Expo SDK Packages Best Practices
A condensed summary of 25 essentials for Expo SDK 57 packages - install hygiene, permission rationale copy, storage tiers, and graceful denial UX. Drawn from every page in this section.
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A condensed summary of 25 essentials for Expo SDK 57 packages - install hygiene, permission rationale copy, storage tiers, and graceful denial UX. Drawn from every page in this section.
Always add Expo modules with npx expo install: Plain npm install can pull native ABIs untested against your expo pin - run npx expo install --fix after every SDK bump.
Treat expo ~57.0.4 as the contract: Every expo-* version is validated against SDK 57 - mixing generations causes native compile failures, not graceful JS errors.
Run npx expo doctor before native builds: Catches duplicate React Native copies, wrong module versions, and missing config plugins before expensive EAS minutes burn.
Config plugins require a new binary: Permission strings, background modes, and notification icons are not OTA-safe - plan store releases when plugins change.
Pre-prompt before OS permission dialogs: Show in-app rationale (why + benefit) on a dedicated screen - requesting on first mount maximizes permanent denials.
Match plugin strings to in-app copy: iOS App Review compares Info.plist usage descriptions to UI - vague "needs location" copy fails review.
Offer graceful denial paths: When users deny, show Linking.openSettings() guidance and a degraded mode that still delivers core value without the capability.
Request the narrowest permission tier first: Location When-In-Use before Always; camera only when user taps capture; photos library only for gallery picks.
Register TaskManager tasks in global scope: defineTask at app entry - never inside components - or cold-start background wakes find no handler.
Import notification handlers before first push: setNotificationHandler side-effect at index.ts or _layout.tsx top - not lazily inside a screen.
Create Android notification channels before posting: Android 8+ silently drops notifications without a channel - separate transactional vs marketing channels.
Register push tokens server-side per device: Upsert on reinstall; delete on logout - tokens in React state alone do not survive process death.
Test push and background location on development builds: Expo Go is insufficient for final QA of credentials, icons, and UIBackgroundModes.
Stop location watches on unmount: subscription.remove() in useEffect cleanup - forgotten watchers drain battery and leak callbacks.
Downscale images before preview and upload: Full-resolution URIs in <Image> cause OOM on mid-tier Android - resize to 1280–1920px and JPEG 0.7–0.8.
Store file paths in SQLite, not blobs: Photos and PDFs live in expo-file-system; databases hold URIs and metadata only.
Prefer SDK 57 File / Directory / Paths: Use expo-file-system/legacy only during migration - URI string concat is a common Android path bug.
Never store refresh tokens in AsyncStorage or plain files: Use expo-secure-store with WHEN_UNLOCKED_THIS_DEVICE_ONLY - see ../auth-session/securestore-and-keychain-keystore/securestore-and-keychain-keystore.md.
Use expo-crypto for randomness and digests: PKCE verifiers and nonces need getRandomBytes - never Math.random(); hash cache keys, not passwords for server auth.
Clear SecureStore on logout and account switch: Namespace keys per userId; pair with queryClient.clear() and navigation reset - stale vault entries are a security defect.
OTA updates change JS only: Native module additions, permission strings, and SDK bumps need a store binary - use expo-updates check/fetch/reload for bundle fixes only.
Prompt before reloadAsync: Mid-form reload loses state - fetch silently, reload on idle screens or after explicit user consent.
Treat background tasks as a safety net: Foreground NetInfo flush is primary; minimumInterval: 15 minutes is not real-time - batch work and return Success/Failed honestly.
Keep background handlers free of React: Open SQLite and fetch imperatively inside defineTask - hooks and Query clients do not exist in OS wake entry.
Document capability matrices per build flavor: Maintain a table of which SDK features work in dev client vs production - prevents shipping features that only worked in Expo Go.
npx expo install <package-name>Never npm install expo-*@latest unless you are intentionally upgrading the SDK with a changelog review.
denied.| Tier | Store |
|---|---|
| Refresh tokens | expo-secure-store |
| PDFs / photos | expo-file-system (document vs cache) |
| Relational rows | expo-sqlite |
| Theme / flags | AsyncStorage or MMKV |
Stack versions: This page was written for React 19.2.3, React Native 0.86.0, and Expo SDK 57 (
expo~57.0.4).
Reviewed by Chris St. John·Last updated Jul 16, 2026