How to use CollectionService tags in Roblox

-- Script in ServerScriptService named Spinners.
-- Every part tagged "Spinner" turns slowly.
local CollectionService = game:GetService("CollectionService")
local RunService = game:GetService("RunService")

local TAG = "Spinner"
local DEGREES_PER_SECOND = 90

local spinning: { [BasePart]: boolean } = {}

local function onAdded(instance: Instance)
	if instance:IsA("BasePart") then
		instance.Anchored = true
		spinning[instance] = true
	end
end

local function onRemoved(instance: Instance)
	if instance:IsA("BasePart") then
		spinning[instance] = nil
	end
end

for _, instance in CollectionService:GetTagged(TAG) do
	onAdded(instance)
end
CollectionService:GetInstanceAddedSignal(TAG):Connect(onAdded)
CollectionService:GetInstanceRemovedSignal(TAG):Connect(onRemoved)

RunService.Heartbeat:Connect(function(deltaTime: number)
	local turn = CFrame.Angles(0, math.rad(DEGREES_PER_SECOND * deltaTime), 0)
	for part in spinning do
		part.CFrame *= turn
	end
end)

-- ModuleScript in ReplicatedStorage named TagBinder.
-- bind(tag, setup) -> stop: setup(instance) runs for every instance with the tag, now and later.
-- If setup returns a function, it runs when the tag is removed or the instance is destroyed.
local CollectionService = game:GetService("CollectionService")

local TagBinder = {}

type Cleanup = () -> ()

function TagBinder.bind(tag: string, setup: (instance: Instance) -> Cleanup?): () -> ()
	local cleanups: { [Instance]: Cleanup } = {}

	local function added(instance: Instance)
		if cleanups[instance] then
			return -- already set up
		end
		local ok, result = pcall(setup, instance)
		if not ok then
			warn("[TagBinder] " .. tag .. " setup failed for " .. instance:GetFullName() .. ": " .. tostring(result))
		elseif typeof(result) == "function" then
			cleanups[instance] = result
		end
	end

	local function removed(instance: Instance)
		local cleanup = cleanups[instance]
		cleanups[instance] = nil
		if cleanup then
			cleanup()
		end
	end

	local removedConnection = CollectionService:GetInstanceRemovedSignal(tag):Connect(removed)
	for _, instance in CollectionService:GetTagged(tag) do
		task.spawn(added, instance)
	end
	local addedConnection = CollectionService:GetInstanceAddedSignal(tag):Connect(added)

	-- call the returned function to stop the binding and clean everything up
	return function()
		addedConnection:Disconnect()
		removedConnection:Disconnect()
		for instance in cleanups do
			removed(instance)
		end
	end
end

return TagBinder

-- Script in ServerScriptService named LavaParts.
local ReplicatedStorage = game:GetService("ReplicatedStorage")

type TagBinderModule = { bind: (string, (Instance) -> (() -> ())?) -> () -> () }
local TagBinder = require(ReplicatedStorage:WaitForChild("TagBinder")) :: TagBinderModule

TagBinder.bind("Lava", function(instance: Instance)
	if not instance:IsA("BasePart") then
		return nil
	end
	local connection = instance.Touched:Connect(function(hit: BasePart)
		local humanoid = hit.Parent and hit.Parent:FindFirstChildOfClass("Humanoid")
		if humanoid then
			humanoid.Health = 0
		end
	end)
	return function()
		connection:Disconnect()
	end
end)

-- LocalScript in StarterPlayerScripts named PickupGlow.
local ReplicatedStorage = game:GetService("ReplicatedStorage")

type TagBinderModule = { bind: (string, (Instance) -> (() -> ())?) -> () -> () }
local TagBinder = require(ReplicatedStorage:WaitForChild("TagBinder")) :: TagBinderModule

TagBinder.bind("Pickup", function(instance: Instance)
	if not instance:IsA("BasePart") then
		return nil
	end
	local light = Instance.new("PointLight")
	light.Color = Color3.fromRGB(255, 220, 120)
	light.Range = 8
	light.Parent = instance
	return function()
		light:Destroy()
	end
end)

-- In a setup function: read a per-part setting, with a default.
local function speedOf(part: BasePart): number
	local value = part:GetAttribute("Speed")
	return if typeof(value) == "number" then value else 90
end

local part = Instance.new("Part")
part:SetAttribute("Speed", 180)
print(speedOf(part)) -- 180