Privacy

Who is responsible

Nostos is operated by Christian Gennari, sole trader (enskild firma), Hudiksvall, Sweden. You can reach us about anything on this page at contact@nostos.page. Our postal address is available on request at the same address.

This website

We do not use analytics, advertising, tracking pixels, or marketing cookies on this site. If you only browse the public pages without signing in, the site does not need an account session.

When you choose to sign in or create a hosted Nostos account, Clerk provides authentication and uses strictly necessary authentication and session cookies so the website can recognize your signed-in state and protect your account page. The sign-in page is also protected against bots by Cloudflare, which sets its own short-lived security cookies. Those cookies are used for account security and service delivery, not advertising or analytics.

The fonts are served from our own server rather than from Google. Your light or dark theme choice is stored in your browser's local storage and never leaves your device.

There is one exception to keeping everything on our own server. The homepage and the checkout page load Paddle.js, the script of our payment provider, from Paddle's servers (cdn.paddle.com), and Paddle.js in turn loads a script for Paddle Retain, Paddle's subscription-recovery service, from public.profitwell.com. Your browser therefore sends those servers what every web request carries: your IP address and your browser's user agent. Paddle's content network also sets a short-lived security cookie on its own domain (__cf_bm, about thirty minutes) to tell browsers from bots. We load these scripts so that checkout and failed-payment recovery work, and we rely on our legitimate interest in offering them (Article 6(1)(f) of the GDPR). We do not use them to analyse or profile visitors. For what Paddle does with that request data, Paddle is a controller in its own right and its privacy notice applies.

What our host sees

The site is served by Vercel, a United States company, which may process requests in the United States. Like any web server it answers, it records the requests it receives — the IP address, the page requested, the time, and your user agent — to deliver the site and to defend it against abuse. An IP address is personal data under the GDPR, which is why this section exists rather than a claim that nothing is collected at all. Our lawful basis is our legitimate interest in running a secure website; Vercel keeps the logs under its own policy, and we do not use them to build a profile of you.

How long we keep logs and records

Operational server and access logs (which record IP addresses, timestamps, requested URLs, and browser user agents) are kept by our hosting providers for up to 7 days. We use these solely to defend against abuse, investigate outages, and maintain system integrity, after which they are permanently overwritten.

Daily library backups taken for disaster recovery are retained for 14 days and then deleted automatically. Separately, our database provider keeps a short recovery history, currently 6 hours.

The accounting records we are required to keep under Swedish accounting law (Bokföringslagen 1999:1078) are kept for 7 years. Paddle, as merchant of record, maintains its own statutory transaction records.

When you subscribe to hosted Nostos

Checkout is handled by Paddle, who are the merchant of record: they are the seller for the transaction, and they collect your payment and billing details directly. Your card details never reach us.

To set up your subscription we give Paddle the email address of your account. What we receive back and keep is what is needed to run the subscription: Paddle's reference numbers for you, your subscription and its payments, and the plan, status and billing period. We process it to perform our contract with you (Article 6(1)(b) of the GDPR), and we keep the purchase records we are required to keep under Swedish accounting law. For anything Paddle collects itself, Paddle is a controller in its own right; their privacy notice explains what they do with it.

When you write to us

If you email us, we keep your message so that we can answer it and follow up. That rests on our legitimate interest in corresponding with the people who contact us. We keep support threads only while they are open, and we delete them when you ask.

The feedback form, which you can use when signed in, sends us your message with your account's email address and name, the page you sent it from, and any screenshot you attach. Your browser, screen size and theme are included only if you tick the box for technical details. Feedback arrives as email in our mailbox, which is hosted by Lark Mail, and is not stored anywhere else.

The content-reporting form can be used without an account. It sends hosted Nostos the location and explanation you give, any supporting context, and your name and email address if you choose to provide them. We keep a report for as long as we need it to handle the matter and to show how it was handled, which rests on our legal obligations as a hosting provider and our legitimate interest in handling reports properly.

Running Nostos yourself

When you run Nostos on your own machine or server, your library, your reading progress and everything else stay on your hardware. Your instance does not send us anything and we have no access to it. If you point the assistant at a model provider of your own, the content you ask it about goes to the provider you chose, under their terms, and not to us.

Hosted Nostos

If you use hosted Nostos, we store what the service needs: your account details (the email address and sign-in identity you use); your library, meaning the books and other files you upload, their covers, your collections, and your reading progress and preferences; and what you make in it, meaning highlights, notes, concepts and Studio documents. So that search and the assistant can find passages, we also store text extracted from your books and a search index built from it. We process all of this to provide the service you signed up for (Article 6(1)(b) of the GDPR).

We also keep the records the service runs on: which version of the terms your account accepted and when, the state of your subscription, and counts of how much you use the assistant and voice transcription. Those counts record amounts and times, never what you asked, said or were answered.

We keep personal data inside the European Union wherever possible:

Application compute

The hosted Nostos application runs on DigitalOcean App Platform in Amsterdam, Netherlands (European Union).

Database

Your personal library, reading progress, and relational database are hosted with Neon in Frankfurt, Germany (European Union).

Storage & Backups

Book covers, uploaded media, and library backups are stored in Backblaze B2's EU data centre in Amsterdam, Netherlands (European Union).

Authentication

Sign-in and account authentication are provided by Clerk. Clerk is a United States provider, processing credentials under the EU–U.S. Data Privacy Framework and Standard Contractual Clauses.

Service email

Emails about your account, such as the welcome message, are sent through Brevo, which receives your email address and name for that purpose. Sign-in codes are emailed by Clerk.

If you use the reading assistant (Ask Nostos), the text needed to answer you — your question, the conversation so far, and the passages and notes it draws on — is sent through Vercel's AI Gateway to the model provider behind it, currently OpenAI. If you dictate, the audio is sent to Groq to be transcribed. Hosted Nostos does not store your assistant conversations in its database: a conversation lives in your browser tab and is gone when you close it, and a transcript is kept only if you save it as a note.

The search index mentioned above is built by sending passages of your books' text through the same gateway to an embedding model, currently one of Alibaba's Qwen models. The index itself is stored in your own database with us.

Vercel and Groq are United States companies, and these providers may process this text outside the European Union. We do not use your library, notes, writing or conversations to train models.

Cancelling a subscription does not delete your library. To delete your hosted account and your library, use Settings in the Nostos app, under Account, or email us. Access closes straight away, your subscription stops renewing, and for 14 days you can still change your mind or export your library. After that your database, your stored files and your backups are erased, together with our subscription and usage records for the account, and any subscription still open is cancelled. We then remove your sign-in identity from Clerk. The record of which terms the account accepted is kept.

Hosted Nostos is in early access, and we are honest about what that means for your data: we take daily backups, but we do not promise that the service or its contents survive a failure of the infrastructure behind it. Keep your own copy of anything you cannot lose.

Your rights

You can ask us for a copy of what we hold about you, ask for it in a portable format, ask us to correct or delete it, and ask us to restrict or to stop processing it. Where we rely on your consent, you can withdraw it at any time. Email contact@nostos.page and we will answer within a month.

If you think we have handled your data badly, you can complain to the Swedish Authority for Privacy Protection (Integritetsskyddsmyndigheten, IMY), which is our supervisory authority.

Changes

If this policy changes in a way that matters, the date below changes with it.