JSPrintManager is a client-side printing and scanning solution enabling web applications to bypass browser print dialogs by communicating with a native client application via WebSocket. The system consists of a core JavaScript library (JSPrintManager.js) that provides APIs for creating print/scan jobs, managing printer connections, and handling device-specific communication protocols (serial, USB, Bluetooth, TCP/IP, HID, IPP). A React-based demo application showcases features including printing various file formats (PDF, images, Office documents), raw printer command languages (ZPL, ESC/POS), bidirectional device communication, printer monitoring, and scanning functionality. The solution requires installation of a lightweight native client on user machines to establish the WebSocket bridge between browser and hardware devices.