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Jupiter V6 Swap API指南

Jupiter API 是开发者获取 Solana 流动性的最简单方法，本文可以帮助开发者在自己的应用中快速集成Jupiter 的能力。

Jupiter V6 Swap API指南

Jupiter API 是开发者获取 Solana 流动性的最简单方法。 只需传入所需的货币对、金额和滑点，API 将返回执行交换所需的序列化交易，然后可以将其与所需的签名一起传递到 Solana 区块链中。

所有 Jupiter 交换都使用版本化交易和地址查找表。 但并非所有钱包都支持版本化交易，因此如果检测到不支持版本化交易的钱包，则需要使用 asLegacyTransaction 参数。

可以在这里查阅Jupiter V6 Swap API的详细文档。

1、Jupiter API快速上手

要运行此示例，至少需要 NodeJS 16。在命令行终端中，安装库：

npm i @solana/web3.js
npm i cross-fetch
npm i @project-serum/anchor
npm i bs58

1.1 从库导入并设置连接

接下来，你可以将以下代码片段复制到 javascript 文件 jupiter-api-example.js。 当准备好运行代码时，只需输入：  node jupiter-api-example.js 。

import { Connection, Keypair, VersionedTransaction } from '@solana/web3.js';
import fetch from 'cross-fetch';
import { Wallet } from '@project-serum/anchor';
import bs58 from 'bs58';

// It is recommended that you use your own RPC endpoint.
// This RPC endpoint is only for demonstration purposes so that this example will run.
const connection = new Connection('https://neat-hidden-sanctuary.solana-mainnet.discover.quiknode.pro/2af5315d336f9ae920028bbb90a73b724dc1bbed/');
提示：始终确保你使用自己的 RPC 端点。 上例中连接对象使用的 RPC 端点可能不再起作用。

1.2 设置钱包

你可以粘贴私钥用于测试目的，但不建议在生产应用程序中这样做。

const wallet = new Wallet(Keypair.fromSecretKey(bs58.decode(process.env.PRIVATE_KEY || '')));

1.3 获取交换路由

在这里，我们获得了从 SOL 兑换成 USDC 的报价。

// Swapping SOL to USDC with input 0.1 SOL and 0.5% slippage
const quoteResponse = await (
  await fetch('https://quote-api.jup.ag/v6/quote?inputMint=So11111111111111111111111111111111111111112\
&outputMint=EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v\
&amount=100000000\
&slippageBps=50'
  )
).json();
// console.log({ quoteResponse })

API 接受整数金额，你必须通过查找该代币的小数点来考虑每个代币的小数点。 例如，USDC 有 6 位小数，1 USDC 传入 API 时，其整数为 1000000。

1.4 获取序列化交易来执行交换

一旦有了报价，我们需要将报价序列化为可以在链上提交的兑换交易。

// get serialized transactions for the swap
const { swapTransaction } = await (
  await fetch('https://quote-api.jup.ag/v6/swap', {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({
      // quoteResponse from /quote api
      quoteResponse,
      // user public key to be used for the swap
      userPublicKey: wallet.publicKey.toString(),
      // auto wrap and unwrap SOL. default is true
      wrapAndUnwrapSol: true,
      // feeAccount is optional. Use if you want to charge a fee.  feeBps must have been passed in /quote API.
      // feeAccount: "fee_account_public_key"
    })
  })
).json();

1.5 反序列化并签署交易

// deserialize the transaction
const swapTransactionBuf = Buffer.from(swapTransaction, 'base64');
var transaction = VersionedTransaction.deserialize(swapTransactionBuf);
console.log(transaction);

// sign the transaction
transaction.sign([wallet.payer]);

1.6 执行交易

// Execute the transaction
const rawTransaction = transaction.serialize()
const txid = await connection.sendRawTransaction(rawTransaction, {
  skipPreflight: true,
  maxRetries: 2
});
await connection.confirmTransaction(txid);
console.log(`https://solscan.io/tx/${txid}`);

2、高级错误处理以从 API 禁用某些 AMM

有时，AMM 在交换时会抛出错误，并且为了防止为同一报价获取失败的 AMM，你可以在获取 /quote 时使用 exceptDexes 参数。

示例 JS，在 @mercurial-finance/optimist 包的帮助下：

import { parseErrorForTransaction } from '@mercurial-finance/optimist';

// TX ID from last step if the transaction failed.
const transaction = connection.getTransaction(txid, {
  maxSupportedTransactionVersion: 0,
  commitment: 'confirmed'
});

const programIdToLabelHash = await (
  await fetch('https://quote-api.jup.ag/v6/program-id-to-label')
).json();
const { programIds } = parseErrorForTransaction(transaction);

let excludeDexes = new Set();
if (programIds) {
  for (let programId of programIds) {
    let foundLabel = programIdToLabelHash[programId];
    if(foundLabel) {
      excludeDexes.add(foundLabel);
    }
  }
}

// Request another quote with `excludeDexes`.
const { data } = await (
  await fetch(`https://quote-api.jup.ag/v6/quote?inputMint=So11111111111111111111111111111111111111112
&outputMint=EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v
&amount=100000000&excludeDexes=${Array.from(excludeDexes).join(',')}
&slippageBps=50`
  )
).json();

3、指令代替交易

有时，你更喜欢使用指令来编写，而不是从 /swap 端点返回的一个交易。 你可以改为发布到 /swap-instructions，它采用与 /swap 端点相同的参数。

const instructions = await (
  await fetch('https://quote-api.jup.ag/v6/swap-instructions', {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({
      // quoteResponse from /quote api
      quoteResponse,
      userPublicKey: swapUserKeypair.publicKey.toBase58(),
    })
  })
).json();

if (instructions.error) {
  throw new Error("Failed to get swap instructions: " + instructions.error);
}

const {
  tokenLedgerInstruction, // If you are using `useTokenLedger = true`.
  computeBudgetInstructions, // The necessary instructions to setup the compute budget.
  setupInstructions, // Setup missing ATA for the users.
  swapInstruction: swapInstructionPayload, // The actual swap instruction.
  cleanupInstruction, // Unwrap the SOL if `wrapAndUnwrapSol = true`.
  addressLookupTableAddresses, // The lookup table addresses that you can use if you are using versioned transaction.
} = instructions;

const deserializeInstruction = (instruction) => {
  return new TransactionInstruction({
    programId: new PublicKey(instruction.programId),
    keys: instruction.accounts.map((key) => ({
      pubkey: new PublicKey(key.pubkey),
      isSigner: key.isSigner,
      isWritable: key.isWritable,
    })),
    data: Buffer.from(instruction.data, "base64"),
  });
};

const getAddressLookupTableAccounts = async (
  keys: string[]
): Promise<AddressLookupTableAccount[]> => {
  const addressLookupTableAccountInfos =
    await connection.getMultipleAccountsInfo(
      keys.map((key) => new PublicKey(key))
    );

  return addressLookupTableAccountInfos.reduce((acc, accountInfo, index) => {
    const addressLookupTableAddress = keys[index];
    if (accountInfo) {
      const addressLookupTableAccount = new AddressLookupTableAccount({
        key: new PublicKey(addressLookupTableAddress),
        state: AddressLookupTableAccount.deserialize(accountInfo.data),
      });
      acc.push(addressLookupTableAccount);
    }

    return acc;
  }, new Array<AddressLookupTableAccount>());
};

const addressLookupTableAccounts: AddressLookupTableAccount[] = [];

addressLookupTableAccounts.push(
  ...(await getAddressLookupTableAccounts(addressLookupTableAddresses))
);

const blockhash = (await connection.getLatestBlockhash()).blockhash;
const messageV0 = new TransactionMessage({
  payerKey: payerPublicKey,
  recentBlockhash: blockhash,
  instructions: [
    // uncomment if needed: ...setupInstructions.map(deserializeInstruction),
    deserializeInstruction(swapInstructionPayload),
    // uncomment if needed: deserializeInstruction(cleanupInstruction),
  ],
}).compileToV0Message(addressLookupTableAccounts);
const transaction = new VersionedTransaction(messageV0);

4、使用maxAccounts

有时，如果你使用 Jupiter Swap 指令编写，可能希望为自己的程序指令腾出一些帐户（1 个 Solana 交易中最多 64 个），这时可以使用 maxAccounts。

// If you know that your instruction will take up 10 accounts, you
// can pass in 54 as `maxAccounts` when quoting.
const { data } = await (
  await fetch('https://quote-api.jup.ag/v6/quote?inputMint=So11111111111111111111111111111111111111112\
&outputMint=EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v\
&amount=100000000\
&slippageBps=50\
&maxAccounts=54'
  )
).json();
const quoteResponse = data;
// console.log(quoteResponse)

maxAccounts 是一个估计值，因为它不考虑帐户重叠，但它是控制每笔交易所需的帐户数量的良好开端。

6、使用Token Ledger指令

有时，你可能不知道 Jupiter 交换的确切输入金额，直到交换发生前的指令为止。

例如：

const instructions = await (
  await fetch('https://quote-api.jup.ag/v6/swap-instructions', {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({
      // quoteResponse from /quote api
      quoteResponse,
      useTokenLedger: true,
  })
).json();

const {
  tokenLedgerInstruction: tokenLedgerPayload, // If you are using `useTokenLedger = true`.
  swapInstruction: swapInstructionPayload, // The actual swap instruction.
  addressLookupTableAddresses, // The lookup table addresses that you can use if you are using versioned transaction.
} = instructions;

// A withdraw instruction that will increase the user input token account amount.
const withdrawInstruction = ...;

// Coupled with the tokenLedgerInstruction, the swap instruction will use the
// user increased amount of the input token account after the withdrawal as input amount.
const tokenLedgerInstruction = new TransactionInstruction({
  programId: new PublicKey(tokenLedgerPayload.programId),
  keys: tokenLedgerPayload.accounts.map((key) => ({
    pubkey: new PublicKey(key.pubkey),
      isSigner: key.isSigner,
      isWritable: key.isWritable,
    })),
  data: Buffer.from(tokenLedgerPayload.data, "base64"),
});

const swapInstruction = new TransactionInstruction({
  programId: new PublicKey(swapInstructionPayload.programId),
  keys: swapInstructionPayload.accounts.map((key) => ({
    pubkey: new PublicKey(key.pubkey),
      isSigner: key.isSigner,
      isWritable: key.isWritable,
    })),
  data: Buffer.from(swapInstructionPayload.data, "base64"),
});

const getAdressLookupTableAccounts = async (
  keys: string[]
): Promise<AddressLookupTableAccount[]> => {
  const addressLookupTableAccountInfos =
    await connection.getMultipleAccountsInfo(
      keys.map((key) => new PublicKey(key))
    );

  return addressLookupTableAccountInfos.reduce((acc, accountInfo, index) => {
    const addressLookupTableAddress = keys[index];
    if (accountInfo) {
      const addressLookupTableAccount = new AddressLookupTableAccount({
        key: new PublicKey(addressLookupTableAddress),
        state: AddressLookupTableAccount.deserialize(accountInfo.data),
      });
      acc.push(addressLookupTableAccount);
    }

    return acc;
  }, new Array<AddressLookupTableAccount>());
};

const addressLookupTableAccounts: AddressLookupTableAccount[] = [];

addressLookupTableAccounts.push(
  ...(await getAdressLookupTableAccounts(addressLookupTableAddresses))
);

const messageV0 = new TransactionMessage({
  payerKey: payerPublicKey,
  recentBlockhash: blockhash,
  instructions: [tokenLedgerInstruction, withdrawInstruction, swapInstruction],
}).compileToV0Message(addressLookupTableAccounts);
const transaction = new VersionedTransaction(messageV0);

如果想从 Solend 提款并立即将提款代币转换为 Jupiter 的另一种代币，这会很有用。

7、为交易设置优先费

如果交易在未经链上确认的情况下到期，这可能意味着你必须支付额外费用才能优先处理你的交易。 为此，你可以设置 computeUnitPriceMicroLamports 参数。

const transaction = await (
  await fetch('https://quote-api.jup.ag/v6/swap', {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({
      // quoteResponse from /quote api
      quoteResponse,
      // user public key to be used for the swap
      userPublicKey: wallet.publicKey.toString(),
      dynamicComputeUnitLimit: true, // allow dynamic compute limit instead of max 1,400,000
      // custom priority fee
      prioritizationFeeLamports: 'auto' // or custom lamports: 1000
    })
  })
).json();

如果使用 auto，Jupiter 将自动为交易设置优先费用，上限为 5,000,000 lamports / 0.005 SOL。

原文链接：V6 Swap API - Jupiter Station

DefiPlot翻译整理，转载请标明出处

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