Do I need an external backend for a Roblox game?

Not necessarily. Roblox DataStoreService is a strong default for durable state inside one game, and MemoryStoreService is designed for fast ephemeral state such as matchmaking queues. An external backend becomes useful when state must also serve other Roblox experiences, companion services, non-Roblox clients, richer operator workflows, or backend-owned systems such as shared economy and leaderboards.

How does Roblox authenticate to Crux?

The Crux Roblox SDK is intended for server-side Luau. A Roblox server uses a Crux server token plus the project and environment IDs. Keep the server token out of LocalScripts and client-visible state.

Can I keep Roblox DataStore and still use Crux?

Yes. Crux does not require an all-or-nothing migration. Keep DataStoreService, MemoryStoreService, TeleportService, and Roblox Configs where they fit, and add Crux only for data or backend workflows that need an external shared system.

Roblox · server-side Luau

Keep Roblox native services. Add an external backend only where they stop fitting.

Crux gives Roblox server scripts a shared backend for verified player records, persistent data, leaderboards, economy, live config and server discovery. The shipped Luau SDK uses HttpService behind a server-only token, so backend authority stays out of LocalScripts.

Create a free Roblox project → Read the Roblox quickstart

Dev BaaS includes 10,000 MAU and every backend feature. No credit card. Roblox integration runs from server-side Scripts with a Crux server token.

ServerScriptService / Luau shipped SDK surface

local Crux = require(game.ServerScriptService.Crux)

local crux = Crux.init(
  PROJECT_ID,
  SERVER_TOKEN,
  ENVIRONMENT_ID
)

game.Players.PlayerAdded:Connect(function(player)
  local record = crux:VerifyPlayer(player.UserId)
  local saves = crux:GetDataStore("progression")
  local value = saves:GetAsync(player.UserId)
end)

Verify before you integrate

Inspect the Roblox integration before you trust it.

The Luau module is public and MIT licensed. The hosted API contract is inspectable, the current service state is live, and the exit commitment is written down.

Live API status

A live check of the hosted API right now. No made-up uptime percentage and no hidden demo environment.

Check current status

Public API contract

The hosted HTTP surface is documented as OpenAPI. Inspect the wire format before choosing an SDK or writing an adapter.

Open the spec

MIT client SDKs

The JavaScript, Godot, Unity, and Roblox client SDK source is public. The hosted backend itself remains a managed proprietary service.

Inspect the SDK source

Documented exit path

Read what is exportable today and the written commitment for advance notice plus an export window if the hosted service winds down.

Read the exit guarantee

Roblox SDK source

Read the exact Luau module that performs HttpService calls, retries transient failures, verifies Roblox users, and exposes data, leaderboard, economy, config and server-registry methods. It also documents the current server-token matchmaking boundary in code.

Inspect Crux.lua

Native first

Do not replace Roblox infrastructure just to say you have a backend.

Roblox already ships durable data stores and fast memory stores. Use them. Add an external system only when the job crosses the boundary of one Roblox game or needs operator/backend behavior you want outside Roblox.

Keep native Roblox services for

Durable state that belongs entirely inside one Roblox game
Fast ephemeral queues and shared state with MemoryStoreService
Reserved-server and place handoff with TeleportService
Simple Roblox-native configuration and platform workflows

Roblox documents DataStoreService for persistent data and MemoryStoreService for frequent, ephemeral data such as matchmaking queues.

Add Crux when you need

One player record shared with another Roblox experience or external service
Server-owned leaderboards, inventory and currency behind one backend contract
Support/admin access to player state without writing bespoke operator tools first
A backend also consumed by web, mobile, PC or dedicated-server code
Server registry, live config and durable backend data outside a single Roblox runtime

Trust boundary

The secret belongs on the Roblox server.

The Crux Roblox module is designed for server Scripts. The server token authenticates the Roblox server to Crux. Do not copy it into a LocalScript, replicated value, client UI, or any place a player can read.

VerifyPlayer(player.UserId) maps the Roblox user into a Crux player record from server-side code. From there the same server can use Crux data stores, leaderboards, economy, live config and server-registry APIs. Crux's current matchmaking queue is player-token scoped, so the Roblox server-token SDK intentionally does not present it as a runnable server-side path.

Shortest useful evaluation

Create the free project and prove its live API responds.
Open the authenticated Roblox setup and create a server token.
Copy Crux.lua into ServerScriptService.
Enable Roblox HTTP requests and initialize the SDK with project, token and environment IDs.
Call VerifyPlayer from PlayerAdded; Crux will mark the project externally connected when that server token is actually used.

Start the Roblox path → Read Crux.lua first

Choose the right Roblox path

Your problem	Start here
External HttpService integration	HttpService guide
DataStore vs external storage	DataStore decision guide
Compare backend vendors	Roblox backend alternatives
Shared progression / multiple experiences	Progression architecture
MemoryStore matchmaking boundaries	Matchmaking guide
Working Crux server script	Roblox + Crux quickstart

One server call is enough to judge the fit

Do not migrate your DataStores first.

Create a free project, wire one server-side feature, and watch Crux confirm the external connection. Keep the rest of your Roblox stack unchanged until the external backend earns its place.

Create free Roblox project → Read the code first

Roblox-native architecture references: DataStoreService, MemoryStoreService, and HttpService.