Terms of Use

Last updated: July 29, 2026

These Terms of Use govern your use of the Cachet mobile app and website, including the page where a sealed letter is opened. Cachet is operated by Niko Ng in Vietnam. By writing, sealing, sending, or opening a letter, you agree to these terms.

License to use Cachet

Subject to these terms, Cachet grants you a personal, non-exclusive, non-transferable, revocable license to use the app and website for their intended purpose of writing, sealing, sending, and opening letters. You may not copy, modify, reverse engineer, distribute, scrape, or use the service in a way that violates applicable law or another person’s rights, and you may not attempt to enumerate, guess, or brute-force share links belonging to other people.

Your letter content

You are responsible for the recipient names, sender names, messages, dates, and other content you put into a letter. Do not send content that is unlawful, harassing, abusive, infringing, or otherwise inappropriate, and do not use Cachet to send unsolicited bulk messages. You retain ownership of your content; you give us permission to process it only as needed to store your letters, deliver them to the people you send them to, and operate and improve the service.

Share links, sending, and opening

When you seal a letter, Cachet creates a share link containing a long random token. You choose how that link is delivered, and you are responsible for sending it to the right person. Share links do not expire on their own; you can revoke a link from the app, after which the letter can no longer be opened through it. Revoking a link does not retrieve a letter someone has already read.

A letter records when it was first opened, and the sender can see that time. Sealing is meant to be final: once a letter is sealed and its link is sent, we do not guarantee that it can be edited or unsent.

If you received a link, you may open and read the letter addressed to you. Do not use a link that was not shared with you.

Objectionable content and reports

Cachet does not allow content that is sexually explicit, violent, hateful, exploitative, threatening, harassing, or otherwise unlawful. This includes custom stamp images as well as the contents of a letter. We may screen, refuse, remove, or replace content that violates these rules or that we reasonably believe could harm someone or the service.

If a letter is not kind or safe, use the report this letter link on its reader page. We record the report for review without adding the letter body to the report. You can also contact us at the address below.

Purchases and ads

Cachet may offer in-app purchases, such as additional wax, seal marks, or paper. Purchases, billing, cancellations, refunds, and restores are handled by the app store from which you downloaded the app and are subject to that store’s terms. We do not process your payment-card details. Access to a purchased item may require a successful store verification or restore. The app may also show advertising.

Availability and changes

We may update, change, suspend, or discontinue parts of Cachet at any time. We aim to keep the service available and your letters intact, but do not guarantee uninterrupted operation, error-free performance, that a share link will remain openable indefinitely, or that a letter will always be recoverable. Keep your own copy of anything you cannot afford to lose.

Disclaimers

Cachet is provided on an “as is” and “as available” basis. To the extent permitted by law, we disclaim all warranties, express or implied, including warranties of merchantability, fitness for a particular purpose, and non-infringement. Cachet is a way to send a message with ceremony; it is not a secure, confidential, or guaranteed-delivery channel, and you should not use it for sensitive information such as credentials, financial details, or health records.

Limitation of liability

To the extent permitted by law, Cachet and Niko Ng will not be liable for indirect, incidental, special, consequential, exemplary, or punitive damages, or for lost letters, data, profits, goodwill, or business opportunities arising from your use of the service, including a letter that fails to deliver, is opened by the wrong person, or is opened at a time you did not intend.

Termination

You may stop using Cachet at any time. We may suspend or end access to the service, and may revoke share links, if we reasonably believe these terms have been violated or if doing so is necessary to protect the service, users, or others.

Governing law and changes

These terms are governed by the laws of Vietnam, excluding conflict of law rules. We may revise these terms from time to time. Continued use after a revised version is posted means you accept the updated terms.

Contact

For questions about these terms, email contact@anng.dev.