Thanks! If you just need backup, with Synchi you set the 'force=root_a' in config, otherwise its bidirectional sync. If you need pure backups, rsync or similar might still be the better fit as they have some backup specific features.

I used Syncthing for years, it's great (if you use it and you are happy, then you dont need to switch), but they are quite different. Syncthing requires daemons on all devices and can't sync two local folders on the same machine. Synchi is on-demand, runs only on one side, and doesn't care where the two root folders are.

I wrote a more detailed comparison here: https://jakobkreft.github.io/synchi/why.html

rclone bisync can do two-way sync, yes, great tool, especially for cloud backends and more automated syncs. Synchi is a lot simpler and more focused: works over SSH, nothing needed on the remote side. The key difference is that Synchi shows you exactly what it's about to do (copy A→B, copy B→A, delete in A, delete in B) and asks before changing anything. Conflicts get an interactive UI. No surprises.

Great question! Let me sum it up here for others:

rsync is one-way only and has no memory between runs, every execution starts from scratch. Synchi is two-way, stateful (knows what changed since last sync), and content-aware (uses hashes, so no false positives from timestamp changes). It also handles conflicts explicitly instead of silently overwriting.

That said, rsync is still the better tool for backups and one-way mirroring. Synchi is for when you need true bidirectional sync.

Here is also a comparison with unison and syncthing: https://jakobkreft.github.io/synchi/why.html

This is exactly how I use Synchi! Same idea but I use Logseq instead of Obsidian (very similar open-source alternative, worth checking out). Works great for syncing markdown notes between computers and my phone on demand. Of course I need to remember to sync before switching devices, but I prefer this then constant running in the background.

Haven't thought about an Obsidian/Logseq plugin but honestly that sounds like a great idea... For now it's CLI only, but I can definitely see the value.

Yes! On android with Termux terminal.

(note: If you sync between computer and phone you don't need to install it on your phone. One side only is enough.)

I'm not too familiar with Steam Deck, but that sounds like it would work! As long as you can point Synchi at both save directories, it would keep them in sync and save you the manual copy-paste.