rag/routes/channels.php

<?php

use App\Models\Chat;
use App\Models\Message;
use App\Models\User;
use Illuminate\Support\Facades\Broadcast;

Broadcast::channel('App.Models.User.{id}', fn (User $user, string $id) => $user->id == $id);

Broadcast::channel('App.Models.Chat.{uuid}', fn (User $user, string $uuid) => $user->id === Chat::findOrFail($uuid)->user_id);
Broadcast::channel('App.Models.Message.{uuid}', fn (User $user, string $uuid) => $user->id == Message::findOrFail($uuid)->chat->user_id);