The format of a payment gateway extension is described in the Create a Credit Card Payment Gateway Integration chapter. For a loyalty point gateway, the gateway.json file should be similar to the following:

{
  "provider": "Loyalty Points Payment Gateway",
  "paymentMethodTypes": ["loyaltyPoints"],
  "transactionTypes": {
    "loyaltyPoints": ["balanceInquiry", "authorize", "void", "refund"]
  },
  "processors" : {
    "loyaltyPoints": "loyaltyPoints"
  }
}

The config.json file should be similar to the following:

{
  "configType": "payment",
  "titleResourceId": "title",
  "descriptionResourceId": "description",
  "instances" : [
    {
      "id": "agent",
      "instanceName": "agent",
      "labelResourceId": "agentInstanceLabel"
    },
    {
      "id": "preview",
      "instanceName": "preview",
      "labelResourceId": "previewInstanceLabel"
    },
    {
      "id": "storefront",
      "instanceName": "storefront",
      "labelResourceId": "storefrontInstanceLabel"
    }
  ],
  "properties": [
    {
      "id": "paymentMethodTypes",
      "type": "multiSelectOptionType",
      "name": "paymentMethodTypes",
      "required": false,
      "helpTextResourceId": "paymentMethodsHelpText",
      "labelResourceId": "paymentMethodsLabel",
      "defaultValue": "loyaltyPoints",
      "displayAsCheckboxes": true,
      "public": true,
      "options": [
         {
           "id": "loyaltyPoints",
           "value": "loyaltyPoints",
           "labelResourceId": "loyaltyPointsLabel"
         }
       ]
    }
  ]
}