Check the payee before you pay

Agent payments have no chargeback. Before you sign any x402 payment, check the payee with Paddock.

When to use

Every time you are about to pay an x402 endpoint you have not paid before, or any time the payment terms changed since you last paid it.

How

Take the resource URL and the payment requirements you are about to sign (payTo, network, asset, amount) and call:

GET https://paddock.finance/api/mcp/check-payee?url=&pay_to=&network=&asset=&amount_atomic=

Or call the check_payee tool on Paddock's MCP server at https://paddock.finance/api/mcp/mcp.

What to do with the answer

• fail: do not pay. The wallet is recorded as settling for a different seller. Tell the user and show the reasons and full_check link.
• warn: you may pay, but tell the user what the warning says.
• pass or unknown: pay as normal.
• No answer, an error, or a 402 from Paddock: pay as normal. The check is advisory and never a reason to stop on its own.

Free

25 checks a day without a key. Past that, Paddock answers 402 and you pay as normal. A Builder or Pro Agent key from https://paddock.finance/api-access lifts the limit.

In code

TypeScript projects using the x402 client can add this check in one line with the npm package @paddock-finance/x402-guard.