A script to integrate Amazon IVS chat into a Unity game.

IVSChat.cs

using System;
using System.Collections;
using System.Collections.Generic;
using System.Threading.Tasks;
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.Networking;
using NativeWebSocket;
using TMPro;

[System.Serializable]
public class ChatAttributes
{
  public string username;
  public static ChatAttributes CreateFromJSON(string jsonString)
  {
    return JsonUtility.FromJson<ChatAttributes>(jsonString);
  }
}

[System.Serializable]
public class ChatSender
{
  public string UserId;
  public ChatAttributes Attributes;
  public static ChatSender CreateFromJSON(string jsonString)
  {
    return JsonUtility.FromJson<ChatSender>(jsonString);
  }
}

[System.Serializable]
public class ChatMessage
{
  public string Type;
  public string Id;
  public string RequestId;
  public string Content;
  public ChatSender Sender;
  public static ChatMessage CreateFromJSON(string jsonString)
  {
    return JsonUtility.FromJson<ChatMessage>(jsonString);
  }
}

[System.Serializable]
public class ChatToken
{
  public System.DateTime sessionExpirationTime;
  public string token;
  public System.DateTime tokenExpirationTime;
  public static ChatToken CreateFromJSON(string jsonString)
  {
    return JsonUtility.FromJson<ChatToken>(jsonString);
  }
}

[System.Serializable]
public class ChatTokenRequest
{
  public string chatArn;
  public string username;
  public string userId;
  public ChatTokenRequest(string chatArn, string username, string userId)
  {
    this.chatArn = chatArn;
    this.username = username;
    this.userId = userId;
  }
}

public class IVSChat : MonoBehaviour
{
  TMP_Text chatContainer;
  ScrollRect scrollRect;
  WebSocket websocket;
  async Task<ChatToken> GetChatToken()
  {
    using UnityWebRequest www = new UnityWebRequest("http://localhost:3000/chat-token");
    ChatTokenRequest tokenRequest = new ChatTokenRequest(
      "arn:aws:ivschat:us-east-1:639934345351:room/0wgOPVl4ZRdu",
      "IVS HUD Chat Demo User",
      System.Guid.NewGuid().ToString()
    );
    www.uploadHandler = new UploadHandlerRaw(System.Text.Encoding.ASCII.GetBytes(JsonUtility.ToJson(tokenRequest)));
    www.downloadHandler = new DownloadHandlerBuffer();
    www.method = UnityWebRequest.kHttpVerbPOST;
    www.SetRequestHeader("Content-Type", "application/json");
    var request = www.SendWebRequest();
    while (!request.isDone)
    {
      await Task.Yield();
    };
    var response = www.downloadHandler.text;
    if (www.result != UnityWebRequest.Result.Success)
    {
      Debug.Log(www.error);
      return default;
    }
    else
    {
      return ChatToken.CreateFromJSON(www.downloadHandler.text);
    }
  }

  async Task<WebSocket> ConnectChat()
  {
    var chatToken = await GetChatToken();
    websocket = new WebSocket("wss://edge.ivschat.us-east-1.amazonaws.com", chatToken.token);
    websocket.OnOpen += () =>
    {
      Debug.Log("Chat Connection: Open");
    };
    websocket.OnError += (e) =>
    {
      Debug.Log("Chat Connection: Error " + e);
    };
    websocket.OnClose += (e) =>
    {
      Debug.Log("Chat Connection: Closed");
    };
    websocket.OnMessage += (bytes) =>
    {
      var msgString = System.Text.Encoding.UTF8.GetString(bytes);
      Debug.Log("Chat Message Received! " + msgString);
      ChatMessage chatMsg = ChatMessage.CreateFromJSON(msgString);
      Debug.Log(chatMsg);
      if (chatMsg.Type == "MESSAGE")
      {
        chatContainer.text += "<b>" + chatMsg.Sender.Attributes?.username + "</b>: " + chatMsg.Content + "\n";
        scrollRect.verticalNormalizedPosition = 0;
      }
    };
    return websocket;
  }

  async void Start()
  {
    chatContainer = GetComponent<TMP_Text>();
    scrollRect = chatContainer.transform.parent.parent.parent.GetComponent<ScrollRect>();
    await ConnectChat();
    await websocket.Connect();
  }

  void Update()
  {
  #if !UNITY_WEBGL || UNITY_EDITOR
    websocket?.DispatchMessageQueue();
  #endif
  }

  async void OnDestroy()
  {
    Debug.Log("OnDestroy");
    if (websocket != null) await websocket.Close();
  }
}