​
Setup

For this example we’ll use starknet.js to interact with the contract, but you can replace it with any Starknet library of your choice.

Make sure to install it first:

yarn add starknet

​
Interacting with the Contract

To execute a bridge transaction, call the deposit_with_id function as follows:

The commitmentId required by the contract corresponds to the quoteId returned by the API.

To obtain the commitmentId, first request a quote from the API, then commit it. The response will include the quoteId, which should be used as the commitmentId in the contract call.

See the API bridge example for details.

import {CallData, cairo} from 'starknet'

export const callStarknetBridgeContract = async (
  {
    token,
    commitmentId,
    amount,
    token,
  }) => {
  // See API Integration -> Fetch Bridge Configs for the full implementation
  const configs = await getBridgeConfigs()
  const chainConfig = configs[chain]

  // Replace with your wallet implementation
  const provider = new RpcProvider({ nodeUrl: chainConfig.rpc });
  const account = new Account(provider, STARKNET_WALLET_ADDRESS, STARKNET_PRIVATE_KEY);

  const tokenConfig = chainConfig.tokens[token]
  const amountWithDecimals = +amount * 10 ** tokenConfig.decimals
  const tokenAddress = tokenConfig.address
  const bridgeContractAddress = chainConfig.contractAddress

  const depositAmount = cairo.uint256(amountWithDecimals)
  const id = `0x${commitmentId}`
  const multiCall = await account.execute([
    {
      contractAddress: tokenAddress,
      entrypoint: 'approve',
      calldata: CallData.compile({
        spender: bridgeContractAddress,
        amount: depositAmount,
      }),
    },
    {
      contractAddress: bridgeContractAddress,
      entrypoint: 'deposit_with_id',
      calldata: CallData.compile({
        token: tokenAddress,
        amount: depositAmount,
        commitment_id: id,
      }),
    },
  ])

  const result = await provider.waitForTransaction(multiCall.transaction_hash)

  if ('revert_reason' in result && 'execution_status' in result) {
    if (result.execution_status === 'REVERTED') {
      throw new Error(result.revert_reason)
    }
  }

  return {transactionHash: multiCall.transaction_hash}
}