expo-expert_skill

Overview

This skill is Expo Expert: a compact, practical guide for building modern mobile apps with Expo SDK 55+. It focuses on development builds, the Expo Modules SDK for native extensions, and orchestrating EAS CI/CD while keeping a managed-like workflow. Use it to avoid ejecting and to deliver high-performance, OTA-updatable apps.

How this skill works

The skill inspects typical Expo workflows and recommends patterns for using expo-dev-client, Expo Modules SDK (Swift/Kotlin), Expo Router, and EAS services. It maps common failure modes to corrective actions (e.g., missing native module => create a development build) and prescribes safe defaults like using SQLite/FileSystem for large assets. It also describes when to apply config plugins and local prebuild debugging steps.

When to use it

• Adding native functionality without permanently ejecting (custom dev client + Expo Modules SDK).
• Configuring EAS Build, Submit, and OTA Update pipelines for production apps.
• Replacing AsyncStorage blobs with SQLite or file storage for performance and reliability.
• Implementing file-based routing and deep linking using Expo Router.
• Debugging build or native module issues before committing ios/android folders.

Best practices

• Prefer development builds (eas build --profile development) for native module verification instead of committing native projects.
• Write native extensions using the Expo Modules SDK DSL (Swift/Kotlin) to avoid fragile bridge code.
• Use config plugins for deterministic native changes; keep app.json minimal and declarative.
• Deliver critical fixes with eas update and use expo-updates APIs to manage caching and rollout.
• Store large binary data in SQLite or the native file system, not AsyncStorage.

Example use cases

• Implementing a high-performance image processor as an Expo Module in Swift and exposing it to JS.
• Setting up EAS Build + Submit pipelines with branch-based OTA releases for staged rollouts.
• Migrating legacy AsyncStorage blobs to SQLite for offline-first app features.
• Using Expo Router to create typed, file-based deep-linked navigation for a multi-screen app.
• Diagnosing a missing native module by producing a dev client build and validating the module export.