Lemma — Flashcards for Obsidian

A modern, FSRS-powered spaced repetition plugin that lives inside your notes.
No separate app. No manual data export. Write, tag, and study directly where your knowledge lives.

Preview

Desktop and mobile · LaTeX math support · Learning analytics · Custom study sessions

Why Lemma?

Most spaced repetition tools require leaving your knowledge base, exporting notes, and managing a secondary database. Lemma embeds spaced repetition directly in Markdown.

Notes are decks. Add #flashcards to any note, write cards in plain Markdown, and let FSRS handle scheduling.

Features

FSRS Scheduling

Lemma uses FSRS (Free Spaced Repetition Scheduler), a modern scheduling algorithm developed from cognitive science research. It models memory stability and retrievability based on your individual recall patterns.

Cards Live in Notes

Write flashcards directly in any Markdown note without imports or app switching.

---card--- ^fsrs-abc123
What is the powerhouse of the cell?
---
**Mitochondria** — produces ATP through cellular respiration.

Cloze Deletions

The ==c1::mitochondria== is the powerhouse of the ==c2::cell==.

Each cloze deletion is scheduled independently.

Dashboard View

View all decks in a single overview with due counts, new cards, and total reviewed.

Custom Study Sessions

Filter review queues by tag, card state (new, learning, due), or configure a card limit for targeted study and exam preparation.

Review Statistics

Analyze learning progress with retention curves, card maturity distribution, interval histograms, 30-day activity, and 7-day forecast charts.

Mobile Support

Responsive review interface designed for desktop and mobile, with safe-area insets and touch-optimized navigation.

Optional CouchDB Sync

Connect to self-hosted CouchDB or Cloudant instances to sync review history seamlessly across devices.

Quick Start

1. Install from Community Plugins: search for Lemma.
2. Add #flashcards to any note's frontmatter or inline:

---
tags: [flashcards]
---

3. Write a card:

---card--- ^my-first-card
What is spaced repetition?
---
A learning technique that schedules reviews at increasing intervals to maximize long-term retention.

4. Open the Lemma dashboard from the status bar or Command Palette (Open dashboard).

Full syntax documentation: FLASHCARD_GUIDE.md

Card Formats

Basic Cards

---card--- ^unique-id
Front content (question)
---
Back content (answer with **Markdown**, $LaTeX$, and images)

Single-Line Cards

Question::Answer ^single-001
Reversed Question:::Reversed Answer ^rev-001

Cloze Deletion Cards

The ==c1::Ebbinghaus== forgetting curve shows memory decays without ==c2::repetition==.

[!TIP] Add a ^block-id to any card so review history persists across content edits.

Keyboard Shortcuts

Commands

Settings

Installation

Community Plugin Directory

1. Open Settings → Community plugins
2. Click Browse and search for Lemma
3. Select Install, then Enable

Manual Installation

1. Download main.js, manifest.json, and styles.css from the latest release
2. Copy the files into:

   <vault>/.obsidian/plugins/lemma-flashcards/
   

3. Reload Obsidian and enable the plugin under Settings → Community plugins

Contributing

Contributions, bug reports, and feature requests are welcome.

• Issue tracker: GitHub issues
• Pull requests: Open a pull request against main

License

ISC License — see LICENSE for details.