Overview
Elefthero is an open-source invoicing workspace for Greek small businesses seeking a transparent, self-hosted approach to AADE myDATA compliance.
Problem and rationale
Small businesses may face both financial and operational barriers when managing invoicing compliance. Elefthero is designed around inspectable XML, local data control, and clear workflows.
Contribution
Product design, software architecture, and implementation of the core application and compliance workflows.
Approach and implementation
The application uses Flask and SQLite, supports AADE test and production submissions, and retains sent and received XML for inspection and audit purposes.
Selected features
- Invoice creation with VAT and classification handling
- AADE submission with MARK, UID, and QR response handling
- PDF generation and client management
- Optional Viva POS webhook automation
- Optional two-factor authentication, rate limiting, and encrypted settings
Design principle
Compliance software should provide transparent feedback. Operators should be able to inspect submitted data and understand the reasons for validation failures.