Capacitor

Comprehensive reference for building cross-platform apps with Capacitor. Covers architecture, CLI, plugins, framework integration, best practices, and Capawesome Cloud.

Core Concepts

Capacitor is a cross-platform native runtime for building web apps that run natively on iOS, Android, and the web. The web app runs in a native WebView, and Capacitor provides a bridge to native APIs via plugins.

Architecture

A Capacitor app has three layers:

1. 1. Web layer -- HTML/CSS/JS app running inside a native WebView (WKWebView on iOS, Android System WebView on Android).
2. Native bridge -- Serializes JS plugin calls, routes them to native code, and returns results as Promises.
3. Native layer -- Swift/ObjC (iOS) and Kotlin/Java (Android) code implementing native functionality.

Data passed across the bridge must be JSON-serializable. Pass files as paths, not base64.

Project Structure

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The android/ and ios/ directories are full native projects -- they are committed to version control and can be modified directly.

Capacitor Config

INLINECODE2 (preferred) or capacitor.config.json controls app behavior:

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For details, see App Configuration.

Creating a New App

Quick Start

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Web asset directories by framework:

• - Angular: dist/<project-name>/browser (Angular 17+ with application builder)
• React (Vite): INLINECODE5
• Vue (Vite): INLINECODE6
• Vanilla: INLINECODE7

For the full guided creation flow, see capacitor-app-creation.

Capacitor CLI

All commands: npx cap <command>. Most important commands:

Command	Purpose
INLINECODE9	Initialize Capacitor in a project
INLINECODE10

Add Android or iOS platform |
| npx cap sync | Copy web assets + update native dependencies (run after every plugin install, config change, or web build) |
| npx cap copy | Copy web assets only (faster, no native dependency update) |
| npx cap run <platform> | Build, sync, and deploy to device/emulator |
| npx cap run <platform> -l --external | Run with live reload |
| npx cap open <platform> | Open native project in IDE |
| npx cap build <platform> | Build native project |
| npx cap doctor | Diagnose configuration issues |
| npx cap ls | List installed plugins |
| npx cap migrate | Automated upgrade to newer Capacitor version |

For the full CLI reference, see CLI Reference.

Framework Integration

Capacitor works with any web framework. Framework-specific patterns:

Angular

• - Wrap Capacitor plugins in Angular services for DI and testability.
• Plugin event listeners run outside NgZone -- always wrap callbacks in NgZone.run().
• Register listeners in ngOnInit, remove in ngOnDestroy.

For details, see capacitor-angular.

React

• - Create custom hooks (useCamera, useNetwork) that wrap Capacitor plugins.
• Use useEffect for listener registration with cleanup to prevent memory leaks.
• React 18 strict mode double-mounts -- ensure cleanup functions work correctly.

For details, see capacitor-react.

Vue

• - Create composables (useCamera, useNetwork) using Vue 3 Composition API.
• Register listeners in onMounted, remove in onUnmounted.
• Vue reactivity picks up ref changes automatically (no NgZone equivalent needed).

For details, see capacitor-vue.

Plugins

Plugins are Capacitor's extension mechanism. Each plugin exposes a JS API backed by native implementations.

Plugin Sources

• - Official (@capacitor/*) -- Camera, Filesystem, Geolocation, Preferences, etc.
• Capawesome (@capawesome/*, @capawesome-team/*) -- SQLite, NFC, Biometrics, Live Update, etc.
• Community (@capacitor-community/*) -- AdMob, BLE, SQLite, Stripe, etc.
• Firebase (@capacitor-firebase/*) -- Analytics, Auth, Messaging, Firestore, etc.
• MLKit (@capacitor-mlkit/*) -- Barcode scanning, face detection, translation.
• RevenueCat (@revenuecat/purchases-capacitor) -- In-app purchases.

Installing a Plugin

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After installation, apply any required platform configuration (permissions in AndroidManifest.xml, Info.plist entries, etc.) as documented by the plugin.

Using a Plugin

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For the full plugin index (160+ plugins) and setup guides, see capacitor-plugins.

Plugin Development

Create custom Capacitor plugins with native iOS (Swift) and Android (Java/Kotlin) implementations:

1. 1. Scaffold with npm init @capacitor/plugin@latest.
2. Define the TypeScript API in src/definitions.ts.
3. Implement the web layer in src/web.ts.
4. Implement iOS plugin in ios/Sources/.
5. Implement Android plugin in android/src/main/java/.
6. Verify with npm run verify.

Key rules:

• - The registerPlugin() name in src/index.ts must match jsName on iOS and @CapacitorPlugin(name = "...") on Android.
• iOS methods need @objc and must be listed in pluginMethods (CAPBridgedPlugin).
• Android methods need @PluginMethod() annotation and must be public.

For full details, see capacitor-plugin-development.

Cross-Platform Best Practices

Platform Detection

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Permissions

Follow the check-then-request pattern:

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Performance

• - Minimize bridge calls -- batch operations instead of many individual calls.
• Use file paths over base64 for binary data.
• Lazy-load plugins with dynamic imports for code splitting.

Error Handling

Always wrap plugin calls in try-catch:

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For full details, see Cross-Platform Best Practices.

Deep Links

Deep links open specific content in the app from external URLs.

• - iOS: Universal Links via apple-app-site-association hosted at https://<domain>/.well-known/.
• Android: App Links via assetlinks.json hosted at https://<domain>/.well-known/.

Listener Setup

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Platform Configuration

• - iOS: Add applinks:<domain> to Associated Domains capability in ios/App/App/App.entitlements.
• Android: Add <intent-filter android:autoVerify="true"> to android/app/src/main/AndroidManifest.xml.

For full setup, see Deep Links.

Storage

Requirement	Solution
App settings, preferences	INLINECODE62 (native key-value, persists reliably)
Sensitive data (tokens, credentials)

@capawesome-team/capacitor-secure-preferences (Keychain/Keystore) | | Relational data, offline-first | SQLite (@capawesome-team/capacitor-sqlite or @capacitor-community/sqlite) | | Files, images, documents | @capacitor/filesystem |

Do NOT use localStorage, IndexedDB, or cookies for persistent data -- the OS can evict them (especially on iOS).

For details, see Storage.

Security

• - Never embed secrets (API keys with write access, OAuth secrets, DB credentials) in client code -- move to a server API.
• Use secure storage (@capawesome-team/capacitor-secure-preferences) for tokens and credentials, not localStorage or @capacitor/preferences.
• HTTPS only -- never allow cleartext HTTP in production.
• Content Security Policy -- add a <meta> CSP tag in index.html.
• Disable WebView debugging in production: set webContentsDebuggingEnabled: false in capacitor.config.ts.
• Prefer Universal/App Links over custom URL schemes (verified via HTTPS).
• iOS Privacy Manifest (PrivacyInfo.xcprivacy) -- required for iOS 17+ when using privacy-sensitive APIs.

For details, see Security.

Testing

Unit Testing

Mock Capacitor plugins in Jest/Vitest since tests run in Node.js, not a WebView:

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E2E Testing

• - Web E2E: Cypress or Playwright (tests web layer, plugins must be mocked).
• Native E2E: Appium (cross-platform) or Detox (iOS-focused).

Debugging

• - Android: Enable webContentsDebuggingEnabled: true, open chrome://inspect in Chrome.
• iOS: Enable webContentsDebuggingEnabled: true, use Safari > Develop menu > select device.

For details, see Testing.

Troubleshooting

Android

• - npx cap sync fails: Verify @capacitor/core and @capacitor/cli versions match. Run cd android && ./gradlew clean.
• Build fails after config changes: Clean with cd android && ./gradlew clean, then rebuild.
• Plugin not found at runtime: Run npx cap sync after plugin installation. Verify Gradle sync completed.
• SDK errors: Verify ANDROID_HOME is set. Install missing SDK versions via Android Studio SDK Manager.
• White square notification icon: Push notification icons must be white pixels on transparent background.

iOS

• - Build fails with "no such module": Run npx cap sync ios. For CocoaPods: cd ios/App && pod install --repo-update.
• Build fails after config changes: Clean build folder (Xcode Product > Clean Build Folder) or delete ios/App/Pods and re-run pod install.
• Simulator cannot receive push notifications: Use a physical device for push notification testing.
• Permission denied permanently: Cannot re-request on iOS. Guide user to Settings > App > Permissions.
• WebView not loading: Verify webDir in capacitor.config.ts matches the actual build output directory.

General

• - Live reload not connecting: Ensure device and dev machine are on the same network. Use --external flag.
• Plugin not found: Run npx cap sync. Verify plugin is in package.json dependencies.
• Capacitor is not defined: Install @capacitor/core (npm install @capacitor/core).

For full troubleshooting, see Android Troubleshooting and iOS Troubleshooting.

Upgrading

Capacitor supports upgrades across major versions (4 through 8). Apply each major version jump sequentially -- do not skip intermediate versions.

Current to Target	Node.js	Xcode	Android Studio
to 5	16+	14.1+	Flamingo 2022.2.1+
to 6

18+ | 15.0+ | Hedgehog 2023.1.1+ |
| to 7 | 20+ | 16.0+ | Ladybug 2024.2.1+ |
| to 8 | 22+ | 26.0+ | Otter 2025.2.1+ |

Quick automated upgrade:

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If npx cap migrate fails partially, apply manual steps from the upgrade guides.

For app upgrades, see capacitor-app-upgrades.
For plugin upgrades, see capacitor-plugin-upgrades.

Capawesome Cloud

Capawesome Cloud provides cloud infrastructure for Capacitor apps: native builds, live updates, and automated app store publishing.

Website: capawesome.io | Cloud Services: cloud.capawesome.io

Getting Started

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Live Updates

Deploy over-the-air (OTA) web updates to Capacitor apps without going through the app stores. Users receive updates immediately on next app launch.

Setup:

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Configure in capacitor.config.ts:

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Deploy an update:

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Native Builds

Build iOS and Android apps in the cloud without local build environments. Supports signing certificates, environments, and build configuration.

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App Store Publishing

Automate submissions to Apple App Store (TestFlight) and Google Play Store.

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CI/CD Integration

Use token-based auth for CI/CD pipelines:

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For full Capawesome Cloud setup, see capawesome-cloud.
For the Capawesome CLI reference, see capawesome-cli.

Push Notifications

Set up push notifications using Firebase Cloud Messaging (FCM) via @capacitor-firebase/messaging:

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Requires Firebase project setup, platform-specific configuration (APNs for iOS, google-services.json for Android), and permission handling.

For the full setup guide, see capacitor-push-notifications.

In-App Purchases

Set up in-app purchases and subscriptions with either:

• - Capawesome Purchases (@capawesome-team/capacitor-purchases) -- lightweight, no third-party backend, requires Capawesome Insiders license.
• RevenueCat (@revenuecat/purchases-capacitor) -- full managed backend with receipt validation, analytics, and integrations.

Both require App Store Connect (iOS) and/or Google Play Console (Android) product configuration.

For the full setup guide, see capacitor-in-app-purchases.

Related Skills

• - capacitor-app-creation -- Create a new Capacitor app from scratch.
• capacitor-app-development -- General Capacitor development topics, configuration, and troubleshooting.
• capacitor-angular -- Angular-specific Capacitor patterns.
• capacitor-react -- React-specific Capacitor patterns.
• capacitor-vue -- Vue-specific Capacitor patterns.
• capacitor-plugins -- Install and configure 160+ Capacitor plugins.
• capacitor-plugin-development -- Create custom Capacitor plugins.
• capacitor-app-upgrades -- Upgrade Capacitor apps across major versions.
• capacitor-plugin-upgrades -- Upgrade Capacitor plugins across major versions.
• capacitor-push-notifications -- Push notifications with FCM.
• capacitor-in-app-purchases -- In-app purchases and subscriptions.
• capawesome-cloud -- Live updates, native builds, app store publishing.
• capawesome-cli -- Capawesome CLI reference.