# API Suite Fundamentals

The following sections are general information required for using the Flute API suite.

 - [BaseURL Environments](https://developer.flute.com/api-reference/api-suite-fundamentals/baseurl-environments.md): ### BaseURL Environments Flute provides different environments to run endpoints <a id="urlbases"></a> **Sandbox**<br> The sandbox environment is for development and testing. No payments, charges, or i
 - [Payment Flow](https://developer.flute.com/api-reference/api-suite-fundamentals/payment-flow.md): ### Payment Flow <h1 style="margin-top: -12px; margin-bottom: 4px;"></h1> The following is a generalized workflow.
 - [Approving  a Purchase Request](https://developer.flute.com/api-reference/api-suite-fundamentals/approving-a-purchase-request.md): #### Approving a Purchase Request 1) The customer completes their shopping experience on the merchant's website by selecting the products or services. They navigate to the checkout page on the mercha
 - [Acknowledging a Purchase Request](https://developer.flute.com/api-reference/api-suite-fundamentals/acknowledging-a-purchase-request.md): #### Acknowledging a Purchase Request 1) After the transaction is processed, the processing center sends back a response to the Flute payment gateway. This response includes details of the transaction
 - [Supported Card Types](https://developer.flute.com/api-reference/api-suite-fundamentals/supported-card-types.md): ### Supported Card Types <h1 style="margin-top: -12px; margin-bottom: 4px;"></h1> The following credit cards and formats are supported. - Diners Club: Card numbers are typically 14 or 16 digits long.
 - [Flute-Defined Enums](https://developer.flute.com/api-reference/api-suite-fundamentals/flute-defined-enums.md): ### Flute-Defined Enums <h1 style="margin-top: -12px; margin-bottom: 4px;"></h1> The following are Flute-defined enumerations and indices used in endpoint fields. <details> <summary>Account Holder Typ