Is there a person on the other end?

Send someone a link. To answer it, they unlock their own device with a fingerprint, face or PIN. You get a signed yes, and nobody needs an account.

How it works

You create a link. You get two addresses: one to send, and one to keep for yourself.
They open it and unlock their device. The fingerprint or face never leaves their device; this site only learns that the unlock worked.
Your page turns into a confirmation, with a signed receipt anyone can check.

What a pass tells you

It proves

A person physically unlocked a real device after your link was created.
It happened once, on your link, within the time limit.
In strict mode, the device is certified hardware, not software posing as one.

It can't prove

Who the person is. There is no identity check.
That they are the one you have been talking to. An AI agent can pass the link to a person, so a pass means a person took part, not that no agent was involved.
In standard mode, that a determined expert didn't emulate the device. Use strict mode when that matters.

For agents and scripts

Create a check with one request and read the result as JSON. Receipts are EdDSA-signed JWTs you can verify with the published key.

curl -X POST https://www.hiumans.com/api/checks \
  -H 'Content-Type: application/json' \
  -d '{"mode":"standard","ttl_hours":24}'

# Send "send_url" to the person. Then poll:
curl "https://www.hiumans.com/api/checks/ID?key=KEY"