roblox-textchat-channels

Roblox custom chat: channels, tabs, cross-server

Modern games use TextChatService (ChatVersion = TextChatService). Here's how to get real, switchable channel tabs and cross-server delivery — the non-obvious parts.

Two channels shown as TABS (the key that's OFF by default)

The modern default chat merges everything into one window UNLESS you enable channel tabs. Two settings, best set as place properties in Edit mode (setting them at runtime is too late — the chat server boots first — and can break the default wiring):

• TextChatService.CreateDefaultTextChannels = false — drop the default RBXGeneral/System tabs so you get EXACTLY your channels.
• TextChatService.ChannelTabsConfiguration.Enabled = true — this is the switch that makes channels appear as tabs. ChannelTabsConfiguration is an auto-created child of TextChatService. Once on, each custom `TextChannel` auto-becomes a tab labelled by its `Name` — no per-channel config needed.

⚠️ Both are place properties → they need a place SAVE to persist across sessions. Also set them in ChatService.start() at runtime as a fallback, but the Edit-mode/place value is what reliably takes effect on boot.

Creating the channels (server)

With CreateDefaultTextChannels = false, the TextChannels container is NOT auto-created. So:

local container = TextChatService:FindFirstChild("TextChannels")
if not container then
    local f = Instance.new("Folder"); f.Name = "TextChannels"; f.Parent = TextChatService; container = f
end
-- Tab order = CREATION order (there is NO reorder API — it's an open devforum feature request).
-- Create the channel you want leftmost FIRST.
local here   = Instance.new("TextChannel"); here.Name   = "Here";   here.Parent   = container
local global = Instance.new("TextChannel"); global.Name = "Global"; global.Parent = container

Add every player to each channel on join so they can read + type: channel:AddUserAsync(player.UserId) (creates their TextSource; pcall-guard it; it yields, so calls run in order).

Displaying messages into a channel (client)

textChannel:DisplaySystemMessage(richText) shows a message on the calling client only, in that channel's tab. Use it to render a game-event feed (pulls, announcements) into a specific tab. RichText works — but escape user-supplied text first (s:gsub("&","&amp;"):gsub("<","&lt;"):gsub(">","&gt;")) or players can inject </font> tags.

Cross-server (chat or an event feed) via MessagingService

DisplaySystemMessage is local-only, and normal channel delivery is per-server. To go cross-server:

• Event feed (e.g. broadcast a rare drop to all servers): on the event, MessagingService:PublishAsync(TOPIC, payload) with payload.j = game.JobId. SubscribeAsync(TOPIC, ...) on every server; when data.j ~= game.JobId (another server), fire a RemoteEvent to local clients → they DisplaySystemMessage it. Fire the LOCAL copy instantly via FireAllClients and skip your own JobId in the subscriber to avoid a double.
• Cross-server player chat: set the channel's ShouldDeliverCallback (runs on the SERVER per recipient) — relay the message once (dedupe by message.MessageId) via MessagingService:PublishAsync, and return true to still deliver locally. Other servers receive it and DisplaySystemMessage it for their clients (local = native message, remote = system message; acceptable).
• Always `pcall`-guard MessagingService — it errors when API access is off (Studio) or rate-limited (~150 + 60×players msgs/min per topic). Then the feature degrades to in-server only instead of crashing.

Testing caveats

• Cross-server can't be tested in solo Studio (one server) — MessagingService round-trips to self only. Verify the in-server path (channels exist, player is a member, DisplaySystemMessage renders) and wire the cross-server path carefully.
• Fire a fake event via Net.event("X"):FireAllClients(payload) from the Server datamodel, then screen_capture the chat (the window pops on a new message) to confirm formatting + which tab it lands in.

Lesson

Before declaring "the platform can't do X" for chat/UI, check create.roblox.com/docs and the devforum — the modern chat is more capable than it first looks (channel tabs, gradients, configs all exist). Docs: create.roblox.com/docs/chat/chat-window ; devforum "Channel Tabs & UI Gradient Now Available in TextChatService".