ON-CHAIN PROOF · PORTABLE
Yourverification,anywhereontheweb.
When you pass KYC or KYB on MettaPay, we publish a tamper-proof, privacy-safe proof to the Ethereum Attestation Service — so anyone can verify you, without ever seeing your documents.
What is an attestation
Three pieces of magic.
01
A signed note
MettaPay cryptographically signs a short note that says "we checked this person and they passed."
02
Pinned publicly
The note lives on EAS — a public bulletin board on Base. Nobody can secretly change or delete it.
03
No private data
Only an opaque hash of your user id, the level (KYC or KYB), and the dates. No name, no docs, no email.
What's stored on-chain
Exactly five fields. Nothing else.
| Field | Meaning |
|---|---|
| bytes32 userIdHash | keccak256(userId + secret salt) — irreversible |
| uint8 level | 1 = KYC (individual), 2 = KYB (business) |
| uint64 issuedAt | Unix timestamp when issued |
| uint64 expiresAt | Unix timestamp when it expires (1 year) |
| bool revoked | False at issue; can be flipped if your status changes |
How to verify someone
Via MettaPay (easiest)
- Visit
mettapays.com/u/{tag}and look for the verified badge. - Or call the public JSON API directly:
curl https://mettapays.com/api/public/attestations/{tag}
Via EAS (trust-minimized)
- Copy the attestation UID from the badge or API response.
- Open
https://base-sepolia.easscan.org/attestation/view/{uid}. - Confirm the attester matches MettaPay's signer, the schema matches, and
revoked = false.
- Active chain
- base-sepolia
- MettaPay signer
- Not configured yet
- KYC schema
- Not configured yet
- KYB schema
- Not configured yet
What it does NOT contain
None of this ever goes on-chain.
✕Your legal name
✕Your date of birth
✕Document images or numbers
✕Your home or business address
✕Your email or phone number
✕Any selfie or biometric data
Even MettaPay cannot reverse the on-chain hash without the private salt — and the salt never leaves our servers.
FAQ
Ready to get verified?
KYC takes about 2 minutes. Your attestation is published as soon as you're approved.