Privacy Policy

Last updated: March 2026

Overview

Cue is a spaced-repetition learning platform for students and teachers at learningcues.org. We collect the minimum data needed to make the app work — your study history, account info, and classroom relationships. We do not sell your data, run ads, or build behavioral profiles. This document explains exactly what we collect, why, and who can see it.

What We Collect

Account Data

When you create an account, we store:

Email address — used for login and account recovery only.
Username — chosen by you, shown to teachers and classmates in multiplayer sessions.
Password — hashed by Supabase Auth using bcrypt. We never see or store your plaintext password.
Role — whether you are a student or teacher.
Language preference — the interface language you select.
Avatar — an optional display image you choose.

Learning and Study Data

This is the core of what Cue does. To schedule cards and show you your progress, we store:

Card review history — each time you rate a card (1 = Again, 2 = Hard, 3 = Good, 4 = Easy), we record the card ID, rating, and how long you spent on it.
FSRS scheduling state per card — stability, difficulty, retrievability estimate, due date, number of repetitions, and number of lapses. This is what drives your personalized review schedule.
Study streaks and session data — number of cards studied per session, session start/end times, cumulative study statistics.
Flashcards you create — the front and back content of any personal decks you build.
Card reports — if you flag a card as incorrectly graded, we store your user ID, the card ID, your typed answer, and a similarity score. This is used to improve grading accuracy.

AI Tutor Data

When you use the AI tutor chat, your messages are sent to xAI's Grok-3 model to generate a response. We do not store your chat messages in our database. The conversation exists only for the duration of your session. What we do store is the FSRS scheduling context (which cards are due, their difficulty) that the AI uses to personalize its responses — but not the conversation itself.

CueBot Answer Grading Data

When you type a free-response answer during a study session, Cue sends that answer to CueBot — an AI grader — along with the correct answer and the question. CueBot returns a rating (1–4) and a one-sentence explanation. We store the following in our database for up to 90 days:

Your typed answer and the correct answer for the card.
The question text (card front).
CueBot's rating and confidence score.
The rating you ultimately chose.

This data is used solely to evaluate and retrain CueBot to improve its grading accuracy. It is never sold, shared with third parties, or used for advertising. You may request deletion of your grading logs at any time by emailing privacy@learningcues.org.

Classroom Data

For teacher accounts, we store the classrooms you create and their 8-character join codes. For students, we store which classrooms you have joined. Assignments created by teachers — including due dates and assigned card sets — are stored and associated with both the classroom and individual students.

Technical and Error Data

Anonymous performance metrics — Vercel Analytics collects page load times and aggregate usage data. This contains no personally identifiable information.
Error reports — Sentry captures stack traces when something breaks. Our audit log policy prohibits logging prompt content or PII. Sentry receives error context (what went wrong, where in the code) but not your flashcard content or chat messages.
IP addresses for rate limiting — to prevent abuse, we track request counts per IP address in server memory. These are not written to the database and are cleared when the server restarts.

What We Do Not Collect

This is the section most people actually want. Here is what Cue does not do:

No location tracking. We do not collect GPS coordinates, city-level location, or any geolocation data.
No microphone or camera access. Cue never requests access to your device's microphone or camera.
No behavioral advertising profiles. We do not build profiles of your interests, habits, or behavior for advertising purposes. There are no ads on Cue.
No sale of data. We do not sell, rent, or trade your personal information to any third party.
AI chat messages are not stored. What you type to the AI tutor is sent to xAI for a response and then discarded. It is not in our database.
No tracking pixels or third-party ad scripts. We do not embed Facebook Pixel, Google Ads tags, or any third-party marketing trackers on Cue pages.
No cross-site tracking. We do not follow you around the web after you leave Cue.
No persistent IP logging. IP addresses used for rate limiting are held in memory only and are never written to our database.

How We Use Your Data

Running the FSRS scheduling algorithm. Your review history and card state are used exclusively to calculate when to show you each card next, targeting an 85% retention rate.
Showing you your progress. Study statistics, streaks, and mastery percentages are computed from your stored review data and displayed to you.
Enabling classroom features. Teachers can see the study progress of students in their classrooms. See the section below for details.
Personalizing AI tutor responses. The AI tutor receives your current card difficulty and scheduling state so it can focus on concepts you are finding hard. It does not receive your full account history or personal information.
Multiplayer sessions. Your username is visible to other players during Cue game sessions. Session state (join codes, scores) is stored temporarily and cleared after the session ends.
Improving grading accuracy. Flagged card reports are reviewed to improve the similarity scoring used to grade free-response answers.
Security and abuse prevention. Rate limiting and error monitoring help us keep the service stable and secure.

Who Can See Your Data

You

You can see all of your own data: your profile, study statistics, card history, and deck contents.

Teachers

If you are a student and you join a teacher's classroom, that teacher can see:

Your username and profile.
Your study progress on cards assigned within that classroom — including how many cards you have studied and your mastery level by chapter.
Assignment completion status.

Teachers cannot see your chat messages with the AI tutor, the content of personal decks you created outside their classroom, or your activity on other platforms.

Other Students

During multiplayer Cue game sessions, other players in the same session can see your username and your score in real time. No other student data is shared between students.

Cue Staff

We can access data in our database for purposes of operating, debugging, and supporting the service. We do not routinely read user flashcard content or study data, and we do not read AI chat conversations (which are not stored).

Third-Party Services

We use a small, deliberate set of third-party services. Here is what each one receives:

Supabase — our database and authentication provider. Supabase stores your account data, learning data, and classroom data on our behalf, secured with Row Level Security and TLS encryption in transit. Supabase is SOC 2 Type II certified.
xAI (Grok-3) — the AI model that powers the tutor chat and AI-assisted flashcard generation features. xAI receives the text of your chat messages and any card context included in the prompt. Chat messages are not stored by us after the response is returned. Refer to xAI's privacy policy for how they handle inference requests.
Vercel — our hosting and deployment platform. Vercel serves the app and collects anonymous performance metrics (page load times, error rates) with no PII attached.
Sentry — our error monitoring service. Sentry receives stack traces and technical context when errors occur. Our logging policy prohibits including flashcard content, chat messages, or personal identifiers in error reports.

We do not use any advertising networks, data brokers, or analytics services beyond those listed above.

Data Retention

We keep your data for as long as your account is active. When you delete your account:

Your profile, email, and username are deleted immediately from our primary database.
Your card review history, FSRS state, and study statistics are deleted.
Flashcards you created in personal decks are deleted.
Your classroom memberships and assignment records are removed.
Card reports you submitted are anonymized — the link between the report and your user ID is severed.

Sentry error logs that captured an error involving your session may be retained for up to 90 days before automatic deletion, consistent with Sentry's data retention policy. These logs contain technical error context only, not your personal content.

AI chat messages are never stored by Cue and therefore have nothing to delete.

Your Rights

You have the following rights with respect to your data:

Access. You can view your profile, study statistics, and card history from within the app at any time.
Correction. You can update your username, email, language preference, and avatar in Settings. If something looks wrong that you cannot fix yourself, contact us.
Deletion. You can delete your account in Settings. This removes your data as described in the Data Retention section above.
Export. You can request a copy of your study data by emailing privacy@learningcues.org. We will send it in a machine-readable format within 30 days.
Objection. If you believe we are using your data in a way that is not described here, contact us and we will investigate.

Students in the EU or UK have additional rights under GDPR and UK GDPR, including the right to restriction of processing and data portability. To exercise any of these rights, email privacy@learningcues.org.

Minimum Age and Schools

Cue requires users to be at least 13 years old. We do not knowingly allow children under 13 to create accounts. If you believe a child under 13 has created an account, contact us at privacy@learningcues.org and we will delete it.

COPPA (the Children's Online Privacy Protection Act) applies to services that knowingly target or collect data from children under 13. Cue does not target children under 13 and is not subject to COPPA.

Schools and districts that use Cue under a formal agreement may have additional protections under FERPA (Family Educational Rights and Privacy Act). When a school deploys Cue for classroom use, Cue acts as a school official under FERPA — meaning student data within that context is governed by the district's FERPA obligations and our data processing agreement. Contact us at privacy@learningcues.org to discuss a district-level agreement.

Contact

Questions about this policy, data requests, or concerns about how your data is handled — email us at privacy@learningcues.org. We aim to respond within 5 business days.

If we make material changes to this policy, we will update the date at the top of this page and, for significant changes, notify users by email.