Minimal Hashi Frontend

Reference frontend for the Hashi BTC bridge on Sui, built with the published @mysten-incubation/hashi SDK.

This repo is an integration guide, not a production app. It intentionally keeps the UI plain and the SDK calls close to the components so partners can see the moving pieces: deposit address derivation, BTC UTXO lookup, Sui wallet signing, hBTC withdrawals, balance reads, and status polling.

See INTEGRATION.md for a walkthrough of the implementation.

Quick Start

pnpm install
pnpm dev

Open the Vite URL and connect a Sui wallet.

Configuration

No environment file is needed for Hashi's standard testnet deployment: the SDK and this app default to its package and object IDs.

To enable automatic Bitcoin transaction-output lookup, copy .env.example to a local, untracked .env.local and replace the placeholder with your signet Bitcoin RPC endpoint:

cp .env.example .env.local

Hashi on Sui testnet uses Bitcoin signet. src/lib/hashi.ts maps Sui testnet and devnet to Bitcoin signet, mainnet to Bitcoin mainnet, and localnet to Bitcoin regtest.

For a custom deployment, set VITE_DEFAULT_NETWORK, VITE_HASHI_PACKAGE_ID, and VITE_HASHI_OBJECT_ID in the appropriate Vite environment file.

Deposit Behavior

Most Bitcoin deposits have one output to the Hashi deposit address. The example still calls hashi.bitcoin.lookupAllVouts() because a Bitcoin transaction can contain more than one output to the same address.

The deposit flow:

1. Derives the user's Bitcoin deposit address with hashi.generateDepositAddress({ suiAddress }).
2. Looks up all Bitcoin outputs in the supplied txid that pay to that address.
3. Checks hashi.view.findUsedUtxos() so already-used outputs are not submitted again.
4. Builds one Sui transaction with hashi.tx.deposit({ txid, utxos, recipient }).
5. Signs and executes through dApp Kit.

The lookup screen uses src/lib/deposit-statuses.ts to render every DepositRequested event emitted by a multi-UTXO deposit transaction. The SDK's hashi.view.depositStatus(txDigest) returns one request, which is enough for the common case but not for displaying all requests in a batch.

As of @mysten-incubation/hashi 0.5.x, deposit addresses are 2-of-2 taproot addresses derived from the on-chain guardian BTC key and the MPC-derived child key. hashi.generateDepositAddress() reads that guardian config and fails if the deployment is not guardian-provisioned.

Dependencies

Package	Purpose
@mysten-incubation/hashi	Hashi protocol SDK
@mysten/dapp-kit-react	Wallet connection and transaction signing
@mysten/sui	Sui client
@tanstack/react-query	Data fetching and polling

Commands

pnpm dev      # start dev server in testnet mode
pnpm build    # type check and production build