Chat and text safety

Non-negotiable rules (Roblox Community Standards)

1. Player-to-player conversation must go through TextChatService TextChannels (handles filtering, privacy/parental settings, and abuse reporting). The legacy Chat service/ChatService Lua modules are gone — TextChatService is the only chat system.
2. Any text authored by one player and shown to another (pet names, signs, guild names, trade notes, custom UI) must be filtered with TextService:FilterStringAsync on the server before display — and re-filtered when loaded from a DataStore later.
3. Editable text others can see (signs, bulletin boards) needs a rate limit of at least 1 minute.
4. Respect privacy settings with CanUserChatAsync/CanUsersChatAsync/CanUsersDirectChatAsync and mark direct-message channels with TextChannel:SetDirectChatRequester().

Not chat (no filtering needed): your own UI text, game status messages, admin announcements you write.

Filtering player-authored text

--!strict
local TextService = game:GetService("TextService")

-- Broadcast (e.g. a sign everyone sees). Returns nil if filtering failed: then show nothing.
local function filterForEveryone(text: string, fromUserId: number): string?
	local ok, result = pcall(function()
		local filterResult = TextService:FilterStringAsync(text, fromUserId, Enum.TextFilterContext.PublicChat)
		return filterResult:GetNonChatStringForBroadcastAsync()
	end)
	return if ok then result else nil
end

-- Per-recipient (respects each viewer's age/settings; e.g. a private note).
local function filterForUser(text: string, fromUserId: number, toUserId: number): string?
	local ok, result = pcall(function()
		local filterResult = TextService:FilterStringAsync(text, fromUserId, Enum.TextFilterContext.PrivateChat)
		return filterResult:GetNonChatStringForUserAsync(toUserId)
	end)
	return if ok then result else nil
end

return { forEveryone = filterForEveryone, forUser = filterForUser }

• Filter on the server, after the player submits (not per keystroke); rate-limit and length-cap first.
• On failure, fail closed (show nothing / a placeholder), never the raw text.
• Store the raw text if you must, but always filter at display time (filters and viewer settings change).
• Numbers-only or short strings can still be filtered (hashtags ###); design UI for that.

TextChatService essentials

• Defaults: CreateDefaultTextChannels creates RBXGeneral and RBXSystem; CreateDefaultCommands adds built-ins (/whisper, /team, /mute, ...). Configure look via ChatWindowConfiguration, ChatInputBarConfiguration, BubbleChatConfiguration (or disable and build your own UI with TextChannel:SendAsync and TextChatService.MessageReceived).
• Flow: client TextChannel:SendAsync(text) → server TextChannel.ShouldDeliverCallback(message, textSource) per recipient → filtering → clients' OnIncomingMessage callbacks → display.
• Callbacks must not yield. ShouldDeliverCallback is server-only; TextChatService.OnIncomingMessage and TextChannel.OnIncomingMessage are client-only (formatting).
• System messages: channel:DisplaySystemMessage(text) on the client (local only).
• Custom channels (team, party, proximity): create TextChannels under TextChatService on the server, channel:AddUserAsync(userId) to add members; check the returned TextSource's CanSend.

--!strict
-- Client: chat tags and colors via OnIncomingMessage (formatting only; never yields).
local Players = game:GetService("Players")
local TextChatService = game:GetService("TextChatService")

TextChatService.OnIncomingMessage = function(message: TextChatMessage)
	local properties = Instance.new("TextChatMessageProperties")
	local source = message.TextSource
	if source then
		local player = Players:GetPlayerByUserId(source.UserId)
		if player and player:GetAttribute("VIP") then
			properties.PrefixText = `<font color="#F5CD30">[VIP]</font> {message.PrefixText}`
		end
	end
	return properties
end

--!strict
-- Server: a /spawn command, restricted to admins.
local Players = game:GetService("Players")
local TextChatService = game:GetService("TextChatService")

local ADMINS: { [number]: boolean } = { [123456] = true }

local command = Instance.new("TextChatCommand")
command.Name = "SpawnCommand"
command.PrimaryAlias = "/spawn"
command.Parent = TextChatService

command.Triggered:Connect(function(source: TextSource, unfilteredText: string)
	if not ADMINS[source.UserId] then
		return
	end
	local player = Players:GetPlayerByUserId(source.UserId)
	print(`{player and player.Name} ran: {unfilteredText}`)
end)

More: proximity chat, team channels, custom UI, and migrating from legacy chat: references/chat-recipes.md.

Quick Words (preset safe phrases for all ages, for coordinating where free chat is limited): add game-specific ones in Creator Hub → game → Configure → Chat → Quick Words — up to 3 categories of 3–10 phrases, in English (auto-translated), reviewed before going live. They replace the default categories; General stays.

PolicyService (per-user restrictions)

PolicyService:GetPolicyInfoForPlayerAsync(player) (server, pcall) returns flags such as ArePaidRandomItemsRestricted, IsPaidItemTradingAllowed, AreAdsAllowed, AllowedExternalLinkReferences, IsSubjectToChinaPolicies, IsContentSharingAllowed. Gate loot boxes, trading, ads, and links to social media (only show platforms listed in AllowedExternalLinkReferences) per player.

Related skills

roblox-security (rate limits, validation), roblox-ui (text input UI), roblox-monetization (paid random items), roblox-data-stores (storing user text).