Issue Robokassa payment links right inside the conversation

The agent works with Robokassa through signed requests to auth.robokassa.ru: it assembles a payment link with the amount, the order description and a 54-FZ fiscal receipt, reads the status of an issued invoice by its number and shows the currencies and payment methods available to your particular shop. The check request on connection is the list of shop currencies: it immediately shows that the signature matches and the shop responds.

There is no token in Robokassa — access rests on the shop passwords, and they are not interchangeable: password #1 signs the payment itself, password #2 signs notifications and the status check. So the agent needs both, otherwise half of the work falls away. The signature itself is assembled from the shop identifier, the amount, the invoice number and the password and hashed with MD5, so the amount in the signature and the amount in the link have to match to the kopeck — otherwise the payment is rejected at the entrance, before the checkout page.

The agent does not handle money: it issues an invoice and reads its status — initiated, on hold, paid or refunded — while crediting and withdrawal stay on the Robokassa side and under your contract with them. On a schedule it walks through the invoices it issued itself and reminds you about the unpaid ones. There is no bank account statement here and there cannot be: Robokassa is about accepting payments from customers, a bank is connected as a separate connector.

Robokassa returns its errors as numeric codes, and the agent decodes them rather than showing a bare «the request failed»: the code tells a signature mismatch apart from a shop that is not live yet and from an invoice number that does not exist. It holds the request rate itself — up to five per second with a small allowance for a burst — so a series of status checks does not run into a refusal. If there is no data on an invoice or the shop does not return it, the agent says so directly instead of showing an empty table.