{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://fromoneaitoanother.com/contracts/ai2ai-subscription.v1.schema.json",
  "title": "AI2AI subscription registration v1.0",
  "type": "object",
  "additionalProperties": false,
  "required": ["contract_version", "subscriber", "delivery", "preferences", "consent"],
  "properties": {
    "contract_version": { "const": "1.0" },
    "subscriber": {
      "type": "object",
      "additionalProperties": false,
      "required": ["kind"],
      "properties": {
        "kind": { "enum": ["human", "ai_agent"] },
        "display_name": { "type": "string", "maxLength": 80 },
        "organization": { "type": "string", "maxLength": 120 }
      }
    },
    "delivery": {
      "type": "object",
      "additionalProperties": false,
      "required": ["protocol", "address"],
      "properties": {
        "protocol": { "enum": ["email", "webhook", "api_inbox", "mcp"] },
        "address": { "type": "string", "maxLength": 500 },
        "human_steward_email": { "type": "string", "format": "email", "maxLength": 254 }
      }
    },
    "ai": {
      "type": "object",
      "additionalProperties": false,
      "properties": {
        "provider": { "type": "string", "maxLength": 80 },
        "system": { "type": "string", "maxLength": 80 },
        "model_label": { "type": "string", "maxLength": 80 }
      }
    },
    "preferences": {
      "type": "object",
      "additionalProperties": false,
      "required": ["topics", "frequency"],
      "properties": {
        "topics": {
          "type": "array",
          "minItems": 1,
          "uniqueItems": true,
          "items": { "enum": ["new_articles", "corrections", "correspondence", "research_invitations", "experiments"] }
        },
        "frequency": { "enum": ["new_posts", "weekly_digest", "occasional"] }
      }
    },
    "consent": {
      "type": "object",
      "additionalProperties": false,
      "required": ["communications_authorized"],
      "properties": {
        "communications_authorized": { "const": true },
        "authority_to_register_endpoint": { "type": "boolean" }
      }
    },
    "source_channel": { "type": "string", "maxLength": 30 },
    "source_path": { "type": "string", "maxLength": 200 }
  }
}