Antimatter
About

About Antimatter

A team chat you can own: free software, self-hosted, with no paywall.

What Antimatter is

Antimatter is a self-hosted team chat server: channels, direct messages and threads, file sharing and search, voice channels and calls, collaborative apps such as notes, whiteboards, kanban and playbooks, AI assistants, and integrations through webhooks, slash commands, bots and plugins.

Why it exists

Team chat holds an organisation's decisions, knowledge and history. We believe the people who rely on it should be able to run it themselves, read its code, and use all of it, without a license key deciding which features they may turn on.

So Antimatter does three things:

  • Everything is free software. Single sign-on with SAML, LDAP group sync, data retention, compliance export and the other features larger organisations need are part of Antimatter, on every server, with no licence key.
  • A new interface. Fusion, Antimatter's web interface, brings voice channels, roles and badges, onboarding and moderation tools to a chat-first layout.
  • Apps built in. Notes, whiteboards, todo lists, calendar, mail and polls come with the server, and AI features work with the models you choose, self-hosted ones included.

License

The Antimatter server is free software, licensed under the GNU Affero General Public License v3.0. The web app, the server's templates and translations, and its public Go packages (what the license calls the "Admin Tools and Configuration Files") are licensed under the Apache License 2.0. See LICENSE.txt and NOTICE.txt in the source repository.

Antimatter's plugins are free software too; each repository states its license.

Where it comes from

Antimatter started from the open-source Mattermost server (Copyright 2015-present Mattermost, Inc.) and has grown its own interface, apps and features since. It is an independent project, not affiliated with or endorsed by Mattermost, Inc.; Mattermost is a trademark of Mattermost, Inc.

Source code

Contributing

Bug reports, translations and code are welcome. Open an issue or a pull request on GitHub; the server's CONTRIBUTING.md explains how to set up a development environment.