Expo provides cloud services to build Android and iOS apps, but there's a major limitation: a maximum of 30 builds per month on the free plan.

To overcome this, I set up a GitHub Action workflow that builds the APK using the EAS Build Toolkit locally, directly on GitHub's CI/CD runners. This avoids consuming your EAS cloud build quota and still produces downloadable artifacts.

In this post, I’ll walk you through the entire setup — from getting your token to generating and downloading the APK file using GitHub Actions.

✅ Prerequisites

To follow along, make sure you have:

• A GitHub repository with your Expo app.
• An Expo account (required for authentication).
• An Expo Robot Token with Admin access.

⚠️ Viewer or Developer tokens may throw permission errors — use a Robot token with Admin rights.

🔧 Step 1: Initialize EAS

In your project directory, run:

eas init

Answer the basic setup questions. After this, update your eas.json to include a preview profile:

// eas.json
{
  "cli": {
    "version": ">= 5.6.0"
  },
  "build": {
    "development": {
      "developmentClient": true,
      "distribution": "internal"
    },
    "preview": {
      "android": {
        "buildType": "apk"
      }
    },
    "production": {}
  },
  "submit": {
    "production": {}
  }
}

⚙️ Step 2: GitHub Action to Build APK

Create a new workflow file in your repo:

# .github/workflows/android-build.yml

on:
  push:
    branches:
      - main

jobs:
  build:
    runs-on: ubuntu-latest

    steps:
      - name: 🏗 Setup repo
        uses: actions/checkout@v3

      - name: 🏗 Setup Node
        uses: actions/setup-node@v3
        with:
          node-version: 18.x
          cache: yarn

      - name: 🏗 Setup EAS
        uses: expo/expo-github-action@v8
        with:
          eas-version: latest
          token: ${{ secrets.EXPO_TOKEN }}

      - name: 📦 Install dependencies
        run: yarn install

      - name: 🚀 Build app
        run: eas build --local --non-interactive --platform android --profile preview

      - name: 📤 Upload Artifact
        uses: actions/upload-artifact@v3
        with:
          name: apk-preview-build
          path: build-*.apk

💡 You must add your EXPO_TOKEN as a GitHub Secret in the repo settings.

🛠️ Step 3: app.json Configuration

Here’s a sample app.json config:

// app.json
{
  "expo": {
    "owner": "myusername",
    "name": "MY_APP",
    "slug": "MY_APP",
    "version": "1.0.0",
    "orientation": "portrait",
    "icon": "./assets/icon.png",
    "userInterfaceStyle": "light",
    "splash": {
      "image": "./assets/splash.png",
      "resizeMode": "contain",
      "backgroundColor": "#ffffff"
    },
    "assetBundlePatterns": ["**/*"],
    "ios": {
      "supportsTablet": true
    },
    "android": {
      "adaptiveIcon": {
        "foregroundImage": "./assets/adaptive-icon.png",
        "backgroundColor": "#ffffff"
      },
      "package": "dev.myapp.studio"
    },
    "web": {
      "favicon": "./assets/favicon.png"
    },
    "extra": {
      "eas": {
        "projectId": "5fafbba5-a3e3-4607-a6b5-5ad150a00132"
      }
    }
  }
}

📦 Result: Preview APK Build

Now, every time you push to the main branch:

• GitHub will run the build workflow.
• A local EAS build will be created for Android (.apk file).
• The final APK will be available in your Actions tab under Artifacts.

⚠️ This is a preview APK and is not signed for production. Use it for testing or internal distribution only.

🔒 Final Note: APK Signing for Production

This post focuses on building a preview .apk. For production-ready APKs, you’ll need to sign them — a process that involves uploading keystores and configuring build credentials.

I’ll cover APK signing and production builds in a future post once I complete the MVP of my app.

📬 Questions or Suggestions?

If you face any issues or have ideas for improvement, drop a comment below! Happy building 🚀