Privacy policy

Last updated October 2026. This policy covers the Dirac apps for desktop, Android and the web, the hosted web app at app.dirac.chat and its preview at staging.dirac.chat, and the website dirac.chat. Dirac is published by Marduk Institute, LLC.

The short version

Dirac is a client for the Matrix network. We do not run the servers your messages pass through, there is no Dirac account, and the app sends nothing to us: no analytics, no telemetry, no crash reports and no advertising identifiers. We cannot read your messages and we do not know who uses Dirac.

The app does contact other parties in order to work. They are listed below.

Who the app contacts

• Your homeserver. Everything you do on Matrix goes to the homeserver you sign in to, and from there to the servers of the people you talk to. Those servers are run by other people, and their privacy policies apply to what they store. In end-to-end encrypted rooms, message content is encrypted on your device before it leaves.
• The sign-in screen. Before you sign in, the sign-in screen checks the homeserver that is selected there, which is matrix.org until you choose another. If a homeserver requires a CAPTCHA to register an account, Google's reCAPTCHA is loaded during registration.
• Calls. Voice and video calls connect to the call servers that the homeservers in the room designate. Those servers see your IP address, your Matrix ID and your device ID while you are in the call.
• Link previews. Most previews are fetched for you by your homeserver, which therefore sees the link. In encrypted rooms previews stay off until you allow them, because fetching one reveals the link. Some preview content is loaded by your device directly from other sites, which then see your IP address:
  • For links to X (Twitter) posts and profiles, Dirac asks the third-party service fxtwitter.com for the content and tells it your interface language. Images and video in those previews load from X's own servers.
  • For YouTube links, the player is embedded from youtube-nocookie.com when the preview is shown, unless you have turned media auto-load off. Google then sees which video was linked.
  • When a preview includes a video, the video is loaded from the site that hosts it.
• Updates. The desktop app checks GitHub for a new version each time it starts. GitHub sees your IP address when it does.
• Settings you sync. Some Dirac settings are stored in your Matrix account on your homeserver so that your devices agree: pinned rooms, per-room notification levels, and the list of people and rooms whose media you have chosen to hide (that sync can be turned off in settings). Your homeserver can read these. Your emoji usage history is also stored there, encrypted with keys from your account's secure storage.

What stays on your device

Your login session, your encryption keys, cached media, the search index for encrypted rooms and your local settings are stored on your device. Signing out removes them, except for a few desktop settings that are not tied to an account, such as the proxy and the tray options. Removing the app does not always remove its data folder; delete that folder, or clear the site's data in your browser, to remove everything.

Our websites

dirac.chat is a set of static pages with no scripts, no cookies of ours and no third-party resources. The hosted web app runs entirely in your browser and connects from there to your homeserver and to the other parties listed above; nothing you do in it passes through a server of ours. Both are delivered by Cloudflare, which processes your IP address and request details in order to deliver and protect them, under its own privacy policy.

What we receive

Only what you choose to send us. An email to support is handled by our mail provider and used to answer you. Issues and comments on GitHub are public, and GitHub's privacy policy applies to them.

Children

Dirac is not directed at children under 13, and we do not knowingly collect information from them. As described above, we do not collect information from anyone through the app.

Changes

If this policy changes, the new version is published here with a new date.

Contact

Questions about privacy: support@dirac.chat.