Shared constants such as USDT_RESOURCE_ID and TOKENS, plus experimental bridge values.
You can use the SDK’s constants to bridge USDT, format token amounts with the right decimals and find the bridge contracts on other chains, without hard-coding any of these values.
Early release. This is published in @uzolabs/sdk 0.2.0 on npm and you can use it today. The API may change before 1.0, so pin the version.
The bridge uses a resource ID to identify each bridged token. Pass this value as the resourceId argument to the bridge router’s deposit and to the fee and pause reads. It’s the same on mainnet, testnet and every connected chain.See it used in Bridge USDT out.
import { formatUnits, parseUnits } from "viem";import { TOKENS } from "@uzolabs/sdk/contracts";const tenUsdt = parseUnits("10", TOKENS.USDT.decimals);console.log(tenUsdt, formatUnits(tenUsdt, TOKENS.USDT.decimals));
Output
10000000n 10
USDT on BOT Chain has 6 decimals, but USDT on BNB Smart Chain has 18. Using 18 for BOT Chain USDT makes amounts 1012 times too large. If you bridge to BNB Smart Chain, you still pass the amount in BOT Chain units.
ExperimentalThe bridge gateway and USDT addresses on the other side of the bridge, keyed by chain ID.
Chain
Key
bridgeGateway
usdt
Ethereum
1
0x2945d3aF6f012e49f7421252b5fB57D1bb7E6Edd
0xdAC17F958D2ee523a2206206994597C13D831ec7
BNB Smart Chain
56
0x3cd6fB6b0CDdD3610f0f4769AA7Bb686Cd4a4b55
0x55d398326f99059fF775485246999027B3197955
gateway.ts
import { EXTERNAL_BRIDGE } from "@uzolabs/sdk/contracts";console.log(EXTERNAL_BRIDGE[56].bridgeGateway);
It’s experimental because the gateway ABIs aren’t published, so the SDK doesn’t call these contracts. Use the addresses to find incoming transfers on BscScan or Etherscan, as shown in Track a bridge transfer. The shape of this export may change. Testnet gateways and Tron aren’t included.
