Errors when trying to partial fulfill an order

[filippo-monteleone]

Hi guys,

I am trying to create a script to buy a NFT on opensea (testnet).

I made a script to find the order of the NFT and then I am trying to buy but the problem is that it buys all the NFT listed instead of just 1.

This is my first script:

import { ethers } from 'ethers';
import { Chain, OpenSeaSDK, OrderSide } from 'opensea-js';

const PRIVATE_KEY = 'xxx';
const NFT_CONTRACT_ADDRESS = '0x3a1368f9e139eb12657ac46233add08c3f1b6c3e';
const NFT_TOKEN_ID = '1';
const ALCHEMY_API_KEY = 'xxx';
const OPENSEA_API_KEY = 'xxx';

async function buy() {
    const provider = new ethers.AlchemyProvider('sepolia', ALCHEMY_API_KEY);
    const wallet = new ethers.Wallet(PRIVATE_KEY, provider);
    const openseaSDK = new OpenSeaSDK(wallet, { chain: Chain.Sepolia, apiKey: OPENSEA_API_KEY });

    try {
        const { orders } = await openseaSDK.api.getOrders({
            assetContractAddress: NFT_CONTRACT_ADDRESS,
            tokenId: NFT_TOKEN_ID,
            side: OrderSide.LISTING,
        });
        console.log(
            orders.map((order) => ({
                maker: order.maker.address,
                price: order.currentPrice,
                quantity: order.remainingQuantity,
            }))
        );

        const teste = await openseaSDK.fulfillOrder({
            order: order,
            accountAddress: wallet.address,
        });

        console.log('Offer created successfully:', teste);
    } catch (error) {
        if (error instanceof Error) console.error('Error message:', error.message);
    }
}

buy();

then someone online told me to use opensea and use its fulfillOrder to buy only one item, but the problem is that the getOrders returns signatures with value null and when I attempt to fulfillOrder it throws an error saying it can't be null. Eventually, I tried to sign it myself using signMessage but then it gives me another error telling me no such account exists.

can someone help me?

this is my final result:

async function buy() {
	const provider = new ethers.AlchemyProvider('sepolia', ALCHEMY_API_KEY);
	const wallet = new ethers.Wallet(PRIVATE_KEY, provider);

	const balance = await provider.getBalance(wallet.address);
	console.log('Wallet balance:', ethers.formatEther(balance), 'ETH');

	if (balance < ethers.parseEther('0.001')) {
		console.error('Insufficient balance. Please fund your wallet with Sepolia ETH.');
		return;
	}

	const openseaSDK = new OpenSeaSDK(wallet, {
		chain: Chain.Sepolia,
		apiKey: OPENSEA_API_KEY,
	});

	const seaport = new Seaport(provider);

	try {
		const { orders } = await openseaSDK.api.getOrders({
			assetContractAddress: NFT_CONTRACT_ADDRESS,
			tokenId: NFT_TOKEN_ID,
			side: OrderSide.LISTING,
		});

		const myOrder = orders[0].protocolData;

		const signature = await wallet.signMessage(JSON.stringify(myOrder));

		myOrder.signature = signature;

		const test = await seaport.fulfillOrder({
			order: orders[0].protocolData,
			unitsToFill: 1,
		});
	} catch (error) {
		console.error('Error creating offer:', error);
		if (error instanceof Error) {
			console.error('Error message:', error.message);
		}
	}
}

buy();

[ryanio]

fulfillOrder does get the fulfillment signature, is the order hash on the order model provided?

[filippo-monteleone]

Thank you for trying to help,

Yes order model does have the order hash in fact orders[0] returns this:

 {
  createdDate: '2024-08-12T10:05:28.949354',
  closingDate: '2024-08-13T10:05:25',
  listingTime: 1723457127,
  expirationTime: 1723543525,
  orderHash: '0x609d49ce4b885d097ca6de5023be3209fd886a3d6efa33931e9f91471ab938b6',
  maker: {
    address: '0xd38fe947c78193c6890c967bc6e68456b5202f0d',
    username: undefined,
    profileImageUrl: undefined,
    bannerImageUrl: undefined,
    website: undefined,
    socialMediaAccounts: [],
    bio: undefined,
    joinedDate: undefined
  },
  taker: null,
  protocolData: {
    parameters: {
      offerer: '0xd38fe947c78193c6890c967bc6e68456b5202f0d',
      offer: [Array],
      consideration: [Array],
      startTime: '1723457127',
      endTime: '1723543525',
      orderType: 1,
      zone: '0x004C00500000aD104D7DBd00e3ae0A5C00560C00',
      zoneHash: '0x0000000000000000000000000000000000000000000000000000000000000000',
      salt: '0x360c6ebe0000000000000000000000000000000000000000ea412b64f0aca631',
      conduitKey: '0x0000007b02230091a7ed01230072f7006a004d60a8d4e71d599b8104250f0000',
      totalOriginalConsiderationItems: 2,
      counter: 0
    },
    signature: null
  },
  protocolAddress: '0x0000000000000068f116a894984e2db1123eb395',
  currentPrice: 500000000000000n,
  makerFees: [ { account: [Object], basisPoints: '250' } ],
  takerFees: [],
  side: 'ask',
  orderType: 'basic',
  cancelled: false,
  finalized: false,
  markedInvalid: false,
  clientSignature: undefined,
  remainingQuantity: 5
}

but as you can see the signature is null but for some reason the fullfillorder of seaport needs it. Do you know if there is a way to get it?

[ryanio]

the signature will be null yes but the code for fulfillOrder should fetch it:

opensea-js/src/sdk.ts

Lines 780 to 796 in 0f01368

	if (orderHash) {
	const result = await this.api.generateFulfillmentData(
	accountAddress,
	orderHash,
	protocolAddress,
	side,
	);
	// If the order is using offer protection, the extraData
	// must be included with the order to successfully fulfill.
	const inputData = result.fulfillment_data.transaction.input_data;
	if ("orders" in inputData && "extraData" in inputData.orders[0]) {
	extraData = (inputData.orders[0] as AdvancedOrder).extraData;
	}
	const signature = result.fulfillment_data.orders[0].signature;
	protocolData.signature = signature;
	}

[filippo-monteleone]

yes it works now i just had to use const seaport = openseaSDK.seaport_v1_6; instead of const seaport = new Seaport(provider);
and the signature was null so I had to sign it with this method openseaSDK.api.generateFulfillmentData(...)