“Verified” is only worth what the method behind it can withstand. A tier badge a skeptic cannot audit is a marketing claim; a tier badge backed by a public, versioned methodology is a standard. This document is that methodology — the exact checks behind each v=AEO1 verification tier, and the precise boundary of what a tier attests.
Every tier is a defined combination of two independent things, which must never be conflated:
The record originates from the domain owner — proven by DNS control — and the facts are untampered since signing — proven by the Ed25519 signature over the NFC-canonical fact set. This is binary and machine-checkable.
How far the issuing authority went to check the facts against independent sources before assigning the tier. This is a claim about diligence at a point in time — not a warranty of ongoing or absolute truth. Consuming agents weight trust by tier and freshness.
| Check | What it verifies | Pass criterion |
|---|---|---|
| C1 · integrity | The _aeo TXT record is well-formed and carries the required tags. | Parses under the AEO1 grammar. |
| C2 · control | The record is published under the described domain's DNS — proving the publisher controls the domain. The anchor other AI-trust mechanisms leave out of scope; AEO1's foundation. | Resolves at _aeo.<domain> (A-label form for IDNs). |
| C3 · signature | The Ed25519 signature verifies over the canonical fact set (NFC + codepoint order) against the issuer's published key. | verify() true; tamper-evident. |
| C4 · key status | Issuer key resolvable at /.well-known/aeo-public-key.json, status active or retired (not revoked). | A usable key is found. |
| C5 · consistency | The facts fetched from catalog= hash to the signed facts_hash. | Recomputed hash == signed hash. |
| C6 · attestation | The domain owner explicitly attested the facts, captured and timestamped. | Attestation on record (last_confirmed_at). |
| C7 · corroboration | Degree of independent checking: none / enrolled-only / human-review-or-1-source / multi-source-agreement. Scored as of the verification date; sources logged. | Meets the depth required by the target tier. |
| C8 · freshness | verified_at within the acceptable window for the fact class; time-sensitive facts (hours, pricing) age faster. | Within window. |
Each tier is a defined set of checks; every higher tier is a strict superset of the one below it.
| Tier | Checks required | What it attests |
|---|---|---|
| self_declared | C1 + owner-supplied | The owner published this. No authority, no signature, no corroboration. |
| listed | C1, C2 + enrolled | Provenance + domain control, catalog published. No fact review. |
| verified | C1–C6 + C7 at “human-review or ≥1 independent source” | Authentic, owner-attested, and checked to that depth as of verified_at. |
| grounded | all of verified + C7 at “≥2 independent sources in agreement” + signed | The highest diligence claim AEO1 makes. |
Consuming agents MAY require a minimum tier for sensitive queries — for example, grounded before citing time-sensitive or safety-relevant facts such as emergency-service hours.
AEO1 attests provenance, authenticity, and corroboration-depth-as-of-a-date. It does not warrant that a fact is true in the world, nor that a fact remains true after verified_at.
“grounded” means “corroborated against multiple independent sources, in agreement, as of verified_at” — not a perpetual guarantee of truth. Consuming agents apply freshness (C8) and their own tier thresholds. The issuing authority's diligence is bounded by the named source types and the verification date; it is not an insurer of the underlying facts.
This is the issuer-vs-truth split every credential ecosystem uses: the signature attests who declared what, when, and the diligence performed — not the truth of the underlying claim.
This is version 1.0. Changes are versioned and linkable, so a verifier can pin the methodology a given record was assessed under. This version supersedes nothing.
Two independent things that must never be conflated. Provenance and authenticity is mechanical and cryptographic: the record came from the domain owner, proven by DNS control, and the facts are untampered since signing, proven by an Ed25519 signature over the canonical fact set. Corroboration depth is operational: how far the issuing authority went to check those facts against independent sources, as of a stated date.
No, and the methodology is explicit about that boundary. A tier attests provenance, authenticity, and corroboration as of a stated date. It is not a warranty of ongoing or absolute truth. Consuming agents are expected to weight trust by tier and freshness rather than treat a tier as a guarantee.
Provenance is binary and machine-checkable — either the signature verifies against the published key and the record resolves under the domain, or it does not. Corroboration is a claim about diligence at a point in time: how many independent sources agreed, and when that was checked. One is arithmetic, the other is method.
By requiring the record to resolve at _aeo.
The Ed25519 signature is computed over the canonical fact set — NFC-normalised and codepoint-ordered — so any change to the facts invalidates it. The record is tamper-evident: a verifier recomputing the signature detects an edit without needing to trust the publisher.
Because a tier a skeptic cannot audit is a marketing claim, not a standard. A badge is only worth what the method behind it can withstand, so the checks, the tier definitions and the stated limits are published and versioned for anyone to examine or challenge.
Yes. It is published as v1.0 with a stated publication date, as a companion to the v=AEO1 standard. Versioning matters because a tier assigned under one revision of the checks should remain interpretable after the checks change.