¶ Offline vs. Cloud Capabilities
What the system can do locally without connectivity and what requires cloud services.
¶ Design Principle
eCozy is designed local-first. The home should function fully — heating, scheduling, automation — without an active internet connection. Cloud connectivity enriches the experience but is never a hard dependency for core comfort.
PlantUML source
¶ Capability Matrix
| Capability | Offline (Local) | Cloud Required |
|---|---|---|
| Room temperature control | ✅ | |
| Thermostat valve operation | ✅ | |
| Local schedules execution | ✅ | |
| Sensor data collection | ✅ | |
| Window-open heating pause | ✅ | |
| Leak detection & alert (local buzzer) | ✅ | |
| Manual setpoint via thermostat display | ✅ | |
| Local device-to-device communication | ✅ | |
| Mobile app control (local network) | ✅ | |
| Remote access (outside home network) | ✅ | |
| Mobile push notifications | ✅ | |
| Historical data & analytics | ✅ | |
| AI-based heating recommendations | ✅ | |
| OTA firmware updates | ✅ | |
| Multi-home management | ✅ | |
| Cross-home energy reporting | ✅ | |
| Third-party integrations (e.g., Alexa) | ✅ |
¶ Offline Behavior
When internet connectivity is lost, the Central Unit:
- Continues executing the last synchronized schedule
- Buffers telemetry data locally (ring buffer, configurable retention)
- Retries cloud sync automatically when connectivity is restored
- Notifies user via on-device display (no silent failure)
¶ Data Retention During Offline Period
- Telemetry buffer: up to 7 days (configurable)
- Event log: up to 30 days (configurable)
- On reconnect: buffered data is uploaded in chronological order
¶ Cloud Degradation Levels
| Scenario | Impact | Behaviour |
|---|---|---|
| Full connectivity | Normal | All features active |
| Mobile data lost | Low | Local network control still works |
| Internet lost | Medium | Local automation continues; no remote access |
| Central Unit offline | High | Thermostats fall back to last known setpoint |
| Full power loss | Critical | Devices return to hardware defaults on boot |