amber-laravel/app/Models/Assistant.php

<?php

namespace App\Models;

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

class Assistant extends Model
{
    protected $fillable = [
        'name',
        'description',
        'prompt',
        'user_id',
    ];

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

    public function tools(): BelongsToMany
    {
        return $this->belongsToMany(Tool::class, 'assistant_tools');
    }

    public function chats(): HasMany
    {
        return $this->hasMany(Chat::class);
    }

    public function chatHistories(): HasMany
    {
        return $this->hasMany(ChatHistory::class);
    }
}