How to Integrate EDI
with Modern Ecommerce

{
  "as2Id": "YOURCOMPANY",
  "partnerId": "RETAILER",
  "url": "https://as2.retailer.com:4080/as2",
  "encryption": "AES-256-CBC",
  "signing": "SHA-256",
  "mdn": {
    "type": "sync",          // request synchronous MDN
    "signed": true
  },
  "certificates": {
    "your_private": "./certs/yourcompany.p12",
    "partner_public": "./certs/retailer.cer"
  }
}

import { X12Parser } from 'node-x12';

async function edi850ToShopifyOrder(rawEdiString) {
  const parser = new X12Parser(true);
  const interchange = parser.parse(rawEdiString);
  const group = interchange.functionalGroups[0];
  const transaction = group.transactions[0]; // 850

  // Extract PO number from BEG segment, element 03
  const poNumber = transaction.get('BEG03');

  // Extract ship-to address from N1/N3/N4 loop
  const n1Loop = transaction.getLoop('N1', 'ST');
  const shippingAddress = {
    address1: n1Loop.get('N301'),
    address2: n1Loop.get('N302') || '',
    city:     n1Loop.get('N401'),
    province: n1Loop.get('N402'),
    zip:      n1Loop.get('N403'),
    country:  n1Loop.get('N404'),
  };

  // Extract line items from PO1 loops
  const lineItems = transaction.getLoops('PO1').map(po1 => ({
    sku:      po1.get('PO107'),         // VN qualifier = vendor SKU
    quantity: parseInt(po1.get('PO102')),
    price:    parseFloat(po1.get('PO104')),
    title:    po1.get('PID05') || '',   // from PID segment in loop
  }));

  // Resolve Shopify variant IDs from SKUs
  const resolvedItems = await Promise.all(
    lineItems.map(async item => {
      const variantId = await lookupVariantBySku(item.sku);
      if (!variantId) throw new Error(`SKU not found: ${item.sku}`);
      return { variant_id: variantId, quantity: item.quantity, price: item.price };
    })
  );

  return {
    order: {
      line_items: resolvedItems,
      shipping_address: shippingAddress,
      tags: [`edi-po:${poNumber}`, 'edi-order'],
      note_attributes: [
        { name: 'edi_po_number', value: poNumber },
        { name: 'edi_source', value: 'X12-850' },
      ],
      financial_status: 'pending',
    }
  };
}

const response = await fetch(
  `https://${SHOP}.myshopify.com/admin/api/2024-04/orders.json`,
  {
    method: 'POST',
    headers: {
      'X-Shopify-Access-Token': ACCESS_TOKEN,
      'Content-Type': 'application/json',
    },
    body: JSON.stringify({
      ...shopifyOrderPayload,
      send_receipt: false,      // suppress email to partner
      send_fulfillment_receipt: false,
      inventory_behaviour: 'decrement_obeying_policy',
    }),
  }
);

if (!response.ok) {
  const error = await response.json();
  // Log full error — Shopify returns field-level validation errors
  throw new Error(`Shopify order creation failed: ${JSON.stringify(error)}`);
}

const { order } = await response.json();
// Store order.id → poNumber mapping in your database for 855/856 generation
await savePoMapping({ shopifyOrderId: order.id, poNumber, partnerId });

ISA*00*          *00*          *ZZ*YOURCOMPANY    *ZZ*RETAILER       *260501*1000*^*00501*000000002*0*P*:
GS*PR*YOURCOMPANY*RETAILER*20260501*1000*2*X*005010
ST*855*0001
BAK*00*AC*PO-98765*20260501  ~ AC = Accepted, references original PO#
PO1*1*24*EA*29.99*VN*SKU-ABC123
ACK*IA*24*EA*202*20260515     ~ IA = Item Accepted
PO1*2*12*EA*49.99*VN*SKU-DEF456
ACK*IA*12*EA*202*20260515
CTT*2
SE*9*0001
GE*1*2
IEA*1*000000002

// Register webhook in Shopify
POST /admin/api/2024-04/webhooks.json
{
  "topic": "orders/fulfilled",
  "address": "https://your-integration.com/webhooks/fulfillment",
  "format": "json"
}

// In your webhook handler:
async function handleFulfillment(shopifyOrder, fulfillment) {
  const poMapping = await getPoMapping(shopifyOrder.id);

  const asnData = {
    shipmentId:  `ASN-${Date.now()}`,
    poNumber:    poMapping.poNumber,
    shipDate:    fulfillment.created_at,
    carrier:     mapCarrierCode(fulfillment.tracking_company),
    trackingNum: fulfillment.tracking_number,
    lines:       fulfillment.line_items.map(li => ({
      sku: li.sku, quantity: li.quantity,
    })),
  };

  const edi856 = generate856(asnData, poMapping.partnerId);
  await transmitViaAS2(edi856, poMapping.partnerId);
}