A user wants to pay a merchant in USDC but only holds ETH. Today that takes two steps: swap ETH to USDC, then transfer the USDC to the merchant. Two transactions, two gas fees, and two points of failure.

The 0x Swap and Gasless APIs now accept a recipient parameter. When included, the output tokens from a swap go directly to the specified address at settlement. The taker pays, the recipient receives, and it all settles in one transaction.

If recipient is omitted, behavior is unchanged and output goes to the taker. Existing integrations are unaffected.

How it works

Add recipient as a query parameter with a valid Ethereum address. The taker signs and submits the transaction as usual, but the buyToken is delivered to the recipient address at settlement instead of back to the taker.

The API validates recipient at the price and quote stage, before any transaction is submitted, so no gas is wasted on bad requests.

const params = new URLSearchParams({
  sellToken: "0xEeeee...", // ETH
  buyToken: "0xA0b...",  // USDC
  sellAmount: "1000000000000000000", // 1 ETH
  taker: "0xUSER_ADDRESS",
  recipient: "0xMERCHANT_ADDRESS", // USDC delivered here
});

const response = await fetch(
  `https://api.0x.org/swap/permit2/quote?${params}`,
  {
    headers: {
      "0x-api-key": process.env.ZEROX_API_KEY!,
      "0x-version": "v2",
    },
  },
);

const quote = await response.json();

The taker sells ETH and the merchant receives USDC in one transaction.

Use cases

Gas top-off: Swap a long-tail token to ETH and send it directly to a wallet that needs gas.

Peer-to-peer payments: Convert to a friend's preferred token and deliver it in one call.

Treasury distributions: A DAO swaps one asset to another and delivers directly to a recipient address.

Gifting: Buy someone a token without them needing to do anything on their end.

Merchant checkout: A user pays with whatever they hold. The merchant receives their preferred stablecoin.

What to know

• Not supported for wrap/unwrap operations (ETH ↔ WETH, MATIC ↔ WMATIC). The API returns an error if recipient is passed on these pairs. Check for native/wrapped token pairs and omit recipient before calling.
• recipient must be a valid Ethereum address (0x + 40 hex characters).
• Swap and Send works identically on the Gasless API.

Swap and Send is live today on all supported chains. See the docs for the full API parameter reference and additional examples.