PCI-Compliant credit card and ACH payments using Authorize.Net. The index.html page contains a demo with two client-side forms. Each of these forms connects with corresponding server-side .php files that use the Authorize.Net PHP API. Additional info regarding usage of the Authorize.Net sandbox is located in the initial information section in index.html.
Relevant constants are stored in php/constants.php. To update API credentials, please update the keys here, as well as in the data-apiLoginID and the data-clientKey fields in the first submit button in index.html.