For people who already know what FSRS is
FSRS flashcards, with nothing to configure
Rayaad has one scheduler and no scheduling settings. FSRS-6 viats-fsrs@5.4.1, 95% target retention, one-minute learning and relearning steps, fuzz off — published rather than described. These are its real intervals.
Generated during this site's build by the same scheduler the app runs, from the same parameter file. The full configuration table.
Beyond the checkbox
Four questions worth asking any tool that says it supports FSRS
Is it on by default, or a setting?
An app where FSRS exists but is opt-in is an app most of whose users are not using it. Rayaad has no other scheduler — there is nothing to switch on and nothing to switch off.
Are the parameters published?
Rayaad's are: FSRS-6, 95% target retention, one-minute learning and relearning steps, fuzz off, and the full weight vector in a configuration file shared by the client and the server.
Does the server agree with the device?
Rayaad recomputes a card by replaying its entire review history on the server through the same scheduler and the same parameters, rather than trusting whichever device synced last. That is what makes three devices agree.
Is the review history append-only?
Every answer is stored permanently with the scheduler version that produced it, so a schedule stays explainable after a parameter change rather than becoming unreconstructable.
The trade Rayaad makes, stated plainly
The strongest argument for a configurable implementation is per-user parameter optimisation: tools expose the weights and expect you to re-fit them against your own history. Rayaad ships one tuned parameter set and publishes it.
What that buys is an empty scheduling screen. No weights, no retention slider, no learning-step editor, no monthly optimisation to remember — and no chance of quietly running a worse schedule because you never got round to it. The tuning is done before you arrive, and the exact parameters are on the FSRS page if you want to read them.
Two answers, not four
Rayaad's review surface has exactly two grades. FSRS handles that correctly — it is a supported way to study, not a degraded one — and removing the middle two removes a judgement call from every card. The judgement was noisy anyway: "hard but I got there" is the grade people are least consistent about, and inconsistent grades make the model worse, not better.
Why fuzz is off
Interval fuzz spreads due dates so a batch of cards created together does not all come back on the same day. Rayaad turns it off, which costs exactly that and buys determinism: an identical history always produces an identical schedule, so the server can recompute a card's state by replaying its full history and get the same answer your device did. That replay is what keeps a phone, a browser and an extension from drifting apart.
More: how FSRS works ·what else to look for in a tool ·moving from Anki
FSRS implementation questions
Which version of FSRS does Rayaad use?
FSRS-6, through the ts-fsrs@5.4.1 implementation. The full parameter set, the target retention, the learning steps and the fuzz setting are published on the FSRS page, and the version tag fsrs-6-ts-fsrs-5.4.1-rayaad-v2 is stored with every review that is recorded.
Can I optimise the parameters against my own history?
No. Rayaad ships one tuned parameter set for everyone and has no settings screen for it. That is a deliberate trade: per-user optimisation genuinely fits a large mature collection better, and it also gives you a number to worry about before you have made a card. If you want that control, Anki is built for it.
Does binary grading weaken FSRS?
No. FSRS is designed to work correctly from Again and Good alone, and Anki’s own documentation supports studying that way. What you lose is the ability to record "hard but I got there"; what you gain is not making that judgement several hundred times a week.
Is fuzz disabled? Does that matter?
It is disabled, and it matters in one useful way: two identical review histories produce identical schedules, which is what lets the server recompute a card by replaying its whole history and get the same answer as your device. The cost is that a large batch of cards created together can come due together.
Can I import an existing FSRS review history?
No. Rayaad can import cards from a CSV or a pasted list, but not another tool’s review history — so a card imported from elsewhere starts fresh. For a large mature collection that history is worth a great deal, and it is the strongest argument for staying where you are.
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