shield_lock
JinDaGe
← Back to skills
extension
Category: Development & EngineeringAPI key requirement unconfirmed

capacitor-best-practices

Best practices for Capacitor app development including project structure, plugin usage, performance optimization, security, and deployment. Use this skill when reviewing Capacitor code, setting up new projects, or optimizing existing apps.

personAuthor: jakexiaohubgithub
open_in_newRepositorydownloadDownload package

Capacitor Best Practices

Review a Capacitor app for structural mistakes that cause broken builds, lost edits, production leaks, and plugin crashes. Route deep topics to the sibling skill that owns them.

When to Use

TRIGGER when:

  • The user asks for a general code/architecture review of a Capacitor or Ionic + Capacitor app.
  • Setting up a new Capacitor project or adding iOS/Android to an existing web app.
  • capacitor.config.ts|json review: webDir, server.url, cleartext, plugin config, env-specific config.
  • Version drift between @capacitor/core, @capacitor/cli, @capacitor/ios, @capacitor/android, or plugin majors that do not match Capacitor's major.
  • Plugin usage review: missing npx cap sync, no availability check, no permission flow, matching on error message strings.
  • Errors such as "<Plugin>" plugin is not implemented on ios, Could not find the web assets directory, ios platform has not been added yet.
  • Pre-release sanity checklist across config, native projects, and live updates.

Do not use:

  • Security audit, secrets, storage, pinning, CSP -> capacitor-security; Xcode hardening -> capacitor-ios-security-hardening.
  • Bundle size, startup time, memory, bridge profiling -> capacitor-performance.
  • Unit/E2E test setup and plugin mocking -> capacitor-testing.
  • Crashes, white screen, native logs -> debugging-capacitor, ios-android-logs.
  • Major upgrades -> capacitor-app-upgrades (8 -> 9: capacitor-app-upgrade-v8-to-v9).
  • CocoaPods -> SPM -> cocoapods-to-spm; UIScene adoption -> capacitor-uiscene-migration.
  • Finding or installing a specific plugin -> capacitor-plugins.
  • Store submission and review -> capacitor-app-store, capacitor-apple-review-preflight; CI -> capacitor-ci-cd; live updates -> capgo-live-updates.

Current baseline (October 2026)

| | Capacitor 8 (stable, latest 8.5.x) | Capacitor 9 (next, alpha) | |---|---|---| | Node | 22+ | 24+ | | iOS min / Xcode | iOS 15 / Xcode 26 (8.5 adopts UIScene so Xcode 27 builds work) | iOS 16 / Xcode 27+ | | Android | minSdk 24, compile/target 36, AGP 8.13, Gradle 8.14.3 | minSdk 26, compile/target 37, AGP 9.2.1, Gradle 9.5.1 | | iOS deps | SPM default for new projects | SPM default |

CocoaPods Trunk is expected to go read-only on December 2, 2026. Recommend SPM for every app still on CocoaPods. Install Capacitor 9 only with @next until it reaches GA, and do not recommend it for production apps.

Review workflow

  1. Inventory (read-only). 
    npx cap doctor          # installed vs latest Capacitor packages
npx cap ls              # plugins Capacitor detects per platform
cat capacitor.config.ts 2>/dev/null || cat capacitor.config.json
ls ios/App/Podfile ios/App/CapApp-SPM 2>/dev/null   # CocoaPods or SPM
grep -nE "minSdkVersion|compileSdkVersion|targetSdkVersion" android/variables.gradle
  2. For large codebases, write a TODO list of areas (config, versions, plugins, native iOS, native Android, live updates, release) and review one at a time.
  3. Report findings before editing, grouped by severity, each with file:line and the fix. Ask before invasive changes (upgrading a major, migrating to SPM, enabling R8, changing appId).
  4. Fix, loading the matching reference.
  5. Run Verification.

Rules that matter most

  1. Keep Capacitor packages on one version. @capacitor/core, cli, ios, android must match. Plugin majors must match the Capacitor major (official and @capgo/* plugins follow it: v8 plugins for Capacitor 8).
  2. npx cap sync after every plugin install/removal and every config change. Missing sync produces "<Plugin>" plugin is not implemented on <platform>.
  3. Never edit generated web assets. android/app/src/main/assets/public/ and ios/App/App/public/ are overwritten by cap copy/sync. Edit src/ and rebuild.
  4. Commit ios/ and android/. They are source code with your native customizations, not build output. Do commit capacitor.config.*; do not commit node_modules, Pods/, build dirs.
  5. No dev settings in release config. server.url, server.cleartext, allowNavigation to dev hosts, webContentsDebuggingEnabled: true. Gate them on an env var (see references/config-and-project.md). On Capacitor 9, use npx cap run <platform> --url <dev-url> for live reload.
  6. Feature-detect before calling plugins. Capacitor.isNativePlatform(), Capacitor.getPlatform(), Capacitor.isPluginAvailable('Name'). Provide a web fallback or hide the feature.
  7. Use the permission API. Call checkPermissions() then requestPermissions() for official plugins that expose them, and handle denied with a path to Settings. Add the matching NS*UsageDescription keys / Android permissions.
  8. Branch on error.code, not error.message. Messages change between versions and platforms. Official plugins expose structured codes (for example OS-PLUG-CAMR-0006 for a cancelled camera capture in @capacitor/camera 8.1+ new APIs); Capacitor core uses UNIMPLEMENTED / UNAVAILABLE.
  9. Move large binary data as files, not base64. Pass file paths/URIs across the bridge and render with Capacitor.convertFileSrc().
  10. iOS lifecycle is scene-based from Capacitor 8.5. After adopting UIScene, AppDelegate application(_:open:options:), continue userActivity, and foreground/background callbacks stop firing. Move custom native code to SceneDelegate (capacitor-uiscene-migration). Avoid UIScreen.main and idiom-based layout for resizable windows.
  11. Live updates: call CapacitorUpdater.notifyAppReady() on every launch, and apply manual updates with next() (on background/relaunch) rather than set() mid-session. Details in capgo-live-updates.
  12. Secrets never go in the app. Anything in the bundle or capacitor.config is extractable. Hand off to capacitor-security for anything beyond this rule.

References

Only load a reference when its topic is in play.

| Reference | Load when | |-----------|-----------| | references/config-and-project.md | Reviewing capacitor.config, env-specific builds, repo layout, .gitignore, version alignment | | references/plugins.md | Plugin install/sync, availability checks, permissions, error codes, web fallbacks, lazy loading, mocking | | references/native-projects.md | iOS SPM vs CocoaPods, UIScene, deployment targets; Android variables.gradle, R8, Capacitor 9 Gradle changes | | references/release-checklist.md | Preparing a release build or reviewing release readiness |

Verification

# Versions aligned (all @capacitor/* core packages show the same version)
npm ls @capacitor/core @capacitor/cli @capacitor/ios @capacitor/android
npx cap doctor

# Web build exists where webDir points, then sync succeeds without errors
npm run build && npx cap sync

# No dev server or debug flags in the synced native config
grep -nE "\"url\"|cleartext|webContentsDebuggingEnabled" \
  android/app/src/main/assets/capacitor.config.json ios/App/App/capacitor.config.json

# No hand edits in generated web assets (should show nothing)
git status --porcelain android/app/src/main/assets/public ios/App/App/public

# Error handling does not depend on message text
grep -rnE "error\.message\s*(===|==|\.includes)" src/

# Native builds
cd android && ./gradlew assembleRelease && cd ..
xcodebuild -project ios/App/App.xcodeproj -scheme App -configuration Release -destination 'generic/platform=iOS' build CODE_SIGNING_ALLOWED=NO

With CocoaPods, build ios/App/App.xcworkspace with -workspace instead of -project. Finally run on a real device and exercise each plugin-backed feature, including permission denial.

Error handling

| Error | Cause | Fix | |-------|-------|-----| | "<Plugin>" plugin is not implemented on ios (or android) | Plugin installed but not synced, plugin has no implementation for that platform, or plugin major does not match Capacitor | npx cap sync; check npx cap ls; install the plugin version matching your Capacitor major; rebuild the native app | | "<Plugin>.<method>()" is not implemented on web | Calling a native-only method in the browser | Guard with Capacitor.isNativePlatform() or isPluginAvailable, provide a web fallback | | Could not find the web assets directory: ./dist. | webDir wrong or web app not built | Build first; set webDir to the real output folder (dist, www, build, out) | | ios platform has not been added yet. | Native project missing | npx cap add ios (SPM default) or restore the committed ios/ folder | | Invalid App ID "<id>" | appId not reverse-domain or contains invalid characters | Use com.company.app style; changing it on a published app creates a new store listing | | App loads a LAN IP or blank screen in production | server.url shipped from a dev config | Remove it, rebuild, npx cap sync, rebuild the native app | | net::ERR_CLEARTEXT_NOT_PERMITTED | HTTP request on Android | Use HTTPS; cleartext only in dev config (see capacitor-security) | | pod install fails / CocoaPods spec errors | CocoaPods trunk deprecation, outdated specs | Migrate with cocoapods-to-spm | | Deep links or resume handling stopped on iOS after 8.5 | Custom code still in AppDelegate after UIScene adoption | Move it to SceneDelegate (capacitor-uiscene-migration) |

Resources

  • Capacitor docs: https://capacitorjs.com/docs
  • Config reference: https://capacitorjs.com/docs/config
  • Environment-specific configurations: https://capacitorjs.com/docs/guides/environment-specific-configurations
  • Updating to 8.5 (UIScene): https://capacitorjs.com/docs/updating/8-5
  • Capgo docs: https://capgo.app/docs/