> ## Documentation Index
> Fetch the complete documentation index at: https://docs.lunarphp.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Tags

Tags provide a way to relate otherwise unrelated models, enabling features like dynamic collections.

## Overview

Tags provide a way to relate otherwise unrelated models in the system. They also impact other features such as Dynamic Collections.

For example, two products "Blue T-Shirt" and "Blue Shoes" are unrelated by nature, but adding a `BLUE` tag to each product allows a Dynamic Collection to include any products with that tag.

```php theme={null}
Lunar\Core\Models\Tag
```

### Fields

| Field        | Type        | Description                                       |
| :----------- | :---------- | :------------------------------------------------ |
| `id`         | `id`        | Primary key                                       |
| `public_id`  | `ulid`      | Public-facing identifier, generated automatically |
| `value`      | `string`    | The tag value                                     |
| `created_at` | `timestamp` |                                                   |
| `updated_at` | `timestamp` |                                                   |

<Tip>
  Tags are automatically converted to uppercase whenever the `value` attribute is set, including through `syncTags`.
</Tip>

## Enabling tags

To enable tagging on a model, add the `HasTags` trait:

```php theme={null}
<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;
use Lunar\Core\Models\Concerns\HasTags;

class SomethingWithTags extends Model
{
    use HasTags;

    // ...
}
```

Tags can then be attached using `syncTags`:

```php theme={null}
$model = SomethingWithTags::first();

$model->syncTags(collect(['TAG ONE', 'TAG TWO', 'TAG THREE']));
```

The `syncTags` method accepts a collection of tag value strings, not `Tag` model instances. It finds or creates a `Lunar\Core\Models\Tag` for each value and syncs the model's `tags` relationship to them. Values are automatically converted to uppercase. The sync process runs via a queued job (`Lunar\Core\Jobs\SyncTags`), so changes may not be reflected immediately if using an asynchronous queue driver.