Privacy Policy

Last updated: October 13, 2026

1. Introduction

Hemistich ("we," "our," or "us") is an AI study companion for students, operated by Creativity Verse Ltd. This Privacy Policy explains how we collect, use, share, and protect your information when you use Hemistich through our website, our web app (including the installable app), or our WhatsApp bot.

By using Hemistich, you agree to the collection and use of information as described in this policy. If you do not agree, please do not use the service.

2. Information We Collect

2.1 Information You Provide

  • Account details: Your name and email address, and a password (stored only as a one-way hash, never in readable form). If you sign in with Google, we receive your verified email address, your name, and a Google account identifier. If you use WhatsApp, we receive your phone number when you message our bot or link it to your account.
  • Profile and study details: What you choose to tell us when you set up your profile, such as whether you are a high school student, undergraduate, postgraduate, graduate, or teacher, and details like your school or university, department, level, and country.
  • Your study material: Text you type or paste, documents and images you upload, and files you save in your vault.
  • Voice: If you use the microphone features, the audio you speak. See section 6 for exactly how this is handled.
  • Things you create: Reminders, timetable entries, academic data you enter for calculations such as GPA, and the results our tools generate for you.
  • Support messages: Anything you send us through the contact form or by email.

2.2 Information Collected Automatically

  • Usage data: Which tools and features you use, when, and how often, including credits used and streak activity.
  • Payment records: The plan or credit pack you bought, the amount, currency, status, and transaction reference. We do not receive or store your full card number.
  • Device and browser information: Browser and device type, screen size, and operating system.
  • Approximate location: We work out your country from your IP address so that we can show and charge prices in your local currency. We do not collect GPS or precise location.
  • Server logs: When you use the service, our servers record technical details such as the time, the page or endpoint requested, the result, and your IP address. We use these to keep the service secure and to fix faults.
  • Pages and screens viewed, and session recordings: On the web app, which screens you visit and a recording of your on-screen interactions. What is and is not recorded is described in section 5.

3. How We Use Your Information

We use the information we collect to:

  • Provide the service: generate summaries, explanations, quizzes, flashcards and other results, run voice features, and send reminders you have set
  • Create and secure your account, and verify your email address
  • Store your vault, saved results, timetable, and other content so you can come back to them
  • Process payments, apply credits and plans, and prevent fraud
  • Show prices in your local currency
  • Send service messages such as verification codes, receipts, and plan expiry notices, and in-app notifications
  • Understand how the product is used, fix errors, and improve it
  • Detect and prevent spam, abuse, and security threats
  • Comply with legal obligations

We do not sell your personal data, and we do not use it for third-party advertising.

4. Third-Party Services

We rely on the following providers to operate Hemistich. Each receives only what it needs to do its job.

  • Google (Vertex AI and Gemini): Generates the AI responses for our tools, and also produces the spoken voice you hear in Talk and Listen (text-to-speech). The text, documents, and transcribed speech you submit are sent to Google to produce a response or to generate speech. Under Google Cloud's terms, content sent through this service is not used to train Google's models without our permission. Subject to Google's Privacy Policy.
  • Google Sign-In: If you choose to sign in with Google, Google tells us that you are who you say you are and shares your verified email and name.
  • Microsoft (Azure AI Speech): Converts your speech into text when you dictate or talk to Hemistich (speech recognition only; the voice that speaks back is Google's). See section 6. Subject to Microsoft's Privacy Statement.
  • Supabase: Hosts our database, which holds your account, profile, saved results, and other records.
  • Amazon Web Services (AWS): Hosts our application servers and stores the files you upload to your vault.
  • Flutterwave: Processes payments. You pay on Flutterwave's secure checkout page, and we do not store your full card details. Subject to Flutterwave's Privacy Policy.
  • Resend: Delivers our emails, such as verification codes and password resets.
  • ipwho.is: A lookup service that receives your IP address so we can work out your country for pricing. It is not given your name or account details.
  • PostHog: Product analytics and session recording on our web app, so we can see which features are used and find broken screens. Subject to PostHog's Privacy Policy. See section 5.
  • Meta (WhatsApp Cloud API): Delivers WhatsApp messages if you use our WhatsApp bot or receive reminders there. Subject to WhatsApp's Privacy Policy.
  • Google Fonts: Our website loads typefaces from Google, which may receive your IP address when it serves them.

5. Product Analytics and Session Recording

On our web app we use PostHog to understand how the product is actually used, so we can fix what is broken and improve what is useful. This applies to the web app only. It is not used on the WhatsApp bot, and it is not included in our native mobile app.

5.1 What we record

  • Pages and screens you open, and the order you move through them.
  • Clicks and taps on buttons, links, and menus.
  • Account events such as signing up, confirming your email, and signing in.
  • Errors and failed requests, so we can find out when the service is broken before you have to tell us.
  • A replay of your on-screen interactions, subject to the exclusions in 5.2.

5.2 What we deliberately do not record

We built specific exclusions into the app because your schoolwork is yours. The following never leaves your device as part of analytics or a session recording:

  • Your questions and our AI's answers. Chat messages and all AI-generated output are excluded at source.
  • What you say aloud in Talk, and the captions of what Hemistich says back. Both the transcript of your speech and the reply shown on screen are excluded.
  • The titles and previews of your saved results. These are taken from your own work, so they are excluded from lists such as Recent results, your decks, and your infographics.
  • Anything you type into a form. All input fields are masked, including your email address, password, and verification codes.
  • The contents of requests to our servers, which is where your questions and answers travel.
  • Your name, email address, and phone number. Analytics identifies your account by its internal ID only. We attach your plan, country, and course details so we can compare how different groups use the product, but not information that names you.
  • Anything in a web link. We strip everything after the page address, so codes carried in links are not recorded.

These exclusions are applied in your browser, which means the excluded content is never transmitted to us or to PostHog, rather than being sent and then hidden. The names of files you upload may appear on screen and are not specifically excluded.

5.3 Why we do this

Our lawful basis is legitimate interests: operating, securing, and improving the service. We have limited what is collected so that this interest does not override your privacy, as described in 5.2.

5.4 Your choice

You can opt out of analytics and session recording at any time by enabling "Do Not Track" in your browser settings, or by contacting us at privacy@hemistich.com and asking us to exclude your account. Opting out does not affect your access to any feature. Most ad and tracker blockers also stop this collection.

6. Voice Features

Hemistich can listen to you and speak back. There are three voice features: Talk (a hands-free spoken conversation with the tutor), Speak (dictating into a tool instead of typing), and Listen (having a result read aloud). They only run when you start them, and your browser will ask for permission before using the microphone.

6.1 How your voice is handled

  • Your audio is sent for transcription. When you speak, the audio is sent through our servers to Microsoft Azure AI Speech, which converts it to text. Our servers do not save your audio, and we do not keep recordings of your voice.
  • Microsoft does not store it either. Microsoft states that for real-time speech recognition, audio is processed in memory and is not retained or stored at rest.
  • The text is processed like anything else you type. In Talk, what you said, transcribed as text, is sent to Google's AI to produce the reply, together with the last few turns of the conversation so it can follow along. The reply text is then sent to Google to be turned into speech.
  • Google produces the voice. The spoken audio is generated by Google's text-to-speech on Vertex AI. Google does not store the text or audio from real-time synthesis, and does not use it to train its models without our permission.
  • We do not save Talk conversations. The transcript and reply are shown on your screen during the session and are not stored on our servers. They disappear when you close Talk.
  • The voice is synthetic. Everything Hemistich says aloud is generated by a computer voice. It is not a recording of a real person.
  • Voice processing happens outside Nigeria. Speech recognition runs on Microsoft Azure (United States), and the voice that speaks back is generated by Google on Vertex AI. See section 12.4.

6.2 What we do keep

We keep a monthly running total of how much voice you have used (characters read aloud, seconds dictated, and seconds of conversation), so we can apply your plan's voice allowance. This is a number, not content. When you use Speak to fill in a tool and then run it, the text you dictated is treated like any other text you submit to that tool, and the result may be saved in your history as described in section 8.

6.3 Your responsibilities

Please do not use the microphone features to record other people without their knowledge and permission. Headphones are recommended for Talk. See our Acceptable Use Policy.

7. Data Storage and Security

Your data is stored on Supabase and AWS infrastructure. We protect it with measures including:

  • Encrypted data transmission (HTTPS/TLS) between your device and our servers
  • Passwords stored only as salted one-way hashes
  • Your sign-in session is kept using a secure, HTTP-only cookie that scripts running on a page cannot read
  • Access controls, authentication, and rate limits on our servers and administrative tools
  • Uploaded files are downloaded through time-limited links rather than public addresses
  • Temporary files are automatically deleted after 24 hours

No online service can be perfectly secure. If you believe your account has been compromised, change your password and contact us straight away.

8. Data Retention

  • Account data: Kept for as long as you have an account. When you delete your account it is closed immediately, and your data is kept for a 30-day grace period so an accidental deletion can be undone, then erased permanently. See our Data Deletion page.
  • Saved results: The results our tools generate for you are saved to your account so you can reopen them. They are kept until your account is deleted. There is not yet a button to delete an individual saved result, so if you want one removed sooner, email privacy@hemistich.com.
  • Chat conversations: Your chat history is stored on your own device, in your browser, and is not kept on our servers. Each message is sent to our servers and to Google's AI so that it can be answered. Clearing your browser data removes the history.
  • Vault files: Kept until you delete them or your account is erased.
  • Voice: Audio is not stored. Usage totals are kept with your account. See section 6.
  • AI response cache: To avoid repeating identical requests, we keep a short-lived cache of AI responses for up to 72 hours. It can include the beginning of the text that was submitted.
  • Temporary files: Deleted automatically after 24 hours.
  • Server logs: Kept for security and troubleshooting.
  • Session recordings and analytics events: Held by PostHog for a limited retention period set in our PostHog account, then deleted automatically. We do not keep separate copies.
  • Support messages: Kept so that we can help you and handle follow-ups. They can remain after an account is deleted, with the link to your account removed.
  • Payment records: Our copy is removed when your account is erased. Flutterwave keeps its own records under its own legal obligations.

9. Your Rights

You have the right to:

  • Access: Request a copy of your personal data.
  • Deletion: Request deletion of all your data. You can delete your account yourself in the app under Profile, or see our Data Deletion page for other ways.
  • Correction: Request correction of inaccurate data. Most of your profile can be edited in the app.
  • Portability: Request your data in a portable format.
  • Objection: Object to certain processing of your data, including analytics (see 5.4).

10. Children's Privacy

Hemistich is designed for students aged 16 and over, from senior secondary school through university and beyond. We do not knowingly collect information from children under 16. If you believe a child under 16 has given us personal information, please contact us immediately and we will delete it.

11. Changes to This Policy

We may update this Privacy Policy from time to time. When we make a material change we will tell you in the app or by email, and we will change the "Last updated" date above. Your continued use of the service after a change means you accept the updated policy.

12. Legal Basis & Compliance (NDPA 2023 & GDPR)

Hemistich is operated from Nigeria and serves students in Nigeria and, increasingly, worldwide. We aim to comply with the Nigeria Data Protection Act (NDPA) 2023 and to follow the core principles of the EU General Data Protection Regulation (GDPR), regardless of where you are located.

12.1 Principles we follow

  • We process personal data lawfully, fairly, and transparently.
  • We collect only what we need for the purposes described in this policy (data minimization).
  • We keep data only as long as necessary, then delete or anonymize it.
  • We apply reasonable technical and organizational measures to keep data secure.

12.2 Lawful bases for processing

  • Performance of a contract: to deliver the features you ask for, including voice features and payments.
  • Consent: where required, for example for optional communications, and when you choose to allow microphone access. You can withdraw consent at any time, for example by turning off microphone permission in your browser.
  • Legitimate interests: to operate, secure, and improve the service, balanced against your rights.
  • Legal obligation: where the law requires us to process or retain data.

12.3 Your rights

Subject to applicable law, you may request access to, correction of, deletion of, or a portable copy of your data, and you may object to or restrict certain processing. To exercise any right, contact us (section 13) or use our Data Deletion page. You also have the right to lodge a complaint with the Nigeria Data Protection Commission (NDPC) or your local data-protection authority.

12.4 International transfers

Our service providers (for example Google, Microsoft, Supabase, AWS, PostHog, Resend, Flutterwave, and Meta) may process data on servers outside your country, including in the United States. Where data is transferred across borders, we rely on the providers' safeguards and applicable legal mechanisms to protect it.

13. Contact Us

If you have questions about this Privacy Policy or your data, contact us:

  • Email: privacy@hemistich.com
  • WhatsApp: Message our bot and type /help