EVM

Step 1. Install and setup

• Ensure your camera stream can feed animated QR frames to the decoder.

Step 2. Decode an incoming animated QR

import { airGapUrUtils } from '@keystonehq/keystone-sdk';

const { receivePart, promiseResultUR } = airGapUrUtils.createAnimatedURDecoder();
// Push each scanned frame (string) from the camera to the decoder
receivePart?.(frameString);
// Wait until all parts are received
const ur = await promiseResultUR; // a complete UR object

Step 3. Build a sign request

import { getAirGapSdk, EAirGapDataTypeEvm } from '@keystonehq/keystone-sdk';
import { v4 as uuidv4 } from 'uuid';

const ur = getAirGapSdk().eth.generateSignRequest({
  requestId: uuidv4(),
  signData: unsignedTxHex, // hex without 0x
  dataType: EAirGapDataTypeEvm.typedTransaction,
  path: "m/44'/60'/0'/0/0",
  xfp: device.xfp,
  chainId: 1,
  origin: 'AirGap App',
});

// Render as animated QR frames
const frames = airGapUrUtils.urToQrcode(ur);

Reference: EthSignRequest

Step 4. Scan device response

Use the same decoder as in Step 2. Parse the typed result eth-signature and extract the signed payload.

Reference: EthSignature

Step 5. Submit/broadcast

Submit the signed payload (transaction/message) to your network stack.