Builder

Build and develop iOS apps from Windows, Linux, or any platform.

Builder is a CLI tool for iOS development without a Mac. It uses GitHub Actions for remote builds and MobAI for on-device development.

Features

• Build from anywhere: Build any iOS app (native, Flutter, React Native) via GitHub Actions
• Flutter & React Native dev tools: Hot reload on real iOS devices from Windows/Linux
• Simple setup: One command to add the workflow to your repo
• Code signing: Optional signing with your certificate and provisioning profile
• Device integration: Install and run apps via MobAI

How It Works

Your Repository                  GitHub Actions (macOS)
 └─ .github/workflows/            └─ ios-build.yml
     └─ ios-build.yml                 ├─ Checkout code
                                      ├─ Build with Xcode
builder ios build ───────────────────► Upload IPA artifact
     │
     └─ Downloads IPA ◄─────────────── artifact: ipa

Quick Start

1. Authenticate with GitHub

builder auth github

2. Initialize (in your project directory)

cd your-ios-project
builder init

This detects your GitHub repo, creates the workflow files, and offers to commit, push, and trigger your first build - all interactively.

3. Build

builder ios build

The CLI triggers the workflow and downloads the IPA to ./dist/.

Supported Frameworks

Framework	iOS Path	Auto-detected
Native iOS/Swift	. (root)	Yes
React Native	ios/	Yes
Expo (ejected)	ios/	Yes
Flutter	ios/	Yes
Cordova/Ionic	platforms/ios/	Yes

Installation

Windows

Download builder.exe from Releases and add to PATH.

macOS/Linux/WSL

curl -sSL https://raw.githubusercontent.com/MobAI-App/ios-builder/main/install.sh | bash

From Source

git clone https://github.com/MobAI-App/ios-builder.git
cd ios-builder
go build -o builder ./cmd/builder

Commands

# Setup
builder auth github           # Authenticate with GitHub
builder init                  # Set up workflow in current repo

# Building
builder ios build             # Trigger build and download IPA to ./dist/
builder ios build --unsigned  # Build without code signing (if signing is configured)

# Development (requires MobAI)
builder dev flutter           # Flutter hot reload with file watching
builder dev flutter --no-watch  # Disable automatic file watching
builder dev flutter --no-attach # Print flutter attach command instead of running it
builder dev rn                # React Native hot reload (alias: react-native)
builder dev flutter --skip-install --bundle-id <id>  # Use already installed app
builder dev rn --metro-port 8082  # Use custom Metro port

# Code signing
builder signing setup         # Set up code signing secrets

Configuration

builder.json:

{
  "project": "MyApp",
  "platform": "ios",
  "github": {
    "owner": "username",
    "repo": "my-ios-app"
  },
  "ios": {
    "path": "ios",
    "scheme": "",
    "signing": true
  },
  "mobai": {
    "url": "http://localhost:8686",
    "device_id": ""
  },
  "flutter": {
    "watch": {
      "dirs": ["lib"],
      "patterns": [".dart"],
      "ignore": [".g.dart", ".freezed.dart"],
      "debounce": 100
    }
  }
}

MobAI Configuration

Field	Description	Default
mobai.url	MobAI API URL	http://localhost:8686
mobai.device_id	Preferred device ID (uses first available if empty)	""

WSL users: MobAI runs on Windows, so you need to:

1. In MobAI, go to Integrations → API server and enable Allow external connections
2. Get your Windows hostname and use it with .local suffix:

# Get Windows hostname from WSL
hostname.exe

{
  "mobai": {
    "url": "http://YOUR-PC-NAME.local:8686"
  }
}

Flutter File Watcher

Field	Description	Default
flutter.watch.dirs	Directories to watch	["lib"]
flutter.watch.patterns	File patterns to match	[".dart"]
flutter.watch.ignore	Patterns to ignore	[".g.dart", ".freezed.dart"]
flutter.watch.debounce	Debounce delay in ms	100

Code Signing

By default, builds are unsigned. To enable code signing:

builder signing setup

This uploads your certificate and provisioning profile to GitHub Secrets:

• IOS_CERTIFICATE - Base64-encoded .p12 file
• IOS_CERTIFICATE_PASSWORD - Certificate password
• IOS_PROVISIONING_PROFILE - Base64-encoded .mobileprovision file

Once configured, builder ios build will produce signed IPAs. Use --unsigned to skip signing.

Installing the IPA

Use MobAI to sign and install your IPA directly to your device. MobAI handles code signing automatically and works with both signed and unsigned builds.

Development on Windows/Linux

Builder supports hot reload for Flutter and React Native on Windows/Linux using MobAI for iOS device control. This allows you to develop iOS apps without a Mac.

Flutter Development

Setup

1. Download and install MobAI, then connect your iOS device
2. Build your app:

   builder ios build

   This creates an IPA in ./dist/
3. Start development with hot reload:

   builder dev flutter

   MobAI will guide you through installation. Re-signing requires an iCloud account - we highly recommend creating a new one at icloud.com instead of using your primary account. If you re-sign, note the new bundle ID (includes team ID suffix, e.g., com.example.myapp.TEAMID).

Subsequent Runs

Once the app is installed, skip the install step:

builder dev flutter --skip-install --bundle-id com.example.myapp.TEAMID

File Watching

By default, builder dev flutter watches for Dart file changes and automatically triggers hot reload. When flutter attach connects, it also sends an initial hot restart to ensure your latest code is running.

• Automatic hot reload: Edit a .dart file and save - hot reload triggers automatically
• Generated files ignored: Files like .g.dart and .freezed.dart are ignored by default
• Configurable: Customize watched directories, patterns, and debounce via builder.json

To disable file watching:

builder dev flutter --no-watch

To print the flutter attach command instead of running it (useful for IDE integration):

builder dev flutter --no-attach

When to Rebuild

• Native code changes (Swift, Objective-C, Podfile, native dependencies): Run builder ios build and reinstall
• Dart code changes only: No rebuild needed - file watcher triggers hot reload automatically

If you don't see your recent Dart changes after launching, press R in the terminal to perform a hot restart.

Troubleshooting

App won't launch / connection error

• Close the app on your device before running builder dev flutter
• Reconnect the device (unplug/replug USB)
• Restart MobAI
• Run builder mobai ping to verify connection

"No devices found" error

• Ensure MobAI is running and device is connected
• Only physical iOS devices are supported (no simulators)

Hot reload not working

• Make sure you're using the correct bundle ID (with team ID suffix)
• Try hot restart with R key
• Check that MobAI shows the device as connected

File watcher not triggering

• Ensure you're editing files in watched directories (default: lib/)
• Check if the file matches watch patterns (default: .dart)
• Generated files (.g.dart, .freezed.dart) are ignored by default
• Try running without --no-watch flag

React Native Development

Setup

1. Download and install MobAI, then connect your iOS device
2. Build your app:

   builder ios build

3. Start development with hot reload:

   builder dev rn

   This will:
   • Start Metro bundler if not running
   • Install the IPA on your device (with optional re-signing)
   • Launch the app with Metro URL configured automatically

Subsequent Runs

Once the app is installed:

builder dev rn --skip-install --bundle-id com.example.myapp.TEAMID

Custom Metro Port

If port 8081 is in use:

builder dev rn --metro-port 8082

When to Rebuild

• Native code changes (Swift, Objective-C, Podfile, native modules): Run builder ios build and reinstall
• JavaScript changes only: No rebuild needed - Metro handles it automatically

Troubleshooting

Metro not starting

• Ensure Node.js and React Native CLI are installed
• Try starting Metro manually: npx react-native start

App not connecting to Metro

• Device must be on the same WiFi network as the computer running Metro
• Check that Metro is running and accessible
• Verify the Metro port is correct (default: 8081)
• On WSL2, ensure MobAI has external connections enabled

Hot reload not working

• Shake device or press d in Metro terminal to open dev menu
• Enable "Fast Refresh" in dev menu
• Try reloading with r in Metro terminal

Build Limits

GitHub Actions free tier:

• 2,000 minutes/month (macOS uses 10x multiplier = ~200 effective minutes)
• Approximately 15-20 builds per month

License

MIT License