Cross-server

The shared secret, the topics, the server list, and what reaches every server.

Some actions have to reach servers you are not in: an announcement, a vote, a lockdown, a shutdown. They travel over MessagingService.

The envelope

Every message is wrapped:

{
    secret = Secret.value,
    origin = game.JobId,
    data   = { … },
}

A message whose secret does not match is dropped and a warning is logged. That is the entire authentication model, and it is why Server/SharedSecret.luau must not keep its placeholder value.

The secret is the only thing protecting these topics

Anything that can publish to your topics with a matching secret can shut your game down. The file ships with REPLACE_WITH_YOUR_OWN_GUID_BEFORE_SHIPPING, which is a value every copy of this system shares.

Generate a GUID, paste it in, and keep the file out of anything public. It lives in Server/ and is never replicated to clients.

The topics

Topic	Carries
`uxr.announcement.v2`	A global server message
`uxr.GlobalPost.v2`	A global post from the panel
`uxr.alert.v2`	A high-priority alert banner
`uxr.AdminChat.v2`	The cross-server admin chat
`uxr.voteStart.v2`	A global vote opening
`uxr.voteCast.v2`	A vote being cast
`uxr.lockdown.v2`	A global lockdown or its lifting
`uxr.shutdown.v2`	A global shutdown
`uxr.migrate.v2`	A global migration
`uxr.place.v2` and `uxr.forcePlace.v2`	Cross-server teleports
`uxr.serverList.v2`	The heartbeat that builds the server list

All of them are versioned in the name, so a future protocol change can run alongside the current one.

The server list

Every public server publishes a heartbeat every fifteen seconds with its job id, its player count and its region. The Servers page shows the result.

Entries that have not been heard from for 45 seconds are removed, so a server that dies disappears within a minute.

Private servers stay out of the list

The heartbeat loop only runs while game.PrivateServerId is empty. A paid private server never advertises itself, which is the right default for a feature meant to show your public servers.

What crosses servers

Command	Reach
`globalservermessage`	Every server
`globalAlert`	Every server
`globalVote`	Every server
`globallockdown`, `globalunlockdown`	Every server
`gshutdown`	Every server
`gmigrate`	Every server
`globalPlace`, `globalForcePlace`	Teleports players from any server
`follow`, `join`	Move you into another player's server

Everything else is local to the server you are in.

Votes

A vote has a question, a list of options, a duration and an id. Local votes are broadcast to this server only; global votes go out over the topic and every server opens the same vote.

Stage
Start	Options are registered, every client shows the vote
Cast	Each vote updates the running tally for everybody
End	The result is broadcast after the duration, plus a quarter
Cleanup	The vote is dropped ten seconds later

Global vote tallies are per server

Each server keeps its own count of the votes it hears about. Casts are published, so the counts converge, but there is no single authority holding the true total and no ordering guarantee between servers.

Read the result as a strong indication rather than as an election.

vote and globalVote are Head Admin. The vote command has a ten second rate limit of its own, which is the highest in the shipped config.

Reliability

MessagingService is best-effort. A message may be delayed, and under heavy load it may be dropped. Everything here is designed around that:

Feature	If a message is lost
Announcement	One server misses it
Server list	The entry ages out and comes back on the next heartbeat
Global lockdown	One server stays open
Global shutdown	One server stays up

For a shutdown that has to be complete, check the Servers page afterwards and finish the job by hand.

Roblox limits how much you can publish

Publishing is rate-limited per universe, and the limit scales with player count. A publish failure is logged as a warning rather than retried.

In practice the heartbeat is the only frequent publisher, and at one message per server every fifteen seconds it stays well clear.

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