Privacy policy

The calculators on this site run entirely in your browser. Figures you type into them — your rent, your wage bill, your prices — are never sent to us. We have no copy, no account for you, and no way to read them.

That is a consequence of how they are built rather than a promise we ask you to take on faith: there is no request to a server for them to travel in.

Signing in is different, and this paragraph used to say otherwise. Your customers, stamps, ledger, shift notes, items and the figures in Settings are stored with us, on the free plan and the paid plan alike, so that every device you sign in on shows the same thing: the tablet at the counter and the laptop in the office. Each shop's rows are fenced off in the database by shop and by the role of the person signing in.

We hold it rather than your browser, because a browser is not a safe place to keep a year of takings. Phone browsers clear site data after a week or two without a visit, and a counter tablet and an office laptop would otherwise hold two different customer lists.

Your customers' data is yours. We never sell it, never email anyone without their yes, staff see only what you allow, and you can export or delete everything.

Two different relationships run through this product, and they carry different duties.

For your own account and the figures you enter, we are the controller — we decide what is held and why, and the rest of this policy describes it.

For the customer details you collect — the phone numbers on your stamp card, the people who use your kiosk — you are the controller and we are only a processor. They are your customers, gathered under your promise to them. We act on your instructions, do not use those records for our own purposes, and never sell them. In practice this means a data-protection obligation toward those people is yours, and we help you meet it rather than assume it for you.

The stamp card stores the phone numbers your customers give you, on your account, on our servers. That is how the tablet at the counter and the laptop in the office show the same list, how a customer opens their own card on their phone, and how a new tablet has your regulars on it the moment you sign in.

Your customers’ data is yours. We never sell it, never email anyone without their yes, staff see only what you allow, and you can export or delete everything.

That does not make them yours to do as you like with. Those numbers belong to the people who gave them to you, which makes you the one responsible for them — under PIPEDA in Canada, the CCPA in California and their equivalents elsewhere. In practice: ask before you type a number, use it for the stamp card and nothing else unless they agreed to more, and remove anyone who asks. The list has a delete control on every row for exactly that reason.

Because a shared counter tablet is a shared counter tablet, the card holds the phone number and nothing else — no names, no birthdays, no notes.

The review-reply writer uses a Google Gemini API key that you supply. It is stored in your browser alongside your other settings and is sent directly from your browser to Google when you generate a reply. It never passes through us.

What you send that way is handled under Google's Privacy Policy. You can remove the key from your browser at any time in Settings.

The calculators genuinely hold nothing: they run in your browser and nothing you type into one leaves it. An account is different, on either plan, and the honest version of that matters more than a reassuring one.

Your shop’s customers, stamps, rewards, ledger, items and figures are stored on our servers. That is what makes them work across your counters, survive a lost tablet and reach people by email at all. The free plan and the paid plan are stored the same way; what you pay for is what KANJIN does with them, never where they are kept.

If you create a KANJIN account, we hold:

• Your email address and the details you enter about your business, so you can sign in and so your emails can carry your name.
• Details of your customers, taken at the kiosk or the counter: their phone number, and where they give it, a first name, birthday or email. Stamp balances, visit counts and total spend sit alongside them.

We do not sell any of it, and we do not use your customer list for anything except showing it back to you.

Creator discovery uses the YouTube Data API. In using it you are also bound by the YouTube Terms of Service, and Google’s handling of your information is governed by the Google Privacy Policy.

What we access, collect and store. Only public data about a channel, returned by the API for the search you ran. For each channel in your results we store:

• The channel ID, and the @handle if the channel has claimed one.
• The channel name and the description the channel has published.
• The thumbnail image URL of the channel’s avatar.
• The subscriber count and the video count, where the channel shows them.
• The country the channel declares, when it declares one.
• Any contact address the channel has published in its own description.

We also store what you searched for — the city, the niche and the filters — and when, so the same search does not have to be run twice.

What we never touch. KANJIN reads public data with its own API key and never asks anyone to sign in with Google or YouTube. We do not use OAuth, we hold no YouTube access token, and we cannot see anybody’s account, subscriptions, watch history, private videos, comments or analytics. There is no YouTube permission for you to revoke, because none was ever granted.

How we use it. To show you a list of creators near your shop, ranked by how well they fit, and to fill your shop’s name and offer into an invitation that you send yourself. KANJIN does not contact any creator. We do not build a profile of a creator beyond what their channel already shows in public, and we do not combine this data with anything else we hold.

How it is processed and who else sees it. The results are held in a cache in our database so a repeated search costs no API call. That cache is shared between KANJIN shops: if another shop has recently searched the same city and niche, you are shown that stored result rather than a fresh call. The only parties that handle it are the ones that run KANJIN itself:

• Supabase — our database, on Amazon Web Services in Singapore, where the cache is stored.
• Vercel — our hosting, in the United States, which runs the code that makes the request and draws the screen.
• You, the shop owner, who sees the results on your own screen.

Nobody else. We do not sell it, we do not use it for advertising, we do not give it to data brokers, and we do not pass it to any AI provider — the invitation is written by our own code from a fixed template, not by a language model. The full list of everyone who touches any KANJIN data is on our subprocessors page.

How often it is refreshed and deleted. A stored result is treated as current for 7 days; after that the next search calls the API again and replaces it. A stored result is never shown once it is more than 21 days old, and rows are deleted at 21 days by a job that runs every hour. That is inside the 30 days the YouTube API Services policies require, deliberately so: a cache that sits exactly on the limit is one clock skew away from being over it. If you delete your KANJIN account, everything belonging to it goes with it.

To ask us what we hold or to have something removed, write to hello@kanjin.app. A creator who wants their channel out of our cache can write to the same address and we will remove it.

Wherever you are, you can ask us what we hold about you, correct it, take a copy, or have it deleted. If you are in the European Economic Area or the United Kingdom, those are formal rights under the GDPR and UK GDPR and we treat them as such: access, rectification, erasure, restriction, portability, and objection to processing. Comparable rights under PIPEDA in Canada, the CCPA and CPRA in California, and Taiwan's Personal Data Protection Act are honoured the same way, including the California right not to be discriminated against for exercising them.

Where we rely on your consent — the AI key, marketing email — you can withdraw it at any time, and withdrawing it does not undo anything lawfully done beforehand.

If you are a customer of a shop that uses KANJIN, you do not have to write to anybody. Your own stamp card page carries two links: one stops that shop emailing you, and one deletes your card and everything attached to it. The shop can also export or delete you from its own customer list, from the same screen it uses to see you.

Our legal bases, plainly:

• Performance of a contract — running the account you signed up for, and taking payment for it.
• Legitimate interests — keeping the service secure, preventing abuse, and understanding which pages are worth keeping. We do not use this basis for anything intrusive.
• Consent — where you have given it, such as storing an AI key or agreeing to hear from us.
• Legal obligation — retaining payment records where tax or accounting law requires it.

If you think we have handled something badly, tell us first and we will try to fix it. You also have the right to complain to your data protection authority — the ICO in the UK, your national supervisory authority in the EEA, or the Office of the Privacy Commissioner in Canada.

Every company that receives data from KANJIN is named on the subprocessors page, with what each one gets and where it runs. The agreement a shop holds with us about its own customers is the data processing agreement.

• The calculators: nothing. What you type into one stays in your own browser and is never sent to us.
• Platform account records: for as long as the account is open, then deleted within 30 days of you closing it or asking us to.
• A shop’s customers: until the shop’s own retention setting is reached, three years by default, counted from their last visit. The shop is told 30 days before anybody is deleted.
• Cached public YouTube data: refreshed or discarded within 30 days, as the YouTube API Services terms require.
• Payment and invoice records: kept for as long as tax and accounting law requires, typically seven years, and used for nothing else.

The calculators store nothing outside your own browser, so nothing crosses a border at all.

Your shop is different, and this is the exact answer. Your account and everything in it are held by Supabase on Amazon Web Services in Singapore (AWS ap‑southeast‑1). KANJIN itself is operated from Taiwan, so information moves between both.

When KANJIN sends an email for you, the recipient’s address and the message go to our email provider, Resend, in the United States, so it can be delivered.

For most shops, that means customer details are stored on servers outside the shop’s own country: in Singapore, and in the United States when an email is sent.

If you are in the UK or EEA, that matters: none of Taiwan, Singapore or the United States has a general adequacy decision, so those transfers are made under the standard contractual clauses our providers publish together with the safeguards their terms require. You can export everything and delete everything at any time, from Settings.

If your shop is in Australia, the Australian Privacy Principles apply to what we do with your customers’ information, and this is how we meet them.

Overseas disclosure (APP 8). Your account and your customer list are held in Singapore, KANJIN is operated from Taiwan, and an email you send goes through our provider in the United States. None of those is Australia, so your customers’ details do leave the country. We take reasonable steps to see that the overseas recipients handle the information consistently with the APPs, through the terms those providers publish; we do not sell it, and nobody else is given it.

Access and correction (APP 12 and 13). You can see and export everything we hold for your shop from Settings, at any time, without asking us, and you can correct any of it on the screen it came from. If one of your own customers asks you for their details, the export gives you their record to hand over. Ask us and we will do it for you instead.

Direct marketing (APP 7). KANJIN only emails somebody who gave their address and said yes, every email carries an unsubscribe that works at once, and an unsubscribe is honoured immediately rather than within the five working days the Spam Act allows.

Complaints. Tell us first, at hello@kanjin.app, and we will answer within one working day. If you are not satisfied with our answer, you can complain to the Office of the Australian Information Commissioner at oaic.gov.au.

KANJIN is a tool for running a business and is not directed at children. We do not knowingly collect information from anyone under 16, and you should not enter a child's details into the stamp card or the customer list. If you believe a child's information has reached us, tell us and we will delete it.

• Free tools: clear your browser data, or use the "Clear all figures" control in Settings. That is the only copy there has ever been.
• Your AI key: remove it in Settings, or clear your browser data.
• Platform account: ask us and we will delete your account and its records. Cached public YouTube data expires on its own within 30 days.

To request deletion, or to ask what we hold, email hello@kanjin.app. You can also revoke our access to your Google account at any time through Google security settings.

This site sets no cookies. The public pages (the homepage, the tools, the blog, the sign-in pages) use Vercel Web Analytics, which counts page views and four named events (a calculator used, its link to the back office pressed, a sign-up started, a sign-up finished) without cookies and without identifying you or following you to other sites. It is not loaded on the kiosk, on a customer’s card, inside an embedded calculator or in the back office.

If you reach us through a campaign link — one with utm_source and utm_campaign in the address — and you create an account in that same visit, those two short words are saved with your shop, so we can tell which post or message brought you. Nothing is stored in your browser to do it: the words travel from the page you landed on to the sign-up form and no further, so if you come back another day without that link, nothing is recorded. They are a tag for a batch, never a tag for a person: no click identifier, no advertising profile, and nothing that follows you to another site.

If your browser asks for a language we publish, a small bar offers that page in it. Closing the bar writes one flag in your browser so it does not ask again. That flag stays in your browser, is never sent to us, and says nothing about you beyond “closed”. Clearing your browser data removes it, and the offer is a link: nothing redirects you, and the address you typed is the page you get.

We never attach analytics to the figures you type into a calculator: knowing that somebody used the break-even page is reasonable; transmitting their rent is not. The same goes for figures that arrive in a link. A tool link can be sent to you with the name of your shop and your prices already in the web address, so before a page view is counted the address is cut back to the page itself. Only a campaign tag and the name of the tool somebody came from survive it; your name, your figures and the page you were heading to are removed first, in your own browser. The back office asks you once whether it may send us usage counts (five event names, a count each: first stamp, poster printed, a day’s sales logged, kiosk opened, first email sent). It is off unless you say yes, it never sends a figure, a name, a phone number or an email, and the server refuses anything else. You can change your answer in Settings.

Everything travels over an encrypted connection, and platform access needs your password. But the free tools trade some safety for privacy, and you should know which: data in your browser is not encrypted at rest. Anyone who can use that device can read what is in it.

On a shared counter tablet holding a customer list, that matters. Use a device lock, and do not leave the back office open on a screen the public can reach.

If this policy changes in a way that affects what we hold, the date at the top changes and material changes are noted here. Questions go to hello@kanjin.app. See also our terms of service.