Multiplayer Hosting Guide

Every NetCrafter game needs a running SmartFoxServer 3 instance that all players connect to. You have two practical options for where that server lives: a dedicated server or player hosting. For smaller games that don’t need SmartFoxServer, NetCrafter Relay is a separate asset.

A dedicated server is the most reliable option and the right choice for any game you plan to ship. SmartFoxServer 3 runs on Linux and Windows VPS instances; a $6/month cloud VM handles dozens of concurrent players comfortably for most indie titles.

What you need

• A VPS or cloud instance with a static public IP (any provider: DigitalOcean, Hetzner, Linode, AWS Lightsail, etc.)
• SFS3 installed and licensed on that server
• Ports 9933 (TCP, default SFS3 binary) and 8080 (HTTP, optional) open in the server’s firewall

Pointing NetCrafter at your server

In Unity, find your generated SmartFoxConnectionManager in the scene. In the Inspector, set the Host field to your server’s public IP or hostname:

Host      = "your.server.ip"   // or a domain name
Port      = 9933               // SFS3 binary protocol default
Zone      = "BasicExamples"    // must match your SFS3 zone name

That’s all. The generated connection manager handles login and room join automatically on Start().

For early playtesting where you don’t want to set up a dedicated server yet, one player can run SFS3 on their own machine and open a port in their home router. This requires a one-time manual step on the host’s router.

Steps for the host

Understanding how NetCrafter’s connection layer is structured helps you build a clean join flow and wire up UI correctly.

INetCrafterConnection

The generated SmartFoxConnectionManager implements INetCrafterConnection, an interface declared in the NetCrafter Runtime assembly. This interface is how all of NetCrafter’s built-in components talk to the connection manager without taking a direct dependency on your generated namespace:

public interface INetCrafterConnection
{
    bool   IsConnected  { get; }
    int    LocalUserId  { get; }
    string LocalUserName { get; }

    void Connect();
    void UpdateHost(string hostIP);
    void SendExtensionRequest(string cmd, ISFSObject data);
}

NetCrafterEventDispatcher

NetCrafterEventDispatcher is a singleton MonoBehaviour that acts as a cross-assembly event bus. The generated connection manager dispatches named events that your UI scripts can subscribe to:

private Action<object> _roomJoinedHandler;

private void Start()
{
    _roomJoinedHandler = _ => OnRoomJoined();
    NetCrafterEventDispatcher.Instance?.Subscribe("RoomJoined",    _roomJoinedHandler);
    NetCrafterEventDispatcher.Instance?.Subscribe("ConnectionLost", OnConnectionLost);
}

private void OnDestroy()
{
    NetCrafterEventDispatcher.Instance?.Unsubscribe("RoomJoined",    _roomJoinedHandler);
    NetCrafterEventDispatcher.Instance?.Unsubscribe("ConnectionLost", OnConnectionLost);
}

private void OnRoomJoined()      { /* show game UI */ }
private void OnConnectionLost(object reason) { Debug.LogWarning("Lost: " + reason); }

UpdateHost() for player-hosted sessions

When building a player-hosted join flow, call UpdateHost() before Connect() to point the connection manager at the host’s IP. This resets any existing SFS3 socket so a fresh connection opens to the new address:

// Find SmartFoxConnectionManager via the interface — no generated-namespace dependency
var all = FindObjectsByType<MonoBehaviour>(FindObjectsInactive.Exclude, FindObjectsSortMode.None);
INetCrafterConnection cm = null;
foreach (var mb in all)
    if (mb is INetCrafterConnection c) { cm = c; break; }

if (cm != null)
{
    cm.UpdateHost("123.45.67.89");
    cm.Connect();
}

A typical player-hosted join flow consists of a UI panel where a joining player enters the host’s IP, a Connect button, status feedback, and navigation to the game scene on success or an error message on failure.

Minimal join panel script

using System;
using UnityEngine;
using UnityEngine.Events;
using UnityEngine.UI;
using TMPro;
using PivecLabs.Netcrafter;

public class JoinPanel : MonoBehaviour
{
    public TMP_InputField ipInput;
    public Button         connectButton;
    public TMP_Text       statusText;
    public UnityEvent     onJoinSuccess;

    private Action<object> _roomJoinedHandler;

    private void Start()
    {
        connectButton.onClick.AddListener(OnConnect);
        _roomJoinedHandler = _ => OnRoomJoined();
        NetCrafterEventDispatcher.Instance?.Subscribe("RoomJoined",    _roomJoinedHandler);
        NetCrafterEventDispatcher.Instance?.Subscribe("ConnectionLost", OnConnectionLost);
    }

    private void OnDestroy()
    {
        NetCrafterEventDispatcher.Instance?.Unsubscribe("RoomJoined",    _roomJoinedHandler);
        NetCrafterEventDispatcher.Instance?.Unsubscribe("ConnectionLost", OnConnectionLost);
    }

    private void OnConnect()
    {
        string ip = ipInput.text.Trim();
        if (!System.Net.IPAddress.TryParse(ip, out _))
        {
            statusText.text = "Invalid IP address.";
            return;
        }

        var cm = FindConnectionManager();
        if (cm == null) { statusText.text = "ConnectionManager not found."; return; }

        statusText.text = "Connecting to " + ip + "...";
        cm.UpdateHost(ip);
        cm.Connect();
    }

    private void OnRoomJoined()      { onJoinSuccess?.Invoke(); }
    private void OnConnectionLost(object r)
    {
        statusText.text = "Connection failed: " + r;
    }

    private INetCrafterConnection FindConnectionManager()
    {
        var all = FindObjectsByType<MonoBehaviour>(FindObjectsInactive.Exclude, FindObjectsSortMode.None);
        foreach (var mb in all)
            if (mb is INetCrafterConnection c) return c;
        return null;
    }
}

You can test a full multiplayer session without any router configuration by running SFS3 and two Unity Editor instances on the same machine.

NetCrafter Relay is a separate, standalone Unity asset from Pivec Labs, available now. It is not an add-on to NetCrafter Pro and doesn’t use SmartFoxServer 3. Instead, players connect through a coturn TURN/STUN relay that you host yourself on a low-cost VPS. There is no Pivec Labs–hosted service.

When to choose Relay instead of NetCrafter Pro

• Choose NetCrafter Relay for smaller multiplayer games. One player hosts and friends join with a short code like GAME-4892, with no port forwarding and no IP sharing, and it works behind Carrier-Grade NAT.
• Choose NetCrafter Pro for larger, room-based multiplayer on SmartFoxServer 3 — server-authoritative logic, zones and rooms, and players who can connect without a host being present.

You understand your hosting options. Here are common next steps: