amber-laravel/app/Models/ChatHistory.php

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\BelongsTo;

class ChatHistory extends Model
{
    protected $fillable = [
        'chat_id',
        'content',
        'role',
        'input_tokens',
        'output_tokens',
        'total_tokens',
    ];

    public function chat(): BelongsTo
    {
        return $this->belongsTo(Chat::class);
    }
}