I sent an empty-wallet payment to 4,256 x402 routes. 38 sellers told me their facilitator was down.

On October 14, 2026, a report was issued about an experiment involving 4,256 payment routes to various sellers. The experiment involved sending an EIP-3009 authorization through a freshly created wallet with no USDC. All Base sellers in the Coinbase CDP Bazaar who had transacted with at least two different payers within the last 30 days were included in the test. Each of their routes received one payment that could not be successful due to the empty wallet.

Out of the 4,256 routes tested, 2,262 were payable, with 935 of those rejecting the payment solely for lack of balance. A total of 916 routes did not respond within 20 seconds, 455 had other reasons for rejection, and 306 were rejected due to input validation errors. Additionally, 91 routes reported the payment failure as a facilitator outage.

The report highlights the issue of sellers providing different responses when confronted with an empty-wallet payment. Some sellers replied with HTTP 400, 502, or 503 errors, indicating that their facilitator was unavailable. Others returned generic error messages or did not respond at all. The report emphasizes that these responses are not necessarily indicative of a defective route but rather an incomplete understanding of how to handle such payments.

The fix suggested in the report involves fetching the facilitator's verification endpoint with a POST request and handling the JSON response appropriately. If the verification fails due to an empty wallet, the route should respond with a 402 status code and include the reason for rejection. This approach ensures that buyers are informed about the payment's status and that sellers can better manage their interactions with buyers who may be facing balance issues.