An Age Attestation Provider (AAP) issues the age attestation that sits in your wallet — for example an "over 18" claim. The attestation is created from a check performed once, by the AAP, so that individual merchants never need to see your documents or identity.
How it's used
Once the attestation is in your wallet, you hold it. When a merchant asks whether you're over a threshold, you approve releasing that claim. Nothing else — no document, no DOB, no name — is transmitted.
The claim, not the proof
The merchant verifies an age claim, not your identity. That separation is why a site "proves you're 18+ without revealing who you are."
Merchant-side
The AVP verifies claims presented by the wallet; a merchant's PPIL client short-circuits verified sessions so returning users don't re-verify.