OpenSync for Obsidian
Notes, folders and structure across desktop, iPad and Android — with the filenames and the contents sealed on your device first. Writing is free and unlimited, because a 504-note vault is 4.7 MB and text has never been the thing that costs money.
wss://relay.opensync.network
Already filled in. Obsidian on desktop and mobile.
Research/
Meeting notes.md
Meeting notes (conflict 2026-09-12 from MacBook).md
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named after the device whose version is inside itFeatures
The free tier carries what a vault is written in — an allow-list of text formats: md, canvas, base, excalidraw, csv, svg, drawio and the rest. Not a quota above which things stop: a boundary drawn by what a thing is, so you cannot cross it without noticing.
Not just the contents. Paths and folder structure live inside a sealed manifest, so the relay sees one opaque blob rather than a tree. There is no version of it that can list your notes.
Edit the same note on two devices and you get the newer one plus a copy beside it — named after the machine whose text is inside it, not the machine you are holding. Naming it the other way round labels every copy with the device you are already sitting at, and says the opposite of what the file contains.
Tiering by file type is a data-loss path and it was open: a manifest is a complete statement of a namespace, so a path missing from one reads as an instruction to delete it. Measured on two real vaults — attachments off on one device, and the other device's image went to the trash reading “up to date”. Manifests declare their scope now.
The plugin is not desktop-only. iPad and Android run the same code and the same encryption, and pair with a ten-character code rather than a pasted key.
What is being sold is running the server, not the feature — so pointing the plugin at anything but our relay unlocks everything, attachments included. The storage is yours and so is the bill.
How it works
Everything that decides what your data is happens on your device. The relay holds bytes and hands them back in the right order.
01
Three files into .obsidian/plugins/, or the community catalogue. It ships pointing at our relay already.
02
A ten-character code from a device that already has the vault. One code, one attempt — no key is ever typed twice.
03
It is chunked, sealed under a key derived on your device, and the manifest describing the vault is sealed too.
04
Only the chunks it does not already hold. Everything it learns, it learns by decrypting.
Download
Every OpenSync app shares an account, a relay and an encryption model — so a second one is a checkbox, not a second signup, a second bill or a second thing to trust.
Privacy
| What | Why, or why not |
|---|---|
| What the relay sees | Sealed bytes and how many of them. Not a filename, not a folder, not a note. |
| What a rotation really removes | Deletion on any relay is advisory — you are asking. Re-sealing the vault under a new key is the only removal that does not depend on the server's goodwill. |
| What we cannot help with | If you lose every device and the printed recovery kit, the vault is gone. That is the cost of the server being unable to read it, and it is not a cost we can remove without removing the property. |
Pricing
The paid side has no price yet, and this page will say so until it does — an app that lists a plan nobody can buy has already promised something.
£0
Images, PDFs and audio are the paid part on this relay. One phone photo is bigger than a year of writing, and attachments are the only part of a vault that costs real storage. On a relay of your own they are free, because there is nothing for us to charge for.
Point an app at itUnmetered
What is being sold is running the server, not the feature. If you are going to end up here eventually, start here.
Run your own OpenSync relayFAQ
No. It is an independent community plugin and is not affiliated with or endorsed by Obsidian. It talks to a relay we run, or to one you run.
Everything a vault is written in — markdown, Canvas, Bases, Excalidraw, CSV, SVG, diagrams.net, themes and snippets — with no limit on how many notes or how many devices. Attachments are the paid part.
No, and it cannot read their names either. Contents, paths and folder structure are all inside a manifest that is encrypted with a key generated on your device and never transmitted.
The newer version wins and the older is kept beside it as a conflict copy, named after the device whose version is inside it. Nothing is discarded silently.
Yes. The plugin is not desktop-only; mobile runs the same code and pairs with a ten-character code rather than a pasted key.
No, and that bug was real and is fixed. A manifest now declares its own scope, so a file missing from one is only a deletion inside that scope. Before it was fixed, one device turning attachments off could send another device's image to the trash.