User Flows

There are two main user flows for interacting with hashi: deposits and withdrawals.

Deposit flow

To use BTC on Sui (for example, as collateral for a loan), you must deposit your BTC to a Hashi MPC-controlled Bitcoin address.

Every Sui address has its own unique Hashi Bitcoin deposit address. See Bitcoin Address Scheme for the full derivation details.

After your deposit address is determined, you can initiate a deposit to Hashi.

Broadcast a Bitcoin transaction depositing BTC into your unique deposit address.
Notify Hashi of the deposit by submitting a transaction to Sui that includes the deposit transaction ID.
Hashi nodes query Bitcoin and watch for confirmation of the deposit transaction.
Hashi nodes communicate, waiting until a quorum has confirmed the deposit (after X block confirmations).
Hashi confirms the deposit onchain, minting the equivalent amount of hBTC and transferring it to your Sui address. You can then immediately use the hBTC to interact with a DeFi protocol. For example, you can use the hBTC as collateral for a loan in USDC.

For a detailed breakdown of each phase, see Deposit.

After you decide you want your BTC back on Bitcoin (for example, after you pay off your loan), you can initiate a withdrawal.

You send a transaction to Sui with the amount of hBTC you want to withdraw and the Bitcoin address you want to withdraw to.
Hashi picks up the withdrawal request and crafts a Bitcoin transaction that sends the requested BTC (minus fees) to the provided Bitcoin address, then uses MPC to sign the transaction.
The transaction is broadcast to the Bitcoin network.

For a detailed breakdown of each phase, see Withdraw.