Oboeru

A spaced repetition flashcard plugin for Obsidian using the FSRS (Free Spaced Repetition Scheduler) algorithm.

Features

• 🧠 FSRS-6 Algorithm - Modern, research-backed spaced repetition
• 📝 Two Card Formats - Simple inline or multi-line cards
• 📊 Smart Scheduling - Optimized review intervals based on your performance
• 🎯 Improved Cram Mode - Focused practice with Again/Good buttons and automatic retry system
• 🔀 Randomized Order - Cards are shuffled for better learning
• 👁️ Clean Editor - Metadata is hidden by default with a compact indicator
• ⚙️ Customizable - Adjust retention rate, intervals, and daily limits
• 📱 Mobile Friendly - Works on all Obsidian platforms

Quick Start

1. Create Flashcards

Tag any note with #flashcards to turn it into a deck. Then add cards using one of these formats:

Single-line format:

What is the capital of France?::Paris

Multi-line format:

What is the capital of France?
?
Paris is the capital and largest city of France.
+++

2. Review Your Cards

1. Click the Oboeru icon in the ribbon (or use the command palette)
2. Select a deck
3. Click "Review" to start your spaced repetition session
4. Rate each card: Again, Hard, Good, or Easy

The plugin automatically schedules cards based on your performance using the FSRS algorithm.

Card Formats

Single-Line Cards

Perfect for simple question-answer pairs:

#flashcards

What is 2 + 2?::4
Who wrote "1984"?::George Orwell
Python uses what for comments?::# (hash symbol)

Multi-Line Cards

Better for detailed answers:

#flashcards

What is the SOLID principle?
?
SOLID is an acronym for five design principles:
- Single Responsibility
- Open/Closed
- Liskov Substitution
- Interface Segregation
- Dependency Inversion
+++

Explain photosynthesis
?
Photosynthesis is the process by which plants convert light energy into chemical energy.

Key components:
1. Chlorophyll captures light
2. Water is split into hydrogen and oxygen
3. CO2 is converted to glucose
+++

Metadata

The plugin stores review data as HTML comments in your notes. By default, these are hidden in the editor and replaced with a compact indicator:

What is the capital of France?::Paris
📊 SRS

Click the 📊 SRS indicator to toggle visibility of the full metadata:

What is the capital of France?::Paris
<!--OBOERU:{"v":1,"algo":"fsrs-6","reviewedAt":"2024-01-15T10:30:00Z","dueAt":"2024-01-20T10:30:00Z","s":5.2,"d":4.1,"rating":3,"reviews":5,"lapses":1}-->

The metadata includes:

• Review schedule (next due date)
• Stability and difficulty parameters
• Review history count
• Lapse count

You can disable metadata hiding in Settings → Oboeru → Editor if you prefer to always see the full metadata.

Settings

Access settings via Settings → Oboeru:

FSRS Algorithm

• Request Retention (0.7-0.97): Target recall probability. Higher = more reviews but better retention.
• Maximum Interval: Longest time between reviews (default: 100 years)
• Daily New Card Limit: Maximum new cards per deck per day

Editor

• Hide FSRS Metadata: Show compact indicator instead of full metadata comment (enabled by default)

Review vs Cram Mode

Review Mode

• Uses FSRS scheduling
• Cards are shown based on due date (randomized)
• Your ratings affect future scheduling
• Limited to daily new card limit
• Four rating options: Again, Hard, Good, Easy
• Shows predicted intervals for each rating

Cram Mode

• Shows all cards in the deck (randomized)
• Perfect for focused practice sessions
• Two simple options: Again or Good
• Cards marked "Again" are added to a retry pile
• After finishing all cards, retry pile is shuffled and shown again
• Continues in rounds until all cards are marked "Good"
• Ratings don't affect long-term scheduling (local state only)
• No daily limits
• Progress shows current round and remaining cards

About FSRS

FSRS (Free Spaced Repetition Scheduler) is a modern alternative to traditional algorithms like SM-2. It uses machine learning to optimize review intervals based on actual human memory patterns.

Key advantages:

• More accurate predictions than SM-2
• Adapts to individual card difficulty
• Reduces unnecessary reviews
• Research-backed and actively maintained

Learn more: FSRS Documentation

Tips & Best Practices

1. Review Daily - Consistency is key to effective spaced repetition
2. Be Honest - Rate cards based on how well you actually remembered
3. Keep Cards Atomic - One concept per card works best
4. Use Tags - Organize related decks with nested tags like #flashcards/japanese
5. Start Small - Begin with 10-20 cards per deck, add more as you get comfortable
6. Use Cram Mode Wisely - Perfect for exam prep or refreshing a deck before a test
7. Mark Again Liberally - In cram mode, don't hesitate to mark cards "Again" if unsure
8. Metadata Indicators - Click the 📊 SRS badge to show/hide metadata when needed

Commands

• Open flashcards - Opens the Oboeru panel

Support

If you encounter issues or have feature requests, please open an issue on GitHub.

License

This plugin is released under the 0-BSD License.

Credits

• FSRS algorithm by Jarrett Ye
• Built for Obsidian