iOS

Add the dependency

source 'https://cdn.cocoapods.org/'
source '<cocoapods-spec-repo-url>'

target 'Runner' do
  use_frameworks! :linkage => :static
  flutter_install_all_ios_pods File.dirname(File.realpath(__FILE__))
  pod 'FlitzLoader', '<plugin-version>'
end

pod repo add flitz <cocoapods-spec-repo-url>
pod install

Subclass the app delegate

In ios/Runner/AppDelegate.swift, extend BundleLoaderAppDelegate instead of FlutterAppDelegate and override registerPlugins(with:) to register your plugins on each bundle engine. Merge these lines into your existing delegate; do not replace the file.

import UIKit
import Flutter
import FlitzLoader

@main
@objc class AppDelegate: BundleLoaderAppDelegate, FlutterImplicitEngineDelegate {
    override func application(
        _ application: UIApplication,
        didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
    ) -> Bool {
        // … your existing launch setup …
        return super.application(application, didFinishLaunchingWithOptions: launchOptions)
    }

    // Your app's own plugins, on the implicit engine — as generated by the template.
    func didInitializeImplicitFlutterEngine(_ engineBridge: FlutterImplicitEngineBridge) {
        GeneratedPluginRegistrant.register(with: engineBridge.pluginRegistry)
    }

    // Loader: register the same plugins on every bundle engine.
    override func registerPlugins(with engine: FlutterEngine) {
        GeneratedPluginRegistrant.register(with: engine)
    }
}

BundleLoaderAppDelegate routes flitz:// URLs that arrive through application(_:open:options:) and presents the loader UI over your root view controller. registerPlugins(with:) is called once per bundle engine, before the engine runs. The loader cannot call GeneratedPluginRegistrant itself — that class is generated in your project — so if you omit the override, bundles run with no plugins and method-channel calls fail with MissingPluginException.

If your project predates the UIScene template, keep the GeneratedPluginRegistrant.register(with: self) call the template put in didFinishLaunchingWithOptions and add only the registerPlugins(with:) override.

Change the scene delegate's base class

A current flutter create project has ios/Runner/SceneDelegate.swift (class SceneDelegate: FlutterSceneDelegate {}) and an Info.plist whose UISceneDelegateClassName already names $(PRODUCT_MODULE_NAME).SceneDelegate. Change the one base class:

import Flutter
import UIKit
import FlitzLoader

class SceneDelegate: BundleLoaderSceneDelegate {}

This step is required in a UIScene app: incoming URLs and the launch lifecycle are delivered to the scene delegate, not the app delegate. BundleLoaderSceneDelegate routes flitz:// URLs, forwards the bundle's own deeplinks to the running bundle engine, and replays the scene connection into that engine — which is created late, after the bundle downloads. Without the replay, a bundle cold-launched from a flitz://download link never delivers its launch event to scene-aware plugins, and plugins such as FirebaseMessaging hang on init.

Edit Info.plist

iOS does not auto-merge plist contributions. Register the URL scheme and the camera usage string in ios/Runner/Info.plist:

<key>CFBundleURLTypes</key>
<array>
  <dict>
    <key>CFBundleURLName</key>
    <string>flitz URL scheme</string>
    <key>CFBundleURLSchemes</key>
    <array>
      <string>flitz</string>
    </array>
  </dict>
</array>
<key>NSCameraUsageDescription</key>
<string>Camera access is needed to scan QR codes containing bundle URLs.</string>

To use your own scheme, change the single <string>flitz</string> value — the loader recognizes its URLs by authority, not scheme. See Custom schemes.

Build and run

Build in profile or release mode and install on a physical device — the engine ships no simulator slice, so a Simulator build does not link and a debug host rejects bundles. Then open a bundle:

• Scan the QR code flitz publish prints (or open its flitz://download?url=https://… link) to download and run a bundle over HTTPS.
• Or open flitz://run?path=<filename> for a bundle already placed in the app's Documents directory. On iOS path is a bare filename inside Documents, not an absolute path.

A cold launch from the link (app not already running) exercises the scene-connection replay from the previous step — the path scene-aware plugins depend on.