Terms and licence

Version 8 October 2026 · all versions

These terms are the agreement between you and Vitalii Kizlov, who makes Cloister (“we”, “us”), for using Cloister. By installing or using Cloister, or by buying a licence, you accept them. If you do not accept them, please do not install Cloister.

In short: you buy Cloister from Paddle, and the licence comes from us. It lets you run Cloister on the number of Macs you paid for, forever, on every version released during your update window. Cloister is built so that a session you start cannot be ended early — that is what it is for — so please read section 6 before relying on it.

1. Who we are

Vitalii Kizlov, a sole trader registered in Poland, ul. Jana III Sobieskiego 112/14, 00-764 Warszawa, Poland. NIP 6751773289. Email: support@getcloister.app.

2. Buying Cloister

Our order process is conducted by our online reseller Paddle.com. Paddle.com is the Merchant of Record for all our orders. Paddle provides all customer service inquiries and handles returns.

In practice: Cloister is sold by Paddle.com Market Limited (Paddle.com Inc. in the United States, Paddle.com (Canada) Ltd. in Canada). Your purchase contract is with Paddle, under Paddle's buyer terms and refund policy: Paddle takes the payment, issues the invoice, handles tax and pays refunds. The software and this licence come from us, and so do answers to questions about how Cloister works.

What each licence covers, its price, and how long its update window runs are shown on our pricing page when you buy, and confirmed on your receipt.

3. Trial

Cloister runs with every feature for 14 days from its first launch on a Mac, without a licence. When the trial ends, Cloister asks for a licence before starting new sessions. A session already running when the trial ends continues to its scheduled end.

4. Your licence

4.1 Grant. We grant you a non-exclusive, perpetual licence to install and use Cloister on the number of Macs your licence covers, for your own use, personal or professional. An organisation that wants Cloister for several people should write to us. You may pass your whole licence to another person: write to us from your licence email — or quoting your licence key, if we no longer hold your email — with theirs, and uninstall Cloister from your Macs; we then move the licence to them. A licence cannot be split.

4.2 Versions covered. Your licence covers every version of Cloister released on or before the last day of your update window. Covered versions stay licensed forever, including when you reinstall them. A version released after your window closes asks you to renew before it counts as licensed — and never ends or shortens a session that is already running. Every version stays available to download from our website for as long as we sell Cloister, so you can reinstall the last version your licence covers. A renewal costs the tier's price on the day you renew — the same as a new licence — and adds a year to your update window: from the day it closes, or from the day you renew if it has already closed. Nothing renews automatically, and we hold no payment method to charge.

4.3 Security fixes. Fixes for security vulnerabilities are free, even after your update window has closed. They are made in the current version only, and a release that fixes a vulnerability counts as licensed for you until your support period ends: five years from when you first bought this licence, with the month and year shown when you buy. Such a release may contain other changes as well, but features released after your update window closed stay locked until you renew.

4.4 Lifetime. The update window of a Lifetime licence lasts for the life of the product: for as long as we develop and publish new versions of Cloister for macOS. It refers to the product's life, not yours or ours.

4.5 Activation. Each Mac is activated once, over the internet. Activation sends our licence server your licence key, a one-way hash of the Mac's hardware identifier, and the Mac's model name. The server checks that your licence has a free seat and returns a licence file signed for that Mac. After that, Cloister checks the licence on the Mac itself, and contacts our server about the licence again only if you unlink that Mac or renew. If you cannot or prefer not to connect, write to us and we will activate by email.

4.6 Moving to another Mac. Unlink a Mac in Cloister's settings, and its seat is free for another Mac. If a Mac is lost or broken, activate Cloister on your new Mac: when every seat is taken, Cloister lists the Macs using your licence, and you can unlink one there. Or write to us. Unlinking frees the seat; it does not switch Cloister off on that Mac, which checks its licence offline — so unlink from the Mac itself while you still can. You can unlink one Mac from a licence every 30 days; to unlink another sooner, write to us.

5. What you may not do

You may not:

• share, sublicense or publish your licence key or licence file, pass on part of a licence, or use one licence on more Macs than it covers;
• circumvent or disable the licence check, or distribute a version of Cloister that does;
• copy, modify, decompile or reverse-engineer Cloister, except where the law allows it and a contract cannot exclude it (for example, decompiling for interoperability under Article 6 of Directive 2009/24/EC and Article 75 of the Polish Copyright and Related Rights Act), or for good-faith security research under our security policy;
• use Cloister to interfere with a Mac or a network you are not authorised to administer.

6. How Cloister works, and what that means for you

6.1 A session cannot be ended early. Once you start a session, or a schedule opens one, the domains in it stay blocked until it ends. Quitting Cloister, restarting the Mac, changing the clock or stopping Cloister's background component does not end it, and nobody can end it for you — not us, and not our support: Cloister has no remote switch. This is the purpose of Cloister, not a defect. A session lasts at most 24 hours of your Mac being on or asleep. Time while it is shut down does not count, beyond ten minutes for each restart, so a shutdown makes a session end later by the clock.

6.2 Choose what you block with care. Before starting a session, make sure you will not need anything it blocks before it ends — including services you rely on for work, health, travel or emergencies. Start with short sessions while you learn how it feels.

6.3 What Cloister is not. Cloister is a focus tool. It is not a security product, a firewall or parental control, it is not a way to protect a network, and it must not be relied on for any safety-critical purpose. It makes giving in deliberate and inconvenient, not impossible: a person with administrator access and the know-how can remove it, and some ways around it exist. We list the ones we know on the support page and keep that list current.

6.4 What Cloister changes on your Mac. To enforce sessions, Cloister installs:

• a background component that runs with administrator (root) privileges;
• entries in the system file /etc/hosts, added when a session starts and removed when it ends;
• a network content filter, a macOS system extension that decides whether connections to blocked domains may go ahead.

macOS asks for your approval before each can run, and you may refuse. Without the background component Cloister cannot block; without the content filter it still blocks, except Safari with iCloud Private Relay switched on. You install these knowingly. They can be removed, and the steps are published on the support page. Removing the background component during a session can leave the block in place with nothing left to remove it, so let the session end first.

7. If something goes wrong

7.1 Consumers. If you are a consumer, or a sole trader in Poland buying outside your profession (whom Polish law protects in the same way), nothing in these terms limits your statutory rights — including your rights if Cloister does not conform to the contract — or our liability under product liability law.

7.2 Everyone. We work to make Cloister reliable, but software has faults. We do not promise that it will run without interruption or error, or that it will stop every connection to a listed domain in every circumstance (section 6.3).

7.3 Business customers. If you use Cloister for business purposes and section 7.1 does not apply to you, then as far as the law allows: Cloister is provided as is; we are not liable for lost profit, lost business, lost data or indirect damage; and our total liability is limited to what you paid for your licence and any renewals. None of this limits liability for damage caused intentionally or through gross negligence, for personal injury, or under product liability law.

8. Support and complaints

We answer questions and fix problems by email; details are on the support page. To complain about Cloister or about the services in section 10, write to support@getcloister.app saying what went wrong and what you would like done. We reply within 14 days. If we cannot settle it, a consumer in Poland can get free help from a municipal or district consumer ombudsman (rzecznik konsumentów), and a consumer elsewhere in the EU from their national European Consumer Centre.

9. Ending the licence

You can stop using Cloister at any time, and uninstall it using the published steps. We may end your licence if you seriously breach section 5, after telling you by email and, where the breach can be put right, giving you the chance to do so. A refund of a purchase also ends the licence; a refund of a renewal takes back only the year it added (see Refunds). When a licence ends because of a refund or a breach, you must stop using Cloister and uninstall it.

10. Our online services

Besides the software, we provide these services electronically: this website, and the licence server that activates Macs. To use them you need a current web browser, or for activation, Cloister on macOS 15 or later with an internet connection. They are free. The agreement for them begins when you start using them and ends when you stop, and you may not send unlawful content through them. Complaints go to support@getcloister.app as in section 8.

Using any online service carries risks such as phishing and malware. We never ask for card details or passwords by email; keep your licence key private.

11. Third-party software

Cloister includes open-source components under their own licences. Their notices are in Cloister's About window, under Acknowledgements. Nothing in these terms limits your rights under those licences.

12. Changes to these terms

We may update these terms. A new version applies to licences bought after it is published. A licence you already own stays under the version you accepted, unless the law requires a change or you accept the new version — for example, by renewing. Earlier versions stay available below.

13. Law and disputes

Polish law governs these terms. If you are a consumer living in another country, you also keep the protection of that country's mandatory consumer law. A consumer living in the EU, the EEA, Switzerland or the UK may also bring a claim in the courts of their country; other consumers bring claims against us in the courts competent for our address. For business customers to whom section 7.1 does not apply, the courts competent for our address have jurisdiction.

Where a term can be read in more than one way, the reading more favourable to a consumer applies. If any part of these terms is found invalid, the rest remains in force.

Versions

• 8 October 2026 — section 1 names the business; section 4.6 unlinks a lost Mac from your new one and says how often a Mac can be unlinked, and sections 4.6 and 10 no longer mention a licence page. Published before the first sale.
• 6 October 2026 — section 7.3 names lost data; section 13 says which consumers may bring a claim in their own courts. Published before the first sale.
• 24 September 2026 — first version, published before the first sale.