Zello Setup

This skill covers everything needed to get the Zello SDK installed and building in the EnforcementMAPS Expo managed workflow.

Prerequisites

Before starting, ensure:

• Zello Work subscription is active with a network created
• SDK credentials (issuer + credentialKey) obtained from Zello Work admin console
• Firebase project created for au.melbourne.patrolzones with FCM enabled

Package Installation

Use pnpm (the project's package manager):

# Core SDK
pnpm add @zelloptt/react-native-zello-sdk

# Firebase (required for background PTT wake)
pnpm add @react-native-firebase/app @react-native-firebase/messaging

# Build properties (for Kotlin/Gradle config)
pnpm add expo-build-properties

Peer Dependencies

The SDK requires react ≥ 18 and react-native ≥ 0.73 — both already satisfied by the project (React 19.1.0, RN 0.81.5).

What NOT to Install

• zello-android-client-sdk — bundled inside the RN wrapper automatically
• Expo FCM notification plugins — Zello manages its own FCM channel

Android Native Configuration

EnforcementMAPS uses Expo managed workflow. All native config goes through app.config.ts — never edit android/ files directly.

Plugins Array

Add to the existing plugins array in app.config.ts:

plugins: [
  'expo-router',
  'expo-secure-store',
  ['expo-notifications', { defaultChannel: 'default' }],
  // ── Zello PTT ──────────────────────────────────────────
  '@react-native-firebase/app',
  ['expo-build-properties', {
    android: {
      kotlinVersion: '1.9.24',
      enableProguardInReleaseBuilds: true,
      packagingOptions: {
        pickFirst: ['**/kotlin/**'],
      },
    },
  }],
],

Firebase google-services.json

Place at project root and reference in app.config.ts:

android: {
  package: 'au.melbourne.patrolzones',
  googleServicesFile: './google-services.json',
  // ...existing config
},

Add google-services.json to .gitignore — credentials must not be committed.

Zello Maven Repository

Handled automatically by the React Native SDK's autolinking. No manual Gradle changes needed in Expo managed workflow.

Permissions

Update the android.permissions array in app.config.ts:

android: {
  permissions: [
    // Existing
    'ACCESS_FINE_LOCATION',
    'ACCESS_COARSE_LOCATION',
    // Zello PTT
    'RECORD_AUDIO',
    'BLUETOOTH_CONNECT',
    'POST_NOTIFICATIONS',
    'FOREGROUND_SERVICE',
    'FOREGROUND_SERVICE_MICROPHONE',
  ],
},

Permission	Purpose	Runtime Prompt?
RECORD_AUDIO	PTT voice capture	Yes (Android 6+)
BLUETOOTH_CONNECT	Hardware PTT button	Yes (Android 12+)
POST_NOTIFICATIONS	Foreground service notification	Yes (Android 13+)
FOREGROUND_SERVICE	Keep Zello alive in background	No (manifest only)
FOREGROUND_SERVICE_MICROPHONE	Mic access in foreground service	No (manifest only)

Runtime Permission Hook

Request on first PTT tap, not on app launch:

// src/features/zello/hooks/useZelloPermissions.ts
import { PermissionsAndroid, Platform } from 'react-native';

export async function requestZelloPermissions(): Promise<boolean> {
  if (Platform.OS !== 'android') return true;
  const grants = await PermissionsAndroid.requestMultiple([
    PermissionsAndroid.PERMISSIONS.RECORD_AUDIO,
    PermissionsAndroid.PERMISSIONS.BLUETOOTH_CONNECT,
    PermissionsAndroid.PERMISSIONS.POST_NOTIFICATIONS,
  ]);
  return grants[PermissionsAndroid.PERMISSIONS.RECORD_AUDIO] === 'granted';
}

Environment Variables

Add to .env.example and all eas.json build profiles:

EXPO_PUBLIC_ZELLO_NETWORK_ISSUER=
EXPO_PUBLIC_ZELLO_CREDENTIAL_KEY=

Build Verification

Create a dev build to verify native linking:

eas build --platform android --profile development

Watch for:

• ✅ @zelloptt/react-native-zello-sdk in autolinking output
• ✅ @react-native-firebase/app resolved
• ❌ Hilt/Dagger errors → see zello-troubleshooting skill

The Zello SDK cannot run in Expo Go — it requires an EAS dev build. See the expo-dev-client skill from use-expo for dev build workflow.

Detailed Documentation

Full installation and config docs at docs/dev/zello/:

• 02-installation.md — Package details
• 03-android-native-config.md — Expo plugin config
• 04-permissions.md — Permission details and timing