create-expo-module

# Desde la raíz de tu aplicación Expo
npx create-expo-module@latest modules/attestation
 
# Responde los prompts: nombre del módulo, descripción, plataformas (ios + android)
 
cd modules/attestation
npm install
npm run build   # compila la superficie TypeScript
 
# Vincula a la aplicación (workspace o dependencia de archivo)
cd ../..
npm install ./modules/attestation
 
# Regenera los proyectos nativos
npx expo prebuild --clean
npx expo run:ios

// Uso de la aplicación después del scaffold
import AttestationModule from "attestation";
 
const result = await AttestationModule.isDeviceTrustedAsync();

npx create-expo-app@latest AttestationApp --template blank-typescript@sdk-57 --yes
cd AttestationApp
npx create-expo-module@latest modules/device-trust

AttestationApp/
├── app.json
├── package.json
├── App.tsx
└── modules/
    └── device-trust/
        ├── android/
        │   └── src/main/java/expo/modules/devicetrust/DeviceTrustModule.kt
        ├── ios/
        │   └── DeviceTrustModule.swift
        ├── src/
        │   ├── DeviceTrustModule.ts
        │   └── index.ts
        ├── expo-module.config.json
        └── package.json

// modules/device-trust/ios/DeviceTrustModule.swift
import ExpoModulesCore
 
public class DeviceTrustModule: Module {
  public func definition() -> ModuleDefinition {
    Name("DeviceTrust")
 
    AsyncFunction("isDeviceTrustedAsync") { () -> Bool in
      // Reemplaza con integración de DeviceCheck / App Attest
      #if targetEnvironment(simulator)
      return false
      #else
      return true
      #endif
    }
  }
}

// modules/device-trust/android/src/main/java/expo/modules/devicetrust/DeviceTrustModule.kt
package expo.modules.devicetrust
 
import expo.modules.kotlin.modules.Module
import expo.modules.kotlin.modules.ModuleDefinition
 
class DeviceTrustModule : Module() {
  override fun definition() = ModuleDefinition {
    Name("DeviceTrust")
 
    AsyncFunction("isDeviceTrustedAsync") {
      // Reemplaza con Play Integrity API
      !Build.FINGERPRINT.contains("generic")
    }
  }
}

// modules/device-trust/src/DeviceTrustModule.ts
import { requireNativeModule } from "expo-modules-core";
 
type DeviceTrustModuleType = {
  isDeviceTrustedAsync: () => Promise<boolean>;
};
 
export default requireNativeModule<DeviceTrustModuleType>("DeviceTrust");

// modules/device-trust/src/index.ts
export { default } from "./DeviceTrustModule";

// AttestationApp/package.json (fragmento)
{
  "dependencies": {
    "device-trust": "file:./modules/device-trust",
    "expo": "~57.0.4",
    "expo-dev-client": "~6.0.0",
    "react": "19.2.3",
    "react-native": "0.86.0"
  }
}

// App.tsx
import { useEffect, useState } from "react";
import { Button, StyleSheet, Text, View } from "react-native";
import DeviceTrust from "device-trust";
 
export default function App() {
  const [trusted, setTrusted] = useState<boolean | null>(null);
 
  useEffect(() => {
    DeviceTrust.isDeviceTrustedAsync().then(setTrusted);
  }, []);
 
  return (
    <View style={styles.container}>
      <Text style={styles.title}>Device Trust Module</Text>
      <Text>Trusted: {trusted === null ? "…" : trusted ? "sí" : "no"}</Text>
      <Button title="Re-check" onPress={() => DeviceTrust.isDeviceTrustedAsync().then(setTrusted)} />
    </View>
  );
}
 
const styles = StyleSheet.create({
  container: { flex: 1, justifyContent: "center", padding: 24, gap: 8 },
  title: { fontSize: 20, fontWeight: "700" },
});

# Compila TypeScript del módulo, prebuild, ejecuta
cd modules/device-trust && npm run build && cd ../..
npx expo install expo-dev-client
npx expo prebuild
npx expo run:ios

{
  "platforms": ["ios", "android"],
  "ios": {
    "modules": ["DeviceTrustModule"]
  },
  "android": {
    "modules": ["expo.modules.devicetrust.DeviceTrustModule"]
  }
}