kUSDT
What kUSDT is
Section titled “What kUSDT is”kUSDT is a token on Kaspa Layer 1 (L1). Each kUSDT is backed by one USDT locked in a vault contract on Ethereum or on BNB Chain. kUSDT has 6 decimals, like USDT on Ethereum.
- On Kaspa, kUSDT is a KCC-20 covenant token. KCC-20 is the Kaspa convention for fungible tokens. A kUSDT balance is an ordinary Kaspa transaction output whose spending rules every Kaspa node checks. kUSDT uses the standard KCC-20 token code unchanged, so wallets that support KCC-20 can read it.
- On Ethereum and BNB Chain, one vault contract per chain holds the locked USDT.
- A bridge of 5 independent signers connects the two sides. Any 3 of them can approve a mint on Kaspa or a payout from a vault, and both sides limit how much can move per day.
- KasPool, a constant-product pool, lets anyone swap KAS for kUSDT and back. It also runs as covenants on Kaspa L1.
- A wallet browser extension with KCC-20 support is built and tested locally, not yet released.
Why Kaspa L1
Section titled “Why Kaspa L1”Everything that happens to kUSDT on the Kaspa side is a Kaspa L1 transaction. kUSDT does not use the Igra or Kasplex layer-2 networks, their contracts or their bridges. Its rules run in Kaspa’s own script engine, and its transactions are ordered and confirmed like any KAS payment. Kaspa L1, not a layer 2 explains the difference.
How it works, in three steps
Section titled “How it works, in three steps”You lock USDT in the vault on Ethereum or BNB Chain and name a Kaspa address. The vault numbers the deposit and keeps a 0.20 % fee (at least 0.50 USDT).
Once the deposit is final, at least 3 of the 5 signers sign it. The BridgeMint covenant on Kaspa checks the signatures and the limits, and creates your kUSDT.
Send kUSDT, or swap it for KAS in KasPool. To redeem, you send it to a burn owner that names your EVM address. The signers approve, and the vault pays you USDT.
The full flows are in Bridge USDT in and Redeem kUSDT.
Key numbers
Section titled “Key numbers”These are the mainnet defaults from the specification. Testnet uses the same rules.
| Item | Value |
|---|---|
| Signers | 5; any 3 approve a mint or a payout; 4 unpause, change limits or replace signers on Kaspa |
| Bridge fee | 0.20 % each way |
| Minimum fee | 0.50 USDT per deposit; 5 USDT per release on Ethereum, 0.50 USDT on BNB Chain |
| Deposit size | 10 to 100 000 USDT |
| Kaspa mint allowance | 500 000 USDT, refills fully in 24 hours |
| Vault release allowance | 250 000 USDT per vault, refills fully in 24 hours |
| Kaspa hard cap | 1 000 000 000 kUSDT; it can only go down |
| Pool fee | 0.30 % per swap (0.25 % to liquidity providers, 0.05 % to the protocol) |
Status
Section titled “Status”| Part | Status |
|---|---|
| Protocol specification | v1, written for testnet |
| BridgeMint and the kUSDT token family (Kaspa) | Written; 21 script-engine tests; full Kaspa flow run on a local kaspad v2.1.0 simnet |
| KasPool (Kaspa) | Written; 12 script-engine tests; full pool flow run on the same simnet |
| KusdtVault (Ethereum, BNB Chain) | Written; 83 Hardhat tests; reviewed line by line against the specification |
| Transaction builders | Written: kusdt-tx CLI and a WebAssembly build of the same code |
| Signer and coordinator services | Written; the whole bridge (two local EVM chains, simnet, 5 signers, coordinator) ran end to end on one machine |
| Monitor and guardian | Written; in the local run it caught a forged 400 000 kUSDT mint and paused both vaults and the minter within seconds |
| Web app | Built and tested against the local stack, with the real wallet extension |
| Refunds | Working in the local load run |
| Wallet extension | Built and tested against the local stack; a testnet build to download, not released to any store |
| Public testnet deployment | Live since 4 November 2026 at kastools.com, test coins only. See Test on the public testnet |
| External audit | Not audited |
Details are on the status page and the roadmap.
Where to go next
Section titled “Where to go next”- New to Kaspa covenants? Start with Covenants in plain words.
- Evaluating the bridge? Read the trust model and the threat model.
- Building on kUSDT? See Developers and the message formats.