Flux Updater

Over-the-Air (OTA) update system for Flux applications. Enables efficient bytecode diff transmission, version control, and seamless updates for both development and production environments.

Part of the Flux ecosystem - a dynamic scripting language for Flutter Server-Driven UI.

Features

• Bytecode Diffing - XOR + GZip compression achieving ~5-10% patch sizes
• Version Control - Semantic versioning with rollback support
• Code Signing - HMAC-SHA256 signature verification
• OTA Server - Shelf-based REST API for release management
• CLI Tools - Compile, release, and push commands
• Flutter Integration - Seamless integration with Flutter apps

Installation

Add to your pubspec.yaml:

dependencies:
  flux_updater: ^1.0.0

Or install via command line:

dart pub add flux_updater

Quick Start

1. Start the OTA Server

dart run packages/flux_updater/bin/ota_server.dart 8080

2. Compile and Release

# Compile Flux source to bytecode
dart run bin/flux_updater.dart compile app.flux -o app.fluxc

# Create signed release
dart run bin/flux_updater.dart release \
  --app-id com.example.myapp \
  --version 1.0.0 \
  --build 1 \
  app.fluxc

# Upload to OTA server
dart run bin/flux_updater.dart push --server http://localhost:8080 app.fluxc

3. Integrate in Flutter

import 'package:flux_updater/flux_updater.dart';

final updateManager = FluxUpdateManager(
  appId: 'com.example.myapp',
  serverUrl: 'https://ota.example.com',
  signingKey: 'your-signing-key',
  currentBuildNumber: 1,
  onChunkReady: (chunk) {
    // Apply via FluxRuntime.hotReload(chunk)
    runtime.hotReload(chunk);
  },
);

// Check for updates
final status = await updateManager.checkForUpdates();
if (status == UpdateStatus.updateAvailable) {
  await updateManager.downloadAndApply();
}

API Reference

FluxUpdateManager

Method	Description
checkForUpdates()	Check if update is available
downloadAndApply()	Download and apply latest update
rollback(version)	Rollback to specific version
progressStream	Stream of update progress

OTA Server Endpoints

Method	Endpoint	Description
POST	/releases	Upload new release
GET	/releases/:appId/latest	Get latest version
GET	/patches/:appId/:from/:to	Download patch
GET	/chunks/:appId/:version	Download full chunk

CLI Commands

flux_updater compile <source.flux> -o <output.fluxc>
flux_updater release --app-id <id> --version <ver> --build <num> <file>
flux_updater push --server <url> <file.fluxc>
flux_updater info <file.fluxc>

Architecture

┌─────────────┐     ┌─────────────┐     ┌─────────────┐
│   Developer │────▶│  OTA Server │◀────│  Flutter App│
└─────────────┘     └─────────────┘     └─────────────┘
      │                    │                    │
      ▼                    ▼                    ▼
  ┌───────┐          ┌───────────┐        ┌─────────┐
  │ CLI   │          │ Releases  │        │ Update  │
  │ Tools │          │ Patches   │        │ Manager │
  └───────┘          └───────────┘        └─────────┘

App Store Compliance

iOS

Flux OTA updates comply with Apple App Store guidelines because:

1. Interpreted Code Exception: Flux uses a bytecode interpreter, not native code execution
2. No Feature Changes: Updates only modify UI/logic within the app's original scope
3. Bundled Interpreter: The Flux VM is bundled with the app, not downloaded

See App Store Guidelines §3.3.2 for details.

Android

Google Play allows OTA updates for interpreted scripts and bytecode. Ensure:

1. Updates don't change app functionality beyond original scope
2. User data privacy is maintained
3. All updates are signed and verified

Testing

# Run all tests
dart test

# Run E2E tests only
dart test test/ota_e2e_test.dart

License

MIT License - see LICENSE for details.