DataService

DataService is a type-safe Roblox data-store wrapper with automatic client replication, nested value wrappers, signals, arrays, and mock-store support.

Features

• Strongly typed server and client APIs using Luau's new type solver
• ProfileStore-backed player data with optional mock stores
• Automatic snapshots and mutation replication
• Callable values for reading, setting, and updating data
• Typed nested tables, dictionaries, and arrays
• Typed Changed, OnInsert, and OnRemove signals
• Array Insert and RemoveAt operations
• Per-mutation replication suppression on writable values
• Runtime protection against direct field assignment

Installation

Add DataService to your wally.toml dependencies:

[dependencies]
DataService = "grunionnn/dataservice@version"

Then install the package:

wally install

DataService expects its server dependencies to be available through the Rojo project. Its current Wally dependencies are Networker, GoodSignal, and ProfileStore.

Quick Example

Create and return one configured DataService module shared by the server and client:

local ReplicatedStorage = game:GetService("ReplicatedStorage")

local DataService = require(ReplicatedStorage.Packages.DataService)

local template = {
	Coins = 0,
	Inventory = {} :: { [string]: number },
	Items = {} :: { number },
	Settings = {
		MusicVolume = 0.5,
	},
}

return DataService({
	template = template,
	useMock = false,
	profileStoreIndex = "PlayerData",
})

Use the configured service on the server:

local Players = game:GetService("Players")
local ReplicatedStorage = game:GetService("ReplicatedStorage")

local Data = require(ReplicatedStorage.Data).server

Data.PlayerInitialized:Connect(function(player)
	local coins = Data[player].Coins()
	Data[player].Coins(coins + 10)

	Data[player].Coins(function(current)
		return current + 1
	end)

	Data[player].Inventory["Sword"](1)
	Data[player].Items.Insert(25)

	Data[player].Coins.Changed:Connect(function(newCoins, oldCoins)
		print(player, oldCoins, newCoins)
	end)
end)

Players.PlayerAdded:Connect(function(player)
	local snapshot = Data:WaitForData(player)
	if snapshot then
		print(`Loaded {snapshot.Coins} coins for {player.Name}`)
	end
end)

Pass true as the second argument to suppress replication for one set or update:

Data[player].Coins(200, true)

Data[player].Coins(function(current)
	return current + 1
end, true)

The mutation is still saved and server-side signals still fire. Pass false or omit the second argument to replicate normally.

Read replicated data on the client:

local ReplicatedStorage = game:GetService("ReplicatedStorage")

local Data = require(ReplicatedStorage.Data).client

local snapshot = Data:WaitForData()
assert(snapshot, "Unable to load data")

local coins: number = snapshot.Coins

Data.Coins.Changed:Connect(function(newCoins, oldCoins)
	print(oldCoins, newCoins)
end)

local index, item = Data.Items.OnInsert:Wait()
print(index, item)

Public value signals expose Connect, Once, and Wait. Signal dispatch remains internal to DataService.

Links

• Getting Started
• API Reference
• Wally package registry
• Wally index
• ProfileStore
• Rojo

Current Version

The current package version is 1.0.1.

Limitations

• DataService requires Luau's new type solver and user-defined type-function support.
• Only one configured DataService instance may be created in a game runtime.
• Data is currently scoped around player profiles.
• Client value wrappers are read-only.
• Luau does not currently support separate read/write indexer types for generated tables. Dictionary and array indexers therefore use a read/write type-system indexer, while direct assignment is rejected at runtime by the value wrapper.
• dontReplicate suppresses only the selected live mutation. A later full snapshot contains the server's current stored data, so it is not a permanent privacy filter.
• Skipping an array or structural mutation can leave the current client state unsuitable for later dependent mutations until a fresh snapshot is received.

License

DataService is available under the MIT License.