The web app

The web app is the public front end of the bridge and the pool: a static single-page app in bridge/web. It is built and tested against the local stack and the testnet. On testnet it is public at kastools.com, built with bridge/web/config/testnet.public.json. Its mainnet URL is to be published. To try it, see Test on the public testnet.

Two wallets

The app never sees a key. It uses two wallets, one per side:

Wallet	Signs	Used for
Your EVM wallet (found through EIP-6963, else window.ethereum)	Ethereum and BNB Chain transactions	Deposits
kUSDT Wallet (the browser extension)	Kaspa transactions, which it builds, shows and signs itself	Redemptions, swaps, liquidity

Without the extension, every Kaspa-side action explains how to get it.

Sections

Section	What it does
Bridge → Kaspa	Deposits USDT into the vault: approves exactly the amount, calls deposit, then follows the deposit until it is minted. On testnet it also has “Get 1,000 test USDT” (MockUSDT’s open mint, paid with gas from your EVM account). See Bridge USDT in
Bridge → EVM	Redeems kUSDT through the wallet, after checking that the named vault can pay it now and would pay the address, and follows it until paid. See Redeem kUSDT
Swap	Quotes exactly with the same core the covenant checks against, shows the 0.30 % fee, the price impact and your slippage setting. See Swap
Pool	Reserves, price and TVL; add liquidity, list your positions, remove one
Reserves	Proof of reserves (INV-1): the coordinator’s figures next to the page’s own reads and the monitor’s check
Activity	Deposits by EVM sender or Kaspa recipient; redemptions, swaps and liquidity started from this browser
Network	The pinned deployment, whether the coordinator serves it, vaults and minter (paused or not), signers

What the page checks itself

Where the page can check something, it does not take the coordinator’s word for it:

• Vaults are read over the configured EVM RPCs, not through your wallet: fees and limits, paused(), backing() and releaseAvailable(). For reserves, backing() is read from every configured RPC and they must agree. Released amounts are summed from each vault’s own Released events.
• The minter state is checked against its own locking script; minted = genesis remaining − the minter’s remaining.
• The pool answer must hash to its UTXO’s script, the UTXO must hold base_value + X + protocol_kas, and the reserve must be the kUSDT state that pool state implies. A pool answer that fails a check is shown, explained, and not offered for swaps.
• The deployment: the coordinator must name the pinned covenant ID, pool ID and vaults, or the page says plainly that it serves another deployment.
• The recipient of a redemption: the page asks the coordinator (GET /recipients/:chain/:address) before every burn and shows the reason inline under “Pay to”. It refuses an address the token blocks, the zero address and the vault’s own, and it refuses too while the coordinator can’t answer, asking again every 30 seconds. It never offers the other chain for a blocked address. See Blocked recipients.
• A held payout: the tracker shows a redemption the coordinator holds (blocked) as “Held …”, with the time of the next check. A held refund shows the same way.

Amounts are exact integers end to end, including values above 2⁵³.

Things that can surprise you

You may notice	Why
You need two wallets	Deposits are EVM transactions; everything on Kaspa is signed by kUSDT Wallet
You need KAS to redeem	A redemption’s burn output carries 0.3 KAS, gone for good since nothing can spend a burn, plus the network fee. An ordinary kUSDT state carries 1.5 KAS, which comes back when it is spent (see Storage mass)
An Ethereum deposit can take three prompts	Ethereum’s USDT refuses to change a non-zero allowance, so the app first resets it to 0, then approves the exact amount, then deposits
Minimum release fees differ per chain	5 USDT on Ethereum, 0.50 USDT on BNB Chain (see Fees)
Position IDs look like txid:index	A position is a Kaspa UTXO, named by its transaction ID and output index

Tests

Suite	Count
Unit tests	72
End to end on the live local stack, in Chromium	73
End to end driving the real wallet extension: a swap, a deposit minted to the wallet, a redemption paid on chain, a blacklisted recipient refused	14

Hosting

npm run build in bridge/web writes a static dist/. Put a config.json next to index.html (the API URL, the deployment, the EVM RPCs and optionally the monitor). Routes are hash routes, so the app works on any static host and under a sub-path. Serve .wasm files as application/wasm. The details are in bridge/web/README.md.