mufify AGENTS.md

AGENTS.md

Instructions for AI coding agents working in this repository. Human contributors should read this too — it's the house style.

Note: create-expo-app generates its own AGENTS.md and CLAUDE.md. Merge this file into the generated one rather than keeping two competing sets of rules.

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Project

An offline-only local music player for Android, built with React Native and Expo. Plays FLAC and other lossless formats from the device. Local playlists, multiple shuffle algorithms, on-device listening statistics, dark/light themes, Turkish and English.

No network. No accounts. No telemetry. No analytics SDK. If a change introduces a network call, it is wrong. This is the app's core promise and the reason it exists.

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Setup

Requirements: Node 22+, JDK 17 or 21, Android Studio with SDK Platform 36+, macOS or Linux. (Expo SDK 57 compiles against 36; this said 35 until app.sh checked it and was wrong.)

Environment (macOS)

None of this is set by default. Put it in ~/.zshrc — every "it works on my machine" failure in this project so far has been one of these three lines missing.

# Android Studio's bundled JBR is a perfectly good JDK. No separate install needed.
export JAVA_HOME="/Applications/Android Studio.app/Contents/jbr/Contents/Home"
export ANDROID_HOME="$HOME/Library/Android/sdk"
export PATH="$JAVA_HOME/bin:$ANDROID_HOME/platform-tools:$ANDROID_HOME/emulator:$PATH"

Verify before blaming the code:

java -version        # 17 or 21
adb devices          # your device, "device" not "unauthorized" or "offline"
npx expo-doctor

Daily loop

npm install
npx expo start --dev-client   # this is the normal one — JS/TS changes hot reload
npm run lint
npm run typecheck
npm test
npm run db:generate           # drizzle-kit: generate migration after schema change

npx expo run:android is only for native changes: adding or removing a native dependency, editing app.json, or changing a config plugin. It is a ten-minute build. Reaching for it after a TypeScript edit is the most common way to waste an afternoon here.