Hashi has launched a testnet on Sui that allows developers to build and test a Bitcoin-backed lending system using native BTC collateral. The testnet provides a sandbox environment for experimenting with a security architecture called the Guardian Layer, which uses 2-of-2 multisig controls between validators and independent guardians combined with MPC threshold signatures.
Bitcoin’s base layer was not designed for smart contract activity. The market has addressed this gap through wrapped BTC, bridges, custodial tokenization, sidechains, restaking systems, and new Bitcoin DeFi protocols. Lending represents one use case where users lock Bitcoin as collateral and borrow stablecoins or other assets against it.
Guardian Layer Security Model
The Guardian Layer adds a security checkpoint around Bitcoin-backed activity on Sui. The architecture combines 2-of-2 multisig between validators and independent guardians with MPC threshold signatures. This dual-control mechanism is intended to protect BTC collateral from unauthorized movement or compromise.
The testnet is designed for developers and security researchers to inspect the model, test edge cases, and observe how the system behaves under stress. Sui has emphasized fast execution, object-based architecture, consumer applications, and DeFi growth as core platform themes.
Collateral Trust and Conservative Users
Bitcoin holders tend to be more conservative than users chasing new DeFi yields. They typically require strong reasons to trust systems that move their Bitcoin exposure into another chain’s lending environment. The testnet phase allows Hashi to demonstrate the robustness of its Guardian Layer design before mainnet deployment.
Developers can now access the testnet through Hashi’s GitHub repository to begin experimenting with the Bitcoin-backed lending design.
