35 x402 hosts served no signed offer. Here is how to check yours in one request.

A developer who runs an x402 store conducted a census of all 35 hosts on the public x402 discovery list and found that 34 of them served no signed offer, meaning buyers were paying without a binding commitment from the seller. The developer released a free checker and open-source packages to help sellers implement signed offers, and plans to run the census weekly with results published and anchored to Bitcoin.

I run an x402 store https://dev.to/seancrecord/an-mcp-server-that-remembers-every-trial-your-agent-signed-you-up-for-5feo where the customers are AI agents. In August I pointed a free checker at every host on the public x402 discovery list. One of them tried to sign its offers. Its signatures did not parse. x402 is the HTTP 402 payment flow Coinbase and Cloudflare revived for agents: request a resource, get a 402 with the price and the address, pay, retry. It works. Thousands of settlements a day go through it. What it does not do, by default, is commit the seller to anything before the money moves. The 402 says "this costs $0.01, pay here." Nobody signed that. If the price changes between the challenge and the settlement, or the payTo address was swapped by whoever sits between you and the origin, the buyer finds out after paying, if at all. The x402 spec has an extension for exactly this: signed offers and signed receipts. A JWS over the offer, Ed25519, with a key the seller publishes. A buyer holds a commitment it can check before paying, against a key anyone can fetch, without asking the seller. It is the cheapest trust signal a seller can ship. So I checked who ships it. On 2026-08-03 I sent one GET to every host on the public x402 discovery list, 35 hosts, and read the 402 each one returned. The checker is free and public, so the whole thing is reproducible by anyone with curl: curl -X POST https://scvd.store/api/preflight/v1 \ -H 'content-type: application/json' \ -d '{"url":"https://your-endpoint.example/api/thing"}' The result: I am not going to name the 34. The point is not who; it is that in August 2026, a buyer paying an x402 endpoint on the public list was paying against terms nobody had committed to, essentially everywhere. What a signed offer costs to ship Almost nothing. Two packages exist for it, zero dependencies, any issuer: x402-sign mints spec-conformant signed offers and receipts for your 402s and generates the did:web document your key lives at. x402-verify checks anyone's, including mine.If you would rather not install anything, the conformance desk at https://scvd.store/conformance https://scvd.store/conformance takes a pasted offer or receipt from any issuer and returns a structured verdict: parse, schema, signature against the key its kid names, liveness. Free, no account, and it checks a competitor's artifact exactly as readily as mine. What I will do next The census runs weekly now and the rows are published, signed, and anchored into Bitcoin, at https://scvd.store/corpus https://scvd.store/corpus . Every week's round says how many hosts were reachable, how many were payable, and how many served a signed offer, with the denominator beside every number. If the 34 becomes 30 by October I will say so, and if it becomes 35 I will say that too. If you run an x402 endpoint: run the check above on your own door. It takes one request. If it comes back with no signed offer, you are in the 34, and the fix is an afternoon. Disclosure: the store in this piece is mine. It sells signed observations to agents for fractions of a cent and publishes the gaps in its own coverage on the same page as the findings. The census, the checker and the corpus are free along with any