Bitcoin has always been the elephant in the DeFi room. It holds the most value of any crypto asset, yet most of it just sits there, doing nothing, while the rest of DeFi runs on Ethereum and its cousins. Hashi, a new Bitcoin collateralization protocol built on Sui, is trying to fix that, and its testnet is now live at devnet.hashi.sui.io.
The core pitch is straightforward: deposit native Bitcoin, mint hBTC on Sui, and use it as programmable collateral for institutional lending and stablecoin borrowing, all while the actual BTC never leaves the Bitcoin blockchain.
What the Guardian Layer actually does
The protocol uses multi-party computation (MPC) threshold signatures, requiring consensus of one-third of validators, which reduces the risk of collusion or any one player getting compromised.
On top of that sits the Guardian Layer. Think of it as a circuit breaker. Before any significant BTC withdrawal clears, the Guardian Layer steps in to verify it against predefined thresholds. In plain terms: if someone tries to pull an unusually large amount of Bitcoin out of the system, an additional layer of verification kicks in before anything moves.
The BTC deposit flow works like this: a user deposits Bitcoin on the native chain, Sui validators confirm the deposit, and hBTC gets minted on Sui for use in smart contracts. The underlying Bitcoin never moves to a wrapped version on another chain. It stays put. The programmability happens on Sui’s side, using the Move programming language to enforce strict asset ownership rules.
Institutional names already in the room
Hashi’s launch has drawn backing from SwissBorg, Cumberland, Fluid, BitGo, and Ledger, a lineup that covers crypto-native trading desks, custody infrastructure, and retail-facing wealth platforms.
The use cases Hashi is prioritizing reflect that: institutional lending against BTC collateral, and stablecoin issuance backed by verifiable Bitcoin positions.
What the July 2026 timeline signals for investors
The current testnet is described as a devnet phase, with a global testnet rollout targeted for July 2026.
The revenue model runs on interest spreads. When institutions borrow against BTC collateral, the spread between deposit rates and borrowing costs generates yield. That yield flows through the protocol, creating an economic engine that doesn’t depend on token inflation or speculative demand.
What to watch in the near term: how the devnet performs under stress conditions, whether any of the named institutional backers publicly commit capital to the mainnet launch, and how Sui’s broader DeFi ecosystem responds to having a native BTC collateral primitive available. If the Guardian Layer holds up under adversarial conditions during testing, that will be the most important data point before the July 2026 rollout.