Extending API Platform generated documentation

ApiDocsOverride.php

<?php

// src/Api/ApiDocsOverride.php

declare(strict_types=1);

namespace App\Api;

use ApiPlatform\Core\OpenApi\Factory\OpenApiFactory;
use ApiPlatform\Core\OpenApi\Factory\OpenApiFactoryInterface;
use ApiPlatform\Core\OpenApi\OpenApi;

final class ApiDocsServerOverride implements OpenApiFactoryInterface
{
    private OpenApiFactoryInterface $decorated;

    public function __construct(OpenApiFactoryInterface $decorated)
    {
        $this->decorated = $decorated;
    }
    
    public function __invoke(array $context = []): OpenApi
    {
        $context[OpenApiFactory::BASE_URL] = '/test/';
        
        return $this->decorated->__invoke($context);
    }
}

services.yaml

# config/services.yaml

services:
    # ...
    
    App\Api\ApiDocsServerOverride:
        decorates: 'api_platform.openapi.factory'