{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "urn:orbiplex:schema:messaging.flag:v1",
  "title": "MessagingFlag v1",
  "description": "Messaging-owned Layer 3 fact recording a replayable local message flag change, such as read/unread.",
  "type": "object",
  "additionalProperties": true,
  "x-dia-workflow": "project",
  "x-dia-status": "draft",
  "x-dia-basis": ["doc/project/40-proposals/060-messaging-middleware.md"],
  "required": [
    "schema",
    "schema/v",
    "fact/id",
    "event/at",
    "message/id",
    "mailbox/id",
    "flag/name",
    "flag/state",
    "actor/ref"
  ],
  "properties": {
    "schema": { "const": "messaging.flag.v1" },
    "schema/v": { "const": 1 },
    "fact/id": {
      "type": "string",
      "pattern": "^fact:messaging.flag:[a-z0-9][a-z0-9:-]*$"
    },
    "event/at": { "type": "string", "format": "date-time" },
    "message/id": { "type": "string", "minLength": 1 },
    "mailbox/id": { "type": "string", "minLength": 1 },
    "flag/name": {
      "type": "string",
      "enum": ["read"]
    },
    "flag/state": {
      "type": "string",
      "enum": ["set", "cleared"]
    },
    "actor/ref": { "type": "string", "minLength": 1 },
    "source/device-id": { "type": "string", "minLength": 1 },
    "causation/ref": { "type": "string", "minLength": 1 }
  }
}