Status: In Development | License: EUPL-1.2 | Developer: Betruger Sp. z o.o.
LLM-powered desktop POS system built with Electron, Svelte, and Node.js. Features natural language configuration via Google Gemini and German fiscal compliance (TSE/DSFinV-K).
- Desktop: Electron.js with a Svelte frontend
- Mobile: Native Android (Kotlin/Jetpack Compose) for standalone and client-only deployments
- Backend: Node.js + Express.js (local HTTP API)
- Database: SQLite with Knex.js migrations
- LLM: Google Gemini (Flash/Pro) via @google/genai
- Communication: WebSocket (primary) + HTTP (fallback)
- Logging: Pino with structured JSON output
- WebSocket - Primary low-latency channel
- HTTP API - Fallback with same operationId system
- Cloud Proxy - Optional remote access via eck(1,2,3).com
All operations use UUID-based operationId for idempotency across channels.
- Natural language POS configuration
- Function calling for direct API execution
- Multi-language support with automatic adaptation
- Contextual help and error diagnostics
- Product and pricing management via conversation
- Products: Three naming levels (menu/button/receipt display)
- Categories: Hierarchical with automatic tax assignment
- Users & Roles: Access control management
- Modifiers: Time/condition-based pricing rules
- Table Management: Bill splitting and item transfers
- TSE Integration: Technical Security Equipment support
- DSFinV-K Export: Tax authority data format
- Time Control: Mandatory TSE clock verification
- Long-term Archival: Hedera blockchain anchoring (daily for audit trail consistency)
- GoBD Compliance: Proper accounting record principles
- Geometric Tessellation: Optimized layout patterns
- Hexagons (6.6.6): Categories - maximum space efficiency
- Squares (4.4.4): Numbers - familiar input patterns
- Octagons (4.8.8): Hierarchical relationships
├── packages/
│ ├── backend/ # Node.js Express API
│ │ ├── src/
│ │ │ ├── config/ # Logger, database config
│ │ │ ├── controllers/ # API endpoint handlers
│ │ │ ├── services/ # Business logic, LLM service
│ │ │ ├── routes/ # Express route definitions
│ │ │ └── db/ # Knex migrations and seeds
│ │ └── package.json
│ └── client-desktop/ # Electron wrapper
│ ├── electron/ # Main process, preload scripts
│ ├── src/renderer/ # Svelte application
│ │ ├── src/
│ │ │ └── components/ # UI components
│ │ └── package.json
│ └── package.json
└── package.json # Monorepo root
- Node.js 18+ (project tested with v24.2.0)
- Google Gemini API key
- Git
git clone https://github.com/xelth-com/eckasse.git
cd eckasse
npm installCreate .env in project root:
GEMINI_API_KEY=your_google_gemini_api_key
BACKEND_PORT=3030
NODE_ENV=development
LOG_LEVEL=debug
DB_FILENAME=./packages/backend/src/db/eckasse_dev.sqlite3# Start all services (backend + React + Electron)
npm run dev
# Individual services
npm run dev:backend # Backend API only
npm run dev:client:svelte # Svelte dev server only
# Database management
npm run migrate:backend # Run database migrations
npm run seed:backend # Seed development data
# Production builds
npm run build:client:desktop # Build Electron app
npm run dist:client:desktop # Create distributable package- Start development environment:
npm run dev - Open Electron app (automatically launches)
- Test Gemini integration in the "Gemini Ping-Pong Test" section
- Example queries:
- "What are the details for product ID 123?"
- "Tell me about the Super Widget product"
- "Add a new coffee drink called Cappuccino for €3.50"
Located in packages/backend/src/services/llm.service.js
- Function Calling: Direct API execution via Gemini tools
- Product Management: getProductDetails function for inventory queries
- Conversation History: Maintains context across requests
- Error Handling: Multi-model fallback (Gemini 2.5 Flash → 2.0 Flash → 1.5 Flash)
Located in packages/client-desktop/src/renderer/src/lib/wsStore.js
- Primary: WebSocket for real-time communication
- Fallback: HTTP requests with same operationId
- Idempotency: UUID-based operation tracking prevents duplicates
- Backend: RESTful API design with LLM service layer
- Frontend: Svelte stores pattern with custom WebSocket management
- Database: Knex.js migrations for schema versioning
- Logging: Structured JSON logs via Pino
- Function declarations follow Google's official structure
- System context defines POS-specific behavior
- All product queries must use available tools
- Error recovery with model fallback chain
// Request format
{
operationId: "uuid-v4",
command: "ping_ws",
payload: { data: "test" }
}
// Response format
{
operationId: "uuid-v4",
status: "success|error|already_processed",
payload: { /* response data */ },
channel: "websocket|http"
}- TSE (Technical Security Equipment): Required for all cash transactions
- DSFinV-K: Standardized export format for tax authorities
- Time Synchronization: Mandatory TSE clock verification on startup
- Data Retention: Long-term archival with cryptographic integrity
- ✅ Basic LLM integration with product management
- ✅ WebSocket/HTTP communication system
- ✅ SQLite database with migrations
- 🔄 TSE integration (planned)
- 🔄 DSFinV-K export (planned)
- 🔄 Hedera blockchain anchoring (planned)
- License: EUPL-1.2 (European Union Public Licence)
- LLM: Google Gemini Flash
- Requirement: User-provided Google API key (BYOK)
- Database: Local SQLite only
- LLM: Google Gemini Pro
- Features: Cloud sync, advanced reporting, priority support
- Archival: Qualified eIDAS timestamps
- Pricing: Subscription-based with transparent cost structure
- Fiscal Compliance: International POS regulations expertise
- UI/UX: Geometric tessellation interface improvements
- Testing: Real-world restaurant environment validation
- Documentation: User guides and API documentation
- Localization: Multi-language support and regional adaptations
- Fork repository
- Set up development environment as above
- Check GitHub Issues for "good first issue" labels
- Submit pull requests with clear descriptions
Currently focused on German market. Contributors needed for:
- 🇫🇷 France: Fiscal printer requirements
- 🇮🇹 Italy: RT compliance and fiscal memory
- 🇬🇧 UK: Making Tax Digital (MTD) requirements
- 🇵🇱 Poland: JPK reporting and online registers
- 🇺🇸 USA: State-specific sales tax regulations
Copyright 2025 Betruger Sp. z o.o.
Original work by Dmytro Surovtsev
Licensed under the European Union Public Licence v. 1.2 (EUPL-1.2).
See LICENSE for details.
- Repository: github.com/xelth-com/eckasse
- Documentation: eckasse.com (planned)
- Issues: GitHub Issues
- Discussions: GitHub Discussions