Privacy Policy

Last updated: 19 Oct 2026

This policy covers Chordant at https://chordant.app: the app, the public event pages, chat links, time pages and the calendar subscription link. The website of Hansestadt Humbug has its own privacy policy.

German version (Deutsch): https://chordant.app/datenschutz

In short

• Chordant stores what you create and write so that your groups can see it. Chordant shows no ads, sells no data and does no tracking.
• The data is stored on an OVHcloud server in Strasbourg, France.
• Chordant uses Google only when you switch it on: to sign in, to read your calendar, or to add your events to a calendar of its own called "Chordant". Each can be switched off on its own. Details are in section 8.
• Chordant sends no e-mails.
• You can delete your account in Settings. What you wrote in groups stays there under "Deleted account".

1. Controller

Alexander Busch
E-mail: contact@chordant.app

I run Chordant as a private individual. For questions about your data and to exercise your rights (section 21), write to me at contact@chordant.app.

2. What Chordant is

Chordant is a web app for groups: chats, events with polls and RSVPs, calendars and tasks. Each event has a public page where guests can answer without an account. On a time page, other people can suggest a time to meet you.

3. Server and page requests

When you open chordant.app, your browser sends your IP address, the address you requested and an identifier of your browser (user agent). The server needs these to send you the page.

• Chordant writes no access logs.
• To limit abuse, the server counts requests per IP address. This happens in memory only; the counters are never written to a file and are gone after a restart.
• When you sign in, Chordant stores the IP address and user agent with your session (section 4).
• Error messages of the server program go to the server's log. They can contain technical identifiers. There is currently no fixed deletion period for them.

Legal basis: Art. 6(1)(f) GDPR. My legitimate interest: delivering the pages securely and reliably, and limiting abuse.

Hosting. The server is in an OVHcloud data centre (OVH SAS, France) in Strasbourg. OVHcloud processes the data on my behalf (Art. 28 GDPR).

Domain and DNS. The domain chordant.app is registered with Cloudflare (Cloudflare, Inc., USA), and Cloudflare answers DNS queries for it. The pages' traffic does not pass through Cloudflare. DNS queries are usually made by your internet provider's DNS server, not by your device.

Certificates. The HTTPS certificate is issued by Let's Encrypt (Internet Security Research Group, USA). Let's Encrypt receives no data about you.

4. Your account

For an account, Chordant stores:

• your name and e-mail address,
• your password, only as a hash, or a passkey: its public key; the private key stays on your device,
• when you sign in with Google, the data in section 8.1,
• for each session: the time, IP address and user agent.

Your e-mail address is your identifier in Chordant. Anyone who knows it can add you to a chat. Chordant sends you no e-mails and does not verify the address.

Purpose: running your account, signing you in, protecting your account. Legal basis for the account: Art. 6(1)(b) GDPR; for the sessions' IP address and user agent: Art. 6(1)(f) GDPR (protecting your account from misuse).

Retention: account data until the account is deleted. A session is valid for 7 days. It is deleted when you sign out, and at the latest with the account.

5. What you create and write in Chordant

Chordant stores what you create in the app:

• chats, messages, attachments (images and files), reactions, acknowledgements and how far you have read,
• events: title, description, place, picture, private details, proposed times, votes, RSVPs and conditions,
• tasks and lists,
• contacts, your profile (picture, one line, pages for your contacts), your availability,
• time pages and calendar shares,
• your settings.

Images are stored as your device sends them. Only images that are too large are scaled down by the app first. A small image can therefore keep its metadata, such as where it was taken (EXIF/GPS). Remove it before uploading if you do not want that.

Who sees what.

• The members of a chat see its messages, events and tasks.
• Anyone with a chat link made by an owner of the chat sees the chat's name, its latest messages with their authors' names, and its events.
• Anyone with the link to an event sees the event and the names and answers of the people taking part. Private details are seen only by members of the chat and admitted guests.
• Your contacts see the profile pages you show them.

The purpose is the feature you use. Legal basis: Art. 6(1)(b) GDPR.

Retention: no fixed limit, until you or the chat delete it. For each chat, Chordant keeps a change log that delivers changes to every device. It is also kept without a fixed limit.

6. Guests without an account

Event page. When you answer on an event page, Chordant stores your name, your answer, your votes and how many people you bring. A cookie remembers your answer in this browser (section 14). Your own link brings it to another device.

Time page. When you suggest a time on someone's time page, Chordant stores your name, what it is about, the times you chose and, if you want, a way to reach you. This becomes an event that the owner of the time page and you can see. If you are one of their contacts, it is in your conversation with them.

E-mail address or phone number. Both are optional. Chordant also stores when you gave it, and next to which sentence in which language. Only the organiser of the event can see it. Chordant sends no e-mails and makes no calls.

Legal bases: for your name and answer Art. 6(1)(b) GDPR, because they are the feature you use. For an e-mail address or phone number, your consent, Art. 6(1)(a) GDPR. You can withdraw it at any time: remove it through your own link, or write to me.

Retention: no fixed limit. You can change your name and remove your contact details. The organiser can remove your answer.

7. Calendar subscription link

In Settings under "Calendar" you can create a subscription link. With it, a calendar such as Google Calendar, Apple Calendar or Outlook shows your Chordant events. You do not need a Google account for this.

• Content: the settled, not cancelled events from your chats that you have not declined, from 30 days ago to one year ahead. For each event: title, time, place, description and a link to the event. Private details are left out.
• The link is secret. Anyone who has it can read these events. Treat it like a password.
• Your calendar provider fetches the link. When you add the link there, the provider fetches it regularly from its own servers and stores the events in your account with them. Their privacy policy applies to that.
• New link or end it: in Settings you can create a new link; the old one then stops working. Or you end the subscription.
• The subscription link contains no data from Google.

Chordant stores the secret part of the link until you end the subscription or delete your account. Legal basis: Art. 6(1)(b) GDPR.

8. Google data

Chordant offers three ways to use Google. Each is optional and can be switched on and off on its own. Chordant asks Google only for the permission that the way needs, and only when you switch it on. Chordant works without any of them.

8.1 Sign in with Google

• Permission: openid, email and profile. Google shows: name, e-mail address and profile picture.
• What Chordant stores: your Google account ID, your name, your e-mail address, the address of your profile picture, and the sign-in token (ID token) carrying these. Access tokens issued by Google are stored encrypted.
• What for: to create your account and sign you in. Your name appears in your chats and events.
• No calendar: signing in does not ask for access to your calendar.
• Legal basis: Art. 6(1)(b) GDPR.
• Retention: until you disconnect Google as a sign-in method in Settings, or delete your account.

8.2 Read Google Calendar

• Permission: https://www.googleapis.com/auth/calendar.events.owned.readonly, which Google describes as "See the events on Google calendars you own".
• What Chordant reads: only the events of your primary calendar, from 7 days ago to 90 days ahead. Chordant reads only when needed: when a page needs your busy times and its copy is older than ten minutes, or when you ask for it in Settings. Chordant reads nothing in the background.
• What Chordant stores: a copy of these events with these fields: the event's ID and its series ID, title, start, end, status (confirmed, tentative, cancelled), whether it is marked "free", whether it is private, its recurrence rule, the ID of a single occurrence of a series, a version marker and the time it last changed. Also the time of the last read, Google's sync marker and, if any, a word for the last error. Not stored: description, location, attendees, organiser, attachments and conference links.
• What for:
  • In a poll, Chordant shows you, on your own row, which time overlaps which of your events, for example "overlaps your calendar: Dentist (10:00–11:00)".
  • Your calendar in Chordant shows your busy times.
  • If you create a calendar share, others see a slice of it (see below).
  • Your time pages offer only times when you are free.
• Who sees what:
  • You see the titles and times of your events.
  • Members of a chat, or your contacts, see something only if you create a calendar share for them. You choose whether they see only "busy" in half-hour steps, or titles and times; on which days and at which hours; and for how long. Private events always appear only as "busy", events marked "free" not at all. You can end a share at any time.
  • Anyone with the link to one of your time pages sees only free start times in half-hour steps for the next 14 days, no titles.
  • Nobody else. Google data does not appear on event pages, through chat links, or in the subscription link.
• Legal basis: your consent, Art. 6(1)(a) GDPR. You give it when you switch reading on and confirm it at Google. A calendar share is a separate consent that you give by creating it.
• Retention: the copy exists while reading is switched on. When you switch it off, Chordant deletes the copy and the connection immediately.

8.3 Add to Google Calendar

• Permission: https://www.googleapis.com/auth/calendar.app.created, which Google describes as "Make secondary Google calendars, and see, create, change, and delete events on them".
• What Chordant does: Chordant creates a calendar of its own called "Chordant" in your Google account. It holds the same events as the subscription link (section 7). For each event Chordant writes the title, time, place, description and a link to the event, no private details.
  • When the title, time, place or description changes, Chordant changes the entry.
  • When an event is cancelled, you decline it, you leave the chat, or it lies more than 30 days in the past, Chordant takes the entry out.
  • Chordant brings the calendar up to date right after your own changes and otherwise every five minutes, so changes made by others appear a few minutes later.
  • An entry you delete in Google is added again only when the event changes.
• Only this calendar: with this permission Chordant cannot see or change any of your other calendars.
• What Chordant stores: the ID of the "Chordant" calendar, its time zone, whether adding is switched on, when Chordant last wrote, and, if there was one, a word for the last error. For each entry: the ID of the event, the ID of the entry at Google, a checksum of what Chordant last wrote, and when.
• Who sees what: you see the "Chordant" calendar in Google Calendar, as does anyone you share it with in Google. Google processes it under its own terms, like your other calendars.
• Legal basis: your consent, Art. 6(1)(a) GDPR.
• Retention: while adding is switched on. When you switch it off, unlink Google as a sign-in method, or delete your account, Chordant deletes the "Chordant" calendar from your Google account and the stored details. If the deletion at Google fails, Chordant tells you, and you delete the calendar yourself in Google Calendar.
• If you delete the calendar in Google: Chordant notices at its next update, switches adding off and does not create the calendar again. It deletes the entry IDs, and revokes its access at Google if reading is off too. So that Settings can tell you, Chordant keeps a note that the calendar was deleted until you switch adding on again, unlink Google as a sign-in method, or delete your account.

8.4 Switching off and revoking access

• In Chordant: under Settings → Calendar.
  • Reading off: Chordant deletes the copy of your calendar.
  • Adding off: Chordant deletes the "Chordant" calendar from your Google account.
  • Both off: Chordant also revokes its access at Google. You can still sign in with Google.
• Unlinking Google as a sign-in method: Chordant deletes the copy, the "Chordant" calendar and the access tokens, and revokes its access at Google.
• At Google: at https://myaccount.google.com/permissions, choose Chordant and remove its access. After that Chordant can no longer read or add anything, and Settings shows this after its next update. You delete the copy in Chordant by switching reading off in Chordant. You then delete the "Chordant" calendar yourself in Google Calendar, because Chordant no longer has access.
• Deleting your account: Chordant deletes the copy, the connection, the access tokens and the "Chordant" calendar in your Google account, and revokes its access at Google. If any of this fails at Google, Chordant tells you after the deletion. Then remove the access at https://myaccount.google.com/permissions and the calendar in Google Calendar yourself.

8.5 What Chordant does not do with Google data

Chordant's use and transfer to any other app of information received from Google APIs will adhere to the Google API Services User Data Policy, including the Limited Use requirements.

This means:

• Chordant uses Google data only for the features in sections 8.1 to 8.3.
• Chordant never uses Google data to train artificial intelligence or machine learning models, neither general nor its own.
• Chordant does not sell Google data and does not use it for advertising.
• Chordant does not transfer Google data to anyone, including GitHub and Anthropic (section 12). The only exceptions are the people you choose with a calendar share, OVHcloud as the hosting provider acting on my behalf, and a legal obligation.
• Nobody reads your Google data unless you ask for it in a specific case (for example when you report a problem), it is needed to deal with abuse, or the law requires it.
• The data travels only encrypted (HTTPS) between Google, the server and your browser. The access tokens are stored encrypted in the database.
• The encrypted database backups (section 20) also contain the calendar copy. They are deleted after at most twelve months.

9. Sign in with Microsoft

Chordant can offer signing in with a Microsoft account. As long as the sign-in page shows no button for it, it does not happen. If you sign in with Microsoft, Chordant receives your account ID, your name and your e-mail address from Microsoft (Microsoft Corporation, USA). Chordant does not read calendar data from Microsoft. Legal basis: Art. 6(1)(b) GDPR. Retention as in section 8.1.

10. Notifications (Web Push)

When you switch notifications on, your browser creates a subscription with its push service. That is the service of your browser's maker, for example Google (Chrome), Mozilla (Firefox), Apple (Safari) or Microsoft (Edge).

• Chordant stores the subscription's address, its keys, your browser's language and the app in which you made it.
• For a new message in one of your chats, Chordant sends the chat's name and "Author: text", cut to 120 characters. The content is encrypted so that only your browser can read it. The push service holds the notification for at most one hour.
• Legal basis: Art. 6(1)(b) GDPR and § 25(2) no. 2 TDDDG.
• Retention: until you sign out in that browser, the push service reports the subscription as invalid, or you delete your account.

11. Place search

When you type a place for an event, Chordant's server sends your search text and the language to Photon, an address search based on OpenStreetMap run by komoot GmbH in Germany. komoot does not learn your IP address or your account. Chordant keeps the answers in memory for up to 24 hours. Legal basis: Art. 6(1)(b) GDPR.

12. Feedback

You can write to me through "Send feedback" in Settings.

• What is stored: your text, the mood you pick, the page in the app and the pages before it, window size, pixel density, the app's version, your browser's user agent and any screenshots you attach. Also a status and my answer.
• Who sees it: you and me.
• GitHub: I keep a copy without your name, your e-mail address and your screenshots as an issue in a private repository at GitHub (GitHub, Inc., USA): the text, the pages, the window size, the version, the time and an ID of the report.
• Anthropic: I go through these issues with Claude, an AI assistant by Anthropic (Anthropic PBC, USA), to find and fix problems.
• Screenshots stay on Chordant's server.
• Please do not put other people's personal data into feedback.
• Legal bases: Art. 6(1)(b) GDPR for the report and the answer. Art. 6(1)(f) GDPR for GitHub and Anthropic; my legitimate interest is handling reports with the tools I build Chordant with.
• Retention: the report and its screenshots until you delete your account. The copy at GitHub has no fixed limit; I delete it on request.

13. Signing in to other apps with Chordant

Two other apps of mine can sign you in with your Chordant account: the Hansestadt Humbug website (hahu.chordant.app) and train4life (t4l.chordant.app). Only when you sign in there does the app learn your account ID, your name and your e-mail address. Legal basis: Art. 6(1)(b) GDPR.

14. Cookies and browser storage

Chordant sets only cookies that the feature you use needs:

In your browser's storage (localStorage) the app keeps your theme, language, views, the hints you have seen and the calendar layers you hid per chat. A service worker stores the app's program files so that it starts faster.

Chordant uses no analytics, no tracking and no content from other providers: fonts, images and code come from chordant.app. When you follow a link out of Chordant, the target does not learn which Chordant page you came from.

Legal basis for cookies and browser storage: § 25(2) no. 2 TDDDG (German Telecommunications Digital Services Data Protection Act); for the processing Art. 6(1)(b) GDPR.

15. Links to other services

"Add to calendar" offers, among others, a link to Google Calendar or Outlook with the event filled in. Only when you click it does your browser send the title, time and place to that service. The same goes for other links out of Chordant, such as to OpenStreetMap. Nothing is loaded from there before.

16. Recipients at a glance

Other people in Chordant see your data as sections 5 to 8 describe.

17. Transfers to third countries

Some recipients are in the USA or may transfer data there (section 16). For the USA there is an adequacy decision of the European Commission for companies certified under the EU-US Data Privacy Framework (Art. 45 GDPR). Google LLC and Microsoft Corporation are certified under it. For the other recipients in the USA, where they are not certified, transfers rely on appropriate safeguards under Art. 46 GDPR, such as the European Commission's standard contractual clauses.

18. Retention at a glance

19. Deleting your account

You delete your account in Settings under "Delete my account". If you have a password, Chordant asks for it.

• If you are the only owner of a chat that other people are still in, Chordant refuses and names those chats. Make someone else an owner there first, or delete the chat.
• What goes: your memberships, sessions, sign-in methods, passkeys, settings, push subscriptions, contacts, availability, feedback, calendar connections with their copy, the "Chordant" calendar in your Google account, calendar shares, time pages, your profile, your personal tasks and lists. Chats nobody else is in are removed as well.
• What stays: messages, events and answers you wrote in groups. They are part of the group's shared record. Instead of your name they show "Deleted account".
• Google: see section 8.4.

If you want individual remaining contributions deleted as well, write to me.

20. Backups

Usually once a day I copy the database to my own computer and encrypt the copy. I keep the newest 14 copies and, for each month, the first one for 12 months. Deleted data can therefore remain in a backup for up to 12 months. I use the copies only to restore Chordant after a failure. Legal basis: Art. 6(1)(f) GDPR; my legitimate interest is preventing data loss.

21. Your rights

You have the right to

• access your data (Art. 15 GDPR),
• rectification (Art. 16 GDPR),
• erasure (Art. 17 GDPR),
• restriction of processing (Art. 18 GDPR),
• data portability (Art. 20 GDPR),
• object to processing based on Art. 6(1)(f) GDPR (Art. 21 GDPR).

You can withdraw consent at any time (Art. 7(3) GDPR). This applies from then on; what happened before stays lawful. For Google, switching the feature off is enough (section 8.4).

Write to me at contact@chordant.app.

You can complain to a data protection supervisory authority (Art. 77 GDPR), in particular in the country where you live or work or where you think the infringement took place.

Whether you must provide data: you do not have to give Chordant any data. Without a name, an e-mail address and a sign-in method Chordant cannot create an account, and without a name it cannot count an answer on an event page.

22. No automated decisions

Chordant makes no automated decisions within the meaning of Art. 22 GDPR and does not evaluate people. When an event becomes settled by a rule, for example because everyone has answered or the deadline has passed, this follows fixed rules of the app.

23. Changes

When Chordant changes, I update this policy. The version published here applies. The date at the top says when it was last updated.