Statamic GraphQL Search Field

Add a new file : app\GraphQL\Queries\SearchableEntriesQuery.php

<?php
namespace App\GraphQL\Queries;

use Statamic\Support\Arr;
use Statamic\Support\Str;
use Statamic\Facades\Entry;
use Statamic\Facades\Search;
use Statamic\Facades\GraphQL;
use Statamic\GraphQL\Queries\EntriesQuery;

class SearchableEntriesQuery extends EntriesQuery
{
    public function args(): array
    {
	   //Extend the parent args adding an optional search and searchIndex argument
        return array_merge(
            parent::args(), [
            'search' => GraphQL::string(),
            'searchIndex' => GraphQL::string(),
            ]
        );
    }

    /**
	 * Overwrite the parent method to add in our search query
	 */
    public function resolve($root, $args)
    {
        $query = Entry::query();

        if ($collection = $args['collection'] ?? null) {
            $query->whereIn('collection', $collection);
        }

        $this->searchQuery($query, $args['search'] ?? null, $args['searchIndex'] ?? null);

        $this->filterQuery($query, $args['filter'] ?? []);

        $this->sortQuery($query, $args['sort'] ?? []);

        return $query->paginate($args['limit'] ?? 1000);
    }

   /**
    * This handles our search methodoloty
	* @param $query - the Entry Query
	* @param $filter - the filter value
	* @param $searchIndex - which index to search - defaults to the default one if not passed / empty / null
	*/
    private function searchQuery($query, $filter, $searchIndex)
    {
        if (empty($filter)) {
            return null;
        }

	  	// get the default index if not set.
        if (empty($searchIndex)) {
            $searchIndex = config('statamic.search.default');
        }

        $builder = Search::index($searchIndex)
            ->ensureExists()
            ->search($filter);

         $results = $builder->get('id')->map(fn($i) => $i->id());

         $this->queryCondition($query, 'id', 'in', $results->toArray());
    }

  /** Direct copy from parent -- due to being private **/
    private function filterQuery($query, $filters)
    {
        if (! isset($filters['status']) && ! isset($filters['published'])) {
            $filters['status'] = 'published';
        }

        foreach ($filters as $field => $definitions) {
            if (! is_array($definitions)) {
                $definitions = [['equals' => $definitions]];
            }

            if (Arr::assoc($definitions)) {
                $definitions = collect($definitions)->map(
                    function ($value, $key) {
                        return [$key => $value];
                    }
                )->values()->all();
            }

            foreach ($definitions as $definition) {
                $condition = array_keys($definition)[0];
                $value = array_values($definition)[0];
                $this->queryCondition($query, $field, $condition, $value);
            }
        }
    }

  /** direct copy from parent due to being private **/
    private function sortQuery($query, $sorts)
    {
        if (empty($sorts)) {
            $sorts = ['id'];
        }

        foreach ($sorts as $sort) {
            $order = 'asc';

            if (Str::contains($sort, ' ')) {
                [$sort, $order] = explode(' ', $sort);
            }

            $query->orderBy($sort, $order);
        }
    }
}

you can now add this query in to the config array or load it in your app service provider.