Custom Commands (C++)

Register a command with RegisterNativeCommand. The handler gets a FServerCoreCommandContext and returns an EServerCoreResult.

#include "ServerCoreSubsystem.h"

void AMyGameMode::BeginPlay()
{
    Super::BeginPlay();

    UServerCoreSubsystem* ServerCore = UServerCoreSubsystem::Get(this);
    if (!ServerCore)
    {
        return;
    }

    FServerCoreCommandInfo Info;
    Info.Name = TEXT("heal");
    Info.Aliases = { TEXT("h") };
    Info.Permission = TEXT("mygame.heal");
    Info.Usage = TEXT("<player> [amount]");
    Info.Description = TEXT("Heals a player.");
    Info.MinArgs = 1;

    ServerCore->RegisterNativeCommand(Info, [ServerCore](FServerCoreCommandContext& Context)
    {
        FString PlayerId, PlayerName, Error;
        if (!ServerCore->FindPlayer(Context.Args[0], /*bIncludeOffline*/ false, PlayerId, PlayerName, Error))
        {
            Context.Reply(Error);
            return EServerCoreResult::PlayerNotFound;
        }

        const float Amount = Context.Args.IsValidIndex(1) ? FCString::Atof(*Context.Args[1]) : 100.f;
        if (APlayerController* Target = ServerCore->GetPlayerController(PlayerId))
        {
            // Heal Target->GetPawn() by Amount
        }

        Context.Reply(FString::Printf(TEXT("Healed %s by %.0f."), *PlayerName, Amount));
        return EServerCoreResult::Success;
    });
}

FServerCoreCommandContext

Member	Description
Caller	Who ran the command
CommandName	The command name (lower case, without prefix)
Args	Arguments. Quoted text is one argument.
Output	Lines sent back to the caller
Reply(Line)	Adds a line to Output
JoinArgs(StartIndex, Fallback)	Joins Args from StartIndex, e.g. for a reason

Tips

• The command's Permission is checked before your handler runs, and MinArgs too. Check extra permissions inside the handler with ServerCore->CallerHasPermission(Context.Caller, ...).
• Act on players through Server Core functions (KickPlayer, MutePlayer, …) with Context.Caller, so priority rules and logging apply.
• Registering a command with an existing name replaces it. UnregisterCommand(Name) removes it.
• The subsystem lives on the game instance, so commands registered once stay registered across map changes. Registering again in every BeginPlay is harmless, it simply replaces the command.