Hashi has launched a testnet on Sui, offering developers a sandbox for a Bitcoin-backed lending architecture that uses native BTC collateral and a Guardian Layer security model.

According to the protocol’s materials published through its GitHub repository, the system is designed around multi-layer transaction security. The architecture includes MPC threshold signatures and a 2-of-2 multisig process involving validators and independent guardians.

The technical design is intended to support a straightforward objective: enabling Bitcoin to be used in Sui-based decentralized finance without treating cross-chain BTC collateral as a simple problem. Bitcoin remains the largest crypto asset, but using BTC in DeFi typically involves wrappers, bridges, custodians, or synthetic representations. Hashi is attempting to create a more structured model for using BTC to support lending on Sui while adding extra checks around transaction security.

The launch is a testnet, not a mainnet product holding real user BTC at scale. Hashi’s design includes a Guardian Layer, MPC threshold signatures, and 2-of-2 multisig controls, but the system is not yet a live mainnet Bitcoin lending product.

Bitcoin Collateral Remains a Key DeFi Target

DeFi protocols have long sought access to Bitcoin liquidity. Bitcoin has the largest market capitalization in crypto, the strongest brand recognition, and broad awareness across the digital asset market. However, Bitcoin’s base layer was not designed for the kind of smart contract activity commonly associated with networks such as Ethereum, Sui, Solana, or Avalanche.

As a result, the crypto market has spent years trying to make BTC usable outside its native network. Wrapped BTC, bridges, custodial tokenization, sidechains, restaking systems, and emerging Bitcoin DeFi protocols all pursue variations of the same objective: allowing BTC holders to use their asset without selling it.

Lending is one of the clearest use cases. If users can lock Bitcoin as collateral and borrow stablecoins or other assets, BTC can be used more actively within DeFi markets. That possibility is attractive, but it also introduces significant risks.

Whenever Bitcoin is brought into another chain’s DeFi environment, users must evaluate how custody works, how collateral is verified, who controls transfers, and what happens if a bridge, signing process, or related security system fails. Hashi’s Guardian Layer is presented as an effort to address those questions in a more structured way.

Guardian Layer Adds a Security Checkpoint

Hashi’s Guardian Layer is designed to add an additional security checkpoint around BTC-backed activity. Rather than depending on a single signer or a basic bridge process, the protocol’s architecture uses a 2-of-2 multisig requirement between validators and independent guardians.

In practical terms, a 2-of-2 multisig setup requires both designated parties in the signing arrangement to approve a transaction, while MPC threshold signing is commonly used to split signing responsibility so that no single participant controls a complete private key. Together with MPC threshold signatures, the model is intended to make unauthorized movement more difficult and to separate responsibilities among different roles.

The architecture is not presented as eliminating all risk. No cross-chain BTC system is risk-free, and smart contract bugs, signing failures, governance errors, validator problems, and economic attacks can still exist.

The value of the layered model is that it recognizes the trade-offs involved in moving Bitcoin exposure into another DeFi ecosystem. It does not assume that Bitcoin can simply appear in a different blockchain environment without additional trust and security considerations.

That is why the testnet stage is important. Developers and security researchers need time to examine the model, test edge cases, and observe whether the system behaves as expected under stress. The testnet allows the design to be evaluated before real user funds are involved at scale.

Sui Gains a Bitcoin DeFi Experiment

For Sui, Hashi introduces another potential DeFi direction: Bitcoin-backed finance on a high-performance Layer 1 network. Sui has already emphasized themes including fast execution, object-based architecture, consumer applications, and DeFi growth. BTC collateral experiments add another area for developers to explore within the ecosystem.

The proposition is broader than simply building DeFi on Sui. Hashi’s testnet is aimed at bringing the largest crypto asset into Sui-based DeFi in a structured manner. That could be relevant for developers working on lending markets, stablecoin borrowing systems, or collateralized products built around BTC.

However, the testnet label remains central. A working sandbox does not mean users should assume safe mainnet liquidity is available. Testnets are designed for experimentation, failure testing, and security review before real money is deployed.

Security Comes Before TVL

New collateral systems in crypto are often assessed quickly by total value locked, or TVL. For BTC-backed lending, the more important initial question is whether the security model works. The amount of value locked becomes meaningful only after a system has shown that it can protect funds, process transactions correctly, and withstand adversarial conditions.

That point is especially important when Bitcoin is involved. BTC holders are often viewed as more conservative than users pursuing new DeFi yield opportunities. They need a strong basis for trusting any system that moves their exposure into another chain’s lending environment.

Hashi’s testnet gives the project an opportunity to build that trust gradually. The focus at this stage is not on proving market adoption or demonstrating that Sui has absorbed substantial Bitcoin liquidity. It is on testing whether the architecture can support Bitcoin-backed lending with additional safeguards around custody, signing, and transaction control.

Testnet Is Not a Finished Product

Hashi’s launch is notable because it addresses a difficult problem without representing itself as a completed mainnet lending market. It is not mainnet Bitcoin lending, it is not a fully proven BTC collateral market, and it is not evidence that Sui has already attracted major Bitcoin liquidity.

Instead, the testnet targets a specific challenge: making Bitcoin more useful in DeFi while reducing some of the risks commonly associated with wrapped or bridged assets. The project’s current value lies in its architecture and the experiment now available for developers and researchers.

If Hashi progresses from testnet to mainnet with strong audits, clear documentation, and developer participation, it could become part of Sui’s DeFi stack. For now, the system remains an experimental environment focused on Bitcoin collateral and multi-layer transaction security.

Bitcoin DeFi is likely to depend less on promotional claims around BTC yield and more on whether systems can make Bitcoin holders comfortable enough to participate. Hashi’s Sui testnet is an attempt to build in that direction.

This article is based on Hashi’s Sui testnet materials published through its GitHub repository. The original report was written by the News Desk and edited by Samuel Rae, and was based on information released in disclosures at primary source documentation.