LoopKit

Production-ready flashcard engine with SM-2 spaced repetition for NestJS and React

LoopKit is a production-ready flashcard engine implementing the SM-2 spaced repetition algorithm. It handles deck hierarchies, note types, card scheduling, and content rendering. It ships as two packages that work together.

Packages

Package	Description
`@hfu.digital/loopkit-nestjs`	Backend NestJS module with pluggable storage, SRS algorithms, and content pipeline
`@hfu.digital/loopkit-react`	Frontend library with headless hooks and pre-styled study components

Key Features

SM-2 Spaced Repetition — Battle-tested algorithm with configurable parameters
Pluggable Storage — Bring your own database via the storage adapter pattern (Prisma adapter included)
Algorithm Pluggability — Swap SM-2 for any custom algorithm via the SRSAlgorithm interface
Headless-First Frontend — Hooks for full control, plus optional pre-styled components
Content Pipeline — Template interpolation with optional Markdown, KaTeX, code-highlighting, and HTML-sanitization transforms
Import / Export — CSV and JSON import/export for deck portability
Statistics — Pure functions for retention rate, study streak, review forecast, and more
Undo Support — Undo the last review during a study session
Deck Hierarchy — Nested decks with inherited configuration

Versioning

CalVer (yyyy.mm.version). Pin exact versions in package.json; range operators (^, ~) do not behave like semver across month boundaries. See the docs root for details.