loopback/common/models/role-mapping.json

{
  "name": "RoleMapping",
  "description": "Map principals to roles",
  "properties": {
    "id": {
      "type": "string",
      "id": true,
      "generated": true
    },
    "principalType": {
      "type": "string",
      "description": "The principal type, such as USER, APPLICATION, ROLE, or user model name in case of multiple user models"
    },
    "principalId": {
      "type": "string",
      "index": true
    }
  },
  "relations": {
    "role": {
      "type": "belongsTo",
      "model": "Role",
      "foreignKey": "roleId"
    }
  }
}