Twitter has begun testing its Spaces feature, the voice-based chat rooms it first announced last month. In the thread announcing the test, the company said a very small group of users would be given the ability to create Spaces, but that in theory anyone could join them — though who would be allowed into any given space depends on the user who created it.

Twitter outlined last month how the first people to be given access to Spaces would be women and people from other marginalized communities, groups who are more likely than others to be subjected to abuse and harassment when trying to engage in conversations in regular, comment-based discussions on the platform.

Moderation seems to be a big focus of Spaces. Creators can control who can or cannot speak in the Space, and there are reporting and blocking features included in the first version.

Other features that are being tested include emoji reactions, being able to share tweets in a Space, and a “very early version” of live voice transcription.

At the moment, it seems like joining a Space only works from the Twitter mobile app — trying to join from the web just takes you to a “page not found” error. Strangely enough, joining one requires having Periscope integration enabled. That’s the live-streaming service that Twitter just announced it was shutting down, so it remains to be seen how Twitter plans to handle the technical backend of its voice chats once Periscope does disappear.