# Manually configure Relay with Netcode for GameObjects

> Integrate Relay with Netcode for GameObjects using the unified Multiplayer Services SDK.

Multiplayer Services work seamlessly with [Netcode for GameObjects](https://docs.unity3d.com/Packages/com.unity.netcode.gameobjects@latest?subfolder=/manual/relay/relay.html), which is a Unity package that provides networking capabilities to `GameObject` and `MonoBehaviour` workflows.

This tutorial demonstrates how to use the underlying Relay API in the Multiplayer Services package with Netcode for GameObjects.

> **Note:**
>
> For most users, the unified [Multiplayer Services package](/mps-sdk.md) replaces the Relay standalone package, which is deprecated in Unity 6. Consider migrating to the unified package to facilitate a smooth transition. Visit the [migration guide](/mps-sdk/migration-path.md) for a step-by-step transition process.

## Installation and configuration

1. In the Unity Editor's [Package Manager](https://docs.unity3d.com/Manual/upm-ui-access.html), select **Unity Registry**.
2. Search for the following package: `com.unity.services.multiplayer`.
3. Select the package, then **Install**. Refer to [Package Manager](https://docs.unity3d.com/Manual/upm-ui.html).
4. Repeat for [`com.unity.netcode.gameobjects`](https://docs.unity3d.com/Packages/com.unity.netcode.gameobjects@latest?subfolder=/manual/install.html).

You must first configure your Unity project for Unity before using Relay with Netcode for GameObjects. Refer to [Get started with Multiplayer Services](../get-started) to learn how to link your project in the project settings.

## Set up the NetworkManager

After installing the packages, you can now set up the `NetworkManager`:

1. Add a new **GameObject** to your scene.
2. Add the **NetworkManager MonoBehaviour**.
3. In the **MonoBehaviour Properties**, select the **UnityTransport** transport. After selecting UnityTransport, you’ll see a `MonoBehaviour` called Unity Transport (script) at the bottom of the components list.
4. Set the **Protocol Type** of the new component to **Relay Unity Transport**.

## Host player

The `StartHostWithRelay` function shows how to create a Relay allocation, and request a join code.
This function requires the maximum number of connections the allocation is expecting and the host player connection type.

The connection type must be one of the following options:

* udp
* dtls
* wss

Refer to [DTLS](../networking/dtls-encryption) to learn more about DTLS encryption, and to [Web Platform Support](#note-about-unity-web-platform-support) to learn about using `wss`.

This code should be adapted to your needs to use a different authentication mechanism, a different error handling, or to use a different connection type.
Similarly, you can call `StartServer` instead of `StartHost` to start a server instead of a host.

> **Note:**
>
> The Multiplayer Services package introduces the concept of sessions. Check out [Build a session with Netcode for GameObjects](./build-your-first-session.md) to learn how to use it.

```cs
public async Task<string> StartHostWithRelay(int maxConnections, string connectionType)
{
    await UnityServices.InitializeAsync();
    if (!AuthenticationService.Instance.IsSignedIn)
    {
        await AuthenticationService.Instance.SignInAnonymouslyAsync();
    }
    var allocation = await RelayService.Instance.CreateAllocationAsync(maxConnections);
    NetworkManager.Singleton.GetComponent<UnityTransport>().SetRelayServerData(AllocationUtils.ToRelayServerData(allocation, connectionType));
    var joinCode = await RelayService.Instance.GetJoinCodeAsync(allocation.AllocationId);
    return NetworkManager.Singleton.StartHost() ? joinCode : null;
}
```

> **Note:**
>
> If this code succeeds in calling the `NetworkManager.Singleton.StartHost()`, it returns the join code retrieved from the Relay allocation.

## Joining player

When your game client functions as a joining player, the relay join code, retrieved in the previous step when the host created the allocation, must be passed to find the allocation. The following code samples show how to join an allocation with a join code and configure the connection type.

The connection type must be one of the following options:

* udp
* dtls
* wss

Refer to [DTLS](../networking/dtls-encryption) to learn more about DTLS encryption, and to [Web Platform Support](#note-about-unity-web-platform-support) to learn about using wss.

> **Note:**
>
> The Multiplayer Services package introduces the concept of session. Check out [Build a session with Netcode for GameObjects](./build-your-first-session.md) to learn how to use it.

```cs
public async Task<bool> StartClientWithRelay(string joinCode, string connectionType)
{
    await UnityServices.InitializeAsync();
    if (!AuthenticationService.Instance.IsSignedIn)
    {
        await AuthenticationService.Instance.SignInAnonymouslyAsync();
    }

    var allocation = await RelayService.Instance.JoinAllocationAsync(joinCode: joinCode);
    NetworkManager.Singleton.GetComponent<UnityTransport>().SetRelayServerData(AllocationUtils.ToRelayServerData(allocation, connectionType));
    return !string.IsNullOrEmpty(joinCode) && NetworkManager.Singleton.StartClient();
}
```

## Note about Unity Web platform support

To use Relay with Netcode for GameObjects in Unity Web platform supported game, upgrade the Unity Transport Package to 2.0.0 or later and configure the Unity transport component to use Web Sockets.

Using the previous code snippets, pass **wss** as `connectionType` and use the following to `SetRelayServerData`:

```cs
NetworkManager.Singleton.GetComponent<UnityTransport>().SetRelayServerData(AllocationUtils.ToRelayServerData(allocation, connectionType));
NetworkManager.Singleton.GetComponent<UnityTransport>().UseWebSockets = true;
```