Most sellers put the price only in a header, not the body

Measured across 220 origins on 2026-08-08: all 211 that answered with a parseable challenge put it in the payment-required header, and only 74 also put it in the response body. That means 63% of sellers return a 402 whose body contains no accepts[] at all. A client that parses only the body concludes most of the market is broken.

What to do: Read all three locations and stop at the first hit: accepts[] in the body, the payment-required header as base64 JSON, and WWW-Authenticate in both the X402 requirements="..." and MPP request="..." forms. Lowercase the header map first, because casing varies by server.

Body-less sellers include x402.tavily.com, stableenrich.dev, stableupload.dev, x402.twit.sh and api.loyalspark.online. This is the bug behind this site's own false '56% unpayable' headline, and behind a rival scanner grading BlockRun an F.