Privacy Policy
This policy explains how Premsan Inc (“Premsan”, “we”, “us”) handles personal data in teechar — this website, the web app, the API, the pages it serves to the people a teacher shares them with, and the teechar apps for iPhone, iPad and Android. Premsan is the controller of the data about you as a teacher who uses teechar. The data a teacher keeps about their students is the teacher’s: for it, the teacher is the controller and Premsan processes it on the teacher’s behalf, as section 3 explains.
1. What we collect
- Your account. Your name, your email address, and either a password — stored only as a hash — or, when you sign in with Apple or Google, your identifier there and the sign-in tokens the provider gives us. Each session records the IP address and the browser or device it was opened from, and when it expires. We also record the date on which you accepted the Terms, and which version, and the day you last used the account.
- Your book. Your time zone and currency; your students — each one’s name, and the email address, time zone, level, goals and notes you give them; your cohorts and courses; your lessons, with their times, join links, who attended, your notes and homework; packages of lessons; and the payments you record, with their amounts, methods and references and the receipts and screenshots you attach.
- Your materials, courses and videos. Each material’s description, its document and the pages it renders to; each course’s outline and sections; each video you upload, its length, and the captions written from its sound.
- Pages you share. For each student’s page or course page you open, the link’s code, and in our shared database only a one-way hash of it, so that the address finds your account and nothing else. A visit to a page is answered from your account; its request is counted against that page’s limit and appears in the server logs like any other request.
- Google Calendar, if you connect it. The permission Google gives us — a token, kept in your account’s storage — and the ids of the events we put on the calendar teechar makes in your Google account. We send Google each coming lesson’s title, time and join link, and, as its guests, the name and email address of each student on it whose email you keep; Google sends them the invitation and its updates, never shows one guest another, and makes the Meet link.
- Your conversation with the assistant. The messages you send it, the notes you dictate — the recording is sent to the model to be written down, and only the words are kept — the photos you attach, made smaller to the size the model reads, the spreadsheets you attach, your time zone so it knows what today is, and its replies and proposals, with whether you approved or discarded each. A material’s own conversation is kept the same way, with the material.
- What the assistant remembers. The facts you tell the assistant about yourself, your work and how you want it to work, kept as memories so every later conversation starts with their titles and descriptions: each one’s kind, title, description and details, whether you or the assistant wrote it last, and when. You see and delete them in Settings, and correct one by telling the assistant; their titles and descriptions go to the model with every message you send it, and a memory’s details when the assistant opens it.
- The plan. When your free use began, how many messages you have sent the assistant since, how much storage your files take, and the state of your subscription. On the web, payment is taken by Stripe: it receives your email address and your account id, and your card details go to Stripe and never reach us. We keep the subscription’s id, your customer id at Stripe, when the current period ends and whether it renews. In the app, payment is taken by the App Store or Google Play; we receive the transaction’s id, confirm it with Apple or Google, and record it against your account.
- Help. When you write to us from Help, we keep your messages, the pictures you attach, and details that help us answer: whether you wrote from the web or the app, your browser or app version and operating system, your language, the screen you were on, the size of your window or screen, your time zone, and your most recent failed requests. They are kept with your account until you delete it. Our team reads them in our own support tool, where, if you have allowed the assistant, teechar’s model may draft a reply that a team member reviews before sending.
- Usage. The number of requests you made to the assistant in the current hour, kept in your own account’s storage for the hourly limit. Server logs hold request metadata, including IP addresses, error reports, and the size and cost of each of the assistant’s runs, for a short time, for security, debugging and our accounting.
- The bot check. Cloudflare Turnstile runs on our sign-in and sign-up pages, and in the app’s sign-in screen, to tell a person from a script.
- Nothing else. There is no advertising, no analytics service, no tracking across sites or apps, no advertising identifier, and no data broker.
How far you get is recorded as you go: the day you sign up and each day you come back, whether on the web or the phone app and in which language; when you allow the assistant; when each request to it ends, which of its agents answered and whether it worked; when you reach what is free; when you pay, and through which store; when a record is added, and whether it is a student, a course, a cohort, lessons, a charge, a payment or a material; when you approve a change the assistant proposed; when you upload a video; and when you connect your calendar. Each record carries a random number kept in your account’s storage, never your name, your address or anything you wrote or made, and we read the records only as counts, to see where people stop. Deleting your account deletes the number; the records stay, with nothing in them that leads back to you.
2. What we do with it
We use personal data to run teechar: to keep your book, your materials and your videos and show them to you; to show what you share to the people you share it with; to put your lessons on your calendar when you connect it; to let the assistant read what you send it, propose changes and write materials; to write captions and dictated notes; to sign you in, send you the emails the account needs — a verification link and a password reset — take payment and keep your subscription’s state; to keep the service running and prevent abuse; to answer you when you write to us; and to meet legal obligations. We do not use what you put in teechar to train models, we do not sell personal data, and we do not share it for advertising.
3. Why we are allowed to
Where the GDPR or a law like it applies, we rely on these bases for the data about you:
- Performing our contract with you — your account, your book, your materials and videos, your conversations, the pages you share, the calendar you connect, and the subscription.
- Our legitimate interests — keeping teechar running, finding failures, and stopping abuse and automated sign-ups. We limit this to the usage counts, the server logs and the bot check. Seeing where people stop, from the record of how far you get, rests on it too.
- A legal obligation — payment records and anything else the law requires us to keep.
The data about your students — their names, email addresses and what you record about them and their lessons and payments, and the people seen or heard in your videos — is yours to decide about: you choose what to keep and why, you tell them, and you answer their requests. We process it only to run teechar for you, on your instructions in these terms and in what you do in the app, keep it confidential, protect it as this policy describes, use only the providers named in section 4, help you answer a request from one of them, and delete it when you delete it or your account. A student who writes to us is pointed to their teacher. Some of your students may be children: where the law asks for a parent’s consent to keep a child’s data or share a page with them, getting it is yours to do.
4. Who else processes it
teechar runs on Cloudflare: the servers, the storage that holds your account, your book, your materials, your videos, your conversation, your photos and your files, the resizing of photos, the document compiler that renders your materials, the models that write captions and dictated notes from sound, the email we send, and the bot check are all Cloudflare services on our own account. The models that read your messages, photos and spreadsheets, propose changes and write your materials run at Anthropic, reached through Cloudflare, and teechar sends any model nothing until you allow that, on the web or in the app, when it asks before your first message, photo or dictated note; you can turn it off in Settings (under Account in the phone app), and teechar then asks again before the next one. Anthropic does not train a model on what it is sent and deletes it under its own retention policy; when Anthropic cannot answer, the same request goes to OpenRouter, which does not train a model on it and passes it only to a model host that keeps nothing once it has answered, or else to Cloudflare Workers AI, and nothing the assistant reads goes to any other AI provider. What it sends is your messages and dictated notes, the photos and spreadsheets you attach, whatever it reads from your book to answer you, and, for captions, the sound of the videos you upload. Some email may be sent through Resend instead.
When you connect it, Google keeps the calendar teechar makes in your Google account, with your coming lessons on it, invites the students on each lesson whose email you keep, and makes their Meet links; teechar can reach only that calendar, not the rest of yours. teechar’s use and transfer of information received from Google APIs adheres to the Google API Services User Data Policy, including the Limited Use requirements: we use it only to keep your lessons on that calendar, never for advertising, never to train models, and a person reads it only with your permission, for security, or where the law requires.
Stripe takes payment on the web and keeps the card; Apple and Google take payment in the app, and each tells us when a subscription you bought there renews, is cancelled or is refunded. When the app opens, it asks Expo’s update service whether a newer version of our code is available; that request carries the operating system, our project id and a random identifier the app created for itself — no account and no device identifier — and Expo sees the IP address it came from. These providers process data only on our instruction and are each bound to protect it at least as well as this policy does; we give notice here before a new one starts.
Signing in with Apple or Google sends us your identifier and email from that provider. Each acts on its own behalf there, not as our processor, and its handling of your account with it is governed by its own privacy policy; if you hide your email from us with Apple, mail reaches you through Apple’s relay. The App Store and Google Play are the sellers of what you buy inside the app, and their handling of your payment is governed by theirs.
When the assistant searches the web, the words it searches for, which it writes from your conversation, go through Cloudflare to Linkup, or to Ceramic.ai when Linkup cannot answer; neither keeps them once it has answered. When the assistant reads a web page, our servers fetch it from its site in a request that names Teechar, and the site sees nothing else of yours.
5. Where it is
Your data is processed on Cloudflare’s network, which spans the world, and stored on it under Cloudflare’s own commitments for international transfers. A request that goes to Anthropic leaves that network for Anthropic’s servers, and one that goes to OpenRouter for OpenRouter’s servers and its model host’s, each under that company’s own commitments for international transfers. Premsan is in Japan, a country the European Commission recognises as protecting personal data adequately.
6. On the phone
The app keeps on your device a sign-in token, the language and appearance you chose, and the random identifier its update check uses; your book stays in your account and is fetched when you open it. It asks for the camera only when you choose to photograph a receipt or a class list for the assistant, and for the microphone only when you choose to dictate a note; you can turn either off in the operating system’s settings. A dictated note is recorded on the phone, sent to be written down, and deleted from the phone once it has been. It reads a photo only when you pick one, to send the assistant or to attach to a payment or a Help message, through the system’s photo picker, which needs no permission, and it makes a photo smaller before sending it. It reads a file only when you pick one — a video to upload, a spreadsheet or a receipt — through the system’s file picker, which needs no permission either. It asks for no other permission, carries no advertising or analytics library, and purchases go through the store’s own sheet.
7. Cookies
On the web we set the cookies the product cannot work without: the one that keeps you signed in, and the ones Cloudflare Turnstile sets to tell a person from a bot on the sign-in and sign-up pages. The pages you share set none. This website and the web app keep your theme and language in your browser’s own storage. That is the whole list: no advertising cookies, no cross-site trackers, and no analytics that follows you between sites. Clearing them signs you out.
8. How long we keep it, and deleting it
We keep your account, your book, your materials and your videos for as long as the account exists, whether or not you subscribe. Deleting a record, a material or a video removes it, closing a page’s link stops it at once, and clearing your conversation with the assistant deletes its messages, its proposals and the photos and files you attached to them. Disconnecting Google Calendar withdraws teechar’s permission and forgets the events; the events already on the calendar stay there until you remove them.
If your account goes unused for a month and has never had a subscription, we delete it and everything in it, as if you had deleted it yourself. One that has had a subscription becomes dormant instead: nothing it does on a schedule runs, and using it again restores it as it was; if it is still unused twelve months after it was last used, we delete it the same way. An account with an active subscription is never made dormant or deleted for going unused.
You can delete your account at any time: on the web under Account in Settings, or in the app under Account. We then erase everything we hold for you — your book and everything in it, your materials, courses, videos and captions, your conversations, photos and files, the pages you shared, Help messages, usage counts and the subscription’s state — withdraw the calendar permission, and then delete the account itself, and a subscription bought on the web ends. This cannot be undone, so download what you want to keep first.
These records remain after the account is deleted:
- A purchase made in the app. We keep the store’s transaction id, the date and the id of the account it was bought for, so that a store sending the same receipt again cannot credit it to another account, and because the law requires payment records to be kept. The account it names no longer exists.
- Payment providers’ records. Stripe, Apple and Google keep their own records of a payment under their own legal obligations.
- Backups. Cloudflare keeps restorable copies of our databases for up to 30 days so that they can be restored after a failure; they then expire.
- Server logs. They are deleted automatically after a short time.
9. Your rights
You can read, change and delete every record, download every video and material, close every page, clear your conversations and delete your account in the web app or the phone app, without asking us. Depending on where you live, you may also have the right to a copy of the rest of what we hold about you, to restrict how we process it, to object to processing we base on legitimate interests, and to move your data elsewhere. Write to support@teechar.com and we will answer within one month. A student’s request about the data their teacher keeps goes to the teacher, and we help the teacher answer it.
If you live in California or another U.S. state with a similar law, you have the right to know what personal data we hold about you, to delete it, and to correct it; the controls above do that. We do not sell or share personal data as those laws define the words, so there is no opt-out to offer, and exercising a right gets you the same service on the same terms.
If you think we have handled your personal data wrongly, you can complain to a data protection authority — in the EEA or the United Kingdom, the one where you live or work or where the problem happened; in Japan, the Personal Information Protection Commission. You may contact us first, but you do not have to.
10. Security
Every connection is encrypted in transit. Passwords are stored as hashes. Each account’s book, files, conversations and calendar permission are kept in their own isolated storage and are deleted with the account, apart from the records listed in section 8. A page’s address is a long random code that only you can open, renew or close, and our shared database keeps only its hash. The app keeps its sign-in token in the operating system’s secure store. Credentials never enter our server logs. If you find a security weakness, write to security@teechar.com and allow us time to fix it before you disclose it to anyone else.
11. Children
teechar accounts are not for anyone under 16, and we do not knowingly hold a child’s account. If you think a child has an account, tell us and we will delete it. A teacher’s students may be children; their data is the teacher’s, as section 3 explains.
12. Changes
We may update this policy. When a change matters we will say so in the web app or the phone app, or by email. The date at the top is the version that stands.
13. Contact
Premsan Inc — 530-0001, 12-12, Osaka Ekimae Dai-2 Bldg., 1-2-2 Umeda, Kita-ku, Osaka-shi, Osaka, Japan. support@teechar.com.