KTN Print Server

KTN Printer Server turns your Android device into a thermal receipt printing server accessible from any app on the same network. Simply send a single HTTP request, and the receipt prints instantly—no drivers, no SDKs, and no custom client-side code.

Suitable for web-based POS applications, queuing systems, kitchen displays, and even e-commerce integrations that require printing receipts to a local thermal printer.

▣ HOW IT WORKS
The app runs a lightweight HTTP server on port 9000. Other devices on the same network (LAN/Wi-Fi) simply send a POST request to the server address to print a formatted receipt. The app forwards the printout to your thermal printer via Bluetooth, USB, or IP.

▣ CONNECTION OPTIONS (TRANSPORT)
• Bluetooth (SPP) — pair the printer once, ready to go
• USB — support for USB Printer class (class 7) printers
• IP / Network — direct connection to IP-based printers (default port 9100, RAW/JetDirect)

▣ RICH RECEIPT FORMATS
The receipt layout uses simple, row-based markup, making it easy to integrate:
• Alignment & columns: left [L], center [C], right [R] — ideal for item + price lines
• Text styles: bold, underline, double underline
• Multi-level font sizes: normal, wide, tall, large, up to 7x
• Images (PNG base64), barcodes (EAN-13, EAN-8, UPC-A, UPC-E, Code128), and QR Codes
• Adjustable spacing to fit receipts across printer models

▣ FLEXIBLE SETTINGS
• Paper width: 58 mm (32 columns) or 80 mm (48 columns)
• Section spacing 0–6 lines
• Auto-cut (on/off)
• Cash drawer open (on/off)
• All settings are automatically saved and remain active after the application is closed

▣ SIMPLE INTERFACE
• Displays server URL and LAN IP, complete with copy button
• Real-time printer connection status indicator
• Test Print button to ensure printer is ready
• Log panel to monitor and debug print activity

▣ HTTP API
• GET /health — check server status
• GET /status — current printer transport & connection info
• POST /print — send receipt for printing (cut, drawer open, and spacing can be set per print)
- Responses are in JSON format with clear error codes, making it easy for developers to integrate.

▣ PERMISSION NOTE
On Android 12+, the app requests Bluetooth permissions (BLUETOOTH_CONNECT & BLUETOOTH_SCAN) upon first launch. These permissions are required to use a Bluetooth connection. The app also requires local network access to run the server.

Turn one device into a receipt printing bridge for your entire system — lightweight, fast, and ready to go.