AI Media Credentialing Spec.

Envelope

One credential, one signature.

{
  "@context": "https://aeoess.com/amcs/v1",
  "subject":  "did:web:nytimes.com/article/2026-04-12-fed",
  "issuer":   "did:aps:pub:nytimes.com",
  "terms_block": {
    "behavioral_derivation": "summarize+attribute",
    "retention":             "session-only",
    "training":              "denied"
  },
  "attribution_root":  "sha256:9f2a…b71c",
  "enforcement_class": "enforcement",
  "expires":           "2026-10-12T00:00:00Z",
  "signature":         "ed25519:Aw3kH7…"
}

Fields

Seven required, all signed over.

Field	Type	Description
subject	DID URI	The artifact under credential. Resolves to a content hash.
issuer	DID URI	The publisher attaching terms. Must be a registered passport.
terms_block	JSON	Behavioral derivation rights. What an agent may do with the bytes.
attribution_root	sha-256	Merkle root over D / P / G / C axes. Proof of provenance.
enforcement_class	enum	advisory · enforcement · structural. Tells the gateway what to do on violation.
expires	iso-8601	Terms TTL. Cascades on expiry.
signature	ed25519	Detached JWS over RFC 8785 canonical bytes.