Noblocks Mobile

The mobile client for Paycrest, built with Expo (SDK 53) and React Native. The app uses Privy for embedded wallets and authentication, Paycrest for swap/payout orders, and LiFi for chain/token metadata.

Requirements

• Node 20+ and Yarn (or npm)
• Watchman (macOS) — brew install watchman
• Xcode 15+ and CocoaPods for iOS
• Android Studio + JDK 17 for Android
• EAS CLI for cloud builds: npm install -g eas-cli
• Expo Orbit (optional, useful for installing dev builds on simulators)

Quick start

# 1. Install deps
yarn install

# 2. Create your local env file from the template
cp .env.example .env
# …then fill in the values (see "Environment variables" below)

# 3. Generate native projects if missing, then start the dev client
yarn prebuild
yarn ios     # or: yarn android
yarn start   # Metro bundler; opens a dev-client build

The first yarn ios / yarn android will compile a native dev client. After that, yarn start is enough.

Environments

There are three environments: development, staging, and production. They share the same bundle identifier (com.paycrest.noblocks), so only one variant can be installed on a device at a time. They differ only by environment variables and EAS build channel.

Environment	EAS profile	Channel	Notes
Development	development	development	Dev client, internal distribution, simulator-friendly
Staging	staging	staging	Internal distribution (APK / ad-hoc iOS)
Production	production	production	App Store / Play Store, auto-incremented version

Environment variables

All variables are documented in .env.example. The codebase reads them via process.env.EXPO_PUBLIC_* (see api/queryConstants.ts, api/apiClient.ts, app/_layout.tsx).

Variable	Description
EXPO_PUBLIC_APP_ENV	One of development / staging / production
EXPO_PUBLIC_API_BASE_URL	Paycrest API base URL
EXPO_PUBLIC_API_KEY	Paycrest API key
EXPO_PUBLIC_PRIVY_BASE_URL	Privy REST base URL
EXPO_PUBLIC_PRIVY_APP_ID	Privy app ID
EXPO_PUBLIC_PRIVY_CLIENT_ID	Privy client ID
EXPO_PUBLIC_PRIVY_APP_SECRET	Privy app secret (inlined — handle with care)

Anything prefixed with EXPO_PUBLIC_ is inlined into the JS bundle and shipped to users' devices. Do not put true server-only secrets in this app.

Local env switching

Expo's bundler auto-loads .env, .env.local, .env.development, .env.development.local, .env.production, .env.production.local based on NODE_ENV (see Expo env vars).

For day-to-day local development against the dev API, keep your values in .env (or .env.development). To run a local build pointed at staging or production, override per-shell:

# Point local dev at staging API
cp .env.example .env.staging   # fill in staging values
cp .env.staging .env           # use it as the active env
yarn start

EAS Build

The three build profiles live in eas.json. Each profile sets APP_ENV / EXPO_PUBLIC_APP_ENV automatically.

# Authenticate once
eas login

# Link this repo to your EAS project (writes extra.eas.projectId)
eas init

# Create a build per environment
eas build --profile development --platform ios
eas build --profile staging     --platform android
eas build --profile production  --platform all

Providing env values to EAS Build

EXPO_PUBLIC_* variables must exist in the build environment when EAS compiles the JS bundle. Choose one of:

1. EAS environment variables (recommended) — store per-environment values in the EAS dashboard or via the CLI:

   eas env:create --environment preview --name EXPO_PUBLIC_PRIVY_APP_ID --value <value>

2. Inline in eas.json — add non-sensitive values directly under each profile's env block.
3. Local .env.<profile> file — present when running eas build locally; EAS will pick it up via Expo's dotenv loader.

OTA updates (optional)

The build profiles already declare channel values, so EAS Update just needs to be wired into app.json:

eas update:configure
eas update --branch staging    --message "Fix bottom sheet on small screens"
eas update --branch production --message "Hotfix"

Project structure

app/             Expo Router screens (file-based routing)
api/             Axios client, query functions, types
components/      Shared UI
hooks/           Custom hooks (auth, payments, dimensions, fonts)
constants/       Colors, Size scale
utils/           Helpers (privy, sample data, styles)
assets/          Fonts and images
ios/, android/   Native projects (regenerated via `yarn prebuild`)
patches/         Patch-package patches applied on postinstall
schema/          Yup validation schemas
scripts/         Maintenance scripts

Scripts

Command	What it does
yarn start	Start Metro and open a dev client
yarn ios	Build and run on the iOS simulator/device
yarn android	Build and run on the Android emulator/device
yarn web	Run the web target
yarn lint	ESLint
yarn prebuild	Regenerate ios/ and android/ from config

Troubleshooting

• process.env.EXPO_PUBLIC_* is undefined — your .env file isn't loaded. Restart Metro with expo start --clear.
• Privy errors on launch — make sure EXPO_PUBLIC_PRIVY_APP_ID and EXPO_PUBLIC_PRIVY_CLIENT_ID match the environment you're pointing at.
• eas build rejects the project — run eas init to write your project ID into app.json#extra.eas.projectId.

Learn more

• Expo docs
• EAS Build
• Privy Expo SDK
• Paycrest API