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Core Concepts

Lock & Release (Liquidity Model)​

Because USDT exists natively on every supported network, the Bridge uses a Lock & Release model backed by USDT liquidity vaults on each chain, rather than minting wrapped tokens.

  • Bridge In: USDT is locked in the TokenVault on the source chain, and an equal amount of USDT is released from the BOT Chain vault to the recipient.

  • Bridge Out: USDT is locked in the BOT Chain vault, and an equal amount (minus the withdrawal fee) is released from the vault on the destination chain.

Validators / Relayers​

Cross-chain transfers are secured by a decentralized set of validators. When a deposit is detected on the source chain, validators independently observe the event and produce signed attestations. Once the required signature threshold is reached, a relayer submits the aggregated proof to the destination chain to release the USDT.

  • Validators never take custody of user funds; they only attest to observed events.

  • The BridgeValidator contract enforces the signature threshold before releasing USDT.

Confirmations & Finality​

To protect against chain reorganizations, the Bridge waits for a minimum number of block confirmations on the source chain before validators attest to a transfer.

  • BOT Chain: Physical Finality — a transaction is final once included, so confirmations are near-instant.

  • External chains (Ethereum, BSC, Tron): the Bridge waits for a network-specific confirmation count before processing.

Security Model​

  • Every transfer is uniquely identified by a transferId and can only be claimed once (replay protected).

  • Release requires a valid quorum of validator signatures verified on-chain.

  • Vault balances are fully backed 1:1 by locked USDT.

  • Pausable: the BridgeRouter can be paused by governance in an emergency to protect user funds.