React Native ML Kit — Digital Ink Recognition

@nitro-mlkit/digital-ink · on-device Google ML Kit via Nitro Modules — JSI, no bridge.

⚠️ Beta (0.1.0-beta.x). Android verified on-device. iOS builds & links but device runtime is pending — see Platform status.

High-performance, on-device handwriting / digital-ink recognition for React Native, built with Nitro Modules (JSI, no bridge).

Powered by Google ML Kit. Feed it the strokes the user drew (points with optional timestamps) and a language tag; get back candidate transcriptions. 300+ languages, plus autodraw/shapes and emoji. The per-language model downloads at runtime on first use. All on-device.

Installation

npm install @nitro-mlkit/digital-ink@beta react-native-nitro-modules

No config plugin (autolinked Expo module). Install and npx expo prebuild. Not available in Expo Go.

Usage

import { NitroDigitalInk, type InkStroke } from "@nitro-mlkit/digital-ink";

// Collect strokes from your canvas (e.g. via PanResponder). Each stroke is the
// list of points between pen-down and pen-up. Timestamps (t) are optional but
// improve accuracy.
const strokes: InkStroke[] = [
  { points: [ { x: 10, y: 20, t: 0 }, { x: 12, y: 22, t: 16 }, /* … */ ] },
];

const candidates = await NitroDigitalInk.recognize(strokes, "en-US");
// → [{ text: "hello", score: … }, { text: "helio", … }, …]  (best first)

// Model management
await NitroDigitalInk.downloadModel("es-ES");
await NitroDigitalInk.isModelDownloaded("es-ES"); // boolean
await NitroDigitalInk.deleteModel("es-ES");

NitroDigitalInk.isAvailable(); // boolean

Language tags follow ML Kit's identifiers (e.g. "en-US", "es-ES", "fr-FR", "zh-Hani", "emoji").

Platform status

| Platform | Min | Status | | -------- | --- | ------ | | Android | API 26+ | ✅ Verified on-device (Pixel 9, API 36) | | iOS | 15.5+ | ⚠️ Swift impl written; on-device build & run pending¹ | | tvOS/macOS | — | 🔜 Planned |

¹ ML Kit's iOS pods ship no arm64 Simulator slice; validate on a physical device.

Part of nitro-mlkit

The full ML Kit suite on Nitro — see the other @nitro-mlkit/* packages.

License

MIT © Gonzalo Polo