System Constraints

ID Constraint
CON-1 Users must interact with the system through a Telegram bot interface in private chat.
CON-2 The system must be self-hosted by end-users using Docker Compose.
CON-3 The MVP must be delivered by December 19, 2025. Self-hosting setup must be achievable within 40 minutes by a test user following the provided README files.
CON-4 The system must synchronize with external calendars via external calendar API that provides iCal (ICS) file (via link)
CON-5 The system must support localization in Russian and English languages. All user-facing messages, notifications, and reminders must be available in both languages.
CON-6 The system must support single-user per instance. The first user who contacts the bot becomes the primary user, and the bot must only respond to commands from this registered user ID.
CON-7 The project must use the MIT license and be open-source.
CON-8 The user can perform CRUD operations only on those events which were not imported from external calendars (created through the bot interface).