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

# React Native options

The SDK can be configured in a few ways.

| Field                      | Optional / Required | Description                                                                                                                                                                                                                                                                                                                               |
| -------------------------- | ------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `gr4vyId`                  | **`Required`**      | Should always be set to `mattilda`.                                                                                                                                                                                                                                                                                                       |
| `token`                    | **`Required`**      | The server-side generated JWT token which will be used to authenticate any of the API calls.                                                                                                                                                                                                                                              |
| `environment`              | `Optional`          | `.sandbox`, `.production`. Defaults to `.production`.                                                                                                                                                                                                                                                                                     |
| `amount`                   | **`Required`**      | The amount to authorize or capture in the specified `currency` only.                                                                                                                                                                                                                                                                      |
| `currency`                 | **`Required`**      | A valid, active, 3-character `ISO 4217` currency code to authorize or capture the `amount` for.                                                                                                                                                                                                                                           |
| `country`                  | **`Required`**      | A valid `ISO 3166` country code.                                                                                                                                                                                                                                                                                                          |
| `buyerId`                  | `Optional`          | An optional ID for a buyer. The transaction will automatically be associated with a buyer with that ID. If no buyer with this ID exists then it will be ignored.                                                                                                                                                                          |
| `buyerExternalIdentifier`  | `Optional`          | An optional external ID for a buyer. The transaction will automatically be associated to a buyer with that external ID. If no buyer with this external ID exists then it will be ignored. This option is ignored if the `buyerId` is provided.                                                                                            |
| `presentingViewController` | **`Required`**      | The view controller that opens the payment sheet.                                                                                                                                                                                                                                                                                         |
| `externalIdentifier`       | `Optional`          | An optional external identifier that can be supplied. This will automatically be associated to any resource that opens the payment sheet and subsequently used to find a resource by that ID.                                                                                                                                             |
| `store`                    | `Optional`          | `'ask'`, `'preselect'`, `true`, `false` - Explicitly store the payment method, ask the buyer or preselect it by default. Requires `buyerId` or `buyerExternalIdentifier`.                                                                                                                                                                 |
| `display`                  | `Optional`          | `all`, `addOnly`, `storedOnly`, `supportsTokenization` - Filters the payment methods to show stored methods only, new payment methods only or methods that support tokenization.                                                                                                                                                          |
| `intent`                   | `Optional`          | `authorize`, `preferAuthorize`, `capture` - Defines the intent of this API call. This determines the desired initial state of the transaction. When used, `preferAuthorize` automatically switches to `capture` if the selected payment method doesn't support delayed capture.                                                           |
| `metadata`                 | `Optional`          | An optional dictionary of keys and values for transaction metadata. All values should be a string.                                                                                                                                                                                                                                        |
| `paymentSource`            | `Optional`          | `installment`, `recurring` - Can be used to signal that Embed is used to capture the first transaction for a subscription or an installment. When used, `store` is implied to be `true` and `display` is implied to be `supportsTokenization`. This means that payment options that do not support tokenization are automatically hidden. |
| `cartItems`                | `Optional`          | An optional array of cart item objects, each object must define a `name`, `quantity`, and `unitAmount`. Other optional properties are `discountAmount`, `taxAmount`, `externalIdentifier`, `sku`, `productUrl`, `imageUrl`, `categories` and `productType`.                                                                               |
| `applePayMerchantId`       | `Optional`          | The Apple merchant ID to be used during Apple Pay transactions.                                                                                                                                                                                                                                                                           |
| `debugMode`                | `Optional`          | `true`, `false`. Defaults to `false`, this prints to the console.                                                                                                                                                                                                                                                                         |
| `theme`                    | `Optional`          | Theme customization options [See Theming Options](/guides/payments/embed/theming#theme-options). The SDK also contains an additional two properties within the `colors` object: `headerBackground` and `headerText`. These are used for the navigation background and foreground colors.                                                  |
| `locale`                   | `Optional`          | An optional locale, this consists of a `ISO 639 Language Code` followed by an optional `ISO 3166 Country Code`, e.g. `en`, `en-gb` or `pt-br`.                                                                                                                                                                                            |
| `requireSecurityCode`      | `Optional`          | An optional boolean which forces security code to be prompted for stored card payments.                                                                                                                                                                                                                                                   |
| `shippingDetailsId`        | `Optional`          | An optional unique identifier of a set of shipping details stored for the buyer.                                                                                                                                                                                                                                                          |
| `merchantAccountId`        | `Optional`          | An optional merchant account ID.                                                                                                                                                                                                                                                                                                          |
| `connectionOptions`        | `Optional`          | An optional set of values passed to a connection when processing a transaction (see [New transaction](/reference/transactions/new-transaction))                                                                                                                                                                                           |