A GraphQL client using the Symfony HttpClient component

example.php

<?php

$query = <<<'GRAPHQL'
query GetUser($user: String!) {
   user (login: $user) {
    name
    email
    repositoriesContributedTo {
      totalCount
    }
  }
}
GRAPHQL;

graphql_query('https://api.github.com/graphql', $query, ['user' => 'dunglas'], 'my-oauth-token');

graphql-client.php

<?php

// composer require symfony/http-client
require __DIR__.'/vendor/autoload.php';

use Symfony\Component\HttpClient\HttpClient;
use Symfony\Component\HttpClient\HttpOptions;

function graphql_query(string $endpoint, string $query, array $variables = [], ?string $token = null): array
{
    $options = (new HttpOptions())
        ->setJson(['query' => $query, 'variables' => $variables])
        ->setHeaders([
            'Content-Type' => 'application/json',
            'User-Agent' => 'Symfony GraphQL client'
        ])
    ;

    if (null !== $token) {
        $options->setAuthBearer($token);
    }

    return HttpClient::create()
        ->request('POST', $endpoint, $options->toArray())
        ->toArray()
    ;
}

<?php
// src/Service/GraphqlClient.php
namespace App\Service;

use Symfony\Contracts\HttpClient\HttpClientInterface;
use Symfony\Component\HttpClient\HttpOptions;
use Symfony\Component\DependencyInjection\ContainerInterface;

class GraphqlClient
{
    private HttpClientInterface $client;
    private ContainerInterface $container;

    public function __construct(HttpClientInterface $client, ContainerInterface $container)
    {
        $this->client = $client;
        $this->container = $container;
    }

    public function query(
        string $query,
        array $variables = [],
        ?string $token = null,
        string $endpoint = null
    ): string|array
    {
        if (is_null($endpoint)) {
            $endpoint = $this->container->getParameter('app.graphql_url');
        }

        $options = (new HttpOptions())
            ->setJson(['query' => $query, 'variables' => $variables])
            ->setHeaders([
                'Content-Type' => 'application/json',
                'User-Agent' => 'Symfony GraphQL client'
            ])
        ;

        if (null !== $token) {
            $options->setAuthBearer($token);
        }
        
        $response = $this->client
            ->request('POST', $endpoint, $options->toArray())
            ->toArray();

        return array_key_exists('errors', $response)
            ? $response['errors'][0]['message']
            : $response;
    }
}

The requests of this example service are profiled in Symfony 5.3 debug toolbar.