{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://real-life.org/trust-tasks/membership-accept/0.1",
  "title": "Payload: membership-accept/0.1 (rltp-membership@0.11, target Trust Tasks framework 0.4)",
  "description": "Payload schema per Trust Tasks 6.3 ($id = Type URI, describes only the payload). The consent artifact: subject MUST equal the document issuer AND the referenced invite's invitee (no transplantation); ref binds this accept to exactly one invite document by document digest; card is the subject's contact card, whose key-agreement key the welcome will be sealed to (card proof MUST verify and card.anchor MUST equal subject — a foreign card would redirect the group keys; retained per Contract section 5 from the accept's issuance; key transport, no freshness claimed). The document MUST carry a proof verifying under the issuer. An accept is consent to ONE MEMBERSHIP: the subject is a member once, however many canonical admissions enclose the accept (concurrent same-subject admissions are idempotent — Access 5.3), and the accept is consumed content-bound and never freed. Normative rules in Membership Tasks 3.2, 3.3; canonicality and consumption in Access 5.3.",
  "type": "object",
  "required": ["accept"],
  "additionalProperties": false,
  "properties": {
    "accept": {
      "type": "object",
      "required": ["group", "subject", "ref", "card"],
      "additionalProperties": false,
      "properties": {
        "group": { "$ref": "#/$defs/didKey" },
        "subject": { "$ref": "#/$defs/didKey" },
        "ref": { "$ref": "#/$defs/multibaseMultihash" },
        "card": {
          "$ref": "https://real-life.org/rltp/v1/schemas/contact-card.schema.json",
          "description": "the subject's contact card (displayed form): carries the key-agreement key the welcome will be sealed to"
        }
      }
    }
  },
  "$defs": {
    "didKey": {
      "type": "string",
      "pattern": "^did:key:z6Mk[1-9A-HJ-NP-Za-km-z]{44}$"
    },
    "multibaseMultihash": {
      "type": "string",
      "pattern": "^(u[A-Za-z0-9_-]{46}|z[1-9A-HJ-NP-Za-km-z]{44,48})$",
      "description": "document digest of the invite being accepted (Contract section 2)"
    }
  }
}