🏗️ EAS Build Setup

Expo Application Services (EAS) provides cloud-based builds for your mobile app. This means you can build Android and iOS binaries without installing Android Studio or Xcode locally. EAS also manages code signing (certificates and provisioning profiles).

1️⃣ Step 1: Install EAS CLI

If you haven't already:

npm install -g eas-cli

2️⃣ Step 2: Log In to Expo

eas login

Enter your Expo account credentials.

3️⃣ Step 3: Link the Project

Navigate to the mobile app directory and initialize the EAS project:

cd packages/mobile
eas init

This creates a project on Expo's servers and adds a projectId to your app.json:

{
  "expo": {
    "extra": {
      "eas": {
        "projectId": "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
      }
    }
  }
}

4️⃣ Step 4: Create eas.json

Create the EAS build configuration file at packages/mobile/eas.json:

{
  "cli": {
    "version": ">= 15.0.0",
    "appVersionSource": "remote"
  },
  "build": {
    "development": {
      "developmentClient": true,
      "distribution": "internal",
      "ios": {
        "simulator": true
      }
    },
    "preview": {
      "distribution": "internal",
      "ios": {
        "simulator": false
      }
    },
    "production": {
      "autoIncrement": true,
      "ios": {
        "image": "latest"
      },
      "android": {
        "image": "latest",
        "buildType": "app-bundle"
      }
    }
  },
  "submit": {
    "production": {
      "ios": {
        "appleId": "your-apple-id@email.com",
        "ascAppId": "your-app-store-connect-app-id",
        "appleTeamId": "YOUR_TEAM_ID"
      },
      "android": {
        "serviceAccountKeyPath": "./google-play-service-account.json",
        "track": "internal"
      }
    }
  }
}

📋 Build Profiles Explained

Profile	Purpose	Output
🧪 development	Testing with full native modules	Dev client for simulators/devices
👀 preview	Share test builds with your team	Installable APK/IPA
🚀 production	App Store / Play Store submission	Optimized, signed binary

5️⃣ Step 5: Configure iOS Credentials

EAS can manage your Apple certificates automatically:

eas credentials --platform ios

Select "Let EAS manage my credentials" (recommended). EAS will:

• 🔐 Create a distribution certificate
• 📄 Create a provisioning profile
• 🔒 Store them securely on Expo's servers

You'll be prompted to sign in with your Apple ID. Use the account enrolled in the Apple Developer Program.

💡

If you prefer to manage credentials yourself, select "I want to provide my own credentials" and upload your .p12 certificate and .mobileprovision file.

6️⃣ Step 6: Configure Android Credentials

EAS can also manage Android signing keys:

eas credentials --platform android

Select "Let EAS manage my credentials". EAS will generate:

• 🔑 An upload keystore (for signing the APK/AAB)
• 🏷️ A key alias and passwords

🚨 Keep Your Keystore Safe

The Android upload keystore is permanent. If you lose it, you can never update your app on Google Play. EAS stores it securely, but you should also download a backup:

eas credentials --platform android
# Select "Download credentials"

Save the downloaded .jks file and passwords in a secure location (password manager, encrypted drive).

7️⃣ Step 7: Set Up Google Play Service Account

To enable automatic submission to Google Play, create a service account:

1. 🌐 Open Google Cloud Console: console.cloud.google.com

2. 📁 Create or select a project associated with your Play Console

3. 🔌 Enable the Google Play Android Developer API:

   • Go to APIs & Services → Library
   • Search for "Google Play Android Developer API"
   • Click Enable

4. 👤 Create a service account:

   • Go to APIs & Services → Credentials
   • Click "Create Credentials" → "Service Account"
   • Name: eas-build-submit
   • Role: none needed at this step
   • Click "Done"

5. 🔑 Generate a JSON key:

   • Click on the service account you just created
   • Go to the "Keys" tab
   • Click "Add Key" → "Create new key" → "JSON"
   • Download the JSON file

6. 🔓 Grant Play Console access:

   • Go to play.google.com/console
   • Settings → Developer account → API access
   • Click "Link" next to the Google Cloud project
   • Find the service account and click "Grant access"
   • Grant these permissions:
     • ✅ Release to production, exclude devices, and use Play App Signing
     • ✅ Release apps to testing tracks
     • ✅ Manage testing tracks and edit tester lists

7. 💾 Save the JSON key:

   • Place the downloaded JSON file at packages/mobile/google-play-service-account.json
   • Add it to .gitignore — never commit this file to version control

echo "google-play-service-account.json" >> packages/mobile/.gitignore

8️⃣ Step 8: Test a Build

Run a test build to verify everything is configured correctly:

# Android test build
eas build --profile preview --platform android

# iOS test build
eas build --profile preview --platform ios

EAS will:

1. ☁️ Upload your project to Expo's build servers
2. 📦 Install dependencies
3. 🔨 Build the native app
4. 🔐 Sign it with your credentials
5. 🔗 Provide a download link

The first build takes 10-20 minutes. Subsequent builds are faster due to caching.

💰 EAS Build Pricing

Plan	Builds per Month	Build Priority
🆓 Free	30	Standard queue
🚀 Production ($99/month)	Unlimited	Priority queue

The free tier is sufficient for most restaurants. You only need builds when publishing updates.

➡️ Next Step

Continue to Building for Android or Building for iOS.