Capacitor Firebase App Check Plugin

Unofficial Capacitor plugin for Firebase App Check.[^1]

Use Cases

The Firebase App Check plugin is typically used to verify that requests to your backend originate from your authentic app, for example:

• Protecting Firebase resources: Ensure that only your genuine app can access services like Cloud Firestore or Cloud Functions by attesting requests with Play Integrity, App Attest, or reCAPTCHA v3.
• Securing custom backends: Retrieve an App Check token with getToken(...) and send it along with requests to your own backend for server-side verification.
• Automatic token refresh: Keep App Check tokens up to date with setTokenAutoRefreshEnabled(...) and react to changes via the tokenChanged listener.
• Local development: Use the debug provider to test your app on unverified devices such as emulators.

Compatibility

Guides

• Firebase App Check in a Capacitor App: Set up the Play Integrity, App Attest, and reCAPTCHA providers and verify tokens server-side with this plugin.
• How to Use Firebase in a Capacitor App: A tour of the Firebase services App Check ends up protecting once enforcement is on.

Installation

You can use our AI-Assisted Setup to install the plugin. Add the Capawesome Skills to your AI tool using the following command:

npx skills add capawesome-team/skills --skill capacitor-plugins

Then use the following prompt:

Use the `capacitor-plugins` skill from `capawesome-team/skills` to install the `@capacitor-firebase/app-check` plugin in my project.

If you prefer Manual Setup, install the plugin by running the following commands and follow the platform-specific instructions below:

npm install @capacitor-firebase/app-check firebase
npx cap sync

Add Firebase to your project if you haven't already (Android / iOS / Web).

Android

See Set up your Firebase project and follow the instructions to set up your app correctly.

Variables

If needed, you can define the following project variable in your app’s variables.gradle file to change the default version of the dependency:

• $firebaseAppCheckPlayIntegrityVersion version of com.google.firebase:firebase-appcheck-playintegrity (default: 19.0.1)
• $firebaseAppCheckDebugVersion version of com.google.firebase:firebase-appcheck-debug (default: 19.0.1)

This can be useful if you encounter dependency conflicts with other plugins in your project.

iOS

On iOS 14 and later, see Set up your Firebase project and follow the instructions to set up your app correctly.

On iOS 13, see Set up your Firebase project and follow the instructions to set up your app correctly.

Make sure that the private key (*.p8) you upload to Firebase has DeviceCheck selected as a service.

Swift Package Manager

Add the following to your capacitor.config.json (or capacitor.config.ts) to avoid a SwiftPM package identity collision:

{
  "experimental": {
    "ios": {
      "spm": {
        "packageOptions": {
          "@capacitor-firebase/app-check": {
            "symlink": true
          }
        }
      }
    }
  }
}

Attention: SPM packageOptions support requires Capacitor CLI 8.4.0+.

Web

See Set up your Firebase project and follow the instructions to set up your app correctly.

Configuration

No configuration required for this plugin.

Firebase JavaScript SDK

Here you can find information on how to use the plugin with the Firebase JS SDK.

Demo

A working example can be found here: robingenz/capacitor-firebase-plugin-demo

Usage

The following examples show how to initialize App Check, get the current token, enable automatic token refresh, and listen for token changes.

Initialize App Check

Activate App Check for your app. This can be called only once per app. On the Web, pass a provider such as ReCaptchaV3Provider; on Android and iOS, the native attestation providers are used:

import { FirebaseAppCheck } from '@capacitor-firebase/app-check';
import { ReCaptchaV3Provider } from '@capacitor-firebase/app-check';
import { Capacitor } from '@capacitor/core';

const initialize = async () => {
  await FirebaseAppCheck.initialize({
    provider: Capacitor.getPlatform() === 'web' ? new ReCaptchaV3Provider('myKey') : undefined,
  });
};

Get the current App Check token

Retrieve the current App Check token, for example to send it to your own backend. Set forceRefresh to true if you always want to fetch a fresh token instead of a cached one:

import { FirebaseAppCheck } from '@capacitor-firebase/app-check';

const getToken = async () => {
  const { token } = await FirebaseAppCheck.getToken({
    forceRefresh: false,
  });
  return token;
};

Enable automatic token refresh

Set whether the App Check token should be refreshed automatically as needed:

import { FirebaseAppCheck } from '@capacitor-firebase/app-check';

const setTokenAutoRefreshEnabled = async () => {
  await FirebaseAppCheck.setTokenAutoRefreshEnabled({ enabled: true });
};

Listen for token changes

Get notified whenever the App Check token changes:

import { FirebaseAppCheck } from '@capacitor-firebase/app-check';

const addTokenChangedListener = async () => {
  await FirebaseAppCheck.addListener('tokenChanged', event => {
    console.log('tokenChanged', { event });
  });
};

Remove all listeners

Remove all listeners for this plugin. Only available on Web:

import { FirebaseAppCheck } from '@capacitor-firebase/app-check';

const removeAllListeners = async () => {
  await FirebaseAppCheck.removeAllListeners();
};

API

• getToken(...)
• initialize(...)
• setTokenAutoRefreshEnabled(...)
• addListener('tokenChanged', ...)
• removeAllListeners()
• Interfaces
• Type Aliases

getToken(...)

getToken(options?: GetTokenOptions | undefined) => Promise<GetTokenResult>

Get the current App Check token.

Returns: Promise<GetTokenResult>

Since: 1.3.0

initialize(...)

initialize(options?: InitializeOptions | undefined) => Promise<void>

Activate App Check for the given app. Can be called only once per app.

Since: 1.3.0

setTokenAutoRefreshEnabled(...)

setTokenAutoRefreshEnabled(options: SetTokenAutoRefreshEnabledOptions) => Promise<void>

Set whether the App Check token should be refreshed automatically or not.

Since: 1.3.0

addListener('tokenChanged', ...)

addListener(eventName: 'tokenChanged', listenerFunc: TokenChangedListener) => Promise<PluginListenerHandle>

Called when the App Check token changed.

Returns: Promise<PluginListenerHandle>

Since: 1.3.0

removeAllListeners()

removeAllListeners() => Promise<void>

Remove all listeners for this plugin.

Only available for Web.

Since: 1.3.0

Interfaces

GetTokenResult

GetTokenOptions

InitializeOptions

SetTokenAutoRefreshEnabledOptions

PluginListenerHandle

TokenChangedEvent

Type Aliases

TokenChangedListener

Callback to receive the token change event.

(event: TokenChangedEvent): void

Testing

Android

Follow these steps to test your implementation on a real device:

1. Start your app on the Android device.
2. Run the following command to grab your temporary secret from the android logs:

adb logcat | grep DebugAppCheckProvider

The output should look like this:

D DebugAppCheckProvider: Enter this debug secret into the allow list in
the Firebase Console for your project: XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX

1. Next, open the App Check project in the Firebase Console and select Manage debug tokens from the overflow menu of your app. Then, register the debug secret from the output.

FAQ

Which attestation providers does this plugin use?

On Android, the plugin uses the Play Integrity provider. On iOS, it uses App Attest on iOS 14 and later and DeviceCheck on iOS 13. On the Web, it uses reCAPTCHA v3 by default, but you can also pass a ReCaptchaEnterpriseProvider or CustomProvider instance via the provider option.

How can I test App Check on emulators and other unverified devices?

Use the debug provider by setting the debugToken option of the initialize(...) method. On Android, you can grab the temporary debug secret from the device logs and register it in the Firebase Console (see Testing). Never use the debug provider in production builds of your app and never share your debug builds with untrusted parties, as it allows access to your Firebase resources from unverified devices.

How do I protect my own backend with App Check?

Call the getToken(...) method to retrieve the current App Check token in JWT format and send it along with requests to your backend, where you can verify it server-side. Use the tokenChanged listener to get notified whenever the token changes.

Why is my App Check token not refreshed automatically?

Automatic token refresh is disabled by default. You can enable it with the isTokenAutoRefreshEnabled option of the initialize(...) method or at any time with the setTokenAutoRefreshEnabled(...) method.

Can I use this plugin with Ionic, React, Vue or Angular?

Yes, the plugin is framework-agnostic. It works in any Capacitor app regardless of the web framework, including Ionic with Angular, React, or Vue, as well as plain JavaScript projects.

Related Plugins

• Firebase Authentication: Unofficial Capacitor plugin for Firebase Authentication.
• Firebase Cloud Firestore: Unofficial Capacitor plugin for Firebase Cloud Firestore.
• Firebase Cloud Functions: Unofficial Capacitor plugin for Firebase Cloud Functions.
• Firebase Cloud Storage: Unofficial Capacitor plugin for Firebase Cloud Storage.

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Changelog

See CHANGELOG.md.

License

See LICENSE.

[^1]: This project is not affiliated with, endorsed by, sponsored by, or approved by Google LLC or any of their affiliates or subsidiaries.