Terms of use

Conditions governing the use of Underanchor. Version 2026-10-19 · 19 October 2026.

1. The service

Underanchor is a tool for writing scientific documents in LaTeX in which every statement is anchored to a specific paragraph of a source PDF. The provider is the one named in the Legal notice. By creating an account you accept these Terms and the Privacy policy.

• Age. You must be 16 or older. To buy a paid plan, once there is one, you must be an adult (18 or older).
• Beta. The service is in beta and provided without availability guarantee: there may be outages, changes and bugs. Keep your own copies of your documents and sources.
• Plans and limits. There is a free plan with limits (articles, library size, projects), visible in your profile. Nothing is charged today; if a paid plan appears you will be told first and nothing is charged without your express acceptance.
• Account. Personal: do not share it. You are responsible for your password and connector URLs.

2. Your content

• It is yours. PDFs, texts, comments and highlights remain yours (or their owners').
• Limited licence. You grant us the minimum permission needed to host and process your content (extract paragraphs, index, compile) and show it to you and to whoever you choose to share it with. We do not use it for anything else, we do not train models on it and we do not share your library with other users, except with whoever you invite.
• Shared libraries. You can give other people, by email, access to one of your libraries (to view, or to view and edit) or to the library of a project you share with a co-author. By doing so you declare that you have the right to make those PDFs available to those people (for example, because they are open access or your university licence allows it): this is your responsibility, as uploading them is. Whoever receives access can read them and, with the edit role, add PDFs, highlight and annotate, but cannot download them in bulk or pass them on to a third party from Underanchor. You can withdraw access at any time. The space they take counts towards your plan, and what invited people highlight or annotate carries their name.
• Co-authorship. If you give someone the “Edit” role, they can change the text of your document at the same time as you and compile it; it is your decision and you can withdraw their access at any time. Version history lets you go back. They do not see your library: only the document and the paragraphs you cite.
• You warrant that you have the right to upload it. Each PDF must be open access, allowed by your institution's licence, or lawful private copy for personal use, and you must be allowed to make it available to your AI through the connector. Many publisher licences restrict passing paid articles to third-party tools or generative AI: checking this is up to you.
• Third-party data. You are responsible for having a legal basis to process any personal data of other people in your documents.

3. Acceptable use

You may not use the service for anything unlawful or infringing, to distribute works (your library is private and for personal use), to abuse the LaTeX compiler or the service's resources, to share or resell your account, to bypass isolation between accounts or look for security flaws without our written permission (if you find one, write to contacto@underanchor.com), or to impersonate others.

4. Illegal content, suspension and appeals

We do not proactively review what you upload; your library is private. Anyone can report content they consider illegal on the reporting page, no account needed (Regulation (EU) 2022/2065, arts. 11, 12, 14 and 16). We assess notices diligently and, where appropriate, remove or block content or suspend accounts. We will always explain the reasons for any removal or suspension (art. 17) and you can appeal by replying to contacto@underanchor.com: a person will review it.

5. Your AI

The connector is a door you open: what an AI client does with the data it receives is governed by your contract with its provider, not by these Terms. Underanchor does not control or answer for any AI's output.

6. Disclaimer

• An anchor tells you where a sentence comes from, not that it is true, nor that the paraphrase is faithful. Always check the cited paragraph.
• «[SIN FUENTE]» is an automatic check and can fail (abbreviations, decimals, split sentences). Its absence does not mean everything has a source.
• PDF reading can be wrong (columns, headers, tables, formulas, wrongly split or merged paragraphs). Check literal quotes against the original.
• Crossref data may be wrong. Review the bibliography before submitting.
• You are the author. Authorship, plagiarism, accuracy and compliance with your institution's and journal's rules (including AI-use disclosure) are your responsibility.
• No academic or legal advice. Not affiliated with Anthropic, OpenAI, Crossref or any publisher.

7. Liability

The service is provided “as is”. To the extent permitted by law, the provider is not liable for indirect damages, lost profits or data loss not caused by its wilful misconduct or gross negligence, nor for interruptions or errors inherent to a beta, nor for what you do with the service or your AI. Nothing here limits liability for wilful misconduct, gross negligence or personal injury, nor consumer rights that cannot be waived.

8. Changes and termination

We may change these Terms; if the change is material we will raise the version and ask you to accept it again. You can stop using the service and delete your account at any time from your profile. We may suspend or close the service with reasonable notice and a chance to export your data.

9. Governing law

These Terms are governed by Spanish law. If you are a consumer, the courts of your domicile are competent; otherwise, the competent Spanish courts under the law.