A customer on your website decides to checkout.
Your website creates a payment on the Mollie platform by calling the Payments API with the amount and description, and with a URL we should redirect the customer to after the payment is made.
The API responds with the unique ID and the unique checkout URL for the newly created payment. Your website stores the id links it to the customer’s order and redirects the customer to the checkout URL (present in _links. checkout).
Note
You should use HTTP GET for the redirect to the _links. checkout URL. Using HTTP POST for redirection will cause issues with some payment methods or iDEAL issuers. Use HTTP status code 303 See Other to force an HTTP GET redirect.
The customer reaches the checkout, chooses a payment method and makes the payment. This process is entirely taken care of by Mollie. You do not have to do anything here.
Mollie will send you a webhook informing your website about the payment’s status change when the payment is made. You can configure the webhook URL per profile in your Mollie account, or per payment in the API request.
In response to your webhook being called your application just needs to issue a 200 OK status. From that response Mollie can tell that your processing of the new status was successful – for any other response, we keep trying.
When your website processes the webhook, it fetches the payment status from the Mollie API. Once the status is paid, your website can send out a confirmation email to the customer and start the order fulfilment.
At this point, Mollie returns the visitor to your website using the redirect URL specified when the payment was created. Your website usually already knows the payment was successful, and thanks to the customer.