从 opensea 购买 NFT

Question

是否可以在不使用 SDK 的情况下从 OpenSea 市场购买 NFT？

我试图从 OpenSea 浏览器获取 TX 数据，但我认为这是不可能的，因为有 SDK。

按下购买按钮时，我正在检查请求和响应，但没有请求与购买相关，并且没有响应包括 TX 数据。

Answer 1

您需要从 Opensea API 中提取订单结构和签名，然后只需发送带有买家签名（您必须提示）的订单即可完成订单。 过程：

1. 从 Opensea API 获取订单
2. 获取买家签名
3. 向Seaport SDK提交订单以完成订单

   这是1）的代码

    var contract = req.query.contract;
           var token_id = req.query.tokenID;
           const options = {
               method: 'GET',
               headers: { Accept: 'application/json', 'X-API-KEY': API-KEY }
           };
   
           fetch('https://api.opensea.io/api/v1/assets?token_ids=' + token_id + '&order_direction=desc&asset_contract_address=' + contract + '&limit=20&include_orders=true', options)
               .then(response => response.json())
               .then(response => {
                   console.log(response)
                   res.send(
                       {
                           wyvern_orders: response.assets[0].sell_orders,
                           seaport_sell_orders: response.assets[0].seaport_sell_orders
                       }
                   )
               })
               .catch(err => {
                   res.send({ msg: "error", err: err })
               });
   

   我将上面的这个集成到一个不同的 api 中单独调用，所以在下面你会看到它是一个对那个 url 的获取来获取那个数据。此外，您会看到我提示用户签名，然后，我会将订单发送到 Seaport 的履行订单。

   export async function buyNFT(contract_address, token_id) {
   
           const buy = async() => {
               try {
                   // create the seaport instance with the provider
                   const provider = new ethers.providers.Web3Provider(window.ethereum);
                   const seaport = new Seaport(provider);
                   const url = "www.personalApiURl.com/..."
                   const options = {
                       method: "GET",
                   }
                   // get the buyer and order
                   let buyer = await getBuyer()
                   let data = await fetch(url, options)
                   let res = await data.json()
                   if (res["seaport_sell_orders"] === null) {
                       console.log("Error getting orders, may not exist for NFT")
                       return
                   }
                   // get the order for that listing
                   let full_order = res["seaport_sell_orders"][0]["protocol_data"]
                   // calculate the tip
                   let new_tip = await getTip(full_order["parameters"])
                   if (new_tip === "E") { 
                       console.log("error getting tip")
                       return 
                   } // return if can't get price
                   // now execute buy order
                   if (typeof seaport !== "undefined" && full_order) {
                       const { executeAllActions: executeAllFullfillActions} = await seaport.fulfillOrder({
                           order: full_order,
                           tips: new_tip,
                           accountAddress: buyer
                       })
                       const transaction = await executeAllFullfillActions()
                       if (transaction[code] === 4001) {
                           console.log("They denied transaction")
                           return
                       }
                   }
               } catch(error) {
                   console.log("Error in purchasing NFT")
                   console.log(error)
               }
           }
   
           async function doAll() {
               // await sell()
               await buy()
           }
           doAll()
       }
   

   这也是 calculateTip 函数。如果您想向另一个地址添加额外的小费或费用，则需要这样做。这是通过 Seaport SDK 启用的。

   async function getTip(full_order) {
           // calculate the tip pricing 
           const receiver_address = "0x0"
           //get the full real price without fees
           let real_price = getRealPrice(full_order["consideration"])
           if (real_price === "E") {return "E"}
           // if you have a price, calculate tip
           let tip_percent = ethers.BigNumber.from("100")
           let price = ethers.BigNumber.from(real_price)
           let tipping_price = price.div(tip_percent)
           // create the tip
           let new_tip = [{
               itemType: 0, //ETH
               token: "0x0000000000000000000000000000000000000000", 
               identifier: "0",
               amount: tipping_price,
               recipient: receiver_address
           }]
           return new_tip
       }