Air-Gap (Offline QR Signing)

Build a “device stays offline” signing loop using UR-encoded QR codes.

How it Works

Build Request: Create a sign request UR payload (per chain), render as animated QR frames
Device Scans: Device scans QR, verifies details on-screen, signs offline
Get Signature: Device displays signature UR as animated QR
Broadcast: App scans response, verifies, and broadcasts via your network

Quick Start by Chain

Chain	Request Type (App → Device)	Response Type (Device → App)
Ethereum & EVM	`eth-sign-request`	`eth-signature`
Bitcoin (PSBT)	`crypto-psbt`	`crypto-psbt`
Solana	`sol-sign-request`	`sol-signature`
Tron	`tron-sign-request`	`tron-signature`

Account Export Types (Device → App)

These UR types are used when the device exports account information to the app during initial setup:

UR Type	Description
`crypto-hdkey`	Single HD key export (BCR-2020-007 )
`crypto-multi-accounts`	Multi-chain account bundle export

API Reference

Basic API – Core UR types: CryptoHDKey, CryptoCoinInfo, CryptoKeypath

Packages


# Keystone SDK & UR registries
npm install @keystonehq/keystone-sdk @keystonehq/bc-ur-registry-eth
 
# UR primitives
npm install @ngraveio/bc-ur

Third-Party Wallet Integration

If you are integrating OneKey Air-Gap into an existing wallet, you need to ensure your QR scanner routes these UR types to a BC-UR v2 decoder (fountain-coded), not a legacy v1 decoder.

UR types your scanner must accept

Direction	UR Type	When
Device → App	`crypto-psbt`	BTC signed PSBT
Device → App	`crypto-hdkey`	HD key export on connect
Device → App	`crypto-multi-accounts`	Multi-account export on connect
Device → App	`eth-signature`	ETH signed transaction
Device → App	`sol-signature`	SOL signed transaction
Device → App	`btc-signature`	BTC signature (non-PSBT)
App → Device	`eth-sign-request`	ETH sign request
App → Device	`sol-sign-request`	SOL sign request
App → Device	`crypto-psbt`	BTC unsigned PSBT

Common pitfall: UR type routing

Some wallets use a whitelist to decide which UR types are decoded with the modern BC-UR v2 decoder (fountain codes via @ngraveio/bc-ur). Types not in the whitelist may fall through to a legacy v1 decoder that uses a completely different encoding scheme, causing the scanner to get stuck.

If your scanner shows “please continue scanning” but never completes, check that the UR type is in your v2 whitelist.

`onekey-app-call-device` (private protocol)

The onekey-app-call-device UR type is a OneKey-internal protocol used for device management operations (e.g., getMultiAccounts, verifyAddress). Third-party wallets should NOT implement this type — it may change without notice. Use the standard Keystone SDK methods instead.

Demo & Examples

React Native Demo: GitHub Air-Gap Demo
- Scanner: AirGapScanner.tsx
- Chain helpers: sdk/

Note: Air-Gap is offline by design. There is no online browser playground.