Introduction

ts-fsrs is a TypeScript toolkit for building spaced repetition systems with FSRS. Its declarative API creates a reusable scheduler definition from a model, a chronology, and optional middleware.

Building blocks

A model is the FSRS algorithm and its parameters. FSRS7Model is the current one; FSRS-3 through FSRS-6 stay available for review histories built on them.

A chronology decides how time is represented. dateChrono works with Date, numericChrono with numbers in days, and temporalInstantChrono with Temporal.Instant.

Middleware adds scheduling policy, such as schedulerLearningStepsMiddleware, schedulerFuzzingMiddleware, schedulerMaximumIntervalMiddleware, or schedulerLeechMiddleware. Add them with .use(...) before creating the scheduler.

defineScheduler combines these into a definition. Calling .create() validates the configuration and returns an independent scheduler, so one definition can back several of them.

Integrate ts-fsrs into my TypeScript application.

Read the documentation index https://open-spaced-repetition.github.io/ts-fsrs/llms.txt and quick start https://open-spaced-repetition.github.io/ts-fsrs/guide/quick-start.md. First check whether the project already uses ts-fsrs. For a v5 → v6 or FSRS-6 → FSRS-7 upgrade, read the migration guide https://open-spaced-repetition.github.io/ts-fsrs/guide/migration.md and follow its implementation and verification steps, keeping existing cards and logs without rescheduling their next review during migration. The installation and new-card example below apply only to a new integration.
Install the `ts-fsrs` package.
Create an FSRS-7 scheduler with `defineScheduler`, `FSRS7Model`, and `dateChrono`.
Create a new card and review it with `Rating.Good`.
Keep the implementation minimal and use the current ts-fsrs public API.

Head to Quick start to install the package and run a scheduler in the browser.

#Introduction

#Building blocks

Introduction

Building blocks