EAS Build – Cloud CI/CD for React Native Apps

Overview

EAS Build is a cloud-based service designed to simplify the compilation and distribution of React Native applications. It functions as a continuous integration and delivery (CI/CD) platform, enabling developers to build production-ready native binaries for iOS and Android without configuring and maintaining local native development environments. This abstraction is particularly beneficial for React Native developers who primarily work with JavaScript and may not have extensive experience with Xcode or Android Studio build processes.

The service integrates directly with the Expo CLI, allowing developers to trigger builds, monitor progress, and manage artifacts from their command line. EAS Build supports both managed Expo projects, which leverage the Expo SDK and toolchain, and bare React Native projects, which offer more control over the native layer while still benefiting from cloud-based builds. This flexibility positions it as a tool for a broad spectrum of React Native development workflows, from rapid prototyping to complex enterprise applications.

EAS Build addresses common challenges in mobile app development, such as environment inconsistencies, dependency management, and the overhead of maintaining dedicated build machines. By offloading these tasks to the cloud, it aims to reduce build times and free up local machine resources. The service provides dedicated build environments for each platform, ensuring that iOS builds run on macOS machines with Xcode installed, and Android builds run on Linux machines with the Android SDK. This setup aligns with platform-specific requirements for app store submission, such as Apple's requirement for iOS apps to be built on macOS with specific Xcode versions, as detailed in Apple's Xcode documentation.

Who is EAS Build for? It is primarily designed for React Native developers and teams seeking to streamline their build and deployment pipelines. This includes individual developers, small startups, and larger organizations that prioritize developer experience and efficiency in cross-platform mobile development. It shines when developers need consistent, reproducible builds across different team members and environments, or when they want to automate the process of generating app store-ready binaries for testing and release. Its integration with other Expo services, like EAS Update for over-the-air updates and EAS Submit for automated app store submissions, creates a comprehensive ecosystem for managing the entire mobile app lifecycle.

Key features

• Cloud-based Build Infrastructure: Provides dedicated cloud environments for compiling iOS and Android applications, eliminating the need for local native build toolchains.
• Cross-platform Support: Builds native binaries for both iOS and Android from a single React Native codebase using the Expo SDK or bare React Native.
• Integration with Expo CLI: Seamlessly integrates with the command-line interface for triggering builds, monitoring progress, and managing build artifacts.
• Automatic Native Dependency Management: Handles native dependencies and project configuration, reducing setup time and potential conflicts.
• Build Profiles: Allows configuration of different build settings (e.g., development, production) through eas.json files to customize outputs.
• Artifact Storage: Stores generated .ipa (iOS) and .apk / .aab (Android) files, making them accessible for testing and distribution.
• Automatic Git Branch Detection: Can automatically detect and use Git branches for clearer build organization and CI/CD workflows.
• Custom Build Environments: Supports custom build commands and scripts for advanced use cases and specific project requirements.
• Build Caching: Implements caching mechanisms to speed up subsequent builds by reusing previously compiled components and dependencies.
• Environment Variables: Securely injects environment variables into the build process for sensitive data like API keys.

Pricing

EAS Build offers a free tier and various paid plans tailored to different usage levels. The pricing structure is designed to scale with the needs of individual developers and teams, providing more builds, storage, and advanced features as usage increases.

For the most current and detailed pricing information, refer to the official Expo pricing page.

Common integrations

• Expo CLI: Core integration for initiating and managing builds directly from the command line. EAS CLI documentation
• EAS Update: Allows for over-the-air updates to deployed React Native applications, patching JavaScript code and assets without requiring a full app store submission. EAS Update documentation
• EAS Submit: Automates the process of submitting app binaries to the Apple App Store and Google Play Store. EAS Submit documentation
• Git Providers (GitHub, GitLab, Bitbucket): Integrates with version control systems for triggering builds on code pushes or pull requests.
• Fastlane: While EAS Submit covers many deployment needs, advanced users can integrate custom Fastlane actions for more complex release workflows, though EAS aims to abstract much of this. EAS Build and Fastlane
• Custom Webhooks: Supports webhooks to notify external services or trigger downstream processes upon build completion or status changes.

Alternatives

• AppCenter: Microsoft's CI/CD service for mobile apps, supporting various platforms including React Native, Xamarin, and native iOS/Android.
• Bitrise: A mobile-first CI/CD platform offering a wide range of integrations and workflows for native, hybrid, and cross-platform mobile development.
• CircleCI: A general-purpose CI/CD platform that can be configured to build and deploy mobile applications, often used for projects with diverse technology stacks.
• GitHub Actions: A flexible CI/CD platform integrated with GitHub repositories, allowing custom workflows for building and deploying mobile apps using self-hosted or GitHub-provided runners.
• GitLab CI/CD: An integrated CI/CD system within GitLab, offering robust automation capabilities for building, testing, and deploying mobile applications.

Getting started

To begin using EAS Build, you need to have Node.js and the Expo CLI installed. This example assumes you have an existing React Native project (either managed Expo or bare) in your directory. If you don't have Expo CLI, install it globally first.

# 1. Install Expo CLI globally (if you haven't already)
npm install -g expo-cli

# 2. Navigate into your React Native project directory
cd my-react-native-app

# 3. Log in to your Expo account
expo login

# 4. Configure your project for EAS Build
# This command will guide you through setting up eas.json
eas build:configure

# 5. Start an Android build
eas build -p android

# 6. Start an iOS build
eas build -p ios

# 7. (Optional) Start a development build for Android
eas build -p android --profile development

# 8. (Optional) Check the status of your builds
eas build:list

After running eas build -p [platform], EAS Build will upload your project to the Expo cloud, initiate the build process, and provide a URL to monitor the build status. Once complete, you can download the generated .apk or .ipa file for testing or submission. For more detailed instructions on specific configurations and advanced usage, refer to the EAS Build documentation.