Attestation Token Schema

The canonical wire format for AAP attestation tokens. Mirrors mnemom-contracts/attestation-token/v1.yaml.

Envelope

JWS Compact Serialization (RFC 7515):

<base64url(header)>.<base64url(payload)>.<base64url(signature)>

Fixed shape:

{
  "alg": "EdDSA",
  "kid": "<key_id>",
  "typ": "AAP-Attestation/v1"
}

Field	Constraint
`alg`	Always `"EdDSA"` (Ed25519).
`kid`	Key identifier; matches a `kid` in `/v1/.well-known/jwks.json`.
`typ`	Always `"AAP-Attestation/v1"`. Mirrored in the payload for defense-in-depth.

Payload

JSON object conforming to JSON Schema 2020-12. All required fields below; additionalProperties: false.

Field	Type	Required	Description
`typ`	const `"AAP-Attestation/v1"`	yes	Mirrors the header `typ`.
`iss`	string (URI)	yes	Issuer — always `https://mnemom.ai` for production. Verifiers reject other issuers.
`sub`	string	yes	Subject — the Mnemom `agent_id` (e.g., `smolt-e2ca60ef`).
`iat`	integer (Unix seconds)	yes	Issued-at, UTC. Verifiers reject `iat > now() + clock_skew_grace` (default 60s).
`exp`	integer (Unix seconds)	yes	Expiry, UTC. Default TTL is `iat + 3600` (1 hour).
`content_hash`	string (`^[0-9a-f]{64}$`)	yes	SHA-256 hex of the canonical card body at attestation time.
`version`	integer (≥ 1)	yes	Monotone canonical-card version at attestation time.
`composed_at`	string (date-time)	yes	ISO-8601 UTC timestamp at which the canonical card was composed.
`card_kind`	enum `"alignment" \| "protection"`	yes	Which canonical card the token attests to.
`smolt_id`	string (`^smolt-[a-z0-9]+$`)	no	Optional convenience claim for consumers binding on smolt-id.
`historic_backfill`	const `true`	no	Present (and only `true`) on tokens minted by the one-shot backfill script for canonical cards that pre-date the transparency log.

Signature

Ed25519 signature over the byte string <base64url(header)>.<base64url(payload)>. Base64url-encoded; no padding, no whitespace, no line wrapping (per RFC 7515 §3.1).

Beyond expiry

Tokens are short-lived. After exp, the embedded token is no longer cryptographically valid for new use, but the transparency log preserves it indefinitely. Consumers wanting to verify a historic posture query the log via mnemom verify-card --at <ISO>; the JWS inside the log row continues to verify against the JWKS as long as the signing key remains in the JWKS (active or retired-within-window).

Editorial source

Schema authored at mnemom-contracts/attestation-token/v1.yaml. Runtime consumers:

mnemom-api/src/attestation/signer.ts — issuer
mnemom-api/src/attestation/verifier.ts — server-side verifier
mnemom-platform/cli/src/commands/verify-card.ts — offline verifier CLI

Overview

Identity & Cards

Posture & Policy

Detection & Safe House

AEGIS

Reputation & Risk

Lifecycle

Gateway

Pricing

Migrations

Policy

Specifications

Changelog

Attestation Token Schema

Envelope

Header

Payload

Signature

Beyond expiry

Editorial source

See also

​Envelope

​Header

​Payload

​Signature

​Beyond expiry

​Editorial source

​See also

Envelope

Header

Payload

Signature

Beyond expiry

Editorial source

See also