# ATProto Sync

Sync your Obsidian vault to your own [ATProto](https://atproto.com) PDS — the
same account you use for Bluesky, Blacksky, Eurosky, or a self-hosted server.
End-to-end encrypted by default.

- **Your storage, your account.** Notes live in your PDS repo as
  `app.notesky.*` records. No third-party sync server, nothing to trust but
  your own host.
- **End-to-end encrypted.** Every note and attachment is encrypted on-device
  (XChaCha20-Poly1305, per-item keys wrapped by an Argon2id passphrase-derived
  master key). Filenames and titles are encrypted too — at rest, your PDS sees
  only ciphertext.
- **Multi-device.** Desktop and mobile converge through three-way sync with
  character-level merging (the same algorithm Obsidian Sync uses). True
  conflicts never lose data: the losing version is kept locally in
  `Sync Conflicts/`.
- **Publish per note.** Toggle a note public and it becomes a plaintext record
  (with its embedded images) that anyone — or any app — can read from your
  PDS. Toggle it back and it re-encrypts with a fresh key. A public web viewer
  for these records is planned at [notesky.app](https://notesky.app).

## Setup

1. Install and enable the plugin.
2. The setup wizard opens: sign in with Bluesky (OAuth, or an app password
   under Advanced), then choose your encryption passphrase.
3. That's it — the status bar shows sync state. Later devices enter the same
   passphrase.

> **Passphrase warning:** if you lose the passphrase, encrypted notes on the
> server cannot be recovered by anyone — including us.

## Permissions and privacy

- **File listing**: as a sync plugin, it enumerates vault file paths to know
  what to sync (respecting your ignore patterns; `.obsidian/` never syncs).
- **Clipboard**: written only when you tap "Copy link instead" during mobile
  sign-in; never read.
- **Browser storage**: sync state and settings live in IndexedDB; the OAuth
  library additionally persists its session material in browser storage.
- **Network**: your PDS, plus public directory endpoints
  (`public.api.bsky.app`, `plc.directory`) to resolve your handle. No
  analytics, no third-party servers.

## Notes on limits

- Files larger than your PDS blob limit (5 MB on the reference PDS) stay
  local-only; they're listed under Settings → Skipped files.
- `.obsidian/` configuration does not sync.

## Development

```bash
pnpm install
pnpm test          # vitest suite (unit, scenario, seeded fuzz)
pnpm run build     # produces main.js
```

The sync engine, crypto, and reconciler are plain TypeScript with no Obsidian
dependency and are fully unit-tested; see `docs/` for the design documents and
the manual testing guide (including a local Docker PDS setup).

## pi extension (sync without Obsidian)

[`pi-extension/`](pi-extension/README.md) runs the same engine against a plain vault directory
from the [pi](https://github.com/earendil-works/pi) coding agent: `/atpsync setup|sync|status|
publish|unpublish|watch`, plus `atpsync_*` tools the model can call. App-password auth, config in
`~/.config/atpsync/`, index in `<vault>/.atpsync/`.

## License

[MIT](LICENSE)