# CalDAV Provider Notes
## Yandex Calendar
**Server URL**: `https://caldav.yandex.ru/`
### ⚠️ Known Limitations
**Rate Limiting**: Yandex Calendar artificially slows down WebDAV operations (60 seconds per MB since 2021).
**Symptoms**:
- Frequent 504 Gateway Timeout errors
- Especially common when creating/updating events
- Operations may take significantly longer than expected
**Recommendations**:
1. **For Write Operations** (create/update/delete):
- Add manual delays (at least 2–5 seconds) between requests
- Wait several minutes before retrying failed operations
- Batch writes carefully to avoid triggering throttling
2. **For Read Operations**:
- Reading events is generally more reliable
- Still may experience delays with large calendars
3. **Best Practices**:
- Avoid rapid successive write operations
- Add delays between operations (2-5 seconds minimum)
- Consider using Google Calendar or Nextcloud for write-heavy workloads
### Configuration
The `CalDAVClient` does not implement automatic retry logic. If you experience throttling, add manual `sleep` calls between operations or schedule writes during off-peak hours.
> **Testing status**: The project’s end-to-end tests run against Yandex Calendar. Other CalDAV providers follow the same protocol and should work, but they have not been exercised end-to-end yet.
### Alternative Providers
If you need more reliable write operations, consider:
- **Google Calendar**: More reliable, better rate limits
- **Nextcloud**: Self-hosted, full control over rate limits
- **iCloud Calendar**: Good reliability, standard CalDAV support
## Other Providers
### Google Calendar
**Server URL**: `https://apidata.googleusercontent.com/caldav/v2/`
- Generally more reliable than Yandex
- Better rate limiting
- Standard CalDAV support
### Nextcloud
**Server URL**: `https://your-nextcloud-instance.com/remote.php/dav/calendars/`
- Self-hosted option
- Full control over rate limits
- Excellent CalDAV support
### iCloud Calendar
**Server URL**: `https://caldav.icloud.com/`
- Reliable service
- Standard CalDAV support
- Good for personal use
