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Payments API: Convert any token to USDC

Jupiter supports the payments use case. You can use Jupiter + SolanaPay to pay for anything with any SPL token. With this, you can specify an exact output token amount. So, this doesn't just support output token to USDC only.

Use Case​

Payments or interaction with a protocol can require an exact amount of token B. Users might not have token A or prefer to hold other tokens long term. The Jupiter API allow building a swap transaction to receive an exact amount of token A for a maximum in amount of token B.

A Practical Example using the API​

Bob is selling a delicious latte for 5 USDC, Alice only holds mSOL but Bob can use the Jupiter API to let Alice swap for exactly 5 USDC then transfer 5 USDC to his payment wallet.

First, we need to show Alice how much mSOL will he have to spend for the latte.

curl -s 'https://quote-api.jup.ag/v6/quote?inputMint=mSoLzYCxHdYgdzU16g5QSh3i5K3z3KZK7ytfqcJm7So&outputMint=EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v&amount=5000000&swapMode=ExactOut&slippageBps=50' | jq '.inAmount, .otherAmountThreshold'

Parameters:

  • The input mint is mSOL and the output mint is USDC.
  • swapMode is ExactOut, as opposed to the default ExactIn.
  • we want to receive amount=5,000,000, 5 USDC.

Response:

  • inAmount is the quoted estimated amount of mSOL required to receive 5 USDC.
  • otherAmountThreshold is the maximum in amount, the quote above with the slippage tolerance.
info

Currently, only Orca Whirlpool and Raydium CLAMM support ExactOut mode. All token pairs may not be available in this mode.

Then Bob creates the transaction with the /swap endpoint, and adds a 5 USDC token transfer from Alice to his payment wallet using the destinationTokenAccount argument, which Alice will verify, sign and send.

info

In the example bellow, we assume the associated token account exists on destinationTokenAccount.

import { Token, TOKEN_PROGRAM_ID, ASSOCIATED_TOKEN_PROGRAM_ID } from '@solana/spl-token'; // version 0.1.x
import { PublicKey } from '@solana/web3.js';

const USDC_MINT = new PublicKey('EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v');
const paymentAmount = 5_000_000; // 5 USDC
const bobWallet = new PublicKey('BUX7s2ef2htTGb2KKoPHWkmzxPj4nTWMWRgs5CSbQxf9');

// This token account has to be created before they can receive USDC.
const bobUSDCTokenAccount = Token.getAssociatedTokenAddress(
  ASSOCIATED_TOKEN_PROGRAM_ID,
  TOKEN_PROGRAM_ID,
  USDC_MINT,
  bobWallet,
  // @ts-ignore
  true,
);

// Get the serialized transactions for the swap
const transactions = 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,
      // Bob will receive the 5 USDC
      destinationTokenAccount: bobUSDCTokenAccount.toString(),
      userPublicKey: aliceWallet.publicKey.toString(),
    })
  })
).json();

const { swapTransaction } = transactions;

// Execute the `swapTransaction`
tip

If you want to add your own fees, check out: Adding Your Own Fees