Conditional Relationship Counts on API Resources

You may conditionally include the count of a relationship in your resource response by using the whenCounted method. By doing so, the attribute is not included if the relationships' count is missing.

public function toArray($request)
{
     return [
          'id' => $this->id,
          'name' => $this->name,
          'email' => $this->email,
          'posts_count' => $this->whenCounted('posts'),
          'created_at' => $this->created_at,
          'updated_at' => $this->updated_at,
     ];
}

Tip given by @mvpopuk