# Lemma

> Lemma is a free Obsidian plugin. Write a question in a note and it becomes a flashcard, reviewed with FSRS-5. Cards stay Markdown. No account or subscription.

Lemma is a plugin for Obsidian. Tag a note, write a question and its answer in plain Markdown, and Lemma schedules your reviews with FSRS-5.

Obsidian desktop and mobile. Free, MIT licensed. No account.

## Pages

- [Lemma](https://lemma.fundaments.work/): Lemma is a plugin for Obsidian. Tag a note, write a question and its answer in plain Markdown, and Lemma schedules your reviews with FSRS-5.
- [Privacy policy](https://lemma.fundaments.work/privacy/): No account, no tracking; where plugin data is stored.
- [llm.txt](https://lemma.fundaments.work/llm.txt): This file, generated from the site's data files.

## Home page sections

- [A note is a deck. A question is a card.](https://lemma.fundaments.work/#what): Add the tag #flashcards to any note and it becomes a deck. Write cards in the note itself, in plain Markdown, next to everything else you have written. Lemma finds them and keeps its own index.
- [How reviews work](https://lemma.fundaments.work/#review): Lemma uses FSRS-5, the Free Spaced Repetition Scheduler. For every card it keeps two numbers: how stable the memory is, and how difficult the card is for you. From those it estimates how likely you are to still remember it on any day.
- [Your data stays yours](https://lemma.fundaments.work/#data): There is no Lemma account, no Lemma server and no subscription. Lemma is free and open source under the MIT licence. Here is where everything lives.
- [Install](https://lemma.fundaments.work/#install): Lemma needs Obsidian 1.4.0 or newer.
- [Questions](https://lemma.fundaments.work/#faq)

## Card formats

- [Basic](https://lemma.fundaments.work/#what): ---card--- / front / --- / back. Several lines on both sides, with full Markdown.
- [Single line](https://lemma.fundaments.work/#what): Question::Answer. A fast card on one line.
- [Reversed](https://lemma.fundaments.work/#what): Term:::Definition. One card that shows the definition and asks for the term.
- [Cloze](https://lemma.fundaments.work/#what): ==c1::hidden==. Each cloze number in a paragraph becomes its own card, scheduled separately.
- [Type in](https://lemma.fundaments.work/#what): Question::Answer ?type. You type the answer first. Lemma tells you Correct, Close match or Not correct, then you rate yourself.
- [Image pair](https://lemma.fundaments.work/#what): ![[question.png]]::![[answer.png]]. If both sides are a single image, the answer image swaps in at the same spot. You supply both images; Lemma does not draw masks.
- [Whole note](https://lemma.fundaments.work/#what): #review. Tag a note #review and review it as one item, with Open in editor, rating and Skip.

## How your data is stored

- [Your cards: In your Markdown notes](https://lemma.fundaments.work/#data): Questions and answers are text in your vault. Lemma changes a note only when you ask it to, for example to insert a card template, a card ID or the deck tag. Open the notes in any editor, back them up or sync them however you already do.
- [Your review history: On your device](https://lemma.fundaments.work/#data): Card memory states and review logs are kept in a local database inside Obsidian (IndexedDB). They are not in your notes, and they are not sent anywhere.
- [Syncing: Your CouchDB, if you want one](https://lemma.fundaments.work/#data): To share history between devices, point Lemma at a CouchDB or Cloudant server you run or rent. It is off until you turn it on.
- Review history is not part of your vault files. If you sync your vault with another tool, your cards travel but your review history does not, unless you also use CouchDB sync.
- If you set up CouchDB sync, the server address, username and password are saved in the plugin's settings file inside your vault, as plain text.
- There is no export or import in the plugin today, and no Anki import.

## Frequently asked questions

- [Is Lemma free?](https://lemma.fundaments.work/#faq): Yes. Lemma is free, open source and released under the MIT licence. There is no account, no subscription and no paid tier. If you want to support the work, the plugin has an optional donation link.
- [Does Lemma work on Obsidian mobile?](https://lemma.fundaments.work/#faq): Yes. The plugin is not desktop-only. It has the same dashboard and review screens on iOS and Android, with a full-screen review and swipe ratings.
- [Where is my review history stored?](https://lemma.fundaments.work/#faq): On the device, in a local database inside Obsidian. Your cards are in your notes, but your review history is not, so it does not travel with your vault by itself.
- [How do I use Lemma on two devices?](https://lemma.fundaments.work/#faq): Cards travel with your vault, however you sync it. For review history, turn on Lemma's CouchDB sync and point it at a CouchDB or Cloudant database that you control. Without it, each device keeps its own history.
- [Does Lemma send my notes or cards to a server?](https://lemma.fundaments.work/#faq): No. The only network connection Lemma makes is the optional sync to the CouchDB address you enter. This website does not use analytics or third-party scripts.
- [Which scheduling algorithm does it use?](https://lemma.fundaments.work/#faq): FSRS-5, through the open source ts-fsrs library. You can change the target retention, the longest interval and the weights in Settings.
- [Can I import my Anki decks?](https://lemma.fundaments.work/#faq): Not today. Lemma has no Anki import and no export in the plugin. Cards are written in Markdown, so notes can be moved by copying text.
- [How do I get cards out of my notes later?](https://lemma.fundaments.work/#faq): They are ordinary Markdown text in your vault, so they stay readable in any editor, with or without the plugin.
- [Is Lemma in the Obsidian Community plugins list?](https://lemma.fundaments.work/#faq): Yes. Search for Lemma under Settings, Community plugins, Browse. You can also install by hand from the files on the GitHub release page.
- [Where do I report a bug or ask for a feature?](https://lemma.fundaments.work/#faq): On the GitHub issue tracker for Lemma. The documentation is at fundaments.work/docs/lemma.

## Project links

- [Install in Obsidian](obsidian://show-plugin?id=lemma-flashcards)
- [Latest release on GitHub](https://github.com/Fundaments-Work/Lemma/releases/latest)
- [Documentation](https://fundaments.work/docs/lemma/)
- [Source code (MIT)](https://github.com/Fundaments-Work/Lemma)
- [Publisher](https://fundaments.work)