@vouch-protocol-official/expo-sonic

Expo native module that bridges React Native to the Vouch Sonic Core (Rust, via UniFFI) for real on-device audio-watermark detection and Ed25519 signature verification. Replaces hand-rolled / mocked SonicBridge implementations with the actual DSP core.

• New-Architecture compatible (Expo SDK 54 / RN 0.81+, expo-modules-core 3.x).
• Registered as the native module VouchSonicCore.
• Android + iOS native bridges (both compile the Rust core from source on the build machine / EAS workers — see Building the native binaries).

Install

npx expo install @vouch-protocol-official/expo-sonic

Add the config plugin (ensures RECORD_AUDIO) to app.json:

{ "expo": { "plugins": ["@vouch-protocol-official/expo-sonic"] } }

This module requires custom native code, so it runs in a dev client or a production build — not in Expo Go. In Expo Go the native module is absent and isSonicAvailable() returns false.

Usage (drop-in SonicListener)

import { SonicListener, isSonicAvailable, verifySignature } from '@vouch-protocol-official/expo-sonic';

if (isSonicAvailable()) {
  const listener = new SonicListener({ sampleRate: 16000, detectionThreshold: 0.5 });
  await listener.start({
    onWatermarkDetected: (r) => console.log('signer:', r.signerDid, r.detectionMethod),
    onStateChanged: (s) => console.log('state:', s),
  });
  // Or feed PCM yourself (base64 of 16-bit LE mono):
  const result = await listener.processBuffer(pcmBase64);
  listener.dispose();
}

Migrating cygn-mobile's SonicBridge.ts

The native contract is identical (createListener/startListening/ processBuffer/events…), so the change is small:

- import { NativeModules, NativeEventEmitter } from "react-native";
- const { VouchSonicCore } = NativeModules;
- const eventEmitter = new NativeEventEmitter(NativeModules.VouchSonicCore);
+ import { SonicListener, isSonicAvailable } from "@vouch-protocol-official/expo-sonic";

Then delete the mockDetection() path and use the exported SonicListener directly (it already exposes start/stop/processBuffer/processSamples/ setDetectionThreshold/getConfig/dispose with the same shapes). The expo-av microphone-capture fallback can stay in the app layer if you still want it for Expo Go.

Building the native binaries

The Rust core is compiled to per-ABI .so during the Android build via cargo-ndk (the crate source is vendored at rust/). The build machine (your laptop or EAS) needs:

rustup target add aarch64-linux-android armv7-linux-androideabi \
                  x86_64-linux-android i686-linux-android
cargo install cargo-ndk
# plus the Android NDK (ANDROID_NDK_HOME)

On EAS, install these in an eas-build-pre-install hook in the app's package.json (so EAS workers have the Rust toolchain before Gradle runs). If you instead vendor prebuilt .so files into android/src/main/jniLibs/<abi>/, pass -Pvouch.skipRustBuild=true to skip the cargo step.

Status / roadmap

• ✅ Android module (Kotlin bridge over UniFFI), config plugin, cargo-ndk wiring.
• ✅ TypeScript API (type-checked against expo-modules-core 3.0.29).
• ✅ iOS module (Swift bridge over UniFFI) + VouchSonicCore.podspec that compiles the Rust core per-triple (aarch64-apple-ios / -sim) in a before_compile script phase on the EAS macOS worker. iOS workers need the Rust toolchain + targets (rustup target add aarch64-apple-ios aarch64-apple-ios-sim), same eas-build-pre-install pattern as Android.
• ⚠️ Validation: neither the Android (Gradle/cargo-ndk) nor iOS (podspec/cargo) native path has been compiled in a real EAS build from this environment (no Android NDK, no macOS here). Exercise both in dev-client builds before production.

Note on detection vs. web embedding

This core's detect_watermark uses a spread-spectrum/chirp scheme. The web watermark embedder (@vouch-protocol-official/sonic-wasm) uses a multi-layer 4-band + Barker-13 scheme. Cross-surface detection (mobile detecting a web-embedded mark) requires the two schemes to match; confirm parameters before relying on web→mobile interop.

License

Apache-2.0. See LICENSE.