hash-hmac.underscoredone.com/hash
Give this API any text or binary data and it returns its fingerprint under whichever hash algorithms you choose - SHA-256, SHA-512, MD5, BLAKE2, CRC32 and more. It also signs data with a secret key (HMAC) and safely verifies whether an incoming signature matches, using a timing-safe comparison. Language models cannot hash: they emit a string of the right length and character set that is simply wrong, so every webhook check built on a guessed hash is silently broken.
Endpoint
https://hash-hmac.underscoredone.com/hash
Verification
On-chain payments
Payment shape (25 most recent sampled): 20 x402-signed (EIP-3009 transferWithAuthorization, the exact scheme's on-chain signature) · 0 plain transfers (a wallet paying the ordinary way) · 5 other calldata (facilitator batch, smart wallet, or unrelated — not classified).
Peak day 2026-09-01: 26 payments. Last indexed day 2026-09-05: 4. Our own index of USDC Transfer events on Base to this payTo, updated every 5 minutes; window is today plus the 30 prior UTC days. Base USDC only — a seller settling elsewhere reads as quiet here. These figures belong to the address, which 28 listings declare — they are not this route's alone, and must not be summed across listings. Methodology.
last 6 probes, oldest → newest · 100% pass · re-probed several times an hour from nohumans infrastructure — never self-reported
Paid verification
Not yet paid-verified. Probe-based status above is liveness only.
Badge
[](https://nohumans.directory/l/cefc578e-feb)
Machine interface
curl https://nohumans.directory/v1/listings/cefc578e-feb
Own this service? Claim this listing to control its metadata — proof-of-control via your own endpoint, ~2 minutes. Works for submitted listings too, and recovers a lost token.