flutter_twain_scanner 3.0.0

A cross-platform Dart/Flutter package for digitizing documents from TWAIN, WIA, SANE, ICA and eSCL compatible scanners through the Dynamic Web TWAIN Service REST API.

Flutter Document Scanner for TWAIN, WIA, SANE, ICA and eSCL Scanners

Desktop (macOS)	Mobile (Android)

A pure Dart client for the Dynamic Web TWAIN Service REST API. The Dynamsoft service runs on the machine that is connected to the scanners, and your app talks to it over HTTP — no native code, so the same package works on Android, iOS, web, Windows, macOS and Linux.

⚙️ Prerequisites

1. Install the Dynamic Web TWAIN Service on the scanner host: Windows · macOS · Linux (.deb) / .rpm
2. Request a free 30-day trial license.
3. The service listens on http://127.0.0.1:18625. Open that URL in a browser to bind it to a LAN IP if you need access from other devices.

🚀 Getting Started

flutter pub add flutter_twain_scanner

Scan a document and download it as a PDF:

import 'package:flutter_twain_scanner/flutter_twain_scanner.dart';

final service = DynamsoftService();
const host = 'http://127.0.0.1:18625';

// List scanners, scan into a document and download it as a PDF.
final scanners = await service.getDevices(host);
final document = await service.createDocument(host, {});
final job = await service.createJob(host, {
  'license': 'YOUR-LICENSE-KEY',
  'device': scanners.first['device'],
  'config': {'IfShowUI': false, 'Resolution': 200},
});

// Copy every scanned page into the document.
while (true) {
  final pages = await service.getImageInfo(host, job['jobuid']);
  if (pages.isEmpty) break;
  await service.insertPage(host, document['uid'], {
    'password': '',
    'source': pages.first['url'],
  });
}
await service.deleteJob(host, job['jobuid']);

final pdfBytes = await service.getDocumentStream(host, document['uid']);

The example app shows a complete scanning UI:

cd example
flutter run -d macos   # or windows, linux, android, ios

📚 API Reference

All methods throw a DynamsoftServiceException when the service returns an error. The scan job parameters follow the service's CreateScanJobOptions schema.

Scanning

Method	Description
getServerInfo(host)	Service version and compatibility
getDevices(host, [scannerType])	List scanners, optionally filtered by ScannerType flags
createJob(host, parameters)	Create a scan job (license, device, config, …)
checkJob(host, jobId) / updateJob(...) / deleteJob(...)	Check, start/cancel or delete a job
getScannerCapabilities(...) / getScannerSettings(...)	Capabilities and TWAIN settings of the scanner running a job
getImageInfo(host, jobId)	Metadata and source URL of the next scanned page (empty when done)
getNextPage(host, jobId) / getImageStreams(host, jobId)	Scanned pages as PNG byte streams
getImageFiles(host, jobId, directory)	Save all pages as PNG files. Not supported on the web
getPageStream(host, jobId, {page, type})	A single page by index as PNG or JPEG

Documents

Method	Description
createDocument(host, parameters)	Create a document, optionally password-encrypted
getDocumentInfo(...) / updateDocument(...) / deleteDocument(...)	Read, re-label or delete a stored document
getDocumentStream(host, docId)	Download a document as a PDF byte stream
getDocumentFile(host, docId, directory)	Download a document as a PDF file. Not supported on the web
insertPage(host, docId, parameters)	Insert a scanned page into a document at an optional position
deletePage(host, docId, page)	Delete a page by UID or index

📄 License

This project is licensed under the MIT License.