Serialises Roblox Instance properties into a JSON-formatted string. Run this via the `Command Bar` or `Model -> Run Script`.

InstanceEncode.server.lua

-- clockworksquirrel.instance-encode

local dump = {}

local http = game:GetService("HttpService")
local response = http:RequestAsync({
	Url = "https://raw.githubusercontent.com/ClockworkSquirrel/roblox-client-dump/master/API-Dump-Tree.json"
})

dump = http:JSONDecode(response.Body)

local function buildTree(currentRoot, obj, tree)
	tree = tree or {}
	
	if (currentRoot) then
		for class, entry in next, currentRoot do
			if (obj:IsA(class)) then
				tree[#tree + 1] = entry
				return buildTree(entry.Children, obj, tree)
			end
		end
	end
	
	return tree
end

local function treeToClass(tree)
	local class = {}
	
	local function mergeTables(table1, table2)
		for key, value in next, table2 do
			if (typeof(table1[key]) == "table" and typeof(value) == "table") then
				table1[key] = mergeTables(table1[key], value)
			else
				table1[key] = value
			end
		end
		
		return table1
	end
	
	for _, node in next, tree do
		mergeTables(class, node)
		class.Children = node.Children
	end
	
	return class
end

local function findInTable(haystack, needle)
	for _, value in next, haystack do
		if (value == needle) then
			return true
		end
	end
end

local function JSONEncodeProperties(obj)
	local objTree = buildTree(dump.Classes, obj)
	local class = treeToClass(objTree)
	
	local properties = {}
	for prop, value in next, class.Properties or {} do
		if not (value.isDeprecated or value.Security.Read ~= "None" or value.Security.Write ~= "None" or findInTable(value.Tags or {}, "NotScriptable") or findInTable(value.Tags or {}, "ReadOnly") and not (value.Serialization.CanLoad and value.Serialization.CanSave)) then
			local ok, objProp = pcall(function() return obj[prop] end)
			
			if (ok) then
				if (type(objProp) == "userdata") then
					local ok, tryEncode = pcall(function()
						return http:JSONDecode("[" .. tostring(objProp) .. "]")
					end)
					
					if (not ok) then
						if (typeof(objProp) == "EnumItem") then
							tryEncode = objProp.Name
						elseif (typeof(objProp) == "Instance") then
							tryEncode = objProp == game and "game" or "game." .. objProp:GetFullName()
						else
							tryEncode = tostring(objProp)
						end
					end
					
					properties[prop] = { datatype = typeof(objProp), value = tryEncode }
				else
					properties[prop] = objProp
				end
			end
		end
	end
	
	return http:JSONEncode(properties)
end

_G.dump = dump
_G.encodeProps = JSONEncodeProperties

print(
	string.format("[%d]", #response.Body),
	"Fetched latest client dump from server. Accessible via _G.dump.",
	"Serialise Instance properties with _G.encodeProps(<Instance>)."
)