Interact with Multiple Contracts

Interacting with more than one contract with one transaction is one of Starknet's features. To use this feature, two contracts are required.

Prerequisites

Before using multicalls, ensure you have:

• A connected Account instance (see Account guide)
• Contract addresses you want to interact with

// Example contract addresses
const ethTokenAddress = '0x049d36570d4e46f48e99674bd3fcc84644ddd6b96f7c741b1562b82f9e004dc7';
const bridgeAddress = '0x078f36c1d59dd29e00a0bb60aa2a9409856f4f9841c47f165aba5bab4225aa6b';

Interact with contracts

Interact with more than one contract by using account.execute([calls]). The example is as follows.

import { CallData, cairo } from 'starknet';

const multiCall = await myAccount.execute([
  // First call: Approve tokens
  {
    contractAddress: ethTokenAddress,
    entrypoint: 'approve',
    calldata: CallData.compile({
      spender: bridgeAddress,
      amount: cairo.uint256(1),
    }),
  },
  // Second call: Use approved tokens
  {
    contractAddress: bridgeAddress,
    entrypoint: 'transfer_ether',
    calldata: CallData.compile({
      amount: cairo.uint256(1),
    }),
  },
]);

await myProvider.waitForTransaction(multiCall.transaction_hash);
console.log('Multicall completed!');

Using Contract.populate()

For better type safety and parameter validation:

// Prepare calls using contract instances
const approveCall = ethContract.populate('approve', {
  spender: bridgeAddress,
  amount: cairo.uint256(transferAmount),
});

const transferCall = bridgeContract.populate('transfer_ether', {
  amount: cairo.uint256(transferAmount),
});

// Execute both calls in one transaction
const tx = await myAccount.execute([approveCall, transferCall]);
await myProvider.waitForTransaction(tx.transaction_hash);