mdsr

Spaced repetition for an Obsidian vault. You write flashcards as callouts inside your notes; mdsr parses them, schedules them with FSRS, and serves a small web UI for reviewing.

Card syntax

> [!sr] What is ...?
> The ...

> [!sr-bi] Cat
> Katze

• [!sr] — one card, front (the question) → back.
• [!sr-bi] — two cards, front ↔ back, marked as siblings (reviewing one hides the other until the next study day).
• Obsidian's fold markers work: [!sr]- (collapsed) and [!sr]+ (expanded). Both are equivalent to [!sr].
• LaTeX, code, images, wikilinks — anything Obsidian renders works here too.

Card identity is sha256(front). Editing the back keeps the schedule. Editing the front creates a new card (the old one is trashed; you can merge its schedule onto the new card from the sidebar).

Run

uv tool install mdsr

sr --vault /path/to/your/vault
# or, clone-on-first-run into $XDG_DATA_HOME/mdsr/vaults/:
sr --vault git@github.com:you/notes.git

If --vault is a git clone (or a git URL, which gets cloned on first run and reused after), the server runs git pull --ff-only every --poll-seconds (default 60), re-parses changed files, and updates card state. You can let trash get auto-purged after --trash-purge-days (default 30). If --vault is a plain directory it skips the pull and detects changes via per-file mtime instead.

Open http://127.0.0.1:8765, sr --help lists all flags.

[!TIP] With the Obsidian web viewer plugin, you can use mdsr directly within Obsidian.

~/.local/share/mdsr/<vault-basename>-<hash8>.db

Deploy on a VPS

A single Python process. Bind it to 127.0.0.1 and reach it via Tailscale.

Keep it running with systemd

The sr command runs in the foreground and exits when its shell dies, so on a server you want something to (re)start it: daemonize at boot, restart on crash, survive logout. A user-level systemd unit:

[Unit]
Description=mdsr review server
After=network-online.target
Wants=network-online.target

[Service]
Type=simple
ExecStart=%h/.local/bin/sr --vault %h/vault --host 127.0.0.1 --port 8765
Restart=on-failure
RestartSec=10

[Install]
WantedBy=default.target

systemctl --user daemon-reload
systemctl --user enable --now mdsr
loginctl enable-linger $USER   # keep the unit running after logout

Expose it on your tailnet

Simplest case — mdsr owns the whole hostname:

tailscale serve --bg --https=443 http://127.0.0.1:8765

Reachable at https://<machine>.<tailnet>.ts.net.

To put it under a URL path (e.g. /sr, leaving room for other services on the same host), tell mdsr its prefix with --root-path and forward the entire hostname to it:

sr --vault ~/vault --port 8765 --root-path /sr
tailscale serve --bg --https=443 http://127.0.0.1:8765

Reachable at https://<machine>.<tailnet>.ts.net/sr/. mdsr answers at /sr/*; other paths 404 at the app layer. For real path-based routing across multiple services, put a reverse proxy (Caddy, nginx) between tailscale and the backends.

TODO

• Core: Properly render note content,images (parsing and rendering step via https://onyx.md)
• Cosmetic: Make wikilinks resolve to published vault (once vault is published via onyx)?
• Cosmetic: Same/configurable css styles as onyx site

Develop

make dev      # uv sync --group dev
make test
make check    # lint + format
make fix      # ruff fix + format
make build    # uv build → dist/
make release-{patch,minor,major} # bumps pyproject.toml version, commits and git tags
make publish  # requires UV_PUBLISH_TOKEN

Inspiration

• The Obsidian Spaced Repetition plugin — the original cards-in-notes Obsidian SRS, and prior art for most of what this does.
• Andy Matuschak's notes on evergreen note-writing — concept-orientation, cards living inside concept notes, and How to write good prompts.
• Michael Nielsen, Using spaced repetition systems to see through a piece of mathematics and Augmenting Long-term Memory.
• FSRS and its Python port fsrs.