Privacy Policy

LinguaDrill AI is a Telegram bot for learning languages. This policy explains what data we process and why.

Data we collect

• your Telegram user and chat IDs, username and display name, app language and, when you open a referral link, the bounded first-touch /start code;
• your learning profile: native and target languages, urgent goal, level, chosen topics, time zone, pace, reminder settings (opt-in, mode, practice time, quiet hours and snooze), and tone;
• the text you voluntarily write in the “About me” section, if you fill it in;
• your message and answer text, generated phrases and materials, and learning history (scores, mistakes, reviews and progress);
• structured usage events: start source, completed flow steps, sessions, reminder interactions and purchase actions. Answer text is not duplicated in product analytics;
• internal learning-action and AI-operation records: action kind, source and status; provider, model, operation, measured duration, token counts (when the provider returns them), estimated cost (only from a provider-reported amount or explicitly configured rates), and success or error code. These records contain no prompt or answer text;
• reminder delivery logs: generated text, template, time, delivery status or failure reason;
• premium status and the Telegram Stars payment record: transaction identifiers, plan, currency, amount and access duration. We do not receive payment-card details.

Why we use it

To run the learning experience: generating and grading tasks, building your personal plan and lessons, spaced repetition, reminders and premium features; to enforce the daily learning-action cap, deliver reminders, account for service reliability and cost, and administer purchases. Structured events let us measure which steps actually help learners start, return and retain the material.

Who we share it with

• AI provider: answer and task text, language pair, level, goal, lesson topic and (if filled in) your “About me” note are sent to generate and grade material. An AI-generated reminder may also include your first name, tone, task count and missed-day count;
• OpenAI: the phrase text — to synthesize pronunciation audio (premium);
• Telegram: message delivery and payment processing (Telegram Stars). We receive the transaction identifier and parameters, but not payment-instrument details;
• Cloudflare: HTTPS traffic delivery and protection through Cloudflare Tunnel; Cloudflare processes request data and network metadata as part of that delivery;
• Sentry: scrubbed technical errors and performance data for monitoring. Before sending, the application removes user data, request bodies, cookies, headers and query strings, stack-trace locals, and free-form exception, log and breadcrumb messages and span descriptions;
• Microsoft OneDrive: encrypted off-site database backups. The dump is encrypted on the server with age before upload; OneDrive receives ciphertext, while the private decryption key is not placed on the server or in OneDrive.

Product events and AI/action logs are analysed internally and are not sent to advertising platforms. We do not sell your data or use it for advertising.

AI-generated content

Phrases, lessons, study plans and PDF worksheets are produced by AI. We check the material automatically before it reaches you, but mistakes are still possible — it is not a substitute for a teacher or a dictionary.

Retention

Your profile, learning material, actions and reminder logs are kept until you use /wipe or contact us. Message previews are automatically deleted after 30 days, AI-operation records after 90 days, webhook deduplication and expired conversation states after 7 days, and product events after 400 days. The payment record, Premium entitlement and minimal account link remain after /wipe so paid access and the transaction record are not lost. Local and encrypted off-site backups follow the configured rotation or manual-deletion policy and can therefore outlive a live-database record. Scrubbed Sentry technical events and Cloudflare technical data follow the relevant processor settings.

Your rights

You can snooze reminders for 6 hours with /later, disable them with /stop, or configure them in settings. /wipe erases profiles, phrases, answers, plans, progress, personalisation, our message and reminder logs, product events, and AI/quota records. It does not erase messages in the Telegram chat, minimal account/channel identifiers, or the paid-purchase record. Erasure first applies to the live database; old encrypted copies disappear through backup rotation or manual deletion. /wipe cannot selectively erase scrubbed Sentry technical events or Cloudflare logs. Contact us (below) to request access, correction, portability, restriction, or broader erasure; some records may be retained where law requires it.

Children

The bot is not intended for children under 13.

Contact

Message @LinguaDrill_Bot on Telegram or email [email protected].