Tarkov Kill Screen Analyzer

A lightweight Windows system tray application that helps players track their kills by analyzing end-of-raid screenshots.

Important Notice for BSG / Battlestate Games

This tool does NOT interact with Escape from Tarkov in any way.

• No game memory access - We never read or write to the game's memory
• No process injection - We never inject code into the game process
• No network interception - We never intercept or modify game traffic
• No file modification - We never modify game files
• No automation - We never send inputs to the game

What this tool actually does:

1. Registers a global hotkey (Print Screen, F12, Scroll Lock, Pause, PageUp, PageDown, Insert, or Delete)
2. When user presses the hotkey, captures the screen directly via Windows API
3. Uploads the screenshot to our web service for OCR text recognition
4. Displays the extracted kill information to the user

This is functionally identical to a user manually uploading screenshots to a website — we just automate the upload process.

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Features

• Hotkey Capture — Press a configurable hotkey to capture screenshots directly from the game display
• Smart Batching — Collects multiple screenshots within a 20-second window (for scrollable kill lists, max 10 per batch)
• Multi-Monitor Support — Automatically captures from the display where Tarkov is running
• Capture Feedback — Screen flash, sound, and mini-overlay on capture (individually configurable)
• Snipping Tool Override — Automatically disables Windows 11 Snipping Tool when PrintScreen is used
• OCR Analysis — Sends screenshots to API for text extraction and kill parsing
• Kill Tracking — Saves analyzed kills to user's profile with full kill details
• Kill Events — Participate in community events with automatic kill assignment
• Re-Capture Prevention — Detects screenshots of screenshots via embedded pixel signature
• Device Lock — Token bound to a single device via UUID for abuse protection
• Auto-Update — Notifies when new versions are available (supports pre-releases)
• Autostart — Optional Windows autostart via registry
• i18n — UI available in German (default) and English
• System Tray — Runs quietly in the background with session statistics

Client-Side Filters

To minimize server costs, the app filters invalid screenshots locally before uploading:

Filter	Description
Tarkov Process Check	Only processes screenshots when EscapeFromTarkov.exe is running
Minimum Size	Rejects images smaller than 800×400 pixels
Aspect Ratio	Accepts ratios between 1.2 and 3.8 (covers 4:3 to 32:9, rejects multi-monitor spans)
Re-Capture Detection	Detects and ignores screenshots of screenshots via embedded pixel signature
Image Viewer Check	Blocks capture when an image viewer is open to prevent accidental re-capture

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Installation

1. Download the latest release from Releases
2. Run screenshoter.exe
3. On first run, enter your API token (get it from tarkov-stammtisch.de)
4. The app starts in the system tray, ready to capture

Usage

1. Start the app (it will minimize to system tray)
2. Play Escape from Tarkov
3. At the end of a raid, press the capture hotkey (default: Print Screen)
4. If you have many kills (scrollable list), take multiple screenshots
5. After 20 seconds of no new screenshots, all images are uploaded together
6. You'll receive a notification with your kill summary

Tip: Use "Process Now" from the tray menu to skip the 20-second wait.

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Project Structure

screenshoter/
├── main.go              # Entry point, single-instance check
├── app.go               # Core logic: tray menu, batching, upload coordination
├── hotkey.go            # Global hotkey registration, screen capture, Snipping Tool override
├── clipboard.go         # Windows clipboard API (legacy fallback)
├── windows.go           # Process enumeration, display mapping, viewer detection
├── upload.go            # HTTP multipart upload, OCR response parsing, kill save
├── config.go            # Configuration file handling (%APPDATA%\TarkovKillcounter)
├── credential.go        # Windows Credential Manager + AES-GCM encrypted backup
├── device.go            # Device ID generation (UUID v4) for token binding
├── events.go            # Kill event fetching and selection
├── settings.go          # Settings dialog UI (token, hotkey, language, feedback, events)
├── i18n.go              # Internationalization (DE/EN translations)
├── signature.go         # Pixel signature embedding/verification (re-capture detection)
├── version.go           # Auto-update checker (GitHub Releases API)
├── splash.go            # Splash screen with cached DIB
├── flash.go             # Screen flash effect (Win32 layered window)
├── overlay.go           # Mini overlay popup with countdown
├── sound.go             # Capture sound via winmm.dll
├── icon.go              # Tray icon generation (crosshair + update indicator)
├── autostart.go         # Windows autostart via registry
├── log.go               # Debug logging utilities
├── admin.go             # Admin build: skip Tarkov check (testing only)
├── debug_debug.go       # Debug build: verbose output, dev API URL
└── debug_release.go     # Release build: quiet output, production API URL

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Building from Source

Requirements

• Go 1.24 or later
• Windows 10/11 (uses Windows-specific APIs)

Build Commands

# Release build (production API, no console output)
GOOS=windows GOARCH=amd64 go build -ldflags "-H=windowsgui -s -w" -o screenshoter.exe

# Debug build (dev API, console output)
GOOS=windows GOARCH=amd64 go build -ldflags "-H=windowsgui -s -w" -tags debug -o screenshoter_debug.exe

# Admin+Debug build (skip Tarkov check, console output, dev API)
GOOS=windows GOARCH=amd64 go build -ldflags "-H=windowsgui -s -w" -tags "admin,debug" -o screenshoter_admin.exe

Build Tags

Tag	Effect
(none)	Release build: production API, quiet output
debug	Dev API URL, verbose console logging, debug screenshots saved as JPEG
admin	Skips Tarkov process check (for testing without game running)

Dependencies

github.com/lxn/walk           # Windows GUI library (dialogs, tray icon)
github.com/lxn/win            # Windows API bindings
github.com/kbinani/screenshot  # Screen capture
golang.org/x/image             # Image scaling (CatmullRom)
golang.org/x/sys               # Windows registry access

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Configuration

Configuration is stored in %APPDATA%\TarkovKillcounter\config.json:

{
  "hotkeys": {
    "capture_key": "PrintScreen"
  },
  "api": {
    "enabled": true,
    "mode": "kills",
    "max_width": 1920,
    "jpeg_quality": 85
  },
  "feedback": {
    "flash_enabled": true,
    "sound_enabled": true,
    "overlay_enabled": true,
    "overlay_duration": 3
  },
  "language": "de",
  "autostart": false,
  "kill_event_id": ""
}

Field	Description
hotkeys.capture_key	Capture hotkey: PrintScreen, F12, ScrollLock, Pause, PageUp, PageDown, Insert, Delete
api.enabled	Enable/disable API uploads
api.mode	OCR mode (always kills)
api.max_width	Max image width before resize (saves bandwidth)
api.jpeg_quality	JPEG compression quality (1-100)
feedback.flash_enabled	Screen flash on capture
feedback.sound_enabled	Sound on capture
feedback.overlay_enabled	Mini overlay popup on capture
feedback.overlay_duration	Overlay display time in seconds (1-10)
language	UI language: de (German) or en (English)
autostart	Start with Windows
kill_event_id	Currently selected kill event (empty = no event)

Note: The API token is stored securely in Windows Credential Manager, not in this file. An encrypted backup is kept in the config for recovery (e.g. after CCleaner wipes credentials).

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Security & Privacy

• API Token — Stored in Windows Credential Manager (encrypted by Windows), with AES-GCM encrypted backup in config
• Device ID — UUID v4 stored in %APPDATA%\TarkovKillcounter\device.id, sent as X-Device-ID header for token binding
• Screenshots — Uploaded via HTTPS only, compressed to JPEG before upload
• No Telemetry — No data collected beyond what you explicitly upload
• Open Source — Full source code available for review

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Technical Details

Screenshot Processing Pipeline

1. Hotkey Press — WatchHotkey() polls GetAsyncKeyState at 50ms intervals
2. Display Detection — Identifies which monitor Tarkov is running on
3. Screen Capture — screenshot.CaptureRect() captures the correct display
4. Validation — Checks minimum size (800×400), aspect ratio (1.2–3.8), re-capture signature
5. Signature Embedding — Writes 8-byte signature into blue channel pixels (4 magic + 4 CRC32 hash)
6. JPEG Compression — Scales if wider than max_width, encodes as JPEG, immediately frees raw image
7. Batching — Adds to batch, resets 20-second timer (max 10 images, auto-uploads at 10)
8. Upload — Multipart POST to /api/ocr, frees JPEG buffers during construction
9. Save Kills — POST parsed kill data to /api/kills/save with device ID and optional event ID
10. Notification — Overlay popup with kill summary and raid details

Memory Management

• Raw RGBA images (~15 MB at 1080p) freed immediately after JPEG compression
• Single-pass BGR→RGB clipboard conversion (no intermediate copy)
• JPEG buffers freed during multipart upload construction
• Splash screen DIB cached and reused across repaints
• Overlay fonts created once and reused

Thread Safety

• sync/atomic for session counters (uploads, kills, failures) and watching state
• sync.Mutex for batch queue, pending queue, and event selection
• sync.RWMutex for active events list
• mainWindow.Synchronize() for all UI updates from goroutines

Windows APIs Used

DLL	Function	Purpose
user32.dll	RegisterHotKey / UnregisterHotKey	Global hotkey registration
user32.dll	GetAsyncKeyState	Hotkey polling fallback
user32.dll	CreateWindowEx / RegisterClassEx	Flash, overlay, splash windows
user32.dll	SetLayeredWindowAttributes	Semi-transparent flash effect
user32.dll	OpenClipboard / CloseClipboard	Clipboard access (legacy fallback)
user32.dll	MonitorFromWindow / GetMonitorInfoW	Multi-monitor display detection
user32.dll	EnumWindows / GetWindowThreadProcessId	Image viewer detection
kernel32.dll	CreateToolhelp32Snapshot	List running processes
kernel32.dll	CreateMutexW	Single-instance check
gdi32.dll	CreateDIBSection / CreateCompatibleDC	Splash screen DIB caching
gdi32.dll	CreateSolidBrush / CreateFontIndirectW	Overlay rendering
winmm.dll	PlaySoundW	Capture sound feedback
advapi32.dll	CredWriteW / CredReadW / CredDeleteW	Credential Manager

All APIs used are standard, documented Windows APIs. No undocumented or game-specific APIs are used.

What We Do NOT Do

• Read game memory
• Inject DLLs or code
• Hook game functions
• Intercept network traffic
• Modify game files
• Send automated inputs
• Bypass anti-cheat

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Author

Martin Wilke — Malaysia

License

MIT License — See LICENSE for details.

Disclaimer

This project is not affiliated with Battlestate Games. Escape from Tarkov is a trademark of Battlestate Games Limited.

This tool only processes screenshots that the user manually captures. It does not interact with the game in any way that would violate the game's Terms of Service.