Leaderstats

Canonical copy (three files): Docs → Example: Leaderstats.

Roblox shows the player list from a Folder named exactly leaderstats under the Player. This service creates those values, then mirrors DataService coins into them.

It does not call DataService.Init. Boot that in Data boot with your PlayerData Template.

Files

File	Role
shared/PlayerData.clh	Template structs (Currencies.Coins, inventory LuaArray)
server/LeaderstatsServer.clh	struct LeaderstatsServer — fields + method decls (same stem)
server/LeaderstatsServer.server.clpp	Class:: bodies + void init()

Rules

Rule	Why
Same-stem header	LeaderstatsServer.clh + LeaderstatsServer.server.clpp. A differently named leaderstats.clh is a require.
.server.clpp	Untagged cpp is a ModuleScript; init() will not run by itself.
Paths.Currencies.Coins	After Init. A local int Coins is not a Data path.
string_concat or string +	Luau ... Do not write .. in the .cpp.
Janitor keyed by player name	Leaving the game must Destroy the folder.
Lambda or named function	GetChangedSignal(...).Connect([coinsValue](int n) { ... }) is valid.

Header

#pragma once
#include <clpp/roblox.clh>
#include <clpp/libs/sweep.clh>
#include <clpp/libs/keep.clh>

struct LeaderstatsServer {
  static constexpr int STARTING_COINS = 0;
  Janitor janitor;
  string GetPlayerJanitorKey(Player player);
  void UpdateLeaderstatsWithValues(IntValue currentValue, int newValue);
  Folder EnsurePlayerLeaderstatsFolder(Player player);
  void PlayerEntered(Player player);
};

PlayerEntered

void LeaderstatsServer::PlayerEntered(Player player) {
  Folder leaderstatsFolder = EnsurePlayerLeaderstatsFolder(player);
  Data playerData = DataService.Server.WaitFor(player);
  IntValue coinsValue = static_cast<IntValue>(leaderstatsFolder.FindFirstChild("Coins"));
  if (coinsValue) {
    playerData.GetChangedSignal(DataService.Server.Paths.Currencies.Coins)~>Connect(func (int newValue) {
        UpdateLeaderstatsWithValues(coinsValue, newValue);
      }
    );
  }
  janitor.Add(leaderstatsFolder, "Destroy", GetPlayerJanitorKey(player));
}

init() constructs LeaderstatsServer, assigns janitor = new Janitor(), runs PlayerEntered for everyone already in the game, then PlayerAdded + BindToClose. Full listing is on the handbook page.