ScanBridge

ScanBridge turns an Android phone or iPhone into a barcode/QR scanner for a Windows, macOS or Linux computer.

• Scans are saved on the phone first, then sent over your local network.
• The computer stores each scan and runs an output template. The template can type the code into the focused app, append it to CSV/text files, and more.
• No accounts, no cloud, no telemetry, and no limits on scans, devices or templates.

This is an independent implementation inspired by the workflows of Barcode to PC. No code, assets or protocol were copied (see docs/PROVENANCE.md).

Screenshots

Desktop host (Windows)

Dashboard and one-time pairing QR	Live feed with delivery and output status
Template builder with dry run	Keyboard output test

Phone app (Android)

From left: home screen, template prompt (quantity and condition), and session scans showing what was delivered, typed or paused.

Download

The app is free for everyone under the MIT license. Get the latest build from Releases:

• Windows: ScanBridge-<version>-windows-x64.zip. Unzip it and run scanbridge_desktop.exe.
• Android: ScanBridge-<version>-android.apk. Sideload it and allow "Install unknown apps".
• Check downloads against SHA256SUMS.txt.

Status

Platform	Role	State
Windows 10/11 x64	Desktop host	✅ Builds and runs. Keyboard typing verified
Android 7+	Phone client	✅ Runs on a device. Pairing, manual entry and offline sync verified
macOS / Linux	Desktop host	Code is shared, but these builds are untested. Keyboard adapters are not built yet (clipboard and file output work)
iOS / iPadOS	Phone client	Configured (camera and local-network strings) but not built here. Needs macOS + Xcode

The full list is in docs/FEATURE_MATRIX.md, and the limits are in docs/KNOWN_LIMITATIONS.md.

Requirements

• Flutter 3.47+ / Dart 3.13+.
• Windows host build: Visual Studio 2022 (or Build Tools) with the Desktop development with C++ workload and the ATL component. flutter_secure_storage needs ATL.
• Android: Android SDK 36, JDK 17.
• iOS and macOS: a Mac with Xcode. Device installs also need code signing.
• Linux: the Flutter desktop prerequisites plus libsecret-1-dev for secure storage.

Build and run

flutter pub get                                   # from the repo root (pub workspace)
cd packages/scanbridge_storage && dart run build_runner build   # only after schema changes
cd apps/desktop && flutter run -d windows         # or: flutter build windows --release
cd apps/mobile  && flutter run -d <android-device-id>

The full pipeline (analyze → tests → builds) is in scripts/build_all.ps1 (Windows) or scripts/build_all.sh. The scripts fail if an expected artifact is missing.

First run (pairing)

1. On the desktop, turn on Allow phones on my local network, then click Start server.
2. When Windows Firewall asks, allow the app on Private networks.
3. Click Show pairing QR. The code is valid for 3 minutes and works once.
4. In the phone app, tap the connection chip, then Scan pairing QR. Or type the computer's IP, the port (default 57900) and the code.
5. Approve the phone on the desktop.
6. Scan. The phone shows Delivered, and the desktop types the code into the focused window.

Keyboard output

• Windows uses SendInput with Unicode events, so the keyboard layout does not matter. It supports Enter, Tab, arrow keys, F1–F12 and modifier combinations.
• Arm/pause with the top-right button (or Ctrl+Shift+P while the window is focused). Scans are still saved while paused.
• Key combinations such as Ctrl+… or Delete wait for confirmation in the Live feed. You can turn this off in Settings.
• Windows blocks typing into apps that run as administrator. ScanBridge detects this and reports it instead of claiming success. Use clipboard fallback or file output there.
• Check typing with Keyboard test before you rely on it.

Templates

• A template is an ordered list of steps, for example BARCODE → TAB → NUMBER(qty) → ENTER → CSV_OUTPUT.
• Variables: {{barcode}}, {{quantity}}, {{scan.timestamp}}, {{session.name}}, {{device.name}} and any step's name.
• Each save creates a new version. The phone collects prompt answers (quantity, options, confirm), and the desktop runs that exact version.
• Built-in samples: Barcode + Enter, POS Lookup, Inventory Intake and Stocktake.
• Templates import and export as JSON. If an import has a bad field, the error names that field. Unknown steps are kept but disabled.

Exports and files

• Sessions export to CSV, TSV, JSON or TXT. On the phone, exports go through the share sheet.
• CSV quoting keeps commas, quotes, newlines, Unicode and leading zeros intact. Values starting with = + - @ are made spreadsheet-safe unless you turn that off.
• File steps (CSV_OUTPUT, FILE_OUTPUT, CSV_LOOKUP) can only use the output folder set in Settings. The default is Documents/ScanBridge.

Network and firewall

• The default is localhost only. LAN mode listens on all IPv4 interfaces on TCP 57900.
• ScanBridge never changes firewall rules. Diagnostics shows instructions for Windows, macOS and Linux.
• The phone and the computer must be on the same network. Guest Wi-Fi often isolates devices from each other.

Data, backup, delete

• Desktop database: %APPDATA%\dev.scanbridge\scanbridge_desktop\scanbridge.db on Windows. Settings → Back up database writes a consistent copy. To restore, close the app and replace the file.
• Phone: the app's private storage.
• Deleting a session removes its scans after you confirm. Single deletes can be undone. Nothing is purged automatically.
• Devices → Forget all revokes every phone.

Privacy and security

• Scans never leave your devices unless you export them.
• Pairing uses a one-time code and your on-screen approval. After that, every message is HMAC-SHA256 signed with a per-device secret kept in OS secure storage.
• Traffic is not encrypted in v1, so use trusted networks. See docs/SECURITY.md and docs/PROTOCOL.md.

Troubleshooting

Symptom	Fix
Phone can't connect	Same Wi-Fi? LAN mode on? Firewall allowed? Try the IP shown on the dashboard
"Pairing code expired or already used"	Click New code. A wrong code also uses up the current one
Scans stay "Queued"	The phone retries automatically. Open the app to trigger a reconnect, or tap the sync icon in the session
Output "failed"	See the error in the Live feed, fix the target, then Resend output
Typing goes nowhere	The target app may be elevated, or it is the lock screen. Use the clipboard fallback
Windows build error atlstr.h	Add the C++ ATL component in the Visual Studio Installer

Development

apps/desktop   Flutter host (Windows/macOS/Linux)      apps/mobile  Flutter client (Android/iOS)
packages/      domain · protocol · template_engine · storage (Drift) · ui (theme + l10n)
docs/          architecture, protocol, security, feature matrix, test plan, audit

Tests: dart test in each pure package, and flutter test in apps/desktop. Details are in docs/TEST_PLAN.md and docs/ARCHITECTURE.md.

Localization

• Strings live in packages/scanbridge_ui/lib/l10n/app_en.arb and app_hi.arb (English and Hindi).
• After editing an ARB file, run flutter gen-l10n in packages/scanbridge_ui.
• To add another language, add app_<code>.arb with the same keys. You need to translate other languages yourself or with a translation tool.

License

The original code is MIT (see LICENSE). Dependency notices are in docs/DEPENDENCY_LICENSES.md.