Configure a development build in cloud

Install expo-dev-client library

To initialize our project for a development build, let's cd inside our project directory and run the following command to install the library:

Start the development server

Run the npx expo start to start the development server:

This command starts the metro bundler. In the terminal window, we see the QR code followed by the Metro waiting on... and a manifest URL:

Let's notice the changes installing the expo-dev-client library:

• The manifest URL contains expo-development-client along with the app scheme
• The development server now operates for a development build (instead of Expo Go).

Since we do not have a development build installed on one of our devices or an emulator/simulator, we can't run our project yet.

Initialize a development build

Install EAS CLI

We need to install the EAS Command Line Interface (CLI) tool as a global dependency on our local machine. Run the following command:

Log in or sign up for an Expo account

If you have an Expo account and are signed in using Expo CLI, skip this step. If you don't have an Expo account, sign up here and proceed with the login command described below.

To log in, run the following command:

This command asks for our Expo account email or username and password to complete the login.

Initialize and link the project to EAS

For any new project, the first step is to initialize and link it to the EAS servers. Run the following command:

On running, this command:

• Requests verification of the account owner by entering our Expo account credentials and asks if we want to create a new EAS project:

  # Output after running eas init
  ✔ Which account should own this project? > your-username
  ✔ Would you like to create a project for @your-username/sticker-smash? … yes
  ✔ Created @your-username/sticker-smash
  ✔ Project successfully linked (ID: XXXX-XX-XX-XXXX) (modified app.json)
  

• Creates EAS project and provides a link to that project which we can open in the Expo dashboard:

• Generates a unique projectId and links this EAS project to the example app on our development machine.
• Modifies app.json to include extra.eas.projectId and updates its value with the unique ID created.

{
  "extra": {
    "eas": {
      "projectId": "0cd3da2d-xxx-xxx-xxx-xxxxxxxxxx"
    }
  }
}

Configure project for EAS Build

To set up our project for EAS Build, run the following command:

On running, this command:

• Prompts to select a platform: Android, iOS, or All. Since we are creating Android and iOS apps, let's select All.
• Creates eas.json in the root of our project's directory with the following configuration:

{
  "cli": {
    "version": ">= 8.0.0"
  },

  "build": {
    "development": {
      "developmentClient": true,
      "distribution": "internal"
    },

    "preview": {
      "distribution": "internal"
    },

    "production": {}
  },

  "submit": {
    "production": {}
  }
}

This is the default configuration for eas.json in a new project. It does two things:

• Defines the current EAS CLI version.
• Adds three build profiles: development, preview, and production.