Slack Connect without Slack – chatting with other companies over Matrix

Email works between companies because every mail server speaks the same standard: your server sends, theirs receives, nobody needs an account with the other. Team chat has mostly not worked like that. Slack Connect links Slack workspaces, Microsoft Teams links Microsoft identities – each inside one vendor’s network. Matrix brings the email principle to chat.

What Matrix is

Matrix is an open, documented standard for chat between servers. Every company can run its own Matrix server; servers exchange messages directly. This is called federation. Many apps and servers speak it – Element is the best known, XenRooms is another.

In XenRooms every company has a Matrix server of its own. Your chat address looks like @anna:firma.xenrooms.app – the part after the colon is your company’s server, the same way the part after the @ is the domain in an email address.

How a shared channel works

1. Someone in your team creates a channel or a direct message and invites a person from another company by their Matrix address.
2. The other person’s server receives the invitation; they accept it in their own app – XenRooms, Element or another Matrix app.
3. From then on, both servers keep a copy of the channel and send each other new messages.

Nobody needs an account with the other company. In XenRooms a shared channel is marked “External”, and people from outside are marked “Other company” with their domain, so nobody posts something internal by mistake.

What your administrator decides

Federation is powerful, so it needs a switch. In XenRooms the administrator chooses one of three settings:

• Internal only – no chat with other companies at all.
• Xenaxio companies and a list (the default) – companies on Xenaxio and XenRooms plus the servers the administrator adds.
• All Matrix servers.

Invitations from outside are never accepted automatically, and unwanted senders can be reported and blocked. New XenRooms Free companies can chat with other companies after seven days – a simple protection against spam.

Where shared messages live

Say it plainly: messages in a channel shared with another company are stored on your server and on theirs – exactly like an email you send. Their rules apply on their server. Everything not shared stays on your company’s server only.

Matrix and encryption

Matrix supports end-to-end encryption, and Element turns it on by default. XenRooms works like Slack instead: no end-to-end encryption, so search, the AI summary and the administrator’s control work; messages still travel encrypted (TLS). Both still talk to each other in unencrypted rooms.

Why an open standard matters

• Partners choose their own tool. They do not have to join your vendor.
• No lock-in. If you change provider, the protocol stays the same.
• Your server, your rules. The administrator sets who can reach your team.

Want to try it? Start XenRooms for free and invite a partner, or read more about chat with other companies and what Matrix is.