# About chat bridges :::info :wave: Welcome! We presume that you've arrived via a link shared in your chat tool, saying something about "bridges". The purpose of this resource is to add some clarity on what _bridging_ means. ::: When a channel is set up to _bridge_ with other channels, it means that someone has arranged so that messages are shuttled between where you are, and some other chat tool (eg. another Slack team). Normally, each chat tool is an isolated kingdom -- people in one of your Slack teams can't talk to people in another unless they create another account and start logging in. But bridges can work around that. The channels to bridge are specifically chosen, and usually share interests. Bridges are not limited to being between just two rooms, but can in fact sync messages between any number of chat rooms in any number of chat tools/teams. We're not even limited to just connecting Slacks -- we can connect [any number of supported chat tools](https://github.com/42wim/matterbridge#requirements). There are some things to note: ### Notes & Caveats - **Message edits** will behave normally, and messages on the other side will be updated. - **Deleting a message** on the side of the original message will delete the message on the bridged side. - **Reaction emoji** will NOT be sent over the bridge. This unfortunately disrupts some "voting" tactics. - **Threaded replies** will NOT be preserved, but "unthreaded" and seen as regular messages on the other side. ### Suggestions - **Leave channel on one side** of bridge to avoid duplicate notifications. - Discuss within your channel about **"preferring" one side** of the bridge, if possible. This will help mitigate the caveats above. (We would suggest favoring the most accessible chat tool.) - **Update your username** to be the same on both ends. ### How this works We use [**Matterbridge**][matterbridge] as the software that creates the bridge. The [`matterbridge-heroku` helper repo][matterbridge-heroku] allows Matterbridge to run on the [Heroku][] hosting platform. It is hosted by [@patcon](https://twitter.com/patconnolly) primarily for [EDGI][], but is not inconvenient to use for other projects as well. The bridge is configured [like so][matterbridge-config]. <!-- Links --> [matterbridge]: https://github.com/42wim/matterbridge [matterbridge-heroku]: https://github.com/edgi-govdata-archiving/matterbridge-heroku [matterbridge-config]: https://github.com/edgi-govdata-archiving/matterbridge-heroku/blob/edgi/config/config-heroku-template.toml [EDGI]: https://envirodatagov.org/about/ [Heroku]: https://www.heroku.com/about