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

# CrossmintCheckoutConfig

> Flutter Final Class

**Final Class**

Configuration for `CrossmintEmbeddedCheckout`.

```dart theme={null}
final class CrossmintCheckoutConfig
```

## Constructors

### CrossmintCheckoutConfig

```dart theme={null}
const CrossmintCheckoutConfig({
  required this.order,
  required this.payment,
  this.appearance,
  this.jwt,
})
```

Creates a checkout config.

## Properties

### order

```dart theme={null}
final CrossmintCheckoutOrder order
```

Order to check out — either a `CrossmintCheckoutNewOrder` built from line items, or a `CrossmintCheckoutExistingOrder` referencing an already-created order by id.

### payment

```dart theme={null}
final CrossmintCheckoutPayment payment
```

Payment method configuration — fiat, crypto, and default method.

### appearance

```dart theme={null}
final CrossmintCheckoutAppearance? appearance
```

Optional appearance customization — CSS variables, rules, fonts.

### jwt

```dart theme={null}
final String? jwt
```

Optional JWT for authenticated checkouts — attaches the user's Crossmint session to the hosted page so the experience is signed-in when the user lands. Pass `client.auth.state.session?.jwt` when you want the checkout to inherit the current app session.

## Methods

### toQueryParams

```dart theme={null}
Map<String, String> toQueryParams()
```

Serializes to query parameters for the checkout URL.