Not Delete Photos on immich

[mesu0815]

Hi everyone,

I'm currently using Immich to automatically back up photos from my mobile device. However, it seems like Immich performs a bidirectional sync, meaning that changes on the server can also be synced back to the device.

What I’m looking for instead is:
Upload-only mode, where photos and videos are only uploaded from the device to the Immich server, but nothing ever gets downloaded or synced back from the server to the device.

My questions:

Is there an option to enable upload-only backup in Immich?
If not: is there any recommended workaround or config to achieve this behavior?
How exactly does the current sync mechanism work – is it a two-way mirror or something else?
The goal is a clean one-way backup system where the device sends files to Immich, but server-side content doesn’t affect or overwrite anything on the mobile device.