knotsys Print

Knotsys

About this app

knotsys Print is a mobile app developed in Flutter that allows users to capture PDF documents generated from a web system, process them, and send them to thermal receipt printers via Bluetooth or network (IP) in a simple, fast, and reliable manner.
It is designed for businesses, stores, and points of sale that need to print receipts, invoices, tickets, or tickets directly from internal web systems or SaaS applications, without relying on complicated configurations or additional hardware.

Key Features:
- Integration with web systems
- Includes an embedded browser (WebView with cookie and download support).
- Allows users to log in to the company's billing or ERP system and directly capture generated PDFs.
- Smart PDF capture.
- Automatically detects and downloads PDF documents from the browser.
- Temporarily stores files for printing or sharing without additional steps.
- Printing on thermal receipt printers.
- Compatibility with Bluetooth and IP (Ethernet/WiFi) printers.
- PDF conversion to ESC/POS format (continuous roll, without unnecessary margins).
- Support for band printing and automatic width adjustment.
- Printer management
- Register multiple ticket machines in the app.
- Ability to test, edit, and delete devices.
- Automatic detection and connection to paired Bluetooth printers.
- Additional features
- Share captured PDFs through other apps.
- Save sessions and user preferences.
- Secure permission control (Bluetooth, network, storage).
- Confirmation before logging out or exiting the app.

Technologies used:
- Flutter 3.5+ for cross-platform development.
- Dart as the main language.

Key libraries:
- flutter_inappwebview → PDF navigation and capture.
- pdfx → PDF rendering and manipulation.
- permission_handler → Bluetooth and location permissions.
- share_plus → file sharing.
- provider and shared_preferences → state management and persistence.
- Native Kotlin implementation for Bluetooth connection via MethodChannel.

Target Audience:
- Stores, restaurants, and retail businesses that issue PDF electronic receipts.
- Companies that use web-based billing systems and need to print tickets in real time.
- Users looking for a practical solution to connect web applications with thermal printers.

Benefits:
- Simplicity: requires no complex configuration or additional driver installation.
- Compatibility: works with most standard ESC/POS thermal receipt printers.
- Time savings: print directly from the web system in seconds.
- Portability: connect via Bluetooth or IP according to business needs.
- Reliability: manages data fragmentation and printing protocols to avoid ticket cuts.

Current and future status:
- Currently, knotsys print includes all the basic features for capturing and sending PDFs to thermal printers.

Future versions plan:
- Support for QR and barcode labels.
- Print history.
- Integration with cloud storage services.
- Advanced customization of ticket templates.