What is json-server?
json-server is a full fake REST API with zero coding in less than 30 seconds. It allows you to create a mock REST API using a simple JSON file as the database.
What are json-server's main functionalities?
Create a Fake REST API
This code sets up a basic JSON server that reads from a 'db.json' file and serves it as a REST API. The server listens on port 3000.
const jsonServer = require('json-server');
const server = jsonServer.create();
const router = jsonServer.router('db.json');
const middlewares = jsonServer.defaults();
server.use(middlewares);
server.use(router);
server.listen(3000, () => {
console.log('JSON Server is running');
});
Custom Routes
This code demonstrates how to use custom routes with json-server. The rewriter middleware is used to map custom routes to the default routes.
const jsonServer = require('json-server');
const server = jsonServer.create();
const router = jsonServer.router('db.json');
const middlewares = jsonServer.defaults();
server.use(middlewares);
server.use(jsonServer.rewriter({
'/api/*': '/$1',
'/blog/:resource/:id/show': '/:resource/:id'
}));
server.use(router);
server.listen(3000, () => {
console.log('JSON Server is running');
});
Add Custom Middleware
This code adds custom middleware to the JSON server. In this example, a timestamp is added to the request body for POST requests.
const jsonServer = require('json-server');
const server = jsonServer.create();
const router = jsonServer.router('db.json');
const middlewares = jsonServer.defaults();
server.use(middlewares);
server.use((req, res, next) => {
if (req.method === 'POST') {
req.body.createdAt = Date.now();
}
next();
});
server.use(router);
server.listen(3000, () => {
console.log('JSON Server is running');
});
Other packages similar to json-server
miragejs
Mirage JS is a client-side server to build, test and share a complete working JavaScript application without having to rely on any backend services. Unlike json-server, which is more focused on quickly setting up a REST API, Mirage JS is designed to work seamlessly with frontend frameworks like React, Vue, and Angular.
prism
Prism is a package for creating mock servers based on OpenAPI and API Blueprint specifications. It allows you to create a mock server that can validate requests and responses against your API specification. Unlike json-server, which uses a JSON file as a database, Prism uses API specifications to generate mock responses.
JSON Server
Give it a JSON or JS seed file and it will serve it through REST routes.
Created with :heart: for front-end developers who need a flexible back-end for quick prototyping and mocking.
Examples
Command line interface
{
"posts": [
{ "id": 1, "body": "foo" }
]
}
$ json-server --file db.json
$ curl -i http://localhost:3000/posts/1
Node module
var server = require('json-server');
server.low.db = {
posts: [
{ id: 1, body: 'foo' }
]
}
server.get('/another/route', function(req, res, next) {
})
server.listen(3000);
You can find a running demo here: http://jsonplaceholder.typicode.com.
Why?
- Lets you use plain JSON or simple JS file
- Supports GET but also POST, PUT, DELETE and even PATCH requests
- Can be used from anywhere through cross domain requests (JSONP or CORS)
- Can load remote JSON files
- Can be deployed on Nodejitsu, Heroku, ...
Installation
$ npm install -g json-server
Usage
Command line interface
Usage: json-server <source> [options]
Options:
--version output version
--port <port> set port
Exemples:
json-server db.json
json-server seed.js
json-server http://example.com/db.json
Input
Here's 2 examples showing how to format JSON or JS seed file:
{
"posts": [
{ "id": 1, "body": "foo" },
{ "id": 2, "body": "bar" }
],
"comments": [
{ "id": 1, "body": "baz", "postId": 1 }
{ "id": 2, "body": "qux", "postId": 2 }
]
}
exports.run = function() {
var data = {};
data.posts = [];
data.posts.push({ id: 1, body: 'foo' });
return data;
}
JSON Server expects JS files to export a run
method that returns an object.
Seed files are useful if you need to programmaticaly create a lot of data.
Node module
run(db, [options])
var server = require('json-server'),
db = require('./seed').run();
var options = { port: 4000, readOnly: true };
server.run(db, options);
By default, port
is set to 3000 and readOnly
to false.
Routes
GET /:resource
GET /:resource?filter=&filter=&
GET /:parent/:parentId/:resource
GET /:resource/:id
POST /:resource
PUT /:resource/:id
PATCH /:resource/:id
DEL /:resource/:id
To slice resources, add _start
and _end
to query parameters.
For routes usage information, have a look at JSONPlaceholder code examples.
GET /db
Returns database state.
GET /
Returns default index file or content of ./public/index.html (useful if you need to set a custom home page).
Articles