> ## Documentation Index
> Fetch the complete documentation index at: https://docs.appcharge.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Implement the Callbacks

## Callback methods

To implement the Android Payment Links SDK, include the following callback methods:

| Method                 | Description                                                                                                                                                               | Argument         | Type                                          |
| ---------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------- | --------------------------------------------- |
| `OnInitialized`        | Triggered when SDK initialization was successful.                                                                                                                         |                  |                                               |
| `OnInitializeFailed`   | Triggered when SDK initialization failed.                                                                                                                                 | `error`          | `SdkError`                                    |
| `OnPricePointsSuccess` | Triggered when price points are successfully retrieved, after calling `GetPricePoints`.                                                                                   | `pricePoints`    | [`PricePointsModel`](./retrieve-price-points) |
| `OnPricePointsFail`    | Triggered when price points can’t be retrieved or are unavailable, after calling `GetPricePoints`.                                                                        | `error`          | `SdkError`                                    |
| `OnPurchaseSuccess`    | Triggered when a purchase was successful.                                                                                                                                 | `order`          | `OrderResponseModel`                          |
| `OnPurchaseFailed`     | Triggered when the checkout window closed or if a server-to-server error occurred during the purchasing process. Returns an error code, message, JSON, and order details. | `error`, `order` | `SdkError`, `OrderResponseModel`              |

### OrderResponseModel properties

The `OrderResponseModel` argument type contains the following properties:

| Property Name       | Type     | Description                                                    | Example                                              |
| ------------------- | -------- | -------------------------------------------------------------- | ---------------------------------------------------- |
| `date`              | `Int`    | Unix timestamp of the order.                                   | `1718182312`                                         |
| `sessionToken`      | `String` | Unique token for the current session.                          | `"xxxxXXXXxxxxXXXXxxxx"`                             |
| `offerName`         | `String` | Name of the purchased offer.                                   | `"Starter Pack"`                                     |
| `offerSku`          | `String` | SKU identifier for the offer.                                  | `"starter_pack_001"`                                 |
| `items`             | `[Item]` | List of items included in the purchase.                        | `[{ name: "Gems", sku: "gem_01", quantity: "100" }]` |
| `items.name`        | `String` | Display name of the item.                                      | `"Gems"`                                             |
| `items.sku`         | `String` | Unique SKU code for the item.                                  | `"gem_01"`                                           |
| `items.quantity`    | `String` | Quantity of the item included.                                 | `"100"`                                              |
| `price`             | `Int`    | Price of the order in minor units. For example, cents for USD. | `499`                                                |
| `currency`          | `String` | ISO 4217 currency code                                         | `"USD"`                                              |
| `customerId`        | `String` | ID of the player who made the purchase.                        | `"cust_98765"`                                       |
| `customerCountry`   | `String` | Country code of the player in ISO 3166-1 alpha-2 format.       | `"US"`                                               |
| `paymentMethodName` | `String` | Payment method.                                                | `"Visa"`                                             |
| `orderId`           | `String` | Order ID.                                                      | `"1234567890"`                                       |
| `purchaseId`        | `String` | A unique ID to track the transaction.                          | `"pr_xxxxxx"`                                        |

### SdkError properties

The `SdkError` argument type contains the following properties:

| Property Name | Type     | Description                              | Example                                                               |
| ------------- | -------- | ---------------------------------------- | --------------------------------------------------------------------- |
| `code`        | `Int`    | Error code identifying the failure.      | `3002`                                                                |
| `message`     | `String` | Detailed message describing the failure. | `"Purchase canceled because the user closed the checkout interface."` |

## Example code

<CodeGroup>
  ```kotlin Kotlin theme={"system"}
  BridgeAPI.init(context, configModel, customerId, object : ICheckoutPurchase {

      override fun onInitialized() {
      // Handle initialization success
      }

      override fun onInitializeFailed(error: SdkError) {
          // Handle initialization fail
      }

      override fun onPurchaseSuccess(order: OrderResponseModel) {
          // Handle purchase success
      }

      override fun onPurchaseFailed(error: SdkError, order: OrderResponseModel? = null) {
          // Handle purchase failure
      }

      override fun onPricePointsSuccess(pricePoints: PricePointsModel) {
          // Handle price points retrieval success
      }

      override fun onPricePointsFail(error: SdkError) {
          // Handle price points retrieval error
      }
  })
  ```
</CodeGroup>