Terms of Service

Last updated 7 September 2026

These Terms of Service (the Terms) are an agreement between you and Sad Coder, Inc., a Delaware corporation (Sad Coder, we, us, or our), governing your use of Tidemarks, including the reader at app.tidemarks.io, the syncing service behind it, and its MCP server (collectively, the Service).

Sad Coder’s business and legal notice address is:

Sad Coder, Inc., 5F., No. 50, Zhongyang 7th St., Xindian Dist., New Taipei City 231014, Taiwan — contact@tidemarks.io

You accept these Terms by creating an account, purchasing a plan, or otherwise using the Service. If you do not agree, do not use the Service. Reading with Tidemarks needs no account, and these Terms still govern that use of the Service.

1. Eligibility and authority

You must have reached the age of majority where you live to create an account or purchase the Service. We do not offer the Service to minors through a parental-consent process.

If you use the Service for an organization, you represent that you have authority to accept these Terms for that organization. In that case, you includes the organization. The Service is not offered where its use or supply would violate applicable law, sanctions, or export-control restrictions.

2. The Service

Tidemarks is an epub reader that runs in your browser. Importing, reading, highlighting, note-taking, typesetting and exporting happen on your own device, and no account is needed for any of them.

An account adds two things, and both run on our servers: your books, notes and reading positions sync between your devices, and an AI agent you authorize can read the books that are syncing, through the Service’s MCP server. A free account syncs three books. A paid plan removes that limit.

Features and plan limits may change. The pricing page and the information shown before purchase describe the included features, billing period, and price for a paid plan. Beta or preview features may be changed or withdrawn and are not subject to a service-level commitment unless we expressly agree otherwise in writing.

3. Accounts and authorized clients

You must provide accurate account information and keep your email account, access tokens, passkeys, devices, and connected clients secure. You are responsible for activity performed with your credentials or by a client or agent you authorize.

An account is reached through a passkey or through a code sent to your email address, so control of that mailbox is control of the account. You are responsible for confirming that an agent, OAuth client, or other integration has only the access you intend to grant; an authorized agent can read the books that are syncing.

Notify us promptly at contact@tidemarks.io if you believe an account or credential has been compromised.

4. Your content

You retain ownership of the books you import and the notes, highlights and reading positions you create (Customer Content). Content that stays on your device is not ours to license; for content you choose to sync, you grant us a worldwide, non-exclusive license to host, copy, transmit, process, and display it only as needed to operate, secure, support, and improve the Service and comply with law.

We do not scan the contents of your books, deduplicate them against anybody else’s copy, or serve them from any address that does not check who is asking. That is a standing commitment rather than a current setting; see the privacy policy.

You represent that you have the rights and permissions needed to import and sync the books you import. You are responsible for your Customer Content and for any instructions you give the Service or an authorized client.

5. Acceptable use

You must not use the Service to:

• break the law, infringe rights, commit fraud, or facilitate abuse;
• distribute books you have no right to distribute, or use the Service as a way to publish or share copyrighted works;
• access another person’s data or account without authorization;
• probe, scan, disrupt, overload, or circumvent the Service or its security, limits, or access controls;
• upload malicious code or content that creates a material security risk; or
• resell or provide the Service in a way that misrepresents Sad Coder or Paddle, or use it to provide an unlawful payment service.

We may investigate suspected misuse and may restrict activity or suspend access when reasonably necessary to protect users, third parties, or the Service. Because we do not scan the contents of your books, an investigation works from account activity rather than from what you are reading.

6. Sad Coder intellectual property

The Service, software, documentation, design, and the Sad Coder and Tidemarks names and marks are owned by Sad Coder or its licensors. The source code of the Service is published under the MIT licence, and that licence — not this section — governs what you may do with the code. This section covers what is not in it: the names and the marks. Except for rights expressly granted under these Terms or that licence, we reserve all rights. If you provide feedback, you permit us to use it without restriction or payment.

7. Paid plans and Paddle

Sad Coder supplies and operates the Service. Paddle is the authorized reseller and merchant of record for purchases made through Paddle Checkout. When you complete such a purchase:

• these Terms govern your use of the Service;
• the Paddle Buyer Terms govern the transaction between you and Paddle; and
• Paddle handles payment collection, applicable transaction taxes, invoices and receipts, transaction refunds, chargebacks, and payment disputes.

The price, currency, taxes, billing interval, renewal terms, and payment method shown in Paddle Checkout control the transaction. The currently listed paid plan is a recurring annual USD subscription for one account; there is no monthly plan. Prices exclude applicable VAT, GST, and sales tax. Paddle calculates and adds tax at Checkout; the Checkout subtotal, tax, and total control the transaction. Paddle may accept promotion codes. The automatic renewal runs until cancelled. You can manage or cancel a subscription through the Paddle customer portal. Unless the checkout or mandatory law says otherwise, cancellation takes effect at the end of the current billing period and does not itself create a refund.

Our Refund Policy explains the refund route and the 14-day window it offers. Beyond that window we provide no prorated refund or additional voluntary refund guarantee beyond Paddle’s policy and statutory rights that cannot lawfully be excluded.

When a subscription ends, the account’s sync limit returns to three books. Books above that limit are frozen rather than deleted: our copy is kept, it stops accepting changes, and an agent can no longer read it. The copies on your own devices are untouched. See the privacy policy for how long a frozen copy is kept.

Sad Coder provides product support at contact@tidemarks.io. Paddle provides transaction and refund support through paddle.net.

8. Third-party services

The Service may interoperate with Paddle, email providers, MCP hosts, OAuth clients, AI agents, and other third-party services. Their terms and privacy notices govern their services. We are not responsible for a third party’s service, content, or actions, but this does not limit responsibility that cannot lawfully be excluded.

9. Suspension, termination, and data export

You may stop using the Service at any time. Stopping use or closing an account does not automatically cancel a Paddle subscription; use the Paddle customer portal to cancel billing.

We may suspend or terminate access for a material breach, unlawful or abusive use, security or fraud risk, non-payment reflected in verified Paddle state, or where required by law. Where reasonably possible, we will give notice and an opportunity to cure.

Tidemarks exports what you have on a device without asking us for anything: the account pane writes your books and their notes and positions to a file you keep. The epub in that file is the one you imported, unaltered. Export before ending your use or subscription. After termination, content is handled according to our Privacy Policy and the Service’s then-current deletion processes. Sections that by their nature should survive termination — including ownership, payment obligations, disclaimers, liability limits, and dispute terms — remain in effect.

10. Changes to the Service or these Terms

We may change the Service and these Terms. We will post the updated Terms and update the date above. For a material change, we will provide reasonable notice through the Service, by email, or by another appropriate method before the change takes effect where required. Continued use after the effective date means you accept the updated Terms; if you do not agree, stop using the Service.

11. Disclaimers

To the maximum extent permitted by law, the Service is provided as is and as available. We disclaim implied warranties of merchantability, fitness for a particular purpose, title, and non-infringement. We do not promise that the Service will be uninterrupted, error-free, or suitable for every use.

These disclaimers do not exclude any warranty, guarantee, or remedy that applicable consumer law does not permit us to exclude.

12. Limitation of liability

To the maximum extent permitted by law, Sad Coder and its directors, officers, employees, and affiliates will not be liable for indirect, incidental, special, consequential, exemplary, or punitive damages, or for lost profits, revenues, goodwill, or data.

For a business user, our total aggregate liability arising out of or relating to the Service or these Terms will not exceed the fees paid for the affected Service through Paddle during the 12 months before the event giving rise to the claim. For a consumer, that limit applies only to the extent permitted by applicable law and does not limit a mandatory consumer guarantee or remedy.

Nothing in these Terms limits liability that cannot lawfully be limited, including liability for fraud or fraudulent misrepresentation, gross negligence or willful misconduct, death or personal injury caused by negligence, or data-protection and consumer liability where applicable law prohibits that limitation. Some jurisdictions do not allow certain exclusions or limits, so they apply only to the extent permitted there.

13. Governing law and disputes

These Terms are governed by Delaware law, without regard to conflict-of-law rules. Subject to the paragraph below, the state and federal courts located in Delaware have exclusive jurisdiction over disputes arising from these Terms or the Service, and each party consents to those courts.

If you are a consumer, this choice does not deprive you of mandatory rights or protections under the law of your habitual residence. You may also bring a claim in another court or forum where applicable consumer law gives you a non-waivable right to do so.

Before filing a claim, please contact contact@tidemarks.io so we can try to resolve it informally. This request does not shorten or suspend any statutory deadline unless the law expressly provides otherwise.

14. General

These Terms, the Privacy Policy, the Refund Policy, and any expressly agreed order or plan terms form the agreement between you and Sad Coder for the Service. Paddle’s Buyer Terms separately govern your transaction with Paddle. If part of these Terms is unenforceable, the remaining parts remain effective. Our failure to enforce a provision is not a waiver. You may not assign these Terms without our consent; we may assign them as part of a merger, reorganization, financing, or sale of the relevant business, subject to applicable law.

15. Contact and notices

Questions, complaints, and legal notices concerning the Service or these Terms may be sent to contact@tidemarks.io or to the Sad Coder address stated at the beginning of these Terms.