Adobe Commerce (Magento) + NeutronEDI

<?php
declare(strict_types=1);

namespace Acme\Edi\Observer;

use Magento\Framework\Event\Observer;
use Magento\Framework\Event\ObserverInterface;
use Magento\Framework\HTTP\Client\Curl;
use Psr\Log\LoggerInterface;

class EdiAsnSender implements ObserverInterface
{
    public function __construct(
        private readonly Curl $curl,
        private readonly LoggerInterface $logger,
    ) {
    }

    public function execute(Observer $observer): void
    {
        $shipment = $observer->getEvent()->getShipment();
        $order    = $shipment->getOrder();

        $payload = [
            'interchange'  => [
                'sender'   => 'ACMECORP',
                'receiver' => $order->getData('edi_partner') ?: 'BIGRETAILER',
            ],
            'transactions' => [
                [
                    'type'                  => '856',
                    'shipmentId'            => $shipment->getIncrementId(),
                    'shipDate'              => $shipment->getCreatedAt(),
                    'purchaseOrderNumber'   => $order->getExtOrderId(),
                    'tracking'              => array_map(
                        fn($t) => $t->getTrackNumber(),
                        $shipment->getAllTracks(),
                    ),
                    'items' => array_map(
                        fn($item) => [
                            'sku' => $item->getSku(),
                            'qty' => (int) $item->getQty(),
                        ],
                        $shipment->getAllItems(),
                    ),
                ],
            ],
        ];

        $this->curl->setHeaders([
            'X-API-Key'    => getenv('NEUTRON_API_KEY'),
            'Content-Type' => 'application/json',
        ]);
        $this->curl->post(
            'https://api.neutronedi.com/api/v1/write/x12',
            json_encode($payload, JSON_THROW_ON_ERROR),
        );

        if ($this->curl->getStatus() !== 200) {
            $this->logger->error('NeutronEDI 856 generation failed', [
                'status' => $this->curl->getStatus(),
                'body'   => $this->curl->getBody(),
            ]);
            return;
        }

        $this->dropOnSftp($shipment->getIncrementId(), $this->curl->getBody());
    }

    private function dropOnSftp(string $shipmentId, string $rawX12): void
    {
        // SSH2 / phpseclib upload to the partner's SFTP server.
    }
}

ISA*00*          *00*          *ZZ*ACMECORP       *ZZ*BIGRETAILER    *260425*1130*U*00401*000001501*0*P*>~
GS*SH*ACMECORP*BIGRETAILER*20260425*1130*1*X*004010~
ST*856*0001~
BSN*00*SHP-90021*20260425*1130*0001~
HL*1**S~
TD1*CTN25*1****G*15*LB~
TD5***ZZ*UPS~
REF*BM*1ZACMETRACK01~
HL*2*1*O~
PRF*PO-99213~
HL*3*2*P~
MAN*GM*00000123450000000456~
HL*4*3*I~
LIN**VC*PART-X1~
SN1**100*EA~
CTT*4~
SE*14*0001~
GE*1*1~
IEA*1*000001501~