Your app creates the output
Generate a PDF at the intended physical page size, or use native ZPL or ESC/POS when your application already owns those commands.
CLOUD PRINT ROUTING
Your backend sends one authenticated print request. An Android, Windows or Linux gateway makes the final local connection without exposing the printer or your API credentials to the public internet.

Generate a PDF at the intended physical page size, or use native ZPL or ESC/POS when your application already owns those commands.
The customer print key scopes the request, the saved alias chooses the printer and a stable job ID lets your application track its result.
A persistent outbound encrypted connection delivers the job to the correct site. The gateway uses the selected direct or operating-system print path.
THREE GATEWAY CHOICES
The host application uses the same API whichever gateway the customer chooses, and one customer can register multiple gateways.
All gateway platforms inspect supported printers reachable on the local network and report their capabilities. Windows and Linux do not require a printer to be installed in the operating system before this discovery can work.
The Windows gateway also reports installed Windows queues, while Linux also reports configured CUPS destinations. Use these when an existing OS driver or queue configuration is useful.
Android additionally discovers paired Bluetooth and connected USB printers, making it useful for a small counter, mobile station or site with no always-on computer.
Send correctly sized PDF documents for broad compatibility, or supported raw ZPL and ESC/POS data when the selected printer and driver match.
Your app requests a temporary setup code. Android users scan its QR code; Windows and Linux users follow their platform setup.
Your app retrieves the discovered printers, shows only the correct customer’s available choices and stores the selected stable ID and current alias.
Keep a Manage Gateways action so the customer can add another gateway, replace a device, rediscover printers or update its selection.