations

To retrieve the list of all games:

curl -X GET http://localhost:5000/games

WRITE Operations

To create a new game entry, send a POST request with a JSON body. json-server will automatically generate a unique id for the new entry.

curl -X POST http://localhost:5000/games \
     -H "Content-Type: application/json" \
     -d '{
           "uuid_match": 103,
           "players_list": ["Eve", "Boris"],
           "winner_name": "Eve",
           "location_name": "Secret Cave",
           "duration_seconds": 300,
           "mode_type": "dice"
         }'

UPDATE Operations

To modify an existing resource, use PUT. You must specify the id of the resource in the URL path.

curl -X PUT http://localhost:5000/games/1 \
     -H "Content-Type: application/json" \
     -d '{
           "uuid_match": 101,
           "players_list": ["Alice", "Bob"],
           "winner_name": "Bob",
           "location_name": "Arena 1 (Updated)",
           "duration_seconds": 150,
           "mode_type": "coinflip"
         }'

DELETE Operations

To remove a resource from your mock database:

curl -X DELETE http://localhost:5000/games/2

WarningData Persistence

Because json-server is a mock tool, it writes changes directly to your db.json file. Be careful when performing DELETE or PUT operations, as they will permanently alter your local file.