Sync Mac/PC and iOS using Syncthing + Möbius Sync

After trying most of the sync methods available for syncing Obsidian between Mac/PC and iOS, Syncthing + Möbius Sync is the best solution I’ve found so far. Once set up, it is (mostly) frictionless, to the point that sync is an afterthought and stays out-of-sight.

This should work for Android as well, but you would use the official Syncthing client instead of Mobius Sync (which is just an iOS version of Syncthing, since there is no official iOS client).

To summarize the advantages of this method:

  • Syncs at the file-system level, not dependent on Obsidian running, no “waiting to sync” on startup. (This means even notes added via iOS shortcuts will sync without having to open Obsidian.)
  • Mac/PC: Effectively syncs in real-time.
  • iOS: Mobius Sync syncs in the background at varied intervals determined by iOS (typically every 5-15min).
  • Syncthing is efficient and performant. Typical note content or images will sync within seconds. Handles large vaults without issue.
  • No storage thresholds, entirely self-hosted / private if desired.
  • Can sync hidden files / configurations, selectively sync folders, etc.

A few caveats:

  • Requires some technical know-how and ideally a server of some sort (NAS, PC) to facilitate transfers.
  • Background sync interval is not configurable, this is an iOS limitation. If you rapidly switch between devices and expect notes to always be up to date automatically, this may not be the optimal set up.
  • iOS Obsidian sandbox is quirky. Once set up, it generally just works - however app updates can break it requiring reconfiguration.
  • Sync is not backup. Make sure you have a separate backup solution. Using Git on the computer in conjunction with Syncthing is a good way to handle this.
  • Mobius Sync is a paid app, although at a very reasonable $5 USD.

Setup

Brief overview of the set up process below. I won’t go into the details of configuring desktop Syncthing, there are other guides out there that cover it.

Use a test vault during set up! Even when configuring sync for the live vault, it is best to use empty folders, and cut/copy files over manually after sync is confirmed working (make a copy of the entire vault to be safe).

  • Install and configure the official Syncthing client on your Mac/PC
  • (Optional) Install Syncthing client on an always-on “server” (NAS, PC, Pi, Docker)
  • Install and configure Mobius Sync Pro (see details below)
  • Add the server or computer as a Remote Device to Mobius, and share the folder you created
  • If using a “server”, accept the invitation, choose where to store notes, in turn share from server to computer
  • On computer, accept the invitation, choose where to store notes (this is where desktop Obsidian will open the vault from)
  • Copy some files to the vault on computer and verify both ends are syncing, open the vault in mobile Obsidian

Mobius Sync Configuration

  • Install Mobius Sync Pro on iOS device - ‎Möbius Sync Pro on the App Store
  • Add a folder, choose “Pick external folder” (this is the tricky bit), browse to the Obsidian folder, create a new folder to use (does not need to be an existing vault, Obsidian will still pick it up). This adds a “bookmark” which is a reference to the Obsidian sandbox folder. Leave the default options for now.
  • Expand the new folder in Mobius and choose “Open folder”. This will open the files app. Make sure it opens the folder located in the Obsidian directory. If you are in Mobius Sync directory, it has failed and you need to remove the folder in Mobius, kill the app and try again - see Syncing files from other apps · MobiusSync/MobiusSync · Discussion #102 · GitHub for additional suggestions.
  • Mobius Settings / iOS, verify the permissions are correct. Under background sync, the default intervals are fine (this is not the sync interval, iOS controls that). You will want to uncheck notifications at some point (it will generate one on every background sync).
  • Mobius Settings / Connections, recommend turning off Discovery, Relaying, NAT traversal, and set listen address to tcp://127.0.0.1:port to increase security.

Additional Notes

  • While Syncthing is decentralized (and could be used in a mesh), unless you have an always-on desktop, using a “server” in between is best so the iOS device can sync in the background on demand, with server always retaining a current copy of the vault.
  • Background sync in Mobius can take up to 24 hours to begin, this is normal. In the meantime, I recommend creating an iOS shortcut to open Mobius, then Obsidian, and add it to the home screen. This will serve as “manual sync” when needed, and also encourages iOS to optimize background sync during initial setup.
  • An always-on VPN is recommended so the iOS device can reach your server/device remotely during background sync.
  • If using a server, notes can be encrypted at-rest in the middle (they remain unencrypted on the end-devices). In this configuration, enter an encryption password when sharing the folder initially, and when accepting the folder on the server, set the mode to “receive encrypted”. Share from the server, and on the other device enter the encryption password.
  • Using a separate mobile configuration (.obsidian-mobile) reduces issues between desktop and mobile. (Yes you do have to duplicate plugins/css snippets/etc this way).
  • If using Git on the computer, add “.git” to the file exclusions in Syncthing, so git history isn’t synced to iOS.
4 Likes

Wow, I gave this a try - once you get past the initial set up, you really don’t even see or think about sync. iCloud is definitely getting replaced…

did anyone try to set up syncthing with docker and traefik?