Slash commands in Mattermost and Slack allow you to control GitLab and view GitLab content right inside your chat client, without having to leave it. For Slack, this requires a [project service configuration](../user/project/integrations/slack_slash_commands.md). Simply type the command as a message in your chat client to activate it.
Note that if you are using the [GitLab Slack application](https://docs.gitlab.com/ee/user/project/integrations/gitlab_slack_application.html) for
your GitLab.com projects, you need to [add the `gitlab` keyword at the beginning of the command](https://docs.gitlab.com/ee/user/project/integrations/gitlab_slack_application.html#usage).