Capacitor Push Notifications

Set up and use push notifications in Capacitor apps using Firebase Cloud Messaging (FCM) via the @capacitor-firebase/messaging plugin.

Prerequisites

1. Capacitor 6, 7, or 8 app.
2. Node.js and npm installed.
3. A Firebase project. Create one at Firebase console if needed.
4. For iOS: A paid Apple Developer Program membership and Xcode installed.
5. For Android: Android Studio installed.
6. @capacitor/push-notifications must not be installed — it conflicts with @capacitor-firebase/messaging.

Agent Behavior

• Guide step-by-step. Walk the user through the process one step at a time. Never present multiple unrelated questions at once.
• Auto-detect before asking. Check the project for platforms (android/, ios/), build tools, framework, and package.json dependencies. Only ask the user when something cannot be detected.
• One decision at a time. When a step requires user input, ask that single question, wait for the answer, then continue.
• Present clear options. Provide concrete choices (e.g., "Do you want to configure topic subscriptions? (yes/no)") instead of open-ended questions.

Procedures

Step 1: Analyze the Project

Auto-detect the following by reading project files — do not ask the user for information that can be inferred:

1. Platforms: Check which directories exist (android/, ios/). These are the platforms to configure.
2. Build tool / framework: Check for vite.config.ts, angular.json, webpack.config.js, next.config.js, etc.
3. Capacitor version: Read @capacitor/core version from package.json.
4. Conflicting plugins: Check if @capacitor/push-notifications is in package.json. If found, warn the user it must be removed before proceeding:

   npm uninstall @capacitor/push-notifications
   

Step 2: Set Up Firebase

Check if Firebase is already configured in the project:

• Android: Check if android/app/google-services.json exists.
• iOS: Check if ios/App/App/GoogleService-Info.plist exists.

If Firebase is not configured for a detected platform, read references/firebase-setup.md and guide the user through the Firebase setup for each missing platform.

Step 3: Install the Plugin

npm install @capacitor-firebase/messaging firebase
npx cap sync

Step 4: Configure Android

Skip if android/ does not exist.

Read references/android-setup.md and apply the Android-specific configuration.

Step 5: Configure iOS

Skip if ios/ does not exist.

Read references/ios-setup.md and apply the iOS-specific configuration. This includes APNs key/certificate setup, AppDelegate.swift modifications, and enabling capabilities.

Step 6: Configure Web (if applicable)

If the project targets the web (detected via build tool config or user confirmation):

Read references/web-setup.md and apply the Web-specific configuration.

Step 7: Configure Capacitor Plugin Options

Ask the user if they want to customize iOS foreground notification presentation. If yes, update capacitor.config.json or capacitor.config.ts:

{
  "plugins": {
    "FirebaseMessaging": {
      "presentationOptions": ["alert", "badge", "sound"]
    }
  }
}

Available options: badge, sound, alert, criticalAlert. Default is ["alert", "badge", "sound"].

Step 8: Add Push Notification Code

Read references/implementation.md and add the push notification code to the project. Adapt imports and structure to match the user's framework.

The implementation covers:

1. Requesting permissions
2. Retrieving the FCM token
3. Listening for incoming notifications
4. Handling notification taps

Step 9: Configure Optional Features

Ask the user which optional features to enable:

1. Topic subscriptions — Subscribe/unsubscribe to FCM topics (Android/iOS only).
2. Notification channels — Create custom Android notification channels (Android SDK 26+ only).
3. Token refresh listener — Listen for FCM token changes.

For each selected feature, read references/implementation.md and apply the relevant code.

Step 10: Sync and Test

1. Sync the project:

   npx cap sync
   

2. Read references/testing.md and guide the user through sending a test notification via the Firebase Console.

Error Handling

• @capacitor/push-notifications conflict: The @capacitor-firebase/messaging plugin cannot coexist with @capacitor/push-notifications. Uninstall the conflicting plugin: npm uninstall @capacitor/push-notifications && npx cap sync.
• iOS: No push notifications received: Verify APNs key/certificate is uploaded to Firebase Console. Verify Push Notifications and Background Modes capabilities are enabled. Verify AppDelegate.swift contains the required delegate methods.
• iOS: didRegisterForRemoteNotificationsWithDeviceToken not called: Ensure the Push Notifications capability is added in Xcode under Signing & Capabilities. Check that the app's bundle ID matches the one registered in Firebase and Apple Developer portal.
• Android: No push notifications received: Verify google-services.json is at android/app/google-services.json. Verify the Google services Gradle plugin is applied.
• Android: White square notification icon: The notification icon must be white pixels on a transparent background. Application icons with color will render as a white square. Add a dedicated push notification icon.
• Web: getToken() fails: Ensure the VAPID key is correct. Ensure firebase-messaging-sw.js exists at the root of the domain. Check that the browser supports the Push API.
• FCM token is null: Ensure requestPermissions() was called and returned granted before calling getToken(). On iOS, verify the device is not a simulator (simulators cannot receive push notifications).
• checkPermissions() returns denied: The user has permanently denied notification permissions. Guide them to re-enable via device settings (Settings > App > Notifications).
• Android 13+: No permission prompt: On Android 13 (API 33) and above, requestPermissions() must be called explicitly. Earlier Android versions grant notification permission by default.