Crypto: How Client-side Validation Complicates Wallet Sdk Architecture:...

A CTDG Dev Hub participant introduces an adapter layer for RGB to facilitate seamless integration with wallet SDKs.

Interoperability is crucial for a seamless experience with blockchains and cryptocurrencies. However, it is largely missing in integrations between many existing wallet SDKs and RGB, a protocol for issuing assets and running smart contracts on Bitcoin.

Utexo, a CTDG Dev Hub participant, has introduced RGB support for Tether’s Wallet Development Kit (WDK) via the Utexo SDK. The support essentially reconciles two fundamentally different views of asset state.

Most wallet SDKs are designed around a narrow and well-defined set of responsibilities: managing keys, tracking balances, constructing transactions and interacting with the underlying chain. They assume that asset state is globally observable, derived from the blockchain and updated monotonically.

These assumptions map cleanly to Bitcoin’s UTXO model or to account-based systems, like Ethereum.

However, RGB breaks all of them by design. RGB does not publish asset state onchain; it is validated client-side and transferred offchain. Onchain Bitcoin transactions only serve as anchors.

This creates a structural mismatch, especially in three areas:

Balance tracking: As validity depends on locally stored proofs and consignments, there is no onchain source of truth for RGB balances.

Transaction lifecycle: Coordination is required between a Bitcoin transaction and an RGB state transition, but neither fully represents the transfer on its own.

State persistence and recovery: Replaying the blockchain fails to recover wallets; local RGB state must also be preserved and validated.

Source: CoinTelegraph