Privacy policy
How Underanchor processes your personal data, under Regulation (EU) 2016/679 (GDPR) and Spanish Organic Law 3/2018. Version 2026-10-19 · 19 October 2026.
1. Controller
- Controller
- Jose Fernandez Franco
- Privacy contact
- contacto@underanchor.com
2. Minimum age
The service is for people aged 16 or older. We do not create accounts for anyone younger, and we close any account we find belongs to someone under that age.
3. What data we process, why, and for how long
| Data | Purpose | Legal basis | Retention |
|---|---|---|---|
| Email, password (stored only as an scrypt hash), Google identifier if you sign in with Google, plan | Your account and sign-in | Contract (art. 6.1.b GDPR) | While the account exists |
| Acceptance of the Terms (date and version) | Proof of acceptance | Contract; legitimate interest | While the account exists |
| What you upload and write: PDFs, extracted paragraphs, LaTeX projects, anchors, comments, highlights, notes, libraries | Providing the service | Contract | While the account exists |
| IP address and server access logs (date, path, result) | Security, rate limiting, abuse prevention | Legitimate interest (art. 6.1.f) | 30 days |
| Email of a person (supervisor, colleague, lawyer…) you invite to review, edit with you or view a project, and the role you give them | So they can view, comment on or, if you give them that role, write in what you share | Contract; legitimate interest | While the sharing lasts |
| Technical state of simultaneous editing (a copy of the document text in the database and, while it is open, the name and cursor position of whoever edits it) | So several people can write at once and a session can resume without losing changes | Contract | The copy, while the project exists; the cursor, only while the document is open |
| Account usage: which kind of action you take each day (sign in, upload a PDF, create a project, anchor, compile, your AI using the connector, invite someone), without the content or names | Know whether the service is useful (how many accounts anchor in their first week and how many come back) and decide what to improve. Looked at in aggregate, not person by person | Legitimate interest (art. 6.1.f) in measuring and improving the service with minimal data; you can object (section 7) | While the account exists |
Sign-up origin: the campaign tags (utm_*) of the address you arrived by, the domain of the page that
linked to us (not the full address) and the first page you saw; and, if you answer it, “How did you hear about
us?” | Know which channels bring users | Legitimate interest; the question is optional | While the account exists |
| That you want the newsletter (and since when) | Send you Underanchor news by email, once a month at most | Consent (art. 6.1.a): optional box when creating the account; withdraw it any time in Profile or with the link in each email | Until you withdraw it |
| Messages sent with the “Feedback” button | Fix bugs and improve the service | Legitimate interest, at your request | While the account exists |
| Illegal-content reports (what the reporter writes and, if given, name and email; a hash of the IP) | Handle the report and comply with the DSA | Legal obligation (art. 6.1.c) | As long as needed to resolve it and handle claims |
| Database and PDF backups (on the server and, encrypted, on a device of the controller in Spain) | Recover the service after a failure | Legitimate interest | 14 days |
We do not use your data for advertising, we do not sell it, we do not profile you, and we do not train AI models on your content. We do not share your libraries with anyone except the people you invite to a library or to a project with access to it (see “Shared libraries” below): each account has its own.
4. Your AI and the connector
Underanchor does not call any AI model on its own. If you choose to connect your AI (for example Claude or ChatGPT) through the connector, that AI reads what the connector returns (paragraphs of your sources, your LaTeX document, your highlights and notes) and that data travels to the AI provider you choose, under your own contract with them. We do not control that processing. The “Ask the AI” feature copies the request to your clipboard and opens the provider's chat with a short sentence, without your text in the address. Connector URLs work like passwords: only a hash is stored and you can revoke them from your profile. OAuth authorisations expire on their own and can be withdrawn at any time.
Shared libraries: if you share a library, the invited people see its articles and everyone's highlights and notes (with the name of whoever made them). With the edit role they can add PDFs, highlight, annotate, correct details and organize folders; never delete articles or the library or change who it is shared with.
Simultaneous editing: if you invite someone with the “Edit” role, or open a document that someone shares with you with that role, the text and each person's cursor position are exchanged over a real-time connection while the document is open. Whoever edits with you sees your name (the part of your email before the @) next to your cursor. We keep a technical copy of the text so editing can resume; it is not sent to anyone else or used for anything else. Role and session are checked again every few seconds: when access is withdrawn, the connection is closed.
Other features that process your data: version history (copies of your document inside your project), shared provenance report (a frozen copy of your anchored sentences and the cited fragments, never whole PDFs; revocable and expirable) and Zotero import (the API key you paste is used only during the import and is not stored).
5. Who we share data with
- Hosting provider (VPS) in the European Union, as processor.
- Email delivery provider, as processor (account confirmation, password recovery, invitations, report notices).
- Google, only if you choose “Continue with Google”: independent controller; may process data in the US under the EU-US Data Privacy Framework.
- Crossref (US), only when you ask to complete an article's data: we send only the DOI or title, never your text. Zotero, only if you import from its API.
- Authorities, when required by law.
There is no advertising, and no third-party analytics or script in the application: the usage measurement in section 3 is done by us on our server, without cookies or anything stored in your browser. The spell checker runs inside your browser.
6. Cookies and local storage
We only use strictly necessary items or ones you choose, exempt from consent (art. 22.2
LSSI), so there is no banner: the anclaje_sesion session cookie (30 days since you last used it, or until you sign out),
the anclaje_oauth cookie (10 minutes, protects Google sign-in), the anclaje_alta cookie
(10 minutes, deleted on return: when you create the account with Google, it carries what you chose in the form and
where you came from), the
anclaje_idioma functional preference cookie (1 year, remembers the language you chose so the server
answers in it: messages, emails and pages) and browser localStorage for your preferences (theme,
spell checker, panel sizes).
7. Your rights
From Profile you can download all your data, including your account's usage and sign-up data (access and portability), unsubscribe from the newsletter and delete your account with all its content (erasure). Deleting an article also deletes its PDF. For other rights (rectification, objection —for example, to us counting your usage—, restriction) or if you cannot sign in, write to contacto@underanchor.com; we reply within one month. Deleted data may remain in encrypted backups for up to 14 days. You can complain to the Spanish Data Protection Agency (www.aepd.es) or to your local authority.
8. Security and third-party data
Passwords are stored with scrypt; sessions and connector tokens only as hashes; data is hosted in the European Union and each account sees only its own. In case of a breach with risk to your rights we notify the AEPD within 72 hours and, if the risk is high, you too. Your documents may contain other people's data: you are responsible for having a legal basis to process and upload it. If your institution contracts the service, we act as processor under a separate agreement (art. 28 GDPR).
9. Changes
If we change this policy materially we will raise the version and ask you to accept it again. Current version: 2026-10-19.