Develop a React App against a Shared Mirage Server

Once you're ready to centralize your Mirage server and share it between development and testing, follow these steps.

Step 1: Install Mirage

First, make sure you've added Mirage to your project:

# Using npm
npm install --save-dev miragejs

# Using Yarn
yarn add --dev miragejs

Step 2: Define your shared server

A common place to define your shared server is src/server.js:

// src/server.js
import { Server, Model } from "miragejs"

export function makeServer({ environment = "test" } = {}) {
  let server = new Server({

    models: {
      user: Model,

    seeds(server) {
      server.create("user", { name: "Bob" })
      server.create("user", { name: "Alice" })

    routes() {
      this.namespace = "api"

      this.get("/users", (schema) => {
        return schema.users.all()

  return server

In an app build with Create React App, make sure this file is under the src/ directory so that changes to it trigger rebuilds.

Step 3: Start your server in development

Open your React app's bootstrap file (src/index.js in a Create React App), import your makeServer function, and call it in the development environment:

// src/index.js
import React from "react"
import ReactDOM from "react-dom"
import App from "./App"
import { makeServer } from "./server"

if (process.env.NODE_ENV === "development") {

ReactDOM.render(<App />, document.getElementById("root"))

We're using the process.env.NODE_ENV environment variable here, which is a common global variable available in many React app environments.

Now, whenever any component in your application makes a network request in development, Mirage will intercept that request and respond with the data from your server definition.

You now have a central place to define and update your Mirage server as you continue local development on your React app.