ASSAY — the quality oracle for the x402 agent economy

The corpus, live

specimen record

services under continuous probe—

paid probes in the evidence corpus—

x402 services catalogued—

sweeps per day, every day6 ×

figures drawn from the working database at page-load; nothing here is a mock-up.

ii.

How a score is earned

method of trial

T·0Settlement40% We pay the advertised price in USDC on Base. Did the service deliver after taking the money?

T·1Schema30% Does the response match the shape the service itself advertises? One in five don’t.

T·2Ground truth20% Where reality is checkable — prices, rates, coordinates — we check it against independent references.

T·3Judge10% A language model grades what mechanical checks can’t: is the translation right, is the news real, is the answer worth its price?

A score is a verdict rendered by purchase. No synthetic pings, no self-reported uptime — the same 402, the same payment, the same response any paying agent would get.

house rule — no score is published before 20 probes spread across days. A service that only behaves when it feels like it cannot hide inside one good afternoon.

iii.

Query the oracle

two counters, one door

tier · free · cache 1h

curl https://assay.nominal-labs.com/tier/{url}

{ "service": "…", "tier": "gold" }

gold · ok · avoid · unrated — all a spend-guard needs.

score · $0.005 usdc · x402

curl https://assay.nominal-labs.com/score/{url}
→ HTTP 402 → any x402 client pays & retries

{ "composite": 93.1, "nProbes": 41,
  "components": { … }, "trend": +1.2 }

Machine-payable. No key, no account, no sales call.

iv.

Trust nothing, verify us

the receipts

Every probe is a real purchase. The probe wallet spends in public — watch it on Basescan — the receipts behind every score, inspectable by anyone.

History is proven, not claimed. Each day’s corpus is sealed under a merkle root and anchored through OpenTimestamps to Bitcoin. Nobody — including us — can quietly rewrite what was observed.

The number is not for sale. Operators may pay for monitoring; the score itself cannot be bought. The day that changes, this instrument is scrap metal. So it won’t.