Executing a trade

[!WARNING]

These code snippets are just examples and the data should never be used as is

Trades are executed on-chain by matching a Maker order with a Taker order. The maker order can be retrieved from the graphQL API. The order used here has the same structure as a maker order, but with an added field signature: string. While the taker order can be obtained by calling the createTaker method as shown here:

import {
  HypercertExchangeClient,
  ChainId,
} from "@hypercerts-org/marketplace-sdk";

const hypercertExchangeClient = new HypercertExchangeClient(
  ChainId.OPTIMISM,
  provider,
  signer
);

// The recipient address is optional, if not provided it will use the signer address
const takerOrder = hypercertExchangeClient.createTaker(
  makerOrder,
  recipientAddress
);

// Set ERC20 approval if needed
const totalPrice = BigInt(order.price);
const approveTx = await hypercertExchangeClient.approveErc20(
  order.currency,
  totalPrice
);
await approveTx.wait();

// Only required the first time a user interacts with the contract
// It will grant the Exchange contract with the right to use your collections approvals done on the transfer manager.
const isTransferManagerApproved =
  await hypercertExchangeClient.isTransferManagerApproved();
if (!isTransferManagerApproved) {
  const transferManagerApprove = await hypercertExchangeClient
    .grantTransferManagerApproval()
    .call();
  await transferManagerApprove.wait();
}

// Set the value if the currency is the zero address currency (ETH)
const overrides =
  currency.address === zeroAddress ? { value: totalPrice } : undefined;
const tx = await hypercertExchangeClient
  .executeOrder(order, takerOrder, order.signature, undefined, overrides)
  .call();
await tx.wait();

From the API response, you will also get the signature, which is necessary to execute the trade on-chain. To execute the trade, you can call the executeOrder method passing the Maker, Taker and the signature. The method will return a contract call. Here is an example:

const tx = await hypercertExchangeClient
  .executeOrder(makerOrder, takerOrder, makerOrder.signature)
  .call();
const receipt = await tx.wait();