CoralDuck Open CoralDuck

Privacy and legal notice

CoralDuck is a cohort analysis tool that runs in your browser. This page explains what happens to your data when you use this site, and who runs it.

Who is responsible

This site is run by me, Klaus Eckelt, in Steyr, Austria. I am responsible for the data processing described here. You can reach me at klaus@eckelt.info.

Your data stays on your device

  • When you load a file, your browser reads it. The database, DuckDB, runs inside your browser tab and does all the analysis there. Your data is not uploaded to this server or to anyone else.
  • Your saved sessions are kept in your browser’s own storage on your device (the Origin Private File System). You can delete them from the app’s Welcome screen. The app also keeps a few small settings in your browser, such as light or dark mode.
  • Clearing this site’s data in your browser settings removes all of it. I cannot see it, so I cannot delete it for you.

Loading a dataset from a URL

You can load a dataset from a web address: by typing it into the app, or by opening a link that names one (a ?data= link). Your browser then fetches the file directly from that host. This server is not involved. The host sees your IP address and browser details, like any website you visit, and its own privacy policy applies.

What this server does

  • The server only delivers the files that make up this site. It needs your IP address to send them to you, but it keeps no access log, so it does not record your IP address or which pages you open.
  • The site sets no cookies of its own. While access is limited, the sign-in sets two, described below.
  • There are no analytics, no trackers and no ads. Fonts, scripts and images all come from this server; the site loads nothing from other websites.
  • Links to other websites, such as GitHub or YouTube, are plain links. Nothing is loaded from them until you click one.

Sign-in while access is limited

For now, the app is open only to invited people. Until the project is public, this applies:

  • Opening the app at /app/ asks you to sign in with Google. This is only to check that your account has been invited. The pages outside /app/, like this one, need no sign-in.
  • The sign-in is handled by a login gateway in front of this server (traefik-forward-auth), not by the app.
  • Google asks you to share your email address and basic profile. Only your email address is used, to compare it with the list of invited accounts. Nothing else from your Google account is read or kept.
  • After you sign in, your browser keeps a signed cookie named _forward_auth. It holds your email address and an expiry time, and it expires after 12 hours. During the sign-in, a second cookie, whose name starts with _forward_auth_csrf, holds a random value that protects the sign-in from forgery; it is removed when the sign-in is done.
  • The address you sign in with is only compared with the list of invited accounts. It is not stored, not shared with anyone, and not used for anything else.
  • If you are invited, your email address is on the gateway’s list of invited accounts on this server. Ask me and I remove it.
  • The sign-in gateway keeps no record of sign-ins: no email address and no IP address.
  • The legal basis is my legitimate interest in limiting the app to invited people while it is not public (Art. 6(1)(f) GDPR).
  • Google processes the sign-in under its own privacy policy.

Your rights

The only personal data I keep is the list of invited email addresses, and any emails you send me.

Under the GDPR you have the right to see the data I hold about you, and to have it corrected or deleted. You can also ask me to restrict its use, object to its use, or give it to you in a portable form. To use any of these rights, email klaus@eckelt.info.

You also have the right to complain to a data protection authority. In Austria, this is the Datenschutzbehörde.

This notice was last updated on .