SimpleTCPServer User Guide

SimpleTCPServer is a lightweight TCP server plugin designed for Unreal Engine.
It supports multi-channel listening, dynamic configuration updates, and offers a fully Blueprint-exposed API for managing client connections at runtime.

• Unreal Engine 5.2–5.8
• Version 1.1.0 (Version 2)

Once enabled, the plugin activates automatically.
It registers as a GameInstanceSubsystem, and its lifecycle persists across level transitions.

You can define server listening channels via Project Settings → SimpleTCPServer Settings.
Using this method is recommended for centralized management and ease of debugging.

• Only IPv4 is supported — domain name, IPv6, and encryption are not supported
• All sockets are internally managed, no manual cleanup required
• Plugin persists across level transitions, bound to GameInstance lifecycle
• Each connected client is assigned a unique SessionChannel in format "IP:Port"

• 🔌 SimpleTCPClient Plugin
  Lightweight plugin designed for client-side usage, ideal for connecting to a SimpleTCPServer instance.

• 🧩 SimpleByteConversion Plugin Enables conversion between native Unreal types (e.g., FString, float, int) and TArray<uint8>, ideal for building structured protocols.

Listen on a port:

bool StartTCPServer(int32 Port)
{
    ISocketSubsystem* SocketSubsystem = ISocketSubsystem::Get(PLATFORM_SOCKETSUBSYSTEM);

    // 创建监听Socket
    FSocket* ListenSocket = SocketSubsystem->CreateSocket(NAME_Stream, TEXT("TCP Server"), false);

    // 绑定端口
    TSharedRef<FInternetAddr> Addr = SocketSubsystem->CreateInternetAddr();
    Addr->SetPort(Port);
    Addr->SetAnyAddress();

    if (!ListenSocket->Bind(*Addr))
    {
        UE_LOG(LogTemp, Error, TEXT("绑定端口失败: %d"), Port);
        return false;
    }

    // 开始监听(最大8个待连接队列)
    if (!ListenSocket->Listen(8))
    {
        UE_LOG(LogTemp, Error, TEXT("监听失败"));
        return false;
    }

    UE_LOG(LogTemp, Log, TEXT("TCP服务器启动,端口: %d"), Port);
    return true;
}

Accept a client connection:

void AcceptClients(FSocket* ListenSocket)
{
    ISocketSubsystem* SocketSubsystem = ISocketSubsystem::Get(PLATFORM_SOCKETSUBSYSTEM);
    TSharedRef<FInternetAddr> ClientAddr = SocketSubsystem->CreateInternetAddr();
    FSocket* ClientSocket = ListenSocket->Accept(*ClientAddr, TEXT("TCP Client"));

    if (ClientSocket)
    {
        FString ClientIP = ClientAddr->ToString(false);
        int32 ClientPort = ClientAddr->GetPort();

        UE_LOG(LogTemp, Log, TEXT("客户端连接: %s:%d"), *ClientIP, ClientPort);

        // 存储客户端Socket用于后续通讯
    }
}

These native examples demonstrate Bind, Listen, and Accept; they are not SimpleTCPServer Blueprint interfaces. Retain ownership of both listening and accepted sockets, and release them on failure, shutdown, or disconnection. The local pointers in these functions do not form a complete server lifecycle.

Listen(8) sets the queue for connections waiting to be accepted. It is not the plugin’s total client limit. IP:Port identifies a network endpoint, not a persistent user identity or authentication. Client data still needs stream framing, partial read/write handling, timeouts, and permission checks. Multiple-client handling should also avoid blocking the game thread.

See the TCP client and network communication guide for protocol choices and shared thread, reconnection, and byte-conversion guidance.

The native communication examples were published on Cnblogs on 2025-10-25.

Open Edit → Project Settings, select the SimpleTCPServer settings page, and set Language to English or Chinese. English is the default. Available user-facing UI, tooltips, notifications, and functional logs update immediately without restarting the editor. Public API names and module startup/shutdown logs remain in English.

For usage questions or collaboration, please visit the contact page.

• Contact: Contact and collaboration