Free Spaced Repetition Scheduler (v5)

Written by Derek Sivers in September 2024. I'm happy to discuss it, so email me if you want, especially if you find errors. Take it and adapt it for you or others to use, since this implementation is meant for my own personal use, suited for just me. I gave my parts the "unlicense" so you don't need to credit me.

cd db/
createuser srs
createdb -O srs srs
psql -U srs -d srs -f tables.sql
sh reload-functions.sh

Every API function returns "ok" boolean and "js" JSON. If "ok" is false, "js" will be {"error": "explanation"}

select add('pets', 'My first dog?', 'Charlie');
select add('pets', 'My last dog?', 'Snoopy');
select add('places', 'Capital of Azerbaijan?', 'Bakoo');

select edit(3, 'places', 'Capital of Azerbaijan?', 'Baku');

select decks();

select next('pets');
select review(1, 'hard');

select next('pets');
select review(2, 'easy');

Front and Back content is interpreted as HTML, so put media files into public/ directory then use HTML to present them:

select add('places',
  'How to say this place? <img src="paris.jpg">',
  'Paris <audio src="paris.mp3"></audio>');

The Free Spaced Repetition Scheduler is in functions.sql, copied from algorithm.ts and basic_scheduler.ts

Thank you to the wonderful people who work so hard on this.

I don't need fuzzing, undo/rollback, log analysis optimization, or differentiation between basic versus long term scheduling, so I didn't add those. I've used Anki every day for 15+ years, so I know what I do and don't need. Simplification was my mission.

gem install pg
gem install sinatra
ruby web.rb

HTML in the views/ directory.

/ webroot in public/ is for cards' media files.

1. media play button smarter
2. test against FSRS to make sure I got scheduler right