Add audit owner resolution and actor display name functions

This commit introduces a new module, `auditOwner.js`, which includes functions for resolving audit owner details and generating display names for actors. The `resolveAuditOwner` function determines the owner type based on the actor's object type, defaulting to 'user' if not specified. The `actorDisplayName` function formats the display name based on the actor's properties, enhancing the clarity of audit logs. Additionally, the `AUDIT_OWNER_TYPES` constant is exported for use in other modules. Updates to existing files incorporate these new functions for improved audit logging and notification handling.
2026-08-24 02:49:38 +01:00 · 2026-08-24 02:49:38 +01:00 · 5ff93be27c
commit 5ff93be27c
parent 8974d1e9da
50 changed files with 3017 additions and 275 deletions
--- a/src/auditOwner.js
+++ b/src/auditOwner.js
@ -0,0 +1,22 @@
+const AUDIT_OWNER_TYPES = ['user', 'printer', 'host', 'marketplace'];
+
+export function resolveAuditOwner(actor) {
+  const ownerType = AUDIT_OWNER_TYPES.includes(actor?._objectType)
+    ? actor._objectType
+    : 'user';
+  return {
+    owner: actor?._id,
+    ownerType,
+  };
+}
+
+export function actorDisplayName(actor) {
+  if (actor?._objectType === 'marketplace' || actor?._objectType === 'host') {
+    return actor.name || actor._objectType;
+  }
+  const firstName = actor?.firstName ?? 'unknown';
+  const lastName = actor?.lastName ?? '';
+  return `${firstName} ${lastName}`.trim();
+}
+
+export { AUDIT_OWNER_TYPES };
--- a/src/database/schemas/tests/stockQuantity.recalculate.test.js
+++ b/src/database/schemas/tests/stockQuantity.recalculate.test.js
@ -0,0 +1,103 @@
+import { beforeEach, describe, expect, it, jest } from '@jest/globals';
+import mongoose from 'mongoose';
+
+jest.unstable_mockModule('../../database.js', () => ({
+  aggregateRollups: jest.fn(),
+  aggregateRollupsHistory: jest.fn(),
+  editObject: jest.fn(),
+  getObject: jest.fn(),
+}));
+
+jest.unstable_mockModule('../../utils.js', () => ({
+  generateId: jest.fn(() => () => 'test-id'),
+}));
+
+const { aggregateRollups, editObject } = await import('../../database.js');
+const { listingModel } = await import('../sales/listing.schema.js');
+const { listingVarientModel } = await import('../sales/listingvarient.schema.js');
+const { productSkuModel } = await import('../management/productsku.schema.js');
+const { productStockModel } = await import('../inventory/productstock.schema.js');
+
+const listingId = new mongoose.Types.ObjectId();
+const productId = new mongoose.Types.ObjectId();
+const productSkuId = new mongoose.Types.ObjectId();
+const stockLocationId = new mongoose.Types.ObjectId();
+const varientId = new mongoose.Types.ObjectId();
+
+describe('listingVarient.recalculate', () => {
+  beforeEach(() => {
+    aggregateRollups.mockReset();
+    editObject.mockReset();
+  });
+
+  it('sums sibling listing varient stock quantities onto the listing', async () => {
+    aggregateRollups.mockResolvedValue({ stockQuantity: { sum: 12 } });
+    editObject.mockResolvedValue({});
+
+    await listingVarientModel.recalculate({ listing: listingId, stockQuantity: 4 }, 'user-1');
+
+    expect(aggregateRollups).toHaveBeenCalledWith(
+      expect.objectContaining({
+        model: listingVarientModel,
+        baseFilter: { listing: listingId },
+      })
+    );
+    expect(editObject).toHaveBeenCalledWith({
+      model: listingModel,
+      id: listingId,
+      updateData: { stockQuantity: 12 },
+      user: 'user-1',
+      recalculate: false,
+    });
+  });
+});
+
+describe('productStock.recalculate', () => {
+  beforeEach(() => {
+    aggregateRollups.mockReset();
+    editObject.mockReset();
+    jest.restoreAllMocks();
+  });
+
+  it('writes the sku/location total onto matching listing varients', async () => {
+    aggregateRollups.mockResolvedValue({ stockQuantity: { sum: 9 } });
+    editObject.mockResolvedValue({});
+    jest.spyOn(productSkuModel, 'findById').mockReturnValue({
+      select: () => ({ lean: async () => ({ product: productId }) }),
+    });
+    jest.spyOn(listingVarientModel, 'find').mockReturnValue({
+      populate: () => ({
+        lean: async () => [
+          {
+            _id: varientId,
+            product: productId,
+            productSku: productSkuId,
+            stockQuantity: 0,
+            listing: { product: productId, stockLocation: stockLocationId },
+          },
+        ],
+      }),
+    });
+
+    await productStockModel.recalculate(
+      { productSku: productSkuId, stockLocation: stockLocationId, currentQuantity: 9 },
+      'user-1'
+    );
+
+    expect(aggregateRollups).toHaveBeenCalledWith(
+      expect.objectContaining({
+        model: productStockModel,
+        baseFilter: {
+          productSku: productSkuId,
+          stockLocation: stockLocationId,
+        },
+      })
+    );
+    expect(editObject).toHaveBeenCalledWith({
+      model: listingVarientModel,
+      id: varientId,
+      updateData: { stockQuantity: 9 },
+      user: 'user-1',
+    });
+  });
+});
--- a/src/database/schemas/inventory/orderitem.schema.js
+++ b/src/database/schemas/inventory/orderitem.schema.js
@ -63,6 +63,9 @@ const orderItemSchema = new Schema(
    invoicedQuantityRemaining: { type: Number, required: false, default: 0 },
    timestamp: { type: Date, default: Date.now },
    shipment: { type: Schema.Types.ObjectId, ref: 'shipment', required: false },
+    listing: { type: Schema.Types.ObjectId, ref: 'listing', required: false },
+    listingVarient: { type: Schema.Types.ObjectId, ref: 'listingVarient', required: false },
+    externalReference: { type: String, required: false },
    orderedAt: { type: Date, required: false },
    receivedAt: { type: Date, required: false },
  },
@ -70,6 +73,7 @@ const orderItemSchema = new Schema(
 );

 orderItemSchema.index({ name: 'text', itemType: 'text', orderType: 'text' });
+orderItemSchema.index({ order: 1, externalReference: 1 }, { unique: true, sparse: true });

 const rollupConfigs = [
  {
@ -132,7 +136,13 @@ orderItemSchema.statics.recalculate = async function (orderItem, user) {
        cached: true,
      });
      if (sku) {
-        const parentId = sku.part?._id || sku.part || sku.product?._id || sku.product || sku.filament?._id || sku.filament;
+        const parentId =
+          sku.part?._id ||
+          sku.part ||
+          sku.product?._id ||
+          sku.product ||
+          sku.filament?._id ||
+          sku.filament;
        if (syncAmount === 'itemCost') {
          if (sku.overrideCost && sku.cost != null) {
            effectiveItemAmount = sku.cost;
--- a/src/database/schemas/inventory/productstock.schema.js
+++ b/src/database/schemas/inventory/productstock.schema.js
@ -1,7 +1,7 @@
 import mongoose from 'mongoose';
 import { generateId } from '../../utils.js';
 const { Schema } = mongoose;
-import { aggregateRollups, aggregateRollupsHistory } from '../../database.js';
+import { aggregateRollups, aggregateRollupsHistory, editObject } from '../../database.js';

 const partStockUsageSchema = new Schema({
  partStock: { type: Schema.Types.ObjectId, ref: 'partStock', required: false },
@ -9,6 +9,12 @@ const partStockUsageSchema = new Schema({
  quantity: { type: Number, required: true },
 });

+const toId = (value) => {
+  if (value == null) return null;
+  if (typeof value === 'object' && value._id) return String(value._id);
+  return String(value);
+};
+
 // Define the main productStock schema - tracks assembled products consisting of part stocks
 const productStockSchema = new Schema(
  {
@ -76,6 +82,64 @@ productStockSchema.statics.history = async function (from, to) {
  return results;
 };

+productStockSchema.statics.recalculate = async function (productStock, user) {
+  const productSkuId = toId(productStock?.productSku);
+  const stockLocationId = toId(productStock?.stockLocation);
+  if (!productSkuId || !stockLocationId) {
+    return;
+  }
+
+  let productId = toId(productStock?.productSku?.product);
+  if (!productId) {
+    const productSku = await mongoose.model('productSku').findById(productSkuId).select('product').lean();
+    productId = toId(productSku?.product);
+  }
+  if (!productId) {
+    return;
+  }
+
+  const rollupResults = await aggregateRollups({
+    model: this,
+    baseFilter: {
+      productSku: new mongoose.Types.ObjectId(productSkuId),
+      stockLocation: new mongoose.Types.ObjectId(stockLocationId),
+    },
+    rollupConfigs: [
+      {
+        name: 'stockQuantity',
+        rollups: [{ name: 'stockQuantity', property: 'currentQuantity', operation: 'sum' }],
+      },
+    ],
+  });
+  const stockQuantity = rollupResults.stockQuantity?.sum || 0;
+
+  const listingVarientModel = mongoose.model('listingVarient');
+  const varients = await listingVarientModel
+    .find({ productSku: productSkuId })
+    .populate('listing')
+    .lean();
+
+  for (const varient of varients) {
+    const varientProductId =
+      toId(varient.product) || toId(varient.listing?.product);
+    const varientLocationId = toId(varient.listing?.stockLocation);
+    if (varientProductId !== productId || varientLocationId !== stockLocationId) {
+      continue;
+    }
+    if (varient.stockQuantity === stockQuantity) {
+      await listingVarientModel.recalculate(varient, user);
+      continue;
+    }
+
+    await editObject({
+      model: listingVarientModel,
+      id: varient._id,
+      updateData: { stockQuantity },
+      user,
+    });
+  }
+};
+
 // Add virtual id getter
 productStockSchema.virtual('id').get(function () {
  return this._id;
--- a/src/database/schemas/inventory/shipment.schema.js
+++ b/src/database/schemas/inventory/shipment.schema.js
@ -13,6 +13,7 @@ const shipmentSchema = new Schema(
    order: { type: Schema.Types.ObjectId, refPath: 'orderType', required: true },
    courierService: { type: Schema.Types.ObjectId, ref: 'courierService', required: false },
    trackingNumber: { type: String, required: false },
+    externalReference: { type: String, required: false },
    amount: { type: Number, required: true },
    amountWithTax: { type: Number, required: true },
    taxRate: { type: Schema.Types.ObjectId, ref: 'taxRate', required: false },
@ -35,6 +36,7 @@ const shipmentSchema = new Schema(
 );

 shipmentSchema.index({ trackingNumber: 'text', orderType: 'text' });
+shipmentSchema.index({ order: 1, externalReference: 1 }, { unique: true, sparse: true });

 shipmentSchema.statics.recalculate = async function (shipment, user) {
  if (shipment.orderType !== 'purchaseOrder' && shipment.orderType !== 'salesOrder') {
--- a/src/database/schemas/inventory/stockevent.schema.js
+++ b/src/database/schemas/inventory/stockevent.schema.js
@ -190,7 +190,7 @@ const recalculateParentStock = async (parentType, parentId, user) => {
      buildParentUpdateData(parentType, parentStock, events)
    ),
    user,
-    recalculate: false,
+    recalculate: parentType === 'productStock',
  });
 };

--- a/src/database/schemas/management/auditlog.schema.js
+++ b/src/database/schemas/management/auditlog.schema.js
@ -30,7 +30,7 @@ const auditLogSchema = new Schema(
    ownerType: {
      type: String,
      required: true,
-      enum: ['user', 'printer', 'host'],
+      enum: ['user', 'printer', 'host', 'marketplace'],
    },
  },
  { timestamps: true }
--- a/src/database/schemas/management/courier.schema.js
+++ b/src/database/schemas/management/courier.schema.js
@ -14,7 +14,14 @@ const courierSchema = new mongoose.Schema(
  { timestamps: true }
 );

-courierSchema.index({ name: 'text', website: 'text', email: 'text', phone: 'text', contact: 'text', country: 'text' });
+courierSchema.index({
+  name: 'text',
+  website: 'text',
+  email: 'text',
+  phone: 'text',
+  contact: 'text',
+  country: 'text',
+});

 courierSchema.virtual('id').get(function () {
  return this._id;
--- a/src/database/schemas/management/courierservice.schema.js
+++ b/src/database/schemas/management/courierservice.schema.js
@ -2,6 +2,14 @@ import mongoose from 'mongoose';
 import { generateId } from '../../utils.js';
 const { Schema } = mongoose;

+const marketplaceMappingSchema = new mongoose.Schema(
+  {
+    marketplace: { type: Schema.Types.ObjectId, ref: 'marketplace', required: true },
+    externalReference: { type: String, required: false },
+  },
+  { _id: true }
+);
+
 const courierServiceSchema = new mongoose.Schema(
  {
    _reference: { type: String, default: () => generateId()() },
@ -18,6 +26,7 @@ const courierServiceSchema = new mongoose.Schema(
    additionalCostWithTax: { required: false, type: Number },
    shippingCurrency: { required: true, type: String, default: 'GBP' },
    international: { required: true, type: Boolean, default: false },
+    marketplaces: { type: [marketplaceMappingSchema], default: [] },
  },
  { timestamps: true }
 );
--- a/src/database/schemas/models.js
+++ b/src/database/schemas/models.js
@ -48,6 +48,7 @@ import { salesOrderModel } from './sales/salesorder.schema.js';
 import { marketplaceModel } from './sales/marketplace.schema.js';
 import { listingModel } from './sales/listing.schema.js';
 import { listingVarientModel } from './sales/listingvarient.schema.js';
+import { marketplaceEventModel } from './sales/marketplaceevent.schema.js';
 import { paymentModel } from './finance/payment.schema.js';

 // Map prefixes to models and id fields
@ -396,6 +397,13 @@ export const models = {
    label: 'Listing Varient',
    referenceField: '_reference',
  },
+  MKE: {
+    model: marketplaceEventModel,
+    idField: '_id',
+    type: 'marketplaceEvent',
+    label: 'Marketplace Event',
+    referenceField: '_reference',
+  },
  PAY: {
    model: paymentModel,
    idField: '_id',
--- a/src/database/schemas/sales/client.schema.js
+++ b/src/database/schemas/sales/client.schema.js
@ -16,6 +16,7 @@ const clientSchema = new mongoose.Schema(
    _reference: { type: String, default: () => generateId()() },
    name: { required: true, type: String },
    marketplace: { type: mongoose.Schema.Types.ObjectId, ref: 'marketplace', required: false },
+    externalReference: { type: String, required: false },
    email: { required: false, type: String },
    phone: { required: false, type: String },
    country: { required: false, type: String },
@ -27,6 +28,7 @@ const clientSchema = new mongoose.Schema(
 );

 clientSchema.index({ name: 'text', email: 'text', phone: 'text', country: 'text', tags: 'text' });
+clientSchema.index({ marketplace: 1, externalReference: 1 }, { unique: true, sparse: true });

 clientSchema.virtual('id').get(function () {
  return this._id;
--- a/src/database/schemas/sales/listing.schema.js
+++ b/src/database/schemas/sales/listing.schema.js
@ -19,15 +19,43 @@ const listingSchema = new Schema(
      message: { type: String, required: false },
    },
    url: { type: String, required: false },
+    description: { type: String, required: false },
+    externalReference: { type: String, required: false },
    price: { type: Number, required: false },
    currency: { type: String, required: false },
    lastSyncedAt: { type: Date, required: false },
+    stockQuantity: { type: Number, required: false, default: 0 },
+    condition: {
+      type: String,
+      enum: [
+        'new',
+        'likeNew',
+        'newOther',
+        'newWithDefects',
+        'manufacturerRefurbished',
+        'certifiedRefurbished',
+        'excellentRefurbished',
+        'veryGoodRefurbished',
+        'goodRefurbished',
+        'sellerRefurbished',
+        'usedExcellent',
+        'usedVeryGood',
+        'usedGood',
+        'usedAcceptable',
+        'forPartsOrNotWorking',
+        'preOwnedExcellent',
+        'preOwnedFair',
+      ],
+      default: 'new',
+      required: false,
+    },
    courierServices: [{ type: Schema.Types.ObjectId, ref: 'courierService', required: true }],
  },
  { timestamps: true }
 );

 listingSchema.index({ title: 'text', url: 'text' });
+listingSchema.index({ marketplace: 1, externalReference: 1 }, { unique: true, sparse: true });

 listingSchema.virtual('id').get(function () {
  return this._id;
--- a/src/database/schemas/sales/listingvarient.schema.js
+++ b/src/database/schemas/sales/listingvarient.schema.js
@ -1,5 +1,6 @@
 import mongoose from 'mongoose';
 import { generateId } from '../../utils.js';
+import { aggregateRollups, editObject } from '../../database.js';
 const { Schema } = mongoose;

 const listingVarientSchema = new Schema(
@ -16,16 +17,19 @@ const listingVarientSchema = new Schema(
      },
      message: { type: String, required: false },
    },
+    externalReference: { type: String, required: false },
    price: { type: Number, required: false },
    currency: { type: String, required: false },
    priceTaxRate: { type: Schema.Types.ObjectId, ref: 'taxRate', required: false },
    priceWithTax: { type: Number, required: false },
    lastSyncedAt: { type: Date, required: false },
+    stockQuantity: { type: Number, required: false, default: 0 },
  },
  { timestamps: true }
 );

 listingVarientSchema.index({ currency: 'text', 'state.type': 'text' });
+listingVarientSchema.index({ listing: 1, externalReference: 1 }, { unique: true, sparse: true });

 listingVarientSchema.virtual('id').get(function () {
  return this._id;
@ -42,4 +46,32 @@ listingVarientSchema.set('toJSON', {
  },
 });

+listingVarientSchema.statics.recalculate = async function (listingVarient, user) {
+  const listingId = listingVarient?.listing?._id || listingVarient?.listing;
+  if (!listingId) {
+    return;
+  }
+
+  const rollupResults = await aggregateRollups({
+    model: this,
+    baseFilter: { listing: new mongoose.Types.ObjectId(listingId) },
+    rollupConfigs: [
+      {
+        name: 'stockQuantity',
+        rollups: [{ name: 'stockQuantity', property: 'stockQuantity', operation: 'sum' }],
+      },
+    ],
+  });
+
+  await editObject({
+    model: mongoose.model('listing'),
+    id: listingId,
+    updateData: {
+      stockQuantity: rollupResults.stockQuantity?.sum || 0,
+    },
+    user,
+    recalculate: false,
+  });
+};
+
 export const listingVarientModel = mongoose.model('listingVarient', listingVarientSchema);
--- a/src/database/schemas/sales/marketplace.schema.js
+++ b/src/database/schemas/sales/marketplace.schema.js
@ -17,13 +17,16 @@ const marketplaceSchema = new mongoose.Schema(
    state: {
      type: {
        type: String,
-        enum: ['active', 'inactive', 'suspended', 'ready', 'offline', 'syncing'],
+        enum: ['active', 'inactive', 'suspended', 'ready', 'offline', 'syncing', 'disconnected'],
        default: 'offline',
      },
      message: { type: String, required: false },
    },
    // Provider-specific API configuration (flexible for eBay, Etsy, TikTok Shop)
    config: { type: mongoose.Schema.Types.Mixed, default: {} },
+    eBay: {
+      availableShippingServices: { type: [String], default: [] },
+    },
  },
  { timestamps: true }
 );
--- a/src/database/schemas/sales/marketplaceevent.schema.js
+++ b/src/database/schemas/sales/marketplaceevent.schema.js
@ -0,0 +1,31 @@
+import mongoose from 'mongoose';
+import { generateId } from '../../utils.js';
+
+const marketplaceEventSchema = new mongoose.Schema(
+  {
+    _reference: { type: String, default: () => generateId()() },
+    marketplace: { type: mongoose.Schema.Types.ObjectId, ref: 'marketplace', required: true },
+    externalReference: { type: String, required: true },
+    topic: { type: String, required: true },
+    status: {
+      type: String,
+      required: true,
+      enum: ['received', 'processed', 'failed'],
+      default: 'received',
+    },
+    processedAt: { type: Date, required: false },
+    error: { type: String, required: false },
+  },
+  { timestamps: true }
+);
+
+marketplaceEventSchema.index({ marketplace: 1, externalReference: 1 }, { unique: true });
+marketplaceEventSchema.index({ topic: 'text', status: 'text' });
+
+marketplaceEventSchema.virtual('id').get(function () {
+  return this._id;
+});
+
+marketplaceEventSchema.set('toJSON', { virtuals: true });
+
+export const marketplaceEventModel = mongoose.model('marketplaceEvent', marketplaceEventSchema);
--- a/src/database/schemas/sales/salesorder.schema.js
+++ b/src/database/schemas/sales/salesorder.schema.js
@ -1,11 +1,7 @@
 import mongoose from 'mongoose';
 import { generateId } from '../../utils.js';
 const { Schema } = mongoose;
-import {
-  aggregateRollups,
-  aggregateRollupsHistory,
-  editObject,
-} from '../../database.js';
+import { aggregateRollups, aggregateRollupsHistory, editObject } from '../../database.js';

 const salesOrderSchema = new Schema(
  {
@ -19,6 +15,7 @@ const salesOrderSchema = new Schema(
    timestamp: { type: Date, default: Date.now },
    client: { type: Schema.Types.ObjectId, ref: 'client', required: true },
    marketplace: { type: Schema.Types.ObjectId, ref: 'marketplace', required: false },
+    externalReference: { type: String, required: false },
    state: {
      type: { type: String, required: true, default: 'draft' },
    },
@ -31,6 +28,7 @@ const salesOrderSchema = new Schema(
 );

 salesOrderSchema.index({ 'state.type': 'text' });
+salesOrderSchema.index({ marketplace: 1, externalReference: 1 }, { unique: true, sparse: true });

 const rollupConfigs = [
  {
--- a/src/database/utils.js
+++ b/src/database/utils.js
@ -2,10 +2,11 @@ import { customAlphabet } from 'nanoid';
 import mongoose from 'mongoose';

 const ALPHABET = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
-export const generateId = () => {
+const createId = () => {
  // 10 characters
  return customAlphabet(ALPHABET, 12);
 };
+export const generateId = createId;

 /** Check if a value is a string that looks like a MongoDB ObjectId (24 hex chars). */
 export function isObjectIdString(value) {
--- a/src/index.js
+++ b/src/index.js
@ -145,7 +145,16 @@ async function initializeApp() {

 // Configure middleware
 app.use(cors(corsOptions));
-app.use(bodyParser.json({ type: 'application/json', strict: false, limit: '50mb' }));
+app.use(
+  bodyParser.json({
+    type: 'application/json',
+    strict: false,
+    limit: '50mb',
+    verify: (req, res, buf) => {
+      req.rawBody = buf.toString('utf8');
+    },
+  })
+);
 app.use(express.json());
 app.use(populateUserMiddleware);

--- a/src/integrations/tests/marketplaceSync.test.js
+++ b/src/integrations/tests/marketplaceSync.test.js
@ -0,0 +1,142 @@
+import { describe, expect, it, jest, beforeEach } from '@jest/globals';
+
+jest.unstable_mockModule('../../database/database.js', () => ({
+  newObject: jest.fn(),
+  editObject: jest.fn(),
+}));
+jest.unstable_mockModule('../../database/schemas/sales/client.schema.js', () => ({
+  clientModel: { findOne: jest.fn() },
+}));
+jest.unstable_mockModule('../../database/schemas/sales/salesorder.schema.js', () => ({
+  salesOrderModel: { findOne: jest.fn(), findById: jest.fn() },
+}));
+jest.unstable_mockModule('../../database/schemas/sales/listing.schema.js', () => ({
+  listingModel: { findOne: jest.fn() },
+}));
+jest.unstable_mockModule('../../database/schemas/sales/listingvarient.schema.js', () => ({
+  listingVarientModel: { findOne: jest.fn() },
+}));
+jest.unstable_mockModule('../../database/schemas/sales/marketplace.schema.js', () => ({
+  marketplaceModel: {},
+}));
+jest.unstable_mockModule('../../database/schemas/inventory/orderitem.schema.js', () => ({
+  orderItemModel: { findOne: jest.fn(), find: jest.fn() },
+}));
+jest.unstable_mockModule('../../database/schemas/inventory/shipment.schema.js', () => ({
+  shipmentModel: { findOne: jest.fn() },
+}));
+jest.unstable_mockModule('../../database/schemas/sales/marketplaceevent.schema.js', () => ({
+  marketplaceEventModel: { findOne: jest.fn() },
+}));
+jest.unstable_mockModule('../../database/schemas/management/productsku.schema.js', () => ({
+  productSkuModel: { findOne: jest.fn() },
+}));
+jest.unstable_mockModule('../../database/schemas/management/product.schema.js', () => ({
+  productModel: { findById: jest.fn() },
+}));
+jest.unstable_mockModule('log4js', () => ({
+  default: { getLogger: () => ({ level: 'off', warn: jest.fn(), info: jest.fn(), debug: jest.fn() }) },
+}));
+jest.unstable_mockModule('../../config.js', () => ({
+  default: { server: { logLevel: 'off' } },
+}));
+
+const { newObject } = await import('../../database/database.js');
+const { clientModel } = await import('../../database/schemas/sales/client.schema.js');
+const { salesOrderModel } = await import('../../database/schemas/sales/salesorder.schema.js');
+const { orderItemModel } = await import('../../database/schemas/inventory/orderitem.schema.js');
+const { marketplaceEventModel } = await import(
+  '../../database/schemas/sales/marketplaceevent.schema.js'
+);
+const { upsertExternalOrder, applyWebhookAction } = await import('../marketplaceSync.js');
+const { resolveAuditOwner } = await import('../../auditOwner.js');
+
+describe('marketplace sync upserts', () => {
+  const marketplace = { _id: 'mkt-1', name: 'eBay UK', config: {} };
+  const actor = { _id: 'mkt-1', name: 'eBay UK', _objectType: 'marketplace' };
+
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
+  it('creates sales orders by externalReference with marketplace actor', async () => {
+    clientModel.findOne.mockResolvedValue(null);
+    salesOrderModel.findOne.mockResolvedValue(null);
+    orderItemModel.findOne.mockResolvedValue(null);
+    newObject.mockImplementation(async ({ newData }) => ({
+      _id: 'created-1',
+      ...newData,
+    }));
+
+    const provider = {
+      mapOrderToSalesOrder: () => ({
+        externalReference: 'ebay-order-1',
+        state: { type: 'confirmed' },
+        totalAmount: 10,
+        totalAmountWithTax: 12,
+        shippingAmount: 2,
+        shippingAmountWithTax: 2,
+        grandTotalAmount: 14,
+        totalTaxAmount: 2,
+      }),
+      mapBuyerToClient: () => ({
+        name: 'Jane',
+        email: 'jane@example.com',
+        externalReference: 'jane-ebay',
+      }),
+      mapOrderLineItems: () => [
+        {
+          externalReference: 'line-1',
+          name: 'Widget',
+          sku: 'SKU-1',
+          quantity: 1,
+          itemAmount: 10,
+          totalAmount: 10,
+          totalAmountWithTax: 12,
+        },
+      ],
+    };
+
+    const result = await upsertExternalOrder(
+      marketplace,
+      provider,
+      { orderId: 'ebay-order-1' },
+      actor
+    );
+    expect(result.action).toBe('created');
+    expect(newObject).toHaveBeenCalledWith(
+      expect.objectContaining({
+        user: actor,
+        newData: expect.objectContaining({ externalReference: 'ebay-order-1' }),
+      })
+    );
+  });
+
+  it('skips duplicate webhook events', async () => {
+    marketplaceEventModel.findOne.mockResolvedValue({
+      _id: 'evt-1',
+      status: 'processed',
+    });
+    const classified = await applyWebhookAction(
+      marketplace,
+      {},
+      { action: 'orderUpdate', orderId: 'o1', notificationId: 'n1' },
+      actor
+    );
+    expect(classified.duplicate).toBe(true);
+    expect(newObject).not.toHaveBeenCalled();
+  });
+});
+
+describe('audit owner resolution', () => {
+  it('uses marketplace ownerType for marketplace actors', () => {
+    expect(resolveAuditOwner({ _id: 'm1', _objectType: 'marketplace' })).toEqual({
+      owner: 'm1',
+      ownerType: 'marketplace',
+    });
+  });
+
+  it('defaults to user', () => {
+    expect(resolveAuditOwner({ _id: 'u1' })).toEqual({ owner: 'u1', ownerType: 'user' });
+  });
+});
--- a/src/integrations/marketplaceSync.js
+++ b/src/integrations/marketplaceSync.js
@ -0,0 +1,482 @@
+import { clientModel } from '../database/schemas/sales/client.schema.js';
+import { salesOrderModel } from '../database/schemas/sales/salesorder.schema.js';
+import { listingModel } from '../database/schemas/sales/listing.schema.js';
+import { listingVarientModel } from '../database/schemas/sales/listingvarient.schema.js';
+import { marketplaceModel } from '../database/schemas/sales/marketplace.schema.js';
+import { orderItemModel } from '../database/schemas/inventory/orderitem.schema.js';
+import { shipmentModel } from '../database/schemas/inventory/shipment.schema.js';
+import { marketplaceEventModel } from '../database/schemas/sales/marketplaceevent.schema.js';
+import { productSkuModel } from '../database/schemas/management/productsku.schema.js';
+import { productModel } from '../database/schemas/management/product.schema.js';
+import { editObject, newObject } from '../database/database.js';
+import { marketplaceActor, marketplaceSku } from './marketplaces/ids.js';
+import config from '../config.js';
+import log4js from 'log4js';
+
+const logger = log4js.getLogger('Marketplace Sync');
+logger.level = config.server.logLevel;
+
+function externalIdOf(mapped = {}) {
+  return mapped.externalReference || mapped.externalId;
+}
+
+function stateType(mapped) {
+  return mapped?.state?.type || mapped?.state;
+}
+
+async function upsertClient(marketplace, clientData, actor) {
+  if (!clientData) return null;
+  const marketplaceId = marketplace._id;
+  let client = null;
+  const externalReference = externalIdOf(clientData);
+  if (externalReference) {
+    client = await clientModel.findOne({ marketplace: marketplaceId, externalReference });
+  }
+  if (!client && clientData.email) {
+    client = await clientModel.findOne({ marketplace: marketplaceId, email: clientData.email });
+  }
+  if (!client && clientData.name) {
+    client = await clientModel.findOne({ marketplace: marketplaceId, name: clientData.name });
+  }
+
+  const payload = {
+    ...clientData,
+    marketplace: marketplaceId,
+    active: true,
+    ...(externalReference ? { externalReference } : {}),
+  };
+  delete payload.externalId;
+
+  if (client) {
+    return editObject({
+      model: clientModel,
+      id: client._id,
+      updateData: payload,
+      user: actor,
+    });
+  }
+
+  return newObject({
+    model: clientModel,
+    newData: payload,
+    user: actor,
+  });
+}
+
+async function upsertOrderItems(salesOrder, externalOrder, provider, actor) {
+  if (typeof provider.mapOrderLineItems !== 'function') return;
+  const lines = provider.mapOrderLineItems(externalOrder) || [];
+  for (const line of lines) {
+    const lineRef = externalIdOf(line);
+    if (!lineRef) continue;
+
+    let listingVarient = null;
+    if (line.sku) {
+      listingVarient = await listingVarientModel.findOne({
+        $or: [{ externalReference: line.sku }, { _reference: line.sku }],
+      });
+    }
+
+    const payload = {
+      orderType: 'salesOrder',
+      order: salesOrder._id,
+      name: line.name || line.sku || 'Marketplace item',
+      itemType: line.itemType || 'product',
+      quantity: line.quantity || 1,
+      itemAmount: line.itemAmount ?? 0,
+      totalAmount: line.totalAmount ?? 0,
+      totalAmountWithTax: line.totalAmountWithTax ?? line.totalAmount ?? 0,
+      externalReference: lineRef,
+      listing: listingVarient?.listing,
+      listingVarient: listingVarient?._id,
+      item: listingVarient?.product,
+      sku: listingVarient?.productSku,
+      state: { type: stateType(salesOrder) === 'cancelled' ? 'cancelled' : 'ordered' },
+    };
+
+    const existing = await orderItemModel.findOne({
+      order: salesOrder._id,
+      externalReference: lineRef,
+    });
+    if (existing) {
+      await editObject({
+        model: orderItemModel,
+        id: existing._id,
+        updateData: payload,
+        user: actor,
+      });
+    } else {
+      await newObject({
+        model: orderItemModel,
+        newData: payload,
+        user: actor,
+      });
+    }
+  }
+}
+
+async function upsertOrderShipments(salesOrder, externalOrder, provider, actor) {
+  if (typeof provider.mapOrderShipments !== 'function') return;
+  const shipments = provider.mapOrderShipments(externalOrder) || [];
+  for (const mapped of shipments) {
+    const shipmentRef = externalIdOf(mapped);
+    if (!shipmentRef) continue;
+    const payload = {
+      orderType: 'salesOrder',
+      order: salesOrder._id,
+      trackingNumber: mapped.trackingNumber || '',
+      amount: mapped.amount ?? 0,
+      amountWithTax: mapped.amountWithTax ?? mapped.amount ?? 0,
+      externalReference: shipmentRef,
+      state: mapped.state || { type: 'planned' },
+      shippedAt: mapped.shippedAt,
+    };
+
+    const existing = await shipmentModel.findOne({
+      order: salesOrder._id,
+      externalReference: shipmentRef,
+    });
+    if (existing) {
+      await editObject({
+        model: shipmentModel,
+        id: existing._id,
+        updateData: payload,
+        user: actor,
+      });
+    } else {
+      await newObject({
+        model: shipmentModel,
+        newData: payload,
+        user: actor,
+      });
+    }
+  }
+}
+
+export async function upsertExternalOrder(marketplace, provider, externalOrder, actor) {
+  const mapped = provider.mapOrderToSalesOrder(externalOrder);
+  const clientData = provider.mapBuyerToClient(externalOrder);
+  const externalReference = externalIdOf(mapped);
+  if (!externalReference) {
+    throw new Error('Mapped sales order is missing externalReference');
+  }
+
+  const client = await upsertClient(marketplace, clientData, actor);
+  const existingOrder = await salesOrderModel.findOne({
+    marketplace: marketplace._id,
+    externalReference,
+  });
+
+  const lifecycle = {};
+  const type = mapped.state?.type;
+  if (type === 'confirmed' || type === 'shipped' || type === 'delivered') {
+    lifecycle.confirmedAt = existingOrder?.confirmedAt || new Date();
+  }
+  if (type === 'cancelled') {
+    lifecycle.cancelledAt = existingOrder?.cancelledAt || new Date();
+  }
+
+  const orderPayload = {
+    client: client?._id,
+    marketplace: marketplace._id,
+    externalReference,
+    state: mapped.state,
+    totalAmount: mapped.totalAmount,
+    totalAmountWithTax: mapped.totalAmountWithTax,
+    shippingAmount: mapped.shippingAmount,
+    shippingAmountWithTax: mapped.shippingAmountWithTax,
+    grandTotalAmount: mapped.grandTotalAmount,
+    totalTaxAmount: mapped.totalTaxAmount,
+    ...lifecycle,
+  };
+
+  let salesOrder = existingOrder;
+  if (existingOrder) {
+    salesOrder = await editObject({
+      model: salesOrderModel,
+      id: existingOrder._id,
+      updateData: orderPayload,
+      user: actor,
+    });
+  } else {
+    salesOrder = await newObject({
+      model: salesOrderModel,
+      newData: orderPayload,
+      user: actor,
+    });
+  }
+
+  await upsertOrderItems(salesOrder, externalOrder, provider, actor);
+  await upsertOrderShipments(salesOrder, externalOrder, provider, actor);
+  return { salesOrder, action: existingOrder ? 'updated' : 'created', externalReference };
+}
+
+async function matchProductSku(mapped) {
+  const skuCodes = [
+    mapped.externalReference,
+    ...(mapped.varients || []).map((v) => v.externalReference || v._reference),
+  ].filter(Boolean);
+
+  for (const code of skuCodes) {
+    const sku = await productSkuModel.findOne({
+      $or: [{ _reference: code }, { barcode: code }],
+    });
+    if (sku) return sku;
+  }
+  return null;
+}
+
+async function upsertInboundListing(marketplace, mapped, actor) {
+  const externalReference = externalIdOf(mapped);
+  if (!externalReference) {
+    logger.warn('Skipping inbound listing without externalReference');
+    return { action: 'skipped' };
+  }
+
+  const defaults = marketplace.config?.defaults || {};
+  const productSku = await matchProductSku(mapped);
+  const product = productSku
+    ? await productModel.findById(productSku.product).lean()
+    : null;
+
+  const existing = await listingModel.findOne({
+    marketplace: marketplace._id,
+    externalReference,
+  });
+
+  const payload = {
+    title: mapped.title,
+    url: mapped.url,
+    price: mapped.price,
+    currency: mapped.currency,
+    description: mapped.description,
+    externalReference,
+    lastSyncedAt: new Date(),
+    state: mapped.state || { type: 'active' },
+    marketplace: marketplace._id,
+  };
+
+  if (product) {
+    payload.product = product._id;
+    payload.vendor = product.vendor;
+  }
+
+  let listing = existing;
+  if (existing) {
+    listing = await editObject({
+      model: listingModel,
+      id: existing._id,
+      updateData: payload,
+      user: actor,
+    });
+  } else {
+    const vendor = payload.vendor || defaults.vendor;
+    const stockLocation = defaults.stockLocation;
+    const courierServices = defaults.courierServices || [];
+    if (!vendor || !stockLocation) {
+      logger.warn(
+        `Skipping inbound listing ${externalReference}: marketplace defaults.vendor and defaults.stockLocation are required to create listings`
+      );
+      return { action: 'skipped', externalReference };
+    }
+    listing = await newObject({
+      model: listingModel,
+      newData: {
+        ...payload,
+        vendor,
+        stockLocation,
+        courierServices,
+      },
+      user: actor,
+    });
+  }
+
+  for (const mappedVarient of mapped.varients || []) {
+    const varientRef = mappedVarient.externalReference || mappedVarient._reference;
+    if (!varientRef) continue;
+    const varientPayload = {
+      listing: listing._id,
+      externalReference: varientRef,
+      price: mappedVarient.price,
+      currency: mappedVarient.currency,
+      state: mappedVarient.state || mapped.state || { type: 'active' },
+      lastSyncedAt: new Date(),
+      product: product?._id || listing.product,
+      productSku: productSku?._id,
+    };
+    const existingVarient = await listingVarientModel.findOne({
+      listing: listing._id,
+      externalReference: varientRef,
+    });
+    if (existingVarient) {
+      await editObject({
+        model: listingVarientModel,
+        id: existingVarient._id,
+        updateData: varientPayload,
+        user: actor,
+      });
+    } else {
+      await newObject({
+        model: listingVarientModel,
+        newData: varientPayload,
+        user: actor,
+      });
+    }
+  }
+
+  return { action: existing ? 'updated' : 'created', listing };
+}
+
+export async function importExternalItems(marketplace, provider, actor) {
+  if (typeof provider.syncItems !== 'function' || typeof provider.mapProductToListing !== 'function') {
+    return [];
+  }
+  const externalItems = await provider.syncItems(marketplace);
+  const results = [];
+  for (const item of externalItems || []) {
+    try {
+      const mapped = provider.mapProductToListing(item);
+      const result = await upsertInboundListing(marketplace, mapped, actor);
+      results.push(result);
+    } catch (err) {
+      logger.warn(`Failed to import marketplace listing: ${err.message}`);
+      results.push({ action: 'error', error: err.message });
+    }
+  }
+  return results;
+}
+
+export async function recordMarketplaceEvent(marketplace, classified, actor) {
+  const externalReference =
+    classified.notificationId ||
+    `${classified.action}:${classified.orderId || classified.itemId || classified.topic || Date.now()}`;
+  const existing = await marketplaceEventModel.findOne({
+    marketplace: marketplace._id,
+    externalReference,
+  });
+  if (existing) {
+    return existing;
+  }
+  return newObject({
+    model: marketplaceEventModel,
+    newData: {
+      marketplace: marketplace._id,
+      externalReference,
+      topic: classified.topic || classified.action || 'unknown',
+      status: 'received',
+    },
+    user: actor,
+  });
+}
+
+export async function markMarketplaceEvent(event, status, actor, error) {
+  if (!event?._id) return;
+  await editObject({
+    model: marketplaceEventModel,
+    id: event._id,
+    updateData: {
+      status,
+      processedAt: status === 'processed' ? new Date() : event.processedAt,
+      error: error || undefined,
+    },
+    user: actor,
+  });
+}
+
+export async function applyWebhookAction(marketplace, provider, classified, actor) {
+  const event = await recordMarketplaceEvent(marketplace, classified, actor);
+  if (event.status === 'processed') {
+    return { ...classified, duplicate: true };
+  }
+
+  try {
+    switch (classified.action) {
+      case 'orderCreate':
+      case 'orderUpdate':
+      case 'orderCancel': {
+        if (classified.orderId && typeof provider.getOrder === 'function') {
+          const order = await provider.getOrder(marketplace, classified.orderId);
+          await upsertExternalOrder(marketplace, provider, order, actor);
+        }
+        break;
+      }
+      case 'productUpdate':
+      case 'productEnded': {
+        await importExternalItems(marketplace, provider, actor);
+        break;
+      }
+      case 'accountDeletion': {
+        if (classified.userId) {
+          const client = await clientModel.findOne({
+            marketplace: marketplace._id,
+            $or: [{ externalReference: classified.userId }, { name: classified.userId }],
+          });
+          if (client) {
+            await editObject({
+              model: clientModel,
+              id: client._id,
+              updateData: {
+                name: 'Deleted marketplace user',
+                email: '',
+                phone: '',
+                address: {},
+              },
+              user: actor,
+            });
+          }
+        }
+        break;
+      }
+      case 'disconnect': {
+        await editObject({
+          model: marketplaceModel,
+          id: marketplace._id,
+          updateData: { connected: false, state: { type: 'disconnected' } },
+          user: actor,
+        });
+        break;
+      }
+      default:
+        break;
+    }
+    await markMarketplaceEvent(event, 'processed', actor);
+  } catch (err) {
+    await markMarketplaceEvent(event, 'failed', actor, err.message);
+    throw err;
+  }
+
+  return classified;
+}
+
+export async function pushShipmentFulfillment(marketplace, provider, shipment, actor) {
+  if (typeof provider.createShippingFulfillment !== 'function') {
+    return;
+  }
+  const orderId = shipment.order?._id || shipment.order;
+  const salesOrder = await salesOrderModel.findById(orderId).lean();
+  if (!salesOrder?.externalReference) {
+    return;
+  }
+  const orderItems = await orderItemModel
+    .find({ order: salesOrder._id, shipment: shipment._id, orderType: 'salesOrder' })
+    .lean();
+  await provider.createShippingFulfillment(marketplace, {
+    orderId: salesOrder.externalReference,
+    trackingNumber: shipment.trackingNumber,
+    shippingCarrierCode: shipment.courierService?._reference || shipment.courierService?.code,
+    lineItems: orderItems.map((item) => ({
+      lineItemId: item.externalReference,
+      quantity: item.quantity,
+    })),
+  });
+  if (shipment._id && !shipment.externalReference) {
+    await editObject({
+      model: shipmentModel,
+      id: shipment._id,
+      updateData: { lastSyncedAt: new Date() },
+      user: actor,
+    });
+  }
+}
+
+export { marketplaceActor, marketplaceSku };
--- a/src/integrations/marketplaces/tests/ids.test.js
+++ b/src/integrations/marketplaces/tests/ids.test.js
@ -0,0 +1,15 @@
+import { describe, expect, it } from '@jest/globals';
+import { marketplaceSku, marketplaceActor } from '../ids.js';
+
+describe('marketplace ids', () => {
+  it('prefers externalReference over _reference', () => {
+    expect(marketplaceSku({ externalReference: 'ebay-sku', _reference: 'LVR-1' })).toBe('ebay-sku');
+    expect(marketplaceSku({ _reference: 'LVR-1' })).toBe('LVR-1');
+  });
+
+  it('marks marketplace actors for audit logs', () => {
+    const actor = marketplaceActor({ _id: 'm1', name: 'eBay UK' });
+    expect(actor._objectType).toBe('marketplace');
+    expect(actor.name).toBe('eBay UK');
+  });
+});
--- a/src/integrations/marketplaces/ebay/tests/fulfillmentPolicies.test.js
+++ b/src/integrations/marketplaces/ebay/tests/fulfillmentPolicies.test.js
@ -0,0 +1,115 @@
+import { describe, expect, it } from '@jest/globals';
+import {
+  buildCategoryTypes,
+  buildFulfillmentPolicy,
+  isDefaultFulfillmentPolicy,
+  validateCourierServices,
+} from '../fulfillmentPolicies.js';
+
+const marketplace = { _id: 'mp1', config: { marketplaceId: 'EBAY_GB' } };
+
+describe('eBay fulfillment policies', () => {
+  it('requires an eBay shipping service code for the listing marketplace', () => {
+    expect(() =>
+      validateCourierServices(
+        [{ name: 'Second Class', active: true, marketplaces: [] }],
+        { _reference: 'LST-1' },
+        marketplace
+      )
+    ).toThrow(
+      'Courier service "Second Class" requires an eBay shipping service code before it can be used on an eBay listing.'
+    );
+  });
+
+  it('uses the marketplace mapping externalReference as the shipping service code', () => {
+    const services = [
+      {
+        name: 'Second Class',
+        active: true,
+        marketplaces: [
+          {
+            marketplace: { _id: 'mp1' },
+            externalReference: 'UK_RoyalMailSecondClassStandard',
+          },
+        ],
+        cost: 2.5,
+        shippingCurrency: 'GBP',
+      },
+    ];
+    const policy = buildFulfillmentPolicy(
+      { _reference: 'LST-1', currency: 'GBP' },
+      marketplace,
+      services
+    );
+
+    expect(policy.shippingOptions[0].shippingServices[0].shippingServiceCode).toBe(
+      'UK_RoyalMailSecondClassStandard'
+    );
+    expect(policy.shippingOptions[0].shippingServices[0].shippingCarrierCode).toBeUndefined();
+    expect(policy.categoryTypes).toEqual([{ name: 'ALL_EXCLUDING_MOTORS_VEHICLES' }]);
+    expect(policy.categoryTypes[0].default).toBeUndefined();
+  });
+
+  it('omits categoryTypes.default on create so the Account API does not receive the deprecated field', () => {
+    expect(buildCategoryTypes()).toEqual([{ name: 'ALL_EXCLUDING_MOTORS_VEHICLES' }]);
+  });
+
+  it('sends categoryTypes.default=true when the existing policy is the account default', () => {
+    const policy = buildFulfillmentPolicy(
+      { _reference: 'LST-1', currency: 'GBP' },
+      marketplace,
+      [
+        {
+          name: 'Second Class',
+          active: true,
+          marketplaces: [
+            {
+              marketplace: { _id: 'mp1' },
+              externalReference: 'UK_RoyalMailSecondClassStandard',
+            },
+          ],
+          cost: 2.5,
+          shippingCurrency: 'GBP',
+        },
+      ],
+      {
+        fulfillmentPolicyId: '6246152000',
+        categoryTypes: [{ name: 'ALL_EXCLUDING_MOTORS_VEHICLES', default: true }],
+      }
+    );
+
+    expect(policy.categoryTypes).toEqual([
+      { name: 'ALL_EXCLUDING_MOTORS_VEHICLES', default: true },
+    ]);
+  });
+
+  it('never sends categoryTypes.default=false, even when GET reports false', () => {
+    expect(
+      buildCategoryTypes({
+        fulfillmentPolicyId: '6246152000',
+        categoryTypes: [{ name: 'ALL_EXCLUDING_MOTORS_VEHICLES', default: false }],
+      })
+    ).toEqual([{ name: 'ALL_EXCLUDING_MOTORS_VEHICLES' }]);
+  });
+
+  it('treats the only fulfillment policy as the account default', () => {
+    expect(
+      isDefaultFulfillmentPolicy(
+        {
+          fulfillmentPolicyId: '6246152000',
+          categoryTypes: [{ name: 'ALL_EXCLUDING_MOTORS_VEHICLES', default: false }],
+        },
+        [{ fulfillmentPolicyId: '6246152000' }]
+      )
+    ).toBe(true);
+    expect(
+      buildCategoryTypes(
+        {
+          fulfillmentPolicyId: '6246152000',
+          categoryTypes: [{ name: 'ALL_EXCLUDING_MOTORS_VEHICLES', default: false }],
+        },
+        [{ fulfillmentPolicyId: '6246152000' }]
+      )
+    ).toEqual([{ name: 'ALL_EXCLUDING_MOTORS_VEHICLES', default: true }]);
+  });
+});
--- a/src/integrations/marketplaces/ebay/tests/listingVarients.test.js
+++ b/src/integrations/marketplaces/ebay/tests/listingVarients.test.js
@ -0,0 +1,111 @@
+import { describe, expect, it, jest } from '@jest/globals';
+
+jest.unstable_mockModule('../../../../database/schemas/inventory/stocklocation.schema.js', () => ({
+  stockLocationModel: { findById: jest.fn() },
+}));
+jest.unstable_mockModule('../../../../database/schemas/inventory/productstock.schema.js', () => ({
+  productStockModel: { find: jest.fn() },
+}));
+jest.unstable_mockModule('../countryCodes.js', () => ({
+  FARMCONTROL_GB_SUBDIVISION_STATE: {},
+  resolveEbayCountry: jest.fn(),
+}));
+jest.unstable_mockModule('../categories.js', () => ({ syncProductCategory: jest.fn() }));
+jest.unstable_mockModule('../fulfillmentPolicies.js', () => ({ syncFulfillmentPolicy: jest.fn() }));
+jest.unstable_mockModule('../shared.js', () => ({
+  makeRequest: jest.fn(),
+  logger: { info: jest.fn(), warn: jest.fn(), debug: jest.fn(), error: jest.fn() },
+}));
+jest.unstable_mockModule('../../ids.js', () => ({
+  marketplaceSku: (record) => record?.externalReference || record?._reference,
+  marketplaceActor: (marketplace) => ({ ...marketplace, _objectType: 'marketplace' }),
+}));
+
+const { productStockModel } =
+  await import('../../../../database/schemas/inventory/productstock.schema.js');
+const { makeRequest } = await import('../shared.js');
+const {
+  fromEbayCondition,
+  resolveListingDescription,
+  resolveVarientQuantity,
+  toEbayCondition,
+  upsertInventoryItem,
+} = await import('../listingVarients.js');
+
+describe('eBay varient quantity', () => {
+  it('sums productStock.currentQuantity for the listing stock location', async () => {
+    productStockModel.find.mockReturnValue({
+      lean: async () => [{ currentQuantity: 3 }, { currentQuantity: 5 }],
+    });
+    const quantity = await resolveVarientQuantity(
+      { productSku: 'sku-1' },
+      { stockLocation: 'loc-1' }
+    );
+    expect(quantity).toBe(8);
+    expect(productStockModel.find).toHaveBeenCalledWith({
+      productSku: 'sku-1',
+      stockLocation: 'loc-1',
+    });
+  });
+
+  it('falls back to varient.inventory when no product SKU is linked', async () => {
+    const quantity = await resolveVarientQuantity({ inventory: 4 }, {});
+    expect(quantity).toBe(4);
+  });
+});
+
+describe('eBay listing description', () => {
+  it('prefers listing.description', () => {
+    expect(resolveListingDescription({ description: 'Custom copy', title: 'Widget' })).toBe(
+      'Custom copy'
+    );
+  });
+
+  it('falls back to title when description is empty', () => {
+    expect(resolveListingDescription({ title: 'Widget' })).toBe('Widget');
+  });
+
+  it('falls back to product SKU description', () => {
+    expect(resolveListingDescription({}, { productSku: { description: 'SKU copy' } })).toBe(
+      'SKU copy'
+    );
+  });
+});
+
+describe('eBay listing condition', () => {
+  it('converts camelCase listing conditions to eBay ConditionEnum values', () => {
+    expect(toEbayCondition('new')).toBe('NEW');
+    expect(toEbayCondition('likeNew')).toBe('LIKE_NEW');
+    expect(toEbayCondition('forPartsOrNotWorking')).toBe('FOR_PARTS_OR_NOT_WORKING');
+    expect(toEbayCondition('USED_GOOD')).toBe('USED_GOOD');
+    expect(toEbayCondition()).toBe('NEW');
+  });
+
+  it('converts eBay ConditionEnum values back to camelCase', () => {
+    expect(fromEbayCondition('NEW')).toBe('new');
+    expect(fromEbayCondition('LIKE_NEW')).toBe('likeNew');
+    expect(fromEbayCondition('FOR_PARTS_OR_NOT_WORKING')).toBe('forPartsOrNotWorking');
+  });
+});
+
+describe('upsertInventoryItem description', () => {
+  it('always sends product.description and eBay condition to eBay', async () => {
+    makeRequest.mockResolvedValue({});
+    await upsertInventoryItem(
+      { config: { accessToken: 'token' } },
+      { _reference: 'SKU-1' },
+      { title: 'Widget', condition: 'usedGood' }
+    );
+    expect(makeRequest).toHaveBeenCalledWith(
+      expect.objectContaining({
+        body: expect.objectContaining({
+          condition: 'USED_GOOD',
+          product: expect.objectContaining({
+            title: 'Widget',
+            description: 'Widget',
+          }),
+        }),
+      })
+    );
+  });
+});
--- a/src/integrations/marketplaces/ebay/tests/listings.test.js
+++ b/src/integrations/marketplaces/ebay/tests/listings.test.js
@ -0,0 +1,76 @@
+import { describe, expect, it, jest } from '@jest/globals';
+
+jest.unstable_mockModule('../listingVarients.js', () => ({
+  buildVarientEntry: (item, offers) => ({
+    _reference: item.sku,
+    externalReference: item.sku,
+    price: offers?.[0]?.pricingSummary?.price?.value
+      ? parseFloat(offers[0].pricingSummary.price.value)
+      : undefined,
+    currency: offers?.[0]?.pricingSummary?.price?.currency,
+    state: { type: offers?.[0]?.status === 'PUBLISHED' ? 'active' : 'draft' },
+  }),
+  fetchOffers: jest.fn(),
+  fromEbayCondition: (condition) =>
+    condition
+      ? condition.toLowerCase().replace(/_([a-z])/g, (_, letter) => letter.toUpperCase())
+      : undefined,
+  resolveListingDescription: (listing) => listing?.description || listing?.title || '',
+  resolveOfferState: (offers = []) =>
+    offers.some((o) => o?.status === 'PUBLISHED') ? 'active' : 'draft',
+  syncOfferAndMaybePublish: jest.fn(),
+  upsertInventoryItem: jest.fn(),
+  withdrawOfferById: jest.fn(),
+}));
+jest.unstable_mockModule('../../ids.js', () => ({
+  marketplaceSku: (record) => record?.externalReference || record?._reference,
+  marketplaceActor: (marketplace) => ({ ...marketplace, _objectType: 'marketplace' }),
+}));
+jest.unstable_mockModule('../shared.js', () => ({
+  makeRequest: jest.fn(),
+  logger: { info: jest.fn(), warn: jest.fn(), debug: jest.fn(), error: jest.fn() },
+}));
+jest.unstable_mockModule('../categories.js', () => ({ syncProductCategory: jest.fn() }));
+jest.unstable_mockModule('../fulfillmentPolicies.js', () => ({ syncFulfillmentPolicy: jest.fn() }));
+
+const { mapProductToListing } = await import('../listings.js');
+
+describe('eBay listing mappers', () => {
+  it('maps grouped inventory to externalReference instead of overwriting _reference', () => {
+    const mapped = mapProductToListing({
+      _type: 'group',
+      _groupKey: 'group-1',
+      _group: { title: 'Widget', description: 'A widget' },
+      _variants: [
+        {
+          sku: 'SKU-RED',
+          _offers: [
+            {
+              listingId: '123456',
+              status: 'PUBLISHED',
+              pricingSummary: { price: { value: '9.99', currency: 'GBP' } },
+            },
+          ],
+        },
+      ],
+    });
+
+    expect(mapped.externalReference).toBe('123456');
+    expect(mapped.title).toBe('Widget');
+    expect(mapped.description).toBe('A widget');
+    expect(mapped.varients[0].externalReference).toBe('SKU-RED');
+    expect(mapped._reference).toBeUndefined();
+  });
+
+  it('maps standalone inventory items', () => {
+    const mapped = mapProductToListing({
+      sku: 'SKU-BLUE',
+      condition: 'LIKE_NEW',
+      product: { title: 'Blue widget', description: 'Blue' },
+      _offers: [{ listingId: '999', status: 'PUBLISHED', pricingSummary: { price: { value: '4.00', currency: 'GBP' } } }],
+    });
+    expect(mapped.externalReference).toBe('999');
+    expect(mapped.varients[0].externalReference).toBe('SKU-BLUE');
+    expect(mapped.condition).toBe('likeNew');
+  });
+});
--- a/src/integrations/marketplaces/ebay/tests/notifications.test.js
+++ b/src/integrations/marketplaces/ebay/tests/notifications.test.js
@ -0,0 +1,70 @@
+import { describe, expect, it, jest } from '@jest/globals';
+import crypto from 'crypto';
+
+jest.unstable_mockModule('../shared.js', () => ({
+  makeRequest: jest.fn(),
+  getApiBaseUrl: () => 'https://api.sandbox.ebay.com',
+  getBasicAuthHeader: () => 'Basic abc',
+  formatDebugPayload: (value) => value,
+  getMarketplaceDebugContext: () => ({}),
+  logger: { info: jest.fn(), warn: jest.fn(), debug: jest.fn(), error: jest.fn() },
+}));
+
+const { makeRequest } = await import('../shared.js');
+const { buildWebhookChallengeResponse, verifyNotificationSignature } = await import(
+  '../notifications.js'
+);
+
+describe('eBay notification challenge', () => {
+  it('hashes challengeCode + verificationToken + endpoint', () => {
+    const marketplace = {
+      config: {
+        verificationToken: 'verify-token-32-characters-long!!',
+        webhookUrl: 'https://example.com/marketplaces/1/hook',
+      },
+    };
+    const challengeCode = 'abc123';
+    const result = buildWebhookChallengeResponse(marketplace, {
+      challengeCode,
+      endpoint: marketplace.config.webhookUrl,
+    });
+    const expected = crypto
+      .createHash('sha256')
+      .update(challengeCode + marketplace.config.verificationToken + marketplace.config.webhookUrl)
+      .digest('hex');
+    expect(result.challengeResponse).toBe(expected);
+  });
+
+  it('throws when challenge inputs are missing', () => {
+    expect(() => buildWebhookChallengeResponse({ config: {} }, { challengeCode: 'x' })).toThrow(
+      /challenge/
+    );
+  });
+});
+
+describe('eBay notification signature', () => {
+  it('verifies ECDSA signatures with a mocked public key', async () => {
+    const { privateKey, publicKey } = crypto.generateKeyPairSync('ec', { namedCurve: 'P-256' });
+    const payload = '{"notification":{"notificationId":"n1"}}';
+    const signature = crypto.createSign('SHA256').update(payload).end().sign(privateKey, 'base64');
+    const header = Buffer.from(
+      JSON.stringify({ kid: 'kid-1', signature, digest: 'SHA256' })
+    ).toString('base64');
+    makeRequest.mockResolvedValue({
+      key: publicKey.export({ type: 'spki', format: 'pem' }),
+    });
+
+    const valid = await verifyNotificationSignature(
+      { config: { accessToken: 'token' } },
+      payload,
+      header
+    );
+    expect(valid).toBe(true);
+  });
+
+  it('rejects missing signature headers', async () => {
+    expect(
+      await verifyNotificationSignature({ config: { accessToken: 'token' } }, '{}', '')
+    ).toBe(false);
+  });
+});
--- a/src/integrations/marketplaces/ebay/tests/orders.test.js
+++ b/src/integrations/marketplaces/ebay/tests/orders.test.js
@ -0,0 +1,118 @@
+import { describe, expect, it } from '@jest/globals';
+import {
+  mapOrderStatus,
+  mapOrderToSalesOrder,
+  mapBuyerToClient,
+  mapOrderLineItems,
+  mapOrderShipments,
+  handleWebhook,
+} from '../orders.js';
+
+const ebayOrder = {
+  orderId: '12-34567-89012',
+  orderFulfillmentStatus: 'NOT_STARTED',
+  pricingSummary: {
+    priceSubtotal: { value: '10.00' },
+    deliveryCost: { value: '2.50' },
+    tax: { value: '1.20' },
+    total: { value: '13.70' },
+  },
+  buyer: {
+    username: 'ebay-buyer',
+    buyerRegistrationAddress: { email: 'buyer@example.com' },
+  },
+  fulfillmentStartInstructions: [
+    {
+      shippingStep: {
+        shipTo: {
+          fullName: 'Jane Buyer',
+          primaryPhone: { phoneNumber: '012345' },
+          contactAddress: {
+            addressLine1: '1 High St',
+            city: 'London',
+            postalCode: 'SW1A 1AA',
+            countryCode: 'GB',
+          },
+        },
+      },
+    },
+  ],
+  lineItems: [
+    {
+      lineItemId: 'line-1',
+      sku: 'SKU-RED',
+      title: 'Red widget',
+      quantity: 2,
+      lineItemCost: { value: '5.00' },
+      taxes: [{ amount: { value: '1.00' } }],
+    },
+  ],
+  shippingFulfillments: [
+    {
+      fulfillmentId: 'ful-1',
+      shipmentTrackingNumber: 'TRACK123',
+      shippedDate: '2026-08-01T10:00:00.000Z',
+      lineItems: [{ lineItemId: 'line-1' }],
+    },
+  ],
+};
+
+describe('eBay order mappers', () => {
+  it('maps sales order totals and externalReference', () => {
+    const mapped = mapOrderToSalesOrder(ebayOrder);
+    expect(mapped.externalReference).toBe('12-34567-89012');
+    expect(mapped.totalAmount).toBe(10);
+    expect(mapped.shippingAmount).toBe(2.5);
+    expect(mapped.totalTaxAmount).toBe(1.2);
+    expect(mapped.state.type).toBe('draft');
+  });
+
+  it('maps cancelled orders', () => {
+    expect(
+      mapOrderStatus({ cancelStatus: { cancelState: 'CANCELED' } })
+    ).toBe('cancelled');
+  });
+
+  it('maps buyer to client with marketplace buyer id', () => {
+    const client = mapBuyerToClient(ebayOrder);
+    expect(client.externalReference).toBe('ebay-buyer');
+    expect(client.email).toBe('buyer@example.com');
+    expect(client.address.city).toBe('London');
+  });
+
+  it('maps line items', () => {
+    const lines = mapOrderLineItems(ebayOrder);
+    expect(lines).toHaveLength(1);
+    expect(lines[0]).toMatchObject({
+      externalReference: 'line-1',
+      sku: 'SKU-RED',
+      quantity: 2,
+      itemAmount: 5,
+      totalAmount: 10,
+      totalAmountWithTax: 11,
+    });
+  });
+
+  it('maps shipments from fulfillments', () => {
+    const shipments = mapOrderShipments(ebayOrder);
+    expect(shipments[0]).toMatchObject({
+      externalReference: 'ful-1',
+      trackingNumber: 'TRACK123',
+    });
+    expect(shipments[0].state.type).toBe('shipped');
+  });
+
+  it('classifies commerce notification topics', async () => {
+    const sold = await handleWebhook(
+      { name: 'eBay' },
+      { metadata: { topic: 'ORDER_CONFIRMATION' }, notification: { data: { orderId: 'o1' }, notificationId: 'n1' } }
+    );
+    expect(sold).toMatchObject({ action: 'orderUpdate', orderId: 'o1', notificationId: 'n1' });
+
+    const deletion = await handleWebhook(
+      { name: 'eBay' },
+      { topic: 'MARKETPLACE_ACCOUNT_DELETION', data: { userId: 'u1' } }
+    );
+    expect(deletion.action).toBe('accountDeletion');
+  });
+});
--- a/src/integrations/marketplaces/ebay/tests/shippingServices.test.js
+++ b/src/integrations/marketplaces/ebay/tests/shippingServices.test.js
@ -0,0 +1,36 @@
+import { describe, expect, it } from '@jest/globals';
+import { parseShippingServiceDetails } from '../shippingServices.js';
+
+const sampleXml = `
+<GeteBayDetailsResponse xmlns="urn:ebay:apis:eBLBaseComponents">
+  <Ack>Success</Ack>
+  <ShippingServiceDetails>
+    <Description>Royal Mail 1st Class</Description>
+    <ShippingService>UK_RoyalMailFirstClassStandard</ShippingService>
+    <ValidForSellingFlow>true</ValidForSellingFlow>
+  </ShippingServiceDetails>
+  <ShippingServiceDetails>
+    <Description>Deprecated</Description>
+    <ShippingService>UK_OldService</ShippingService>
+    <ValidForSellingFlow>false</ValidForSellingFlow>
+  </ShippingServiceDetails>
+  <ShippingServiceDetails>
+    <Description>Royal Mail 2nd Class</Description>
+    <ShippingService>UK_RoyalMailSecondClassStandard</ShippingService>
+    <ValidForSellingFlow>true</ValidForSellingFlow>
+  </ShippingServiceDetails>
+</GeteBayDetailsResponse>
+`;
+
+describe('eBay shipping service details', () => {
+  it('extracts selling-flow shipping service codes', () => {
+    expect(parseShippingServiceDetails(sampleXml)).toEqual([
+      'UK_RoyalMailFirstClassStandard',
+      'UK_RoyalMailSecondClassStandard',
+    ]);
+  });
+
+  it('returns an empty list when no details are present', () => {
+    expect(parseShippingServiceDetails('<Ack>Success</Ack>')).toEqual([]);
+  });
+});
--- a/src/integrations/marketplaces/ebay/auth.js
+++ b/src/integrations/marketplaces/ebay/auth.js
@ -8,12 +8,21 @@ import {
  isAccessTokenExpired,
  getRequiredAuthConfig,
  getBasicAuthHeader,
+  formatDebugPayload,
+  getMarketplaceDebugContext,
  logger,
 } from './shared.js';

 const TOKEN_PATH = '/identity/v1/oauth2/token';

 async function mintToken(marketplace, body) {
+  logger.debug('eBay token request', {
+    ...getMarketplaceDebugContext(marketplace),
+    grantType: body.grant_type,
+    scope: body.scope,
+  });
+
+  const startedAt = Date.now();
  const response = await fetch(`${getApiBaseUrl(marketplace)}${TOKEN_PATH}`, {
    method: 'POST',
    headers: {
@ -24,12 +33,26 @@ async function mintToken(marketplace, body) {
  });

  const data = await response.json();
+  const durationMs = Date.now() - startedAt;
  if (!response.ok || data.error) {
    const message = data.error_description || data.error || response.statusText;
-    logger.error(`eBay token request failed: ${message}`);
+    logger.error(`eBay token request failed: ${message}`, {
+      status: response.status,
+      durationMs,
+      ...getMarketplaceDebugContext(marketplace),
+      response: formatDebugPayload(data),
+    });
    throw new Error(`eBay token request failed: ${message}`);
  }

+  logger.debug(`eBay token request succeeded (${durationMs}ms)`, {
+    ...getMarketplaceDebugContext(marketplace),
+    grantType: body.grant_type,
+    expiresIn: data.expires_in,
+    tokenType: data.token_type,
+    hasRefreshToken: !!data.refresh_token,
+  });
+
  return data;
 }

@ -124,9 +147,18 @@ export async function refreshAuth(marketplace) {

 export async function ensureAuthenticatedMarketplace(marketplace) {
  if (!isAccessTokenExpired(marketplace)) {
+    logger.debug(`eBay access token still valid for "${marketplace.name}"`, {
+      ...getMarketplaceDebugContext(marketplace),
+      expiresAt: marketplace.config?.accessTokenExpiresAt,
+    });
    return { marketplace };
  }

+  logger.debug(`eBay access token expired for "${marketplace.name}", refreshing`, {
+    ...getMarketplaceDebugContext(marketplace),
+    expiresAt: marketplace.config?.accessTokenExpiresAt,
+  });
+
  const authResult = await refreshAuth(marketplace);
  return {
    marketplace: {
--- a/src/integrations/marketplaces/ebay/fulfillmentPolicies.js
+++ b/src/integrations/marketplaces/ebay/fulfillmentPolicies.js
@ -3,6 +3,7 @@ import { courierServiceModel } from '../../../database/schemas/management/courie
 import { makeRequest, logger } from './shared.js';

 const SELLING_POLICY_PROGRAM = 'SELLING_POLICY_MANAGEMENT';
+const FULFILLMENT_CATEGORY_TYPE = 'ALL_EXCLUDING_MOTORS_VEHICLES';

 async function fetchOptedInPrograms(marketplace) {
  const result = await makeRequest({
@ -42,11 +43,7 @@ function isPopulatedCourierService(service) {
    service &&
    typeof service === 'object' &&
    !(service instanceof mongoose.Types.ObjectId) &&
-    service.name != null &&
-    service.courier &&
-    typeof service.courier === 'object' &&
-    !(service.courier instanceof mongoose.Types.ObjectId) &&
-    service.courier._reference
+    service.name != null
  );
 }

@ -62,14 +59,45 @@ async function resolveCourierServices(listing) {
  const serviceIds = serviceRefs.map((service) => service?._id || service).filter(Boolean);
  const services = await courierServiceModel
    .find({ _id: { $in: serviceIds } })
-    .populate('courier')
+    .populate(['courier', 'marketplaces.marketplace'])
    .lean();
  const servicesById = new Map(services.map((service) => [String(service._id), service]));

  return serviceIds.map((id) => servicesById.get(String(id))).filter(Boolean);
 }

-function validateCourierServices(services, listing) {
+function idOf(value) {
+  if (value == null) return '';
+  if (typeof value === 'object') return String(value._id || '');
+  return String(value);
+}
+
+export function getCourierServiceMarketplaceMappings(service) {
+  if (Array.isArray(service?.marketplaces) && service.marketplaces.length) {
+    return service.marketplaces;
+  }
+  if (service?.marketplace) {
+    return [
+      {
+        marketplace: service.marketplace,
+        externalReference: service.externalReference,
+      },
+    ];
+  }
+  return [];
+}
+
+export function getCourierServiceShippingCode(service, marketplace) {
+  const marketplaceId = idOf(marketplace);
+  const mappings = getCourierServiceMarketplaceMappings(service);
+  if (!marketplaceId) {
+    return mappings[0]?.externalReference || service?.externalReference || '';
+  }
+  const mapping = mappings.find((entry) => idOf(entry?.marketplace) === marketplaceId);
+  return mapping?.externalReference || '';
+}
+
+export function validateCourierServices(services, listing, marketplace) {
  const activeServices = services.filter((service) => service.active !== false);
  if (!activeServices.length) {
    throw new Error(
@ -78,14 +106,9 @@ function validateCourierServices(services, listing) {
  }

  for (const service of activeServices) {
-    if (!service._reference) {
+    if (!getCourierServiceShippingCode(service, marketplace)) {
      throw new Error(
-        `Courier service "${service.name}" requires a reference containing its eBay shipping service code.`
-      );
-    }
-    if (!service.courier?._reference) {
-      throw new Error(
-        `The courier for service "${service.name}" requires a reference containing its eBay shipping carrier code.`
+        `Courier service "${service.name}" requires an eBay shipping service code before it can be used on an eBay listing.`
      );
    }
  }
@ -101,13 +124,12 @@ function validateCourierServices(services, listing) {
  return activeServices;
 }

-function buildShippingService(service, index, defaultCurrency) {
+function buildShippingService(service, index, defaultCurrency, marketplace) {
  const cost = Number(service.costWithTax ?? service.cost ?? 0);
  const additionalCost = Number(service.additionalCostWithTax ?? service.additionalCost ?? 0);
  const shippingService = {
    sortOrder: index + 1,
-    shippingCarrierCode: service.courier._reference,
-    shippingServiceCode: service._reference,
+    shippingServiceCode: getCourierServiceShippingCode(service, marketplace),
    buyerResponsibleForShipping: false,
    freeShipping: cost === 0 && additionalCost === 0,
    shippingCost: {
@ -126,25 +148,71 @@ function buildShippingService(service, index, defaultCurrency) {
  return shippingService;
 }

-function buildShippingOption(optionType, services, defaultCurrency) {
+function buildShippingOption(optionType, services, defaultCurrency, marketplace) {
  if (!services.length) return null;
  return {
    optionType,
    costType: 'FLAT_RATE',
    shippingServices: services.map((service, index) =>
-      buildShippingService(service, index, defaultCurrency)
+      buildShippingService(service, index, defaultCurrency, marketplace)
    ),
  };
 }

-function buildFulfillmentPolicy(listing, marketplace, services) {
+export function isDefaultFulfillmentPolicy(existingPolicy, allPolicies = []) {
+  if (!existingPolicy?.fulfillmentPolicyId) {
+    return false;
+  }
+
+  const existingId = String(existingPolicy.fulfillmentPolicyId);
+  const sources = [existingPolicy, ...allPolicies];
+  if (
+    sources.some(
+      (policy) =>
+        String(policy?.fulfillmentPolicyId) === existingId &&
+        (policy.categoryTypes || []).some((type) => type?.default === true)
+    )
+  ) {
+    return true;
+  }
+
+  const uniqueIds = [
+    ...new Set(
+      allPolicies
+        .filter((policy) => policy?.fulfillmentPolicyId)
+        .map((policy) => String(policy.fulfillmentPolicyId))
+    ),
+  ];
+  return uniqueIds.length === 1 && uniqueIds[0] === existingId;
+}
+
+export function buildCategoryTypes(existingPolicy, allPolicies = []) {
+  const categoryType = { name: FULFILLMENT_CATEGORY_TYPE };
+
+  // Never send default: false. eBay's GET can report false for the account-default
+  // policy, and updateFulfillmentPolicy then rejects it as changing default status
+  // (20403). Keep the default flag only when this policy is (or must remain) default.
+  if (isDefaultFulfillmentPolicy(existingPolicy, allPolicies)) {
+    categoryType.default = true;
+  }
+
+  return [categoryType];
+}
+
+export function buildFulfillmentPolicy(
+  listing,
+  marketplace,
+  services,
+  existingPolicy,
+  allPolicies = []
+) {
  const marketplaceId = marketplace.config?.marketplaceId || 'EBAY_GB';
  const defaultCurrency = marketplace.config?.currency || listing.currency || 'GBP';
  const domesticServices = services.filter((service) => !service.international);
  const internationalServices = services.filter((service) => service.international);
  const shippingOptions = [
-    buildShippingOption('DOMESTIC', domesticServices, defaultCurrency),
-    buildShippingOption('INTERNATIONAL', internationalServices, defaultCurrency),
+    buildShippingOption('DOMESTIC', domesticServices, defaultCurrency, marketplace),
+    buildShippingOption('INTERNATIONAL', internationalServices, defaultCurrency, marketplace),
  ].filter(Boolean);
  const deliveryTime = Math.max(0, ...services.map((service) => Number(service.deliveryTime ?? 1)));

@ -152,7 +220,7 @@ function buildFulfillmentPolicy(listing, marketplace, services) {
    name: `FarmControl ${listing._reference}`.slice(0, 64),
    description: `Managed by FarmControl for listing ${listing._reference}`.slice(0, 250),
    marketplaceId,
-    categoryTypes: [{ name: 'ALL_EXCLUDING_MOTORS_VEHICLES' }],
+    categoryTypes: buildCategoryTypes(existingPolicy, allPolicies),
    handlingTime: { value: deliveryTime, unit: 'DAY' },
    localPickup: false,
    globalShipping: false,
@ -162,18 +230,61 @@ function buildFulfillmentPolicy(listing, marketplace, services) {
  };
 }

+function getMarketplaceId(marketplace) {
+  return marketplace.config?.marketplaceId || 'EBAY_GB';
+}
+
 async function fetchFulfillmentPolicyByName(marketplace, name) {
  return makeRequest({
    marketplace,
    path: '/sell/account/v1/fulfillment_policy/get_by_policy_name',
    params: {
-      marketplace_id: marketplace.config?.marketplaceId || 'EBAY_GB',
+      marketplace_id: getMarketplaceId(marketplace),
      name,
    },
    acceptableStatuses: [404],
  });
 }

+async function fetchFulfillmentPolicies(marketplace) {
+  const result = await makeRequest({
+    marketplace,
+    path: '/sell/account/v1/fulfillment_policy',
+    params: { marketplace_id: getMarketplaceId(marketplace) },
+    acceptableStatuses: [404],
+  });
+  return result?.fulfillmentPolicies || [];
+}
+
+function isDefaultStatusError(err) {
+  return /changing the default status/i.test(err?.message || '');
+}
+
+async function updateFulfillmentPolicy(marketplace, fulfillmentPolicyId, policy) {
+  const path = `/sell/account/v1/fulfillment_policy/${encodeURIComponent(fulfillmentPolicyId)}`;
+  try {
+    await makeRequest({ marketplace, method: 'PUT', path, body: policy });
+    return;
+  } catch (err) {
+    if (policy.categoryTypes?.[0]?.default === true || !isDefaultStatusError(err)) {
+      throw err;
+    }
+
+    logger.debug(
+      `Retrying fulfillment policy ${fulfillmentPolicyId} with categoryTypes.default=true`
+    );
+    await makeRequest({
+      marketplace,
+      method: 'PUT',
+      path,
+      body: {
+        ...policy,
+        categoryTypes: [{ name: FULFILLMENT_CATEGORY_TYPE, default: true }],
+      },
+    });
+  }
+}
+
 export async function syncFulfillmentPolicy(marketplace, listing) {
  await ensureSellingPolicyManagement(marketplace);

@ -181,19 +292,26 @@ export async function syncFulfillmentPolicy(marketplace, listing) {
    return { fulfillmentPolicyId: String(listing.fulfillmentPolicyId) };
  }

-  const services = validateCourierServices(await resolveCourierServices(listing), listing);
-  const policy = buildFulfillmentPolicy(listing, marketplace, services);
-  const existingPolicy = await fetchFulfillmentPolicyByName(marketplace, policy.name);
+  const services = validateCourierServices(
+    await resolveCourierServices(listing),
+    listing,
+    marketplace
+  );
+  const policyName = `FarmControl ${listing._reference}`.slice(0, 64);
+  const [existingPolicy, allPolicies] = await Promise.all([
+    fetchFulfillmentPolicyByName(marketplace, policyName),
+    fetchFulfillmentPolicies(marketplace),
+  ]);
+  const policy = buildFulfillmentPolicy(
+    listing,
+    marketplace,
+    services,
+    existingPolicy,
+    allPolicies
+  );

  if (existingPolicy?.fulfillmentPolicyId) {
-    await makeRequest({
-      marketplace,
-      method: 'PUT',
-      path: `/sell/account/v1/fulfillment_policy/${encodeURIComponent(
-        existingPolicy.fulfillmentPolicyId
-      )}`,
-      body: policy,
-    });
+    await updateFulfillmentPolicy(marketplace, existingPolicy.fulfillmentPolicyId, policy);
    logger.info(
      `Updated eBay fulfillment policy "${policy.name}" (${existingPolicy.fulfillmentPolicyId})`
    );
--- a/src/integrations/marketplaces/ebay/index.js
+++ b/src/integrations/marketplaces/ebay/index.js
@ -26,5 +26,19 @@ export {
  mapOrderStatus,
  mapOrderToSalesOrder,
  mapBuyerToClient,
+  mapOrderLineItems,
+  mapOrderShipments,
+  getOrder,
+  createShippingFulfillment,
  handleWebhook,
 } from './orders.js';
+
+export {
+  buildWebhookChallengeResponse,
+  ensureWebhookSubscriptions,
+  verifyNotificationSignature,
+  canVerifyNotificationSignature,
+} from './notifications.js';
+
+export { makeRequest as debugGet } from './shared.js';
+export { syncMarketplaceMetadata } from './shippingServices.js';
--- a/src/integrations/marketplaces/ebay/listingVarients.js
+++ b/src/integrations/marketplaces/ebay/listingVarients.js
@ -1,9 +1,11 @@
 import mongoose from 'mongoose';
 import { stockLocationModel } from '../../../database/schemas/inventory/stocklocation.schema.js';
+import { productStockModel } from '../../../database/schemas/inventory/productstock.schema.js';
 import { FARMCONTROL_GB_SUBDIVISION_STATE, resolveEbayCountry } from './countryCodes.js';
 import { syncProductCategory } from './categories.js';
 import { syncFulfillmentPolicy } from './fulfillmentPolicies.js';
 import { makeRequest, logger } from './shared.js';
+import { marketplaceSku } from '../ids.js';

 const WAREHOUSE_ADDRESS_DEFAULTS = {
  GB: { city: 'London', stateOrProvince: 'England', postalCode: 'SW1A 1AA' },
@ -22,6 +24,23 @@ const LISTING_STATUS_MAP = {
  UNPUBLISHED: 'draft',
 };

+export function toEbayCondition(condition) {
+  if (!condition || typeof condition !== 'string') {
+    return 'NEW';
+  }
+  if (condition.includes('_') || condition === condition.toUpperCase()) {
+    return condition.toUpperCase();
+  }
+  return condition.replace(/[A-Z]/g, (letter) => `_${letter}`).toUpperCase();
+}
+
+export function fromEbayCondition(condition) {
+  if (!condition || typeof condition !== 'string') {
+    return undefined;
+  }
+  return condition.toLowerCase().replace(/_([a-z])/g, (_, letter) => letter.toUpperCase());
+}
+
 function isPopulatedStockLocation(stockLocation) {
  if (!stockLocation || typeof stockLocation !== 'object') return false;
  if (stockLocation instanceof mongoose.Types.ObjectId) return false;
@ -175,23 +194,72 @@ function applyMarketplaceOfferDefaults(
  if (Object.keys(listingPolicies).length) offer.listingPolicies = listingPolicies;
 }

-function mapVarientToInventoryItem(varient, listing) {
+export function resolveListingDescription(listing, varient) {
+  const candidates = [
+    listing?.description,
+    varient?.productSku?.description,
+    listing?.title,
+    listing?.product?.name,
+    marketplaceSku(varient),
+    listing?._reference,
+  ];
+  for (const candidate of candidates) {
+    if (typeof candidate === 'string' && candidate.trim()) {
+      return candidate.trim();
+    }
+  }
+  return 'No description provided.';
+}
+
+function inventoryItemPutBody(existing, listing, sku, varient) {
+  const product = { ...(existing?.product || {}) };
+  product.title = product.title || listing?.title || sku;
+  product.description = resolveListingDescription(listing, varient);
+  const body = { product };
+  if (existing?.availability) body.availability = existing.availability;
+  body.condition = toEbayCondition(listing?.condition || existing?.condition);
+  if (existing?.conditionDescription) body.conditionDescription = existing.conditionDescription;
+  if (existing?.packageWeightAndSize) body.packageWeightAndSize = existing.packageWeightAndSize;
+  return body;
+}
+
+async function ensureInventoryItemDescription(marketplace, sku, listing, varient) {
+  const existing = await makeRequest({
+    marketplace,
+    path: `/sell/inventory/v1/inventory_item/${encodeURIComponent(sku)}`,
+    acceptableStatuses: [404],
+  });
+  if (!existing) return;
+
+  await makeRequest({
+    marketplace,
+    method: 'PUT',
+    path: `/sell/inventory/v1/inventory_item/${encodeURIComponent(sku)}`,
+    body: inventoryItemPutBody(existing, listing, sku, varient),
+  });
+}
+
+function mapVarientToInventoryItem(varient, listing, quantity = 0) {
  const item = {
-    product: { title: listing.title || varient._reference || '' },
+    condition: toEbayCondition(listing?.condition),
+    product: {
+      title: listing.title || marketplaceSku(varient) || '',
+      description: resolveListingDescription(listing, varient),
+    },
    availability: {
-      shipToLocationAvailability: { quantity: varient.inventory ?? 0 },
+      shipToLocationAvailability: { quantity },
    },
  };
-  if (listing.description) item.product.description = listing.description;
  if (listing.imageUrls?.length) item.product.imageUrls = listing.imageUrls;
  return item;
 }

 function mapVarientToOffer(varient, listing, marketplace, merchantLocationKey) {
  const offer = {
-    sku: varient._reference,
+    sku: marketplaceSku(varient),
    marketplaceId: marketplace.config?.marketplaceId || 'EBAY_GB',
    format: 'FIXED_PRICE',
+    listingDescription: resolveListingDescription(listing, varient),
  };
  applyMarketplaceOfferDefaults(
    offer,
@ -213,12 +281,28 @@ function mapVarientToOffer(varient, listing, marketplace, merchantLocationKey) {
  return offer;
 }

+export async function resolveVarientQuantity(varient, listing) {
+  const skuId = varient.productSku?._id || varient.productSku;
+  if (!skuId) {
+    return Number(varient.inventory) || 0;
+  }
+  const locationId = listing?.stockLocation?._id || listing?.stockLocation;
+  const filter = { productSku: skuId };
+  if (locationId) {
+    filter.stockLocation = locationId;
+  }
+  const stocks = await productStockModel.find(filter).lean();
+  return stocks.reduce((sum, stock) => sum + (Number(stock.currentQuantity) || 0), 0);
+}
+
 export async function upsertInventoryItem(marketplace, varient, listing) {
-  const inventoryItem = mapVarientToInventoryItem(varient, listing);
+  const sku = marketplaceSku(varient);
+  const quantity = await resolveVarientQuantity(varient, listing);
+  const inventoryItem = mapVarientToInventoryItem(varient, listing, quantity);
  const result = await makeRequest({
    marketplace,
    method: 'PUT',
-    path: `/sell/inventory/v1/inventory_item/${encodeURIComponent(varient._reference)}`,
+    path: `/sell/inventory/v1/inventory_item/${encodeURIComponent(sku)}`,
    body: inventoryItem,
  });
  logger.debug('inventoryItem', inventoryItem);
@ -242,12 +326,15 @@ export async function fetchOffers(marketplace, sku) {

 async function upsertOrCreateOffer(marketplace, varient, listing) {
  const merchantLocationKey = await ensureMerchantLocation(marketplace, listing);
-  const offers = await fetchOffers(marketplace, varient._reference);
+  const offers = await fetchOffers(marketplace, marketplaceSku(varient));
  const existingOffer = offers[0];
  const price = varient.price ?? listing.price;

  if (existingOffer?.offerId) {
-    const offerUpdate = { merchantLocationKey };
+    const offerUpdate = {
+      merchantLocationKey,
+      listingDescription: resolveListingDescription(listing, varient),
+    };
    if (price != null) {
      offerUpdate.pricingSummary = {
        price: {
@ -309,15 +396,18 @@ export async function syncOfferAndMaybePublish(marketplace, listing, varient) {
    try {
      const publishResult = await publishOfferById(marketplace, offerResult.offerId);
      if (publishResult?.listingId) {
-        return `https://www.ebay.com/itm/${publishResult.listingId}`;
+        return {
+          url: `https://www.ebay.com/itm/${publishResult.listingId}`,
+          listingId: publishResult.listingId,
+        };
      }
    } catch (err) {
      logger.warn(
-        `Created offer but failed to publish for varient ${varient._reference}: ${err.message}`
+        `Created offer but failed to publish for varient ${marketplaceSku(varient)}: ${err.message}`
      );
    }
  }
-  return '';
+  return { url: '', listingId: offerResult?.listingId };
 }

 export async function publishOfferForSku(marketplace, sku, listing) {
@ -344,6 +434,9 @@ export async function publishOfferForSku(marketplace, sku, listing) {
    );
  }

+  const listingDescription = resolveListingDescription(listing, { _reference: sku });
+  await ensureInventoryItemDescription(marketplace, sku, listing, { _reference: sku });
+
  await makeRequest({
    marketplace,
    method: 'PUT',
@ -352,6 +445,7 @@ export async function publishOfferForSku(marketplace, sku, listing) {
      ...existingOffer,
      merchantLocationKey,
      categoryId: String(category.categoryId),
+      listingDescription,
      listingPolicies: {
        ...(existingOffer.listingPolicies || {}),
        fulfillmentPolicyId: fulfillmentPolicy.fulfillmentPolicyId,
@ -387,6 +481,7 @@ export function buildVarientEntry(item, offers) {
  const offer = offers?.[0];
  return {
    _reference: item.sku,
+    externalReference: item.sku,
    price: offer?.pricingSummary?.price?.value
      ? parseFloat(offer.pricingSummary.price.value)
      : undefined,
--- a/src/integrations/marketplaces/ebay/listings.js
+++ b/src/integrations/marketplaces/ebay/listings.js
@ -3,11 +3,15 @@ import { syncFulfillmentPolicy } from './fulfillmentPolicies.js';
 import {
  buildVarientEntry,
  fetchOffers,
+  fromEbayCondition,
+  resolveListingDescription,
  resolveOfferState,
  syncOfferAndMaybePublish,
  upsertInventoryItem,
+  withdrawOfferById,
 } from './listingVarients.js';
 import { makeRequest, logger } from './shared.js';
+import { marketplaceSku } from '../ids.js';

 function sleep(ms) {
  return new Promise((resolve) => setTimeout(resolve, ms));
@ -15,17 +19,14 @@ function sleep(ms) {

 async function createOrReplaceGroup(marketplace, listing, varients) {
  const groupKey = listing._reference;
-  const variantSKUs = varients.map((v) => v._reference).filter(Boolean);
+  const variantSKUs = varients.map((v) => marketplaceSku(v)).filter(Boolean);

  const body = {
    title: listing.title || groupKey,
    variantSKUs,
+    description: resolveListingDescription(listing),
  };

-  if (listing.description) {
-    body.description = listing.description;
-  }
-
  if (listing.imageUrls?.length) {
    body.imageUrls = listing.imageUrls;
  }
@ -78,17 +79,17 @@ async function syncGroupedListing(marketplace, listing, varients) {
  await sleep(1000);
  await createOrReplaceGroup(marketplace, listing, varients);

-  let firstPublishedUrl = '';
+  let firstPublished = { url: '' };
  for (const varient of varients) {
    try {
-      const publishedUrl = await syncOfferAndMaybePublish(marketplace, listing, varient);
-      if (publishedUrl && !firstPublishedUrl) firstPublishedUrl = publishedUrl;
+      const published = await syncOfferAndMaybePublish(marketplace, listing, varient);
+      if (published?.url && !firstPublished.url) firstPublished = published;
    } catch (err) {
      logger.warn(`Failed to create offer for varient ${varient._reference}: ${err.message}`);
    }
  }

-  return firstPublishedUrl;
+  return firstPublished;
 }

 async function syncListing(marketplace, listing, varients, actionLabel) {
@ -116,12 +117,25 @@ async function syncListing(marketplace, listing, varients, actionLabel) {
    logger.info(
      `Syncing standalone eBay inventory item "${validVarients[0]._reference}" for listing "${ref}"`
    );
-    const url = await syncSingleVarientListing(marketplace, listingWithContext, validVarients[0]);
-    return { url };
+    const published = await syncSingleVarientListing(
+      marketplace,
+      listingWithContext,
+      validVarients[0]
+    );
+    return listingSyncResult(published);
  }

-  const url = await syncGroupedListing(marketplace, listingWithContext, validVarients);
-  return { url };
+  const published = await syncGroupedListing(marketplace, listingWithContext, validVarients);
+  return listingSyncResult(published);
+}
+
+function listingSyncResult(published) {
+  if (!published) return { url: '' };
+  if (typeof published === 'string') return { url: published };
+  return {
+    url: published.url || '',
+    ...(published.listingId ? { externalReference: published.listingId } : {}),
+  };
 }

 export async function createItem(marketplace, listing, varients) {
@ -132,12 +146,37 @@ export async function updateItem(marketplace, listing, varients) {
  return syncListing(marketplace, listing, varients, 'update');
 }

-export async function deleteItem(marketplace, listing) {
-  const ref = listing._reference;
-  if (!ref) return;
+export async function deleteItem(marketplace, listing, varients = []) {
+  const skus = varients.map((v) => marketplaceSku(v)).filter(Boolean);

+  for (const sku of skus) {
+    const offers = await fetchOffers(marketplace, sku);
+    for (const offer of offers) {
+      if (!offer?.offerId) continue;
+      try {
+        await withdrawOfferById(marketplace, offer.offerId);
+      } catch (err) {
+        logger.warn(`Failed to withdraw offer ${offer.offerId} for SKU ${sku}: ${err.message}`);
+      }
+    }
+
+    try {
+      await makeRequest({
+        marketplace,
+        method: 'DELETE',
+        path: `/sell/inventory/v1/inventory_item/${encodeURIComponent(sku)}`,
+        acceptableStatuses: [404],
+      });
+    } catch (err) {
+      logger.warn(`Failed to delete eBay inventory item "${sku}": ${err.message}`);
+    }
+  }
+
+  const ref = listing._reference;
+  if (ref) {
    logger.info(`Deleting eBay inventory item group "${ref}"`);
    await deleteGroup(marketplace, ref);
+  }
 }

 // --- Sync helpers (inbound from eBay) ---
@ -278,8 +317,10 @@ export function mapProductToListing(ebayItem) {
    const varients = variants.map((v) => buildVarientEntry(v, v._offers || []));

    return {
-      _reference: ebayItem._groupKey,
+      externalReference: firstPublishedOffer?.listingId || ebayItem._groupKey,
      title: group.title || ebayItem._groupKey,
+      description: group.description,
+      condition: fromEbayCondition(variants[0]?.condition),
      state: { type: stateType },
      price,
      currency,
@ -301,8 +342,10 @@ export function mapProductToListing(ebayItem) {
  const varients = [buildVarientEntry(ebayItem, ebayItem._offers || [])];

  return {
-    _reference: ebayItem.sku,
+    externalReference: offer?.listingId || ebayItem.sku,
    title: ebayItem.product?.title || ebayItem.sku,
+    description: ebayItem.product?.description,
+    condition: fromEbayCondition(ebayItem.condition),
    state: { type: stateType },
    price,
    currency,
--- a/src/integrations/marketplaces/ebay/notifications.js
+++ b/src/integrations/marketplaces/ebay/notifications.js
@ -0,0 +1,251 @@
+import crypto from 'crypto';
+import { getApiBaseUrl, getBasicAuthHeader, makeRequest, logger, formatDebugPayload, getMarketplaceDebugContext } from './shared.js';
+
+const NOTIFICATION_BASE = '/commerce/notification/v1';
+const APPLICATION_SCOPE =
+  'https://api.ebay.com/oauth/api_scope/commerce.notification.subscription';
+
+const HANDLED_TOPIC_MATCHERS = [
+  'MARKETPLACE_ACCOUNT_DELETION',
+  'AUTHORIZATION_REVOCATION',
+  'ITEM_AVAILABILITY',
+  'ITEM_PRICE_REVISION',
+  'ORDER',
+];
+
+function getVerificationToken(marketplace) {
+  return (
+    marketplace.config?.verificationToken ||
+    marketplace.config?.verificationToken ||
+    ''
+  );
+}
+
+function getWebhookEndpoint(marketplace) {
+  return marketplace.config?.webhookUrl || '';
+}
+
+export function buildWebhookChallengeResponse(marketplace, { challengeCode, endpoint } = {}) {
+  const verificationToken = getVerificationToken(marketplace);
+  const destination = endpoint || getWebhookEndpoint(marketplace);
+  if (!challengeCode || !verificationToken || !destination) {
+    throw new Error(
+      'eBay webhook challenge requires challengeCode, verificationToken, and endpoint'
+    );
+  }
+
+  const challengeResponse = crypto
+    .createHash('sha256')
+    .update(challengeCode + verificationToken + destination)
+    .digest('hex');
+
+  return { challengeResponse };
+}
+
+async function getApplicationToken(marketplace) {
+  logger.debug('eBay application token request', getMarketplaceDebugContext(marketplace));
+
+  const startedAt = Date.now();
+  const response = await fetch(`${getApiBaseUrl(marketplace)}/identity/v1/oauth2/token`, {
+    method: 'POST',
+    headers: {
+      'Content-Type': 'application/x-www-form-urlencoded',
+      Authorization: getBasicAuthHeader(marketplace),
+    },
+    body: new URLSearchParams({
+      grant_type: 'client_credentials',
+      scope: APPLICATION_SCOPE,
+    }).toString(),
+  });
+  const data = await response.json();
+  const durationMs = Date.now() - startedAt;
+  if (!response.ok || data.error) {
+    logger.error('eBay application token request failed', {
+      status: response.status,
+      durationMs,
+      ...getMarketplaceDebugContext(marketplace),
+      response: formatDebugPayload(data),
+    });
+    throw new Error(data.error_description || data.error || 'Failed to mint eBay application token');
+  }
+
+  logger.debug(`eBay application token request succeeded (${durationMs}ms)`, {
+    ...getMarketplaceDebugContext(marketplace),
+    expiresIn: data.expires_in,
+    tokenType: data.token_type,
+  });
+  return data.access_token;
+}
+
+async function notificationRequest(marketplace, { method = 'GET', path, body, useApplicationToken = false }) {
+  if (!useApplicationToken) {
+    return makeRequest({ marketplace, method, path, body, acceptableStatuses: [404] });
+  }
+
+  const token = await getApplicationToken(marketplace);
+  const url = `${getApiBaseUrl(marketplace)}${path}`;
+  const startedAt = Date.now();
+  logger.debug(`eBay notification API ${method} ${path}`, {
+    ...getMarketplaceDebugContext(marketplace),
+    useApplicationToken: true,
+    body: body ? formatDebugPayload(body) : undefined,
+  });
+
+  const response = await fetch(url, {
+    method,
+    headers: {
+      Authorization: `Bearer ${token}`,
+      Accept: 'application/json',
+      ...(body ? { 'Content-Type': 'application/json' } : {}),
+    },
+    ...(body && method !== 'GET' ? { body: JSON.stringify(body) } : {}),
+  });
+  const durationMs = Date.now() - startedAt;
+  if (response.status === 204 || response.status === 404) {
+    logger.debug(
+      `eBay notification API ${method} ${path} -> ${response.status} (${durationMs}ms)`,
+      getMarketplaceDebugContext(marketplace)
+    );
+    return response.status === 404 ? null : null;
+  }
+  const data = await response.json().catch(() => null);
+  if (!response.ok) {
+    const message = data?.errors?.[0]?.message || data?.error_description || response.statusText;
+    logger.error(`eBay notification API error (${response.status}): ${message}`, {
+      path,
+      durationMs,
+      ...getMarketplaceDebugContext(marketplace),
+      response: data ? formatDebugPayload(data) : undefined,
+    });
+    throw new Error(`eBay notification API error (${response.status}): ${message}`);
+  }
+
+  logger.debug(`eBay notification API ${method} ${path} -> ${response.status} (${durationMs}ms)`, {
+    ...getMarketplaceDebugContext(marketplace),
+    response: data ? formatDebugPayload(data) : undefined,
+  });
+  return data;
+}
+
+function topicIsHandled(topicId = '') {
+  const id = String(topicId).toUpperCase();
+  return HANDLED_TOPIC_MATCHERS.some((matcher) => id.includes(matcher));
+}
+
+export async function ensureWebhookSubscriptions(marketplace) {
+  const endpoint = getWebhookEndpoint(marketplace);
+  const verificationToken = getVerificationToken(marketplace);
+  if (!endpoint || !verificationToken) {
+    logger.warn(
+      `Skipping eBay webhook subscription for "${marketplace.name}" (missing webhookUrl or verificationToken)`
+    );
+    return { skipped: true };
+  }
+
+  const destinations = await notificationRequest(marketplace, {
+    path: `${NOTIFICATION_BASE}/destination`,
+  });
+  let destination = (destinations?.destinations || []).find(
+    (item) => item.deliveryConfig?.endpoint === endpoint
+  );
+
+  if (!destination) {
+    destination = await notificationRequest(marketplace, {
+      method: 'POST',
+      path: `${NOTIFICATION_BASE}/destination`,
+      body: {
+        name: `FarmControl ${marketplace.name}`.slice(0, 200),
+        status: 'ENABLED',
+        deliveryConfig: {
+          endpoint,
+          verificationToken,
+        },
+      },
+    });
+  }
+
+  const destinationId = destination?.destinationId || destination?.id;
+  if (!destinationId) {
+    throw new Error('Failed to create or resolve eBay notification destination');
+  }
+
+  const topics = await notificationRequest(marketplace, { path: `${NOTIFICATION_BASE}/topic` });
+  const subscriptions = await notificationRequest(marketplace, {
+    path: `${NOTIFICATION_BASE}/subscription`,
+  });
+  const existingTopicIds = new Set(
+    (subscriptions?.subscriptions || []).map((item) => item.topicId)
+  );
+
+  const created = [];
+  for (const topic of topics?.topics || []) {
+    if (topic.status && String(topic.status).toUpperCase() !== 'ENABLED') continue;
+    if (!topicIsHandled(topic.topicId)) continue;
+    if (existingTopicIds.has(topic.topicId)) continue;
+
+    const useApplicationToken = String(topic.scope || '').toUpperCase() === 'APPLICATION';
+    try {
+      await notificationRequest(marketplace, {
+        method: 'POST',
+        path: `${NOTIFICATION_BASE}/subscription`,
+        useApplicationToken,
+        body: {
+          topicId: topic.topicId,
+          status: 'ENABLED',
+          destinationId,
+          payload: { format: 'JSON', schemaVersion: topic.supportedPayloads?.[0]?.schemaVersion || '1.0' },
+        },
+      });
+      created.push(topic.topicId);
+    } catch (err) {
+      logger.warn(`Failed to subscribe to eBay topic ${topic.topicId}: ${err.message}`);
+    }
+  }
+
+  logger.info(
+    `eBay webhook destination ${destinationId} ready for "${marketplace.name}" (${created.length} new subscription(s))`
+  );
+  return { destinationId, created };
+}
+
+async function getPublicKey(marketplace, kid) {
+  return makeRequest({
+    marketplace,
+    path: `${NOTIFICATION_BASE}/public_key/${encodeURIComponent(kid)}`,
+  });
+}
+
+export async function verifyNotificationSignature(marketplace, rawBody, signatureHeader) {
+  if (!signatureHeader) {
+    return false;
+  }
+
+  try {
+    const decodedJson = Buffer.from(signatureHeader, 'base64').toString('utf8');
+    const decoded = JSON.parse(decodedJson);
+    const kid = decoded.kid;
+    const signature = decoded.signature;
+    if (!kid || !signature) {
+      return false;
+    }
+
+    const publicKey = await getPublicKey(marketplace, kid);
+    const pem = publicKey?.key;
+    if (!pem) {
+      return false;
+    }
+
+    const digest = (decoded.digest || publicKey.digest || 'SHA256').replace('-', '');
+    const verifier = crypto.createVerify(digest);
+    verifier.update(rawBody);
+    verifier.end();
+    return verifier.verify(pem, signature, 'base64');
+  } catch (err) {
+    logger.warn(`eBay notification signature verification failed: ${err.message}`);
+    return false;
+  }
+}
+
+export function canVerifyNotificationSignature(marketplace) {
+  return !!marketplace.config?.accessToken;
+}
--- a/src/integrations/marketplaces/ebay/orders.js
+++ b/src/integrations/marketplaces/ebay/orders.js
@ -90,6 +90,7 @@ export function mapOrderToSalesOrder(ebayOrder) {
  const grandTotal = parseFloat(pricingSummary.total?.value || 0);

  return {
+    externalReference: ebayOrder.orderId,
    externalId: ebayOrder.orderId,
    state: { type: mapOrderStatus(ebayOrder) },
    totalAmount,
@ -112,6 +113,7 @@ export function mapBuyerToClient(ebayOrder) {
    name: fullName,
    email: buyer.buyerRegistrationAddress?.email || '',
    phone: address.primaryPhone?.phoneNumber || '',
+    externalReference: buyer.username || '',
    address: {
      addressLine1: contactAddress.addressLine1 || '',
      addressLine2: contactAddress.addressLine2 || '',
@ -123,34 +125,131 @@ export function mapBuyerToClient(ebayOrder) {
  };
 }

+export async function getOrder(marketplace, orderId) {
+  const order = await makeRequest({
+    marketplace,
+    path: `/sell/fulfillment/v1/order/${encodeURIComponent(orderId)}`,
+  });
+  const fulfillments = await makeRequest({
+    marketplace,
+    path: `/sell/fulfillment/v1/order/${encodeURIComponent(orderId)}/shipping_fulfillment`,
+    acceptableStatuses: [404],
+  });
+  return {
+    ...order,
+    shippingFulfillments: fulfillments?.fulfillments || [],
+  };
+}
+
+export function mapOrderLineItems(ebayOrder) {
+  return (ebayOrder.lineItems || []).map((line) => {
+    const unit = parseFloat(line.lineItemCost?.value || 0);
+    const tax = (line.taxes || []).reduce(
+      (sum, taxLine) => sum + parseFloat(taxLine.amount?.value || 0),
+      0
+    );
+    const quantity = line.quantity || 1;
+    return {
+      externalReference: line.lineItemId,
+      sku: line.sku || '',
+      name: line.title || line.sku || 'Marketplace item',
+      quantity,
+      itemAmount: unit,
+      totalAmount: unit * quantity,
+      totalAmountWithTax: unit * quantity + tax,
+      itemType: 'product',
+    };
+  });
+}
+
+export function mapOrderShipments(ebayOrder) {
+  const shippingAmount = parseFloat(ebayOrder.pricingSummary?.deliveryCost?.value || 0);
+  const fulfillments = ebayOrder.shippingFulfillments || [];
+  if (!fulfillments.length) {
+    return [];
+  }
+  const splitAmount = shippingAmount / fulfillments.length;
+  return fulfillments.map((fulfillment) => ({
+    externalReference: fulfillment.fulfillmentId,
+    trackingNumber: fulfillment.shipmentTrackingNumber || '',
+    amount: splitAmount,
+    amountWithTax: splitAmount,
+    state: { type: fulfillment.shippedDate ? 'shipped' : 'planned' },
+    shippedAt: fulfillment.shippedDate ? new Date(fulfillment.shippedDate) : undefined,
+    lineItemIds: (fulfillment.lineItems || []).map((line) => line.lineItemId).filter(Boolean),
+  }));
+}
+
+export async function createShippingFulfillment(marketplace, { orderId, lineItems, trackingNumber, shippingCarrierCode }) {
+  if (!orderId) {
+    throw new Error('orderId is required to create an eBay shipping fulfillment');
+  }
+  if (!trackingNumber) {
+    throw new Error('trackingNumber is required to create an eBay shipping fulfillment');
+  }
+
+  return makeRequest({
+    marketplace,
+    method: 'POST',
+    path: `/sell/fulfillment/v1/order/${encodeURIComponent(orderId)}/shipping_fulfillment`,
+    body: {
+      lineItems: (lineItems || []).map((line) => ({
+        lineItemId: line.lineItemId || line.externalReference,
+        quantity: line.quantity || 1,
+      })),
+      shippingCarrierCode: shippingCarrierCode || 'Other',
+      trackingNumber,
+    },
+  });
+}
+
 export async function handleWebhook(marketplace, event) {
-  const { topic, data } = event;
+  const topic =
+    event?.metadata?.topic ||
+    event?.topic ||
+    event?.notification?.topic ||
+    '';
+  const data = event?.notification?.data || event?.data || {};
+  const notificationId =
+    event?.notification?.notificationId || event?.notificationId || '';

  logger.info(`eBay webhook received: ${topic} for marketplace ${marketplace.name}`);

-  if (topic?.startsWith('marketplace.account_deletion')) {
-    return { action: 'accountDeletion', userId: data?.userId };
+  const orderId = data.orderId || data.order?.orderId || data.legacyOrderId;
+  const sku = data.sku || data.itemId || data.listingId;
+
+  const normalized = String(topic).toUpperCase();
+
+  if (normalized.includes('ACCOUNT_DELETION') || normalized.includes('MARKETPLACE_ACCOUNT_DELETION')) {
+    return {
+      action: 'accountDeletion',
+      userId: data.userId || data.username,
+      notificationId,
+      topic,
+    };
  }

-  switch (topic) {
-    case 'item.sold':
-      return { action: 'orderCreate', orderId: data?.orderId };
+  if (normalized.includes('AUTHORIZATION_REVOCATION')) {
+    return { action: 'disconnect', notificationId, topic };
+  }

-    case 'item.created':
-    case 'item.updated':
-      return { action: 'productUpdate', itemId: data?.itemId };
+  if (normalized.includes('ORDER') || normalized === 'ITEM.SOLD' || normalized === 'ORDER.FULFILLMENT') {
+    return {
+      action: orderId && topic.toLowerCase().includes('cancel') ? 'orderCancel' : 'orderUpdate',
+      orderId,
+      notificationId,
+      topic,
+    };
+  }

-    case 'item.ended':
-      return { action: 'productEnded', itemId: data?.itemId };
+  if (
+    normalized.includes('ITEM') ||
+    normalized.includes('AVAILABILITY') ||
+    normalized.includes('PRICE')
+  ) {
+    return { action: 'productUpdate', itemId: sku, sku, notificationId, topic };
+  }

-    case 'order.cancelled':
-      return { action: 'orderCancel', orderId: data?.orderId };
-
-    case 'order.fulfillment':
-      return { action: 'orderUpdate', orderId: data?.orderId };
-
-    default:
  logger.debug(`Unhandled eBay webhook topic: ${topic}`);
-      return { action: 'unknown', topic };
-  }
+  return { action: 'unknown', topic, notificationId };
 }
--- a/src/integrations/marketplaces/ebay/shared.js
+++ b/src/integrations/marketplaces/ebay/shared.js
@ -4,6 +4,35 @@ import log4js from 'log4js';
 const logger = log4js.getLogger('eBay');
 logger.level = config.server.logLevel;

+const DEBUG_PAYLOAD_MAX_LENGTH = 4000;
+
+function formatDebugPayload(value, { maxLength = DEBUG_PAYLOAD_MAX_LENGTH } = {}) {
+  if (value === null || value === undefined) {
+    return value;
+  }
+
+  let text;
+  try {
+    text = typeof value === 'string' ? value : JSON.stringify(value);
+  } catch {
+    text = String(value);
+  }
+
+  if (text.length <= maxLength) {
+    return text;
+  }
+
+  return `${text.slice(0, maxLength)}... [truncated ${text.length - maxLength} chars]`;
+}
+
+function getMarketplaceDebugContext(marketplace) {
+  return {
+    marketplace: marketplace?.name,
+    marketplaceId: marketplace?.config?.marketplaceId,
+    sandbox: marketplace?.config?.sandbox ?? false,
+  };
+}
+
 const SANDBOX_API_URL = 'https://api.sandbox.ebay.com';
 const PRODUCTION_API_URL = 'https://api.ebay.com';
 const SANDBOX_AUTH_URL = 'https://auth.sandbox.ebay.com';
@ -14,6 +43,7 @@ const DEFAULT_SCOPES = [
  'https://api.ebay.com/oauth/api_scope/sell.inventory',
  'https://api.ebay.com/oauth/api_scope/sell.fulfillment',
  'https://api.ebay.com/oauth/api_scope/sell.account',
+  'https://api.ebay.com/oauth/api_scope/commerce.notification.subscription',
 ];
 const MARKETPLACE_LANGUAGE_MAP = {
  EBAY_US: 'en-US',
@ -144,11 +174,21 @@ export async function makeRequest({
    fetchOptions.body = JSON.stringify(body);
  }

-  logger.debug(`eBay API ${method} ${path}`);
+  const startedAt = Date.now();
+  logger.debug(`eBay API ${method} ${path}`, {
+    ...getMarketplaceDebugContext(marketplace),
+    params: Object.keys(params).length ? params : undefined,
+    body: body ? formatDebugPayload(body) : undefined,
+    acceptableStatuses: acceptableStatuses.length ? acceptableStatuses : undefined,
+  });

  const response = await fetch(url, fetchOptions);
+  const durationMs = Date.now() - startedAt;

  if (response.status === 204) {
+    logger.debug(`eBay API ${method} ${path} -> 204 No Content (${durationMs}ms)`, {
+      ...getMarketplaceDebugContext(marketplace),
+    });
    return null;
  }

@ -163,19 +203,40 @@ export async function makeRequest({
  }

  if (!response.ok && acceptableStatuses.includes(response.status)) {
+    logger.debug(
+      `eBay API ${method} ${path} -> ${response.status} (acceptable) (${durationMs}ms)`,
+      {
+        ...getMarketplaceDebugContext(marketplace),
+        response: data ? formatDebugPayload(data) : undefined,
+      }
+    );
    return null;
  }

  if (!response.ok) {
    const message =
-      (typeof data === 'object' && (data?.errors?.[0]?.message || data?.error_description)) ||
+      (typeof data === 'object' &&
+        (data?.errors?.[0]?.longMessage ||
+          data?.errors?.[0]?.message ||
+          data?.error_description)) ||
      (typeof data === 'string' && data) ||
      response.statusText;
-    logger.error(`eBay API error: ${message}`, { status: response.status, path });
+    logger.error(`eBay API error: ${message}`, {
+      status: response.status,
+      path,
+      durationMs,
+      ...getMarketplaceDebugContext(marketplace),
+      response: data ? formatDebugPayload(data) : undefined,
+    });
    throw new Error(`eBay API error (${response.status}): ${message}`);
  }

+  logger.debug(`eBay API ${method} ${path} -> ${response.status} (${durationMs}ms)`, {
+    ...getMarketplaceDebugContext(marketplace),
+    response: data ? formatDebugPayload(data) : undefined,
+  });
+
  return data;
 }

-export { logger };
+export { logger, formatDebugPayload, getMarketplaceDebugContext };
--- a/src/integrations/marketplaces/ebay/shippingServices.js
+++ b/src/integrations/marketplaces/ebay/shippingServices.js
@ -0,0 +1,144 @@
+import { logger, getMarketplaceDebugContext } from './shared.js';
+
+const TRADING_COMPATIBILITY_LEVEL = '1399';
+const TRADING_SANDBOX_URL = 'https://api.sandbox.ebay.com/ws/api.dll';
+const TRADING_PRODUCTION_URL = 'https://api.ebay.com/ws/api.dll';
+
+const MARKETPLACE_SITE_IDS = {
+  EBAY_US: '0',
+  EBAY_ENCA: '2',
+  EBAY_GB: '3',
+  EBAY_AU: '15',
+  EBAY_AT: '16',
+  EBAY_FRBE: '23',
+  EBAY_FR: '71',
+  EBAY_DE: '77',
+  EBAY_IT: '101',
+  EBAY_NLBE: '123',
+  EBAY_NL: '146',
+  EBAY_ES: '186',
+  EBAY_CH: '193',
+  EBAY_HK: '201',
+  EBAY_IN: '203',
+  EBAY_IE: '205',
+  EBAY_MY: '207',
+  EBAY_PH: '211',
+  EBAY_PL: '212',
+  EBAY_SG: '216',
+};
+
+function getTradingApiUrl(marketplace) {
+  return marketplace.config?.sandbox ? TRADING_SANDBOX_URL : TRADING_PRODUCTION_URL;
+}
+
+function getSiteId(marketplace) {
+  const marketplaceId = marketplace.config?.marketplaceId || 'EBAY_GB';
+  return MARKETPLACE_SITE_IDS[marketplaceId] || MARKETPLACE_SITE_IDS.EBAY_GB;
+}
+
+export function parseShippingServiceDetails(xml = '') {
+  const blocks = xml.match(/<ShippingServiceDetails>[\s\S]*?<\/ShippingServiceDetails>/g) || [];
+  const services = [];
+  const seen = new Set();
+
+  for (const block of blocks) {
+    const validMatch = block.match(/<ValidForSellingFlow>([^<]+)<\/ValidForSellingFlow>/i);
+    if (validMatch && String(validMatch[1]).toLowerCase() !== 'true') {
+      continue;
+    }
+    const serviceMatch = block.match(/<ShippingService>([^<]+)<\/ShippingService>/i);
+    const code = serviceMatch?.[1]?.trim();
+    if (!code || seen.has(code)) continue;
+    seen.add(code);
+    services.push(code);
+  }
+
+  return services.sort((a, b) => a.localeCompare(b));
+}
+
+function buildGeteBayDetailsRequest() {
+  return `<?xml version="1.0" encoding="utf-8"?>
+<GeteBayDetailsRequest xmlns="urn:ebay:apis:eBLBaseComponents">
+  <ErrorLanguage>en_GB</ErrorLanguage>
+  <WarningLevel>High</WarningLevel>
+  <DetailName>ShippingServiceDetails</DetailName>
+</GeteBayDetailsRequest>`;
+}
+
+export async function fetchEbayShippingServices(marketplace) {
+  const accessToken = marketplace.config?.accessToken;
+  if (!accessToken) {
+    throw new Error(
+      'eBay marketplace is not authenticated. Complete marketplace authorization first.'
+    );
+  }
+
+  const url = getTradingApiUrl(marketplace);
+  const siteId = getSiteId(marketplace);
+  const startedAt = Date.now();
+  logger.debug('eBay Trading API GeteBayDetails request', {
+    ...getMarketplaceDebugContext(marketplace),
+    siteId,
+    url,
+  });
+
+  const response = await fetch(url, {
+    method: 'POST',
+    headers: {
+      'Content-Type': 'text/xml',
+      'X-EBAY-API-CALL-NAME': 'GeteBayDetails',
+      'X-EBAY-API-SITEID': siteId,
+      'X-EBAY-API-COMPATIBILITY-LEVEL': TRADING_COMPATIBILITY_LEVEL,
+      'X-EBAY-API-IAF-TOKEN': accessToken,
+    },
+    body: buildGeteBayDetailsRequest(),
+  });
+
+  const xml = await response.text();
+  const durationMs = Date.now() - startedAt;
+  if (!response.ok) {
+    logger.error(`GeteBayDetails failed (${response.status})`, {
+      durationMs,
+      ...getMarketplaceDebugContext(marketplace),
+      siteId,
+    });
+    throw new Error(`eBay GeteBayDetails error (${response.status})`);
+  }
+
+  const ackMatch = xml.match(/<Ack>([^<]+)<\/Ack>/);
+  const ack = ackMatch?.[1];
+  if (ack && ack !== 'Success' && ack !== 'Warning') {
+    const message =
+      xml.match(/<LongMessage>([^<]+)<\/LongMessage>/)?.[1] ||
+      xml.match(/<ShortMessage>([^<]+)<\/ShortMessage>/)?.[1] ||
+      ack;
+    logger.error(`GeteBayDetails failed: ${message}`, {
+      ack,
+      durationMs,
+      ...getMarketplaceDebugContext(marketplace),
+      siteId,
+    });
+    throw new Error(`eBay GeteBayDetails failed: ${message}`);
+  }
+
+  const services = parseShippingServiceDetails(xml);
+  logger.debug(`GeteBayDetails succeeded (${durationMs}ms)`, {
+    ...getMarketplaceDebugContext(marketplace),
+    siteId,
+    serviceCount: services.length,
+  });
+  logger.info(
+    `Fetched ${services.length} eBay shipping service(s) for marketplace "${marketplace.name}"`
+  );
+  return services;
+}
+
+export async function syncMarketplaceMetadata(marketplace) {
+  const availableShippingServices = await fetchEbayShippingServices(marketplace);
+  return {
+    eBay: {
+      ...(marketplace.eBay && typeof marketplace.eBay === 'object' ? marketplace.eBay : {}),
+      availableShippingServices,
+    },
+  };
+}
--- a/src/integrations/marketplaces/ids.js
+++ b/src/integrations/marketplaces/ids.js
@ -0,0 +1,9 @@
+export function marketplaceSku(record) {
+  return record?.externalReference || record?._reference;
+}
+
+export function marketplaceActor(marketplace) {
+  const plain =
+    typeof marketplace?.toObject === 'function' ? marketplace.toObject() : { ...marketplace };
+  return { ...plain, _objectType: 'marketplace' };
+}
--- a/src/integrations/marketplaces/tiktokShop.js
+++ b/src/integrations/marketplaces/tiktokShop.js
@ -429,8 +429,8 @@ function mapListingToProduct(listing) {
    };
  }

-  if (listing.externalId) {
-    sku.seller_sku = listing.externalId;
+  if (listing.externalReference || listing.externalId) {
+    sku.seller_sku = listing.externalReference || listing.externalId;
  }

  product.skus = [sku];
@ -452,15 +452,16 @@ export async function createItem(marketplace, listing) {
  const productId = result?.product_id || result?.id;

  return {
+    externalReference: productId,
    externalId: productId,
    url: '',
  };
 }

 export async function updateItem(marketplace, listing) {
-  const productId = listing.externalId;
+  const productId = listing.externalReference || listing.externalId;
  if (!productId) {
-    throw new Error('Listing must have an externalId to update on TikTok Shop');
+    throw new Error('Listing must have an externalReference to update on TikTok Shop');
  }

  logger.info(`Updating TikTok Shop product: ${productId}`);
@ -473,7 +474,7 @@ export async function updateItem(marketplace, listing) {
    body: productBody,
  });

-  return { externalId: productId };
+  return { externalReference: productId, externalId: productId };
 }

 export async function syncItems(marketplace) {
@ -537,6 +538,7 @@ export function mapOrderToSalesOrder(tiktokOrder) {
  const totalTax = parseFloat(paymentInfo.tax || 0);

  return {
+    externalReference: tiktokOrder.id,
    externalId: tiktokOrder.id,
    state: { type: mapOrderStatus(tiktokOrder.status) },
    totalAmount,
@ -579,6 +581,7 @@ export function mapProductToListing(tiktokProduct) {
        : undefined;
    return {
      _reference: sku.id || sku.seller_sku || '',
+      externalReference: sku.seller_sku || sku.id || '',
      price: skuPrice,
      currency: sku.price?.currency || currency,
      state: { type: PRODUCT_STATUS_MAP[tiktokProduct.status] || 'draft' },
@ -586,6 +589,7 @@ export function mapProductToListing(tiktokProduct) {
  });

  return {
+    externalReference: tiktokProduct.id,
    _reference: tiktokProduct.id,
    title: tiktokProduct.title || '',
    state: { type: PRODUCT_STATUS_MAP[tiktokProduct.status] || 'draft' },
@ -602,6 +606,7 @@ export function mapBuyerToClient(tiktokOrder) {
  const address = tiktokOrder.recipient_address || {};

  return {
+    externalReference: buyer.open_id || buyer.username || '',
    name: buyer.name || address.name || 'Unknown',
    email: buyer.email || '',
    phone: buyer.phone_number || address.phone_number || '',
@ -616,6 +621,42 @@ export function mapBuyerToClient(tiktokOrder) {
  };
 }

+export async function getOrder(marketplace, orderId) {
+  return fetchOrderDetail(marketplace, orderId);
+}
+
+export function mapOrderLineItems(tiktokOrder) {
+  return (tiktokOrder.line_items || []).map((line) => {
+    const quantity = Number(line.quantity || 1);
+    const unit = parseFloat(line.sale_price || line.original_price || 0);
+    return {
+      externalReference: String(line.id || line.sku_id || ''),
+      sku: line.seller_sku || line.sku_id || '',
+      name: line.product_name || line.sku_name || 'Marketplace item',
+      quantity,
+      itemAmount: unit,
+      totalAmount: unit * quantity,
+      totalAmountWithTax: unit * quantity,
+      itemType: 'product',
+    };
+  });
+}
+
+export function mapOrderShipments(tiktokOrder) {
+  const packages = tiktokOrder.packages || [];
+  const shippingAmount = parseFloat(tiktokOrder.payment?.shipping_fee || 0);
+  const split = packages.length ? shippingAmount / packages.length : 0;
+  return packages
+    .filter((pkg) => pkg.id || pkg.tracking_number)
+    .map((pkg) => ({
+      externalReference: String(pkg.id || pkg.tracking_number),
+      trackingNumber: pkg.tracking_number || '',
+      amount: split,
+      amountWithTax: split,
+      state: { type: pkg.tracking_number ? 'shipped' : 'planned' },
+    }));
+}
+
 export async function handleWebhook(marketplace, event) {
  const { type, data } = event;

--- a/src/integrations/marketplaceworker.js
+++ b/src/integrations/marketplaceworker.js
@ -1,13 +1,19 @@
 import config from '../config.js';
 import log4js from 'log4js';
-import { clientModel } from '../database/schemas/sales/client.schema.js';
-import { salesOrderModel } from '../database/schemas/sales/salesorder.schema.js';
 import { listingModel } from '../database/schemas/sales/listing.schema.js';
 import { listingVarientModel } from '../database/schemas/sales/listingvarient.schema.js';
 import { marketplaceModel } from '../database/schemas/sales/marketplace.schema.js';
-import { editObject, newObject } from '../database/database.js';
+import { editObject } from '../database/database.js';
 import * as tiktokShop from './marketplaces/tiktokShop.js';
 import * as ebay from './marketplaces/ebay/index.js';
+import {
+  marketplaceActor,
+  marketplaceSku,
+  upsertExternalOrder,
+  importExternalItems,
+  applyWebhookAction,
+  pushShipmentFulfillment,
+} from './marketplaceSync.js';

 const logger = log4js.getLogger('Marketplace Worker');
 logger.level = config.server.logLevel;
@ -128,8 +134,17 @@ export async function exchangeAuthorizationCode(marketplace, user, { code, state
    user
  );

+  let marketplaceWithAuth = updatedMarketplace;
+  try {
+    marketplaceWithAuth = await syncMarketplaceMetadata(marketplaceWithAuth, user);
+  } catch (err) {
+    logger.warn(
+      `Failed to sync marketplace metadata after authorization for "${marketplace.name}": ${err.message}`
+    );
+  }
+
  return {
-    marketplace: updatedMarketplace,
+    marketplace: marketplaceWithAuth,
    ...(authResult?.data ? { data: authResult.data } : {}),
  };
 }
@ -156,10 +171,17 @@ export async function refreshMarketplaceAuth(marketplace, user) {

 export function canVerifyWebhookSignature(marketplace) {
  const provider = getProvider(marketplace);
-  if (typeof provider.verifyWebhookSignature !== 'function') {
+  if (
+    typeof provider.verifyWebhookSignature !== 'function' &&
+    typeof provider.verifyNotificationSignature !== 'function'
+  ) {
    return false;
  }

+  if (typeof provider.canVerifyNotificationSignature === 'function') {
+    return provider.canVerifyNotificationSignature(marketplace);
+  }
+
  if (typeof provider.canVerifyWebhookSignature === 'function') {
    return provider.canVerifyWebhookSignature(marketplace);
  }
@ -169,6 +191,9 @@ export function canVerifyWebhookSignature(marketplace) {

 export function verifyWebhookSignature(marketplace, rawBody, signature) {
  const provider = getProvider(marketplace);
+  if (typeof provider.verifyNotificationSignature === 'function') {
+    return provider.verifyNotificationSignature(marketplace, rawBody, signature);
+  }
  if (!provider.verifyWebhookSignature) {
    logger.warn(`Provider ${marketplace.provider} does not support webhook signature verification`);
    return true;
@ -177,9 +202,67 @@ export function verifyWebhookSignature(marketplace, rawBody, signature) {
  return provider.verifyWebhookSignature(marketplace, rawBody, signature);
 }

-export async function handleWebhook(marketplace, event) {
+export async function handleWebhook(marketplace, event, { rawBody, signature } = {}) {
  const provider = getProvider(marketplace);
-  return provider.handleWebhook(marketplace, event);
+  const actor = marketplaceActor(marketplace);
+
+  if (signature && (await canVerifyWebhookSignature(marketplace))) {
+    const valid = await verifyWebhookSignature(marketplace, rawBody || JSON.stringify(event), signature);
+    if (!valid) {
+      const error = new Error('Invalid webhook signature');
+      error.status = 401;
+      throw error;
+    }
+  }
+
+  const classified = await provider.handleWebhook(marketplace, event);
+  return applyWebhookAction(marketplace, provider, classified, actor);
+}
+
+export function buildWebhookChallengeResponse(marketplace, query) {
+  const provider = getProvider(marketplace);
+  if (typeof provider.buildWebhookChallengeResponse !== 'function') {
+    return null;
+  }
+  return provider.buildWebhookChallengeResponse(marketplace, query);
+}
+
+export async function syncMarketplaceMetadata(marketplace, user) {
+  const authenticatedMarketplace = await ensureMarketplaceAuth(marketplace, user);
+  const provider = getProvider(authenticatedMarketplace);
+  if (typeof provider.syncMarketplaceMetadata !== 'function') {
+    return authenticatedMarketplace;
+  }
+  const metadataUpdates = await provider.syncMarketplaceMetadata(authenticatedMarketplace);
+  if (!metadataUpdates || !Object.keys(metadataUpdates).length) {
+    return authenticatedMarketplace;
+  }
+  return persistMarketplaceUpdate(authenticatedMarketplace, {}, metadataUpdates, user);
+}
+
+export async function ensureWebhookSubscriptions(marketplace, user) {
+  const authenticatedMarketplace = await ensureMarketplaceAuth(marketplace, user);
+  const provider = getProvider(authenticatedMarketplace);
+  if (typeof provider.ensureWebhookSubscriptions !== 'function') {
+    return { skipped: true };
+  }
+  return provider.ensureWebhookSubscriptions(authenticatedMarketplace);
+}
+
+export async function debugMarketplaceGet(marketplace, user, path, params = {}) {
+  const authenticatedMarketplace = await ensureMarketplaceAuth(marketplace, user);
+  const provider = getProvider(authenticatedMarketplace);
+  if (typeof provider.debugGet !== 'function') {
+    throw new Error(`Provider ${marketplace.provider} does not support debug GET`);
+  }
+  if (!String(path).startsWith('/sell/') && !String(path).startsWith('/commerce/')) {
+    throw new Error('Debug proxy only allows /sell and /commerce paths');
+  }
+  return provider.debugGet({
+    marketplace: authenticatedMarketplace,
+    path,
+    params,
+  });
 }

 async function setListingState(listingId, stateType, user, message) {
@ -262,13 +345,18 @@ export function createListing(marketplace, user, listingData) {
      if (listingData._id) {
        const updateData = { lastSyncedAt: new Date(), state: { type: 'active' } };
        if (result?.url) updateData.url = result.url;
+        if (result?.externalReference) updateData.externalReference = result.externalReference;
        await editObject({ model: listingModel, id: listingData._id, updateData, user });

        for (const varient of varients) {
+          const varientUpdate = { lastSyncedAt: new Date(), state: { type: 'active' } };
+          if (!varient.externalReference && marketplaceSku(varient)) {
+            varientUpdate.externalReference = marketplaceSku(varient);
+          }
          await editObject({
            model: listingVarientModel,
            id: varient._id,
-            updateData: { lastSyncedAt: new Date(), state: { type: 'active' } },
+            updateData: varientUpdate,
            user,
          }).catch(() => {});
        }
@ -312,21 +400,28 @@ export function updateListing(marketplace, user, listingData) {
      logger.info(
        `Updating listing on marketplace "${marketplace.name}" (${marketplace.provider})`
      );
-      await provider.updateItem(authenticatedMarketplace, fullListing, varients);
+      const result = await provider.updateItem(authenticatedMarketplace, fullListing, varients);

      if (listingData._id) {
+        const updateData = { state: { type: 'active' }, lastSyncedAt: new Date() };
+        if (result?.url) updateData.url = result.url;
+        if (result?.externalReference) updateData.externalReference = result.externalReference;
        await editObject({
          model: listingModel,
          id: listingData._id,
-          updateData: { state: { type: 'active' }, lastSyncedAt: new Date() },
+          updateData,
          user,
        });

        for (const varient of varients) {
+          const varientUpdate = { lastSyncedAt: new Date(), state: { type: 'active' } };
+          if (!varient.externalReference && marketplaceSku(varient)) {
+            varientUpdate.externalReference = marketplaceSku(varient);
+          }
          await editObject({
            model: listingVarientModel,
            id: varient._id,
-            updateData: { lastSyncedAt: new Date(), state: { type: 'active' } },
+            updateData: varientUpdate,
            user,
          }).catch(() => {});
        }
@ -359,7 +454,10 @@ export function deleteListing(marketplace, user, listingData) {
      logger.info(
        `Deleting listing from marketplace "${marketplace.name}" (${marketplace.provider})`
      );
-      await provider.deleteItem(authenticatedMarketplace, listingData);
+      const varients = listingData._id
+        ? await fetchListingVarients(listingData._id)
+        : [];
+      await provider.deleteItem(authenticatedMarketplace, listingData, varients);
      logger.info(`Background deleteListing complete for marketplace "${marketplace.name}"`);
    } catch (err) {
      logger.error(
@ -380,10 +478,29 @@ export function syncItems(marketplace, user) {
    try {
      const provider = getProvider(marketplace);
      const authenticatedMarketplace = await ensureMarketplaceAuth(marketplace, user);
+      const actor = marketplaceActor(authenticatedMarketplace);
      logger.info(
        `Starting item sync for marketplace "${marketplace.name}" (${marketplace.provider})`
      );

+      if (typeof provider.syncMarketplaceMetadata === 'function') {
+        try {
+          const metadataUpdates = await provider.syncMarketplaceMetadata(authenticatedMarketplace);
+          if (metadataUpdates && Object.keys(metadataUpdates).length) {
+            Object.assign(
+              authenticatedMarketplace,
+              await persistMarketplaceUpdate(authenticatedMarketplace, {}, metadataUpdates, user)
+            );
+          }
+        } catch (err) {
+          logger.warn(
+            `Failed to sync marketplace metadata for "${marketplace.name}": ${err.message}`
+          );
+        }
+      }
+
+      await importExternalItems(authenticatedMarketplace, provider, actor);
+
      const existingListings = await listingModel
        .find({
          marketplace: authenticatedMarketplace._id,
@ -428,6 +545,9 @@ export function syncItems(marketplace, user) {
          if (result?.url) {
            listingUpdateData.url = result.url;
          }
+          if (result?.externalReference) {
+            listingUpdateData.externalReference = result.externalReference;
+          }

          await editObject({
            model: listingModel,
@ -443,6 +563,9 @@ export function syncItems(marketplace, user) {
              updateData: {
                lastSyncedAt: new Date(),
                state: varient.state || { type: 'draft' },
+                ...(!varient.externalReference && marketplaceSku(varient)
+                  ? { externalReference: marketplaceSku(varient) }
+                  : {}),
              },
              user,
            }).catch(() => {});
@ -490,6 +613,7 @@ export function syncOrders(marketplace, user, { startTime, endTime } = {}) {
    try {
      const provider = getProvider(marketplace);
      const authenticatedMarketplace = await ensureMarketplaceAuth(marketplace, user);
+      const actor = marketplaceActor(authenticatedMarketplace);
      logger.info(
        `Starting order sync for marketplace "${marketplace.name}" (${marketplace.provider})`
      );
@ -502,75 +626,24 @@ export function syncOrders(marketplace, user, { startTime, endTime } = {}) {

      for (const externalOrder of externalOrders) {
        try {
-          const mapped = provider.mapOrderToSalesOrder(externalOrder);
-          const clientData = provider.mapBuyerToClient(externalOrder);
-
-          let client = await clientModel.findOne({
-            name: clientData.name,
-            marketplace: authenticatedMarketplace._id,
-          });
-
-          if (!client) {
-            client = await newObject({
-              model: clientModel,
-              newData: {
-                ...clientData,
-                marketplace: authenticatedMarketplace._id,
-                active: true,
-              },
-              user,
-            });
-            logger.debug(`Created client "${clientData.name}" from marketplace order`);
-          }
-
-          const existingOrder = await salesOrderModel.findOne({
-            marketplace: authenticatedMarketplace._id,
-            _reference: mapped.externalId,
-          });
-
-          if (existingOrder) {
-            await editObject({
-              model: salesOrderModel,
-              id: existingOrder._id,
-              updateData: {
-                state: mapped.state,
-                totalAmount: mapped.totalAmount,
-                totalAmountWithTax: mapped.totalAmountWithTax,
-                shippingAmount: mapped.shippingAmount,
-                shippingAmountWithTax: mapped.shippingAmountWithTax,
-                grandTotalAmount: mapped.grandTotalAmount,
-                totalTaxAmount: mapped.totalTaxAmount,
-                updatedAt: new Date(),
-              },
-              user,
-            });
+          const result = await upsertExternalOrder(
+            authenticatedMarketplace,
+            provider,
+            externalOrder,
+            actor
+          );
          results.push({
-              externalId: mapped.externalId,
-              action: 'updated',
-              id: existingOrder._id,
+            externalReference: result.externalReference,
+            action: result.action,
+            id: result.salesOrder?._id,
          });
-          } else {
-            const salesOrder = await newObject({
-              model: salesOrderModel,
-              newData: {
-                _reference: mapped.externalId,
-                client: client._id,
-                marketplace: authenticatedMarketplace._id,
-                state: mapped.state,
-                totalAmount: mapped.totalAmount,
-                totalAmountWithTax: mapped.totalAmountWithTax,
-                shippingAmount: mapped.shippingAmount,
-                shippingAmountWithTax: mapped.shippingAmountWithTax,
-                grandTotalAmount: mapped.grandTotalAmount,
-                totalTaxAmount: mapped.totalTaxAmount,
-              },
-              user,
-            });
-            results.push({ externalId: mapped.externalId, action: 'created', id: salesOrder._id });
-          }
        } catch (err) {
          logger.warn(`Failed to process order: ${err.message}`);
-          results.push({ externalId: externalOrder.id, action: 'error', error: err.message });
+          results.push({
+            externalId: externalOrder.id || externalOrder.orderId,
+            action: 'error',
+            error: err.message,
+          });
        }
      }

@ -589,3 +662,16 @@ export function syncOrders(marketplace, user, { startTime, endTime } = {}) {

  work();
 }
+
+export async function pushMarketplaceShipmentFulfillment(marketplace, user, shipment) {
+  const authenticatedMarketplace = await ensureMarketplaceAuth(marketplace, user);
+  const provider = getProvider(authenticatedMarketplace);
+  return pushShipmentFulfillment(
+    authenticatedMarketplace,
+    provider,
+    shipment,
+    marketplaceActor(authenticatedMarketplace)
+  );
+}
+
+export { marketplaceSku, marketplaceActor };
--- a/src/keycloak.js
+++ b/src/keycloak.js
@ -80,6 +80,20 @@ const isAuthenticated = async (req, res, next) => {
    }
  }

+  // CURL/sandbox helper: when MARKETPLACE_DEBUG_TOKEN is set, Bearer that token
+  // impersonates the oldest Mongo user. Disabled unless the env var is present.
+  if (process.env.MARKETPLACE_DEBUG_TOKEN && authHeader && authHeader.startsWith('Bearer ')) {
+    const token = authHeader.substring(7);
+    if (token === process.env.MARKETPLACE_DEBUG_TOKEN) {
+      const user = await userModel.findOne({}).sort({ createdAt: 1 }).lean();
+      if (user) {
+        req.user = { ...user, _objectType: 'user' };
+        req.session = { user, debug: true };
+        return next();
+      }
+    }
+  }
+
  const hostId = req.headers['x-host-id'];
  const authCode = req.headers['x-auth-code'];
  if (hostId && authCode) {
--- a/src/routes/management/courierservice.js
+++ b/src/routes/management/courierservice.js
@ -15,6 +15,7 @@ const listAllowedFilters = [
  'deliveryTime',
  'cost',
  'costWithTax',
+  'marketplaces.marketplace',
  'createdAt',
  'updatedAt',
  '_reference',
@ -41,6 +42,7 @@ const propertiesAllowedFilters = [
    'deliveryTime',
    'cost',
    'costWithTax',
+    'marketplaces.marketplace',
  ];
 import {
  listCourierServicesRouteHandler,
--- a/src/routes/sales/listings.js
+++ b/src/routes/sales/listings.js
@ -12,6 +12,7 @@ const listAllowedFilters = [
  'vendor._id',
  'stockLocation',
  'stockLocation._id',
+  'stockQuantity',
  'marketplace',
  'marketplace._id',
  'courierServices',
@ -25,6 +26,7 @@ const listAllowedSorters = [
  'title',
  'vendor',
  'state',
+  'stockQuantity',
  'price',
  'lastSyncedAt',
  'createdAt',
@ -35,6 +37,7 @@ const propertiesAllowedFilters = [
    'product',
    'vendor',
    'stockLocation',
+    'stockQuantity',
    'marketplace',
    'courierServices',
    'state',
--- a/src/routes/sales/listingvarients.js
+++ b/src/routes/sales/listingvarients.js
@ -12,18 +12,20 @@ const listAllowedFilters = [
  'product._id',
  'productSku',
  'productSku._id',
+  'stockQuantity',
  'state',
  'state.type',
  'createdAt',
  'updatedAt',
  '_reference',
 ];
-const listAllowedSorters = ['state', 'price', 'lastSyncedAt', 'createdAt', 'updatedAt', '_id'];
+const listAllowedSorters = ['state', 'stockQuantity', 'price', 'lastSyncedAt', 'createdAt', 'updatedAt', '_id'];
 const propertiesAllowedFilters = [
    'listing',
    'listing._id',
    'product',
    'productSku',
+    'stockQuantity',
    'state',
    'state.type',
    'createdAt',
--- a/src/routes/sales/marketplaces.js
+++ b/src/routes/sales/marketplaces.js
@ -26,7 +26,15 @@ const listAllowedSorters = [
  'updatedAt',
  '_id',
 ];
-const propertiesAllowedFilters = ['name', 'provider', 'active', 'connected', 'state.type', 'createdAt', 'updatedAt'];
+const propertiesAllowedFilters = [
+  'name',
+  'provider',
+  'active',
+  'connected',
+  'state.type',
+  'createdAt',
+  'updatedAt',
+];
 import {
  listMarketplacesRouteHandler,
  getMarketplaceRouteHandler,
@ -39,22 +47,39 @@ import {
  getMarketplaceAuthUrlRouteHandler,
  exchangeMarketplaceAuthCodeRouteHandler,
  refreshMarketplaceAuthRouteHandler,
+  syncMarketplaceRouteHandler,
  syncMarketplaceItemsRouteHandler,
  syncMarketplaceOrdersRouteHandler,
  marketplaceWebhookRouteHandler,
+  marketplaceWebhookChallengeRouteHandler,
+  subscribeMarketplaceWebhooksRouteHandler,
+  debugEbayRouteHandler,
  searchMarketplacesRouteHandler,
  getMarketplacePropertyValuesRouteHandler,
-
-  getMarketplaceNeighborsRouteHandler
+  getMarketplaceNeighborsRouteHandler,
 } from '../../services/sales/marketplaces.js';

 router.get('/', isAuthenticated, async (req, res) => {
  const { page, limit, property, search, sortProperty, sortOrder } = req.query;
  const filter = await getFilter(req.query, listAllowedFilters);
-  listMarketplacesRouteHandler(req, res, page, limit, property, filter, search, getSort(sortProperty, listAllowedSorters), sortOrder);
+  listMarketplacesRouteHandler(
+    req,
+    res,
+    page,
+    limit,
+    property,
+    filter,
+    search,
+    getSort(sortProperty, listAllowedSorters),
+    sortOrder
+  );
 });

-router.get('/properties', checkPermissions('marketplace', 'list'), isAuthenticated, async (req, res) => {
+router.get(
+  '/properties',
+  checkPermissions('marketplace', 'list'),
+  isAuthenticated,
+  async (req, res) => {
    let properties = convertPropertiesString(req.query.properties);
    const filter = await getFilter(req.query, propertiesAllowedFilters, false);
    var masterFilter = {};
@ -62,17 +87,27 @@ router.get('/properties', checkPermissions('marketplace', 'list'), isAuthenticat
      masterFilter = JSON.parse(req.query.masterFilter);
    }
    listMarketplacesByPropertiesRouteHandler(req, res, properties, filter, masterFilter);
-});
+  }
+);

-router.get('/values', checkPermissions('marketplace', 'list'), isAuthenticated, async (req, res) => {
+router.get(
+  '/values',
+  checkPermissions('marketplace', 'list'),
+  isAuthenticated,
+  async (req, res) => {
    const { property } = req.query;
    getMarketplacePropertyValuesRouteHandler(req, res, property);
-});
-router.get('/search', checkPermissions('marketplace', 'list'), isAuthenticated, async (req, res) => {
+  }
+);
+router.get(
+  '/search',
+  checkPermissions('marketplace', 'list'),
+  isAuthenticated,
+  async (req, res) => {
    const { search } = req.query;
    searchMarketplacesRouteHandler(req, res, search);
-});
-
+  }
+);

 router.post('/', isAuthenticated, checkPermissions('marketplace', 'new'), async (req, res) => {
  newMarketplaceRouteHandler(req, res);
@ -90,7 +125,10 @@ router.get('/:id/auth/url', isAuthenticated, async (req, res) => {
  getMarketplaceAuthUrlRouteHandler(req, res);
 });

-router.post('/:id/auth/exchange', isAuthenticated, async (req, res, next) => {
+router.post(
+  '/:id/auth/exchange',
+  isAuthenticated,
+  async (req, res, next) => {
    try {
      const allowed =
        (await hasPermission(req.user, 'marketplace', 'connect')) ||
@ -102,31 +140,92 @@ router.post('/:id/auth/exchange', isAuthenticated, async (req, res, next) => {
    } catch (err) {
      return next(err);
    }
-}, async (req, res) => {
+  },
+  async (req, res) => {
    exchangeMarketplaceAuthCodeRouteHandler(req, res);
-});
+  }
+);

-router.post('/:id/auth/refresh', isAuthenticated, checkPermissions('marketplace', 'refreshToken'), async (req, res) => {
+router.post(
+  '/:id/auth/refresh',
+  isAuthenticated,
+  checkPermissions('marketplace', 'refreshToken'),
+  async (req, res) => {
    refreshMarketplaceAuthRouteHandler(req, res);
-});
+  }
+);

-router.post('/:id/sync/items', isAuthenticated, checkPermissions('marketplace', 'syncListings'), async (req, res) => {
+router.post(
+  '/:id/sync',
+  isAuthenticated,
+  checkPermissions('marketplace', 'sync'),
+  async (req, res) => {
+    syncMarketplaceRouteHandler(req, res);
+  }
+);
+
+router.post(
+  '/:id/sync/items',
+  isAuthenticated,
+  checkPermissions('marketplace', 'sync'),
+  async (req, res) => {
    syncMarketplaceItemsRouteHandler(req, res);
-});
+  }
+);

-router.post('/:id/sync/orders', isAuthenticated, checkPermissions('marketplace', 'syncOrders'), async (req, res) => {
+router.post(
+  '/:id/sync/orders',
+  isAuthenticated,
+  checkPermissions('marketplace', 'sync'),
+  async (req, res) => {
    syncMarketplaceOrdersRouteHandler(req, res);
+  }
+);
+
+router.get('/:id/hook', async (req, res) => {
+  marketplaceWebhookChallengeRouteHandler(req, res);
+});
+router.get('/:id/ebay-challenge', async (req, res) => {
+  marketplaceWebhookChallengeRouteHandler(req, res);
 });

 // Webhook endpoint — no auth, provider verifies via signature
 router.post('/:id/hook', async (req, res) => {
  marketplaceWebhookRouteHandler(req, res);
 });
+router.post('/:id/ebay-webhook', async (req, res) => {
+  marketplaceWebhookRouteHandler(req, res);
+});
+
+router.post(
+  '/:id/webhooks/subscribe',
+  isAuthenticated,
+  checkPermissions('marketplace', 'connect'),
+  async (req, res) => {
+    subscribeMarketplaceWebhooksRouteHandler(req, res);
+  }
+);
+
+router.get('/:id/debug-ebay', isAuthenticated, async (req, res) => {
+  debugEbayRouteHandler(req, res);
+});
+router.get('/:id/debug/ebay', isAuthenticated, async (req, res) => {
+  debugEbayRouteHandler(req, res);
+});

 router.get('/neighbors', isAuthenticated, async (req, res) => {
  const { property, search, sortProperty, sortOrder, id } = req.query;
  const filter = await getFilter(req.query, listAllowedFilters);
-  getMarketplaceNeighborsRouteHandler(req, res, property, filter, search, getSort(sortProperty, listAllowedSorters), sortOrder, id);
+  getMarketplaceNeighborsRouteHandler(
+    req,
+    res,
+    property,
+    filter,
+    search,
+    getSort(sortProperty, listAllowedSorters),
+    sortOrder,
+    id
+  );
 });

 router.get('/:id', isAuthenticated, checkPermissions('marketplace', 'info'), async (req, res) => {
--- a/src/services/inventory/shipments.js
+++ b/src/services/inventory/shipments.js
@ -20,6 +20,9 @@ import {
 const logger = log4js.getLogger('Shipments');
 logger.level = config.server.logLevel;
 import { orderItemModel } from '../../database/schemas/inventory/orderitem.schema.js';
+import { salesOrderModel } from '../../database/schemas/sales/salesorder.schema.js';
+import { marketplaceModel } from '../../database/schemas/sales/marketplace.schema.js';
+import * as marketplaceIntegration from '../../integrations/marketplaceworker.js';

 export const listShipmentsRouteHandler = async (
  req,
@ -316,6 +319,30 @@ export const shipShipmentRouteHandler = async (req, res) => {
  }
  logger.debug(`Shipped shipment with ID: ${id}`);
  res.send(result);
+
+  const orderId = result.order?._id || result.order;
+  if (result.orderType === 'salesOrder' && orderId) {
+    salesOrderModel
+      .findById(orderId)
+      .lean()
+      .then(async (salesOrder) => {
+        if (!salesOrder?.marketplace) return;
+        const marketplace = await marketplaceModel.findById(salesOrder.marketplace);
+        if (!marketplace) return;
+        const shipment = await shipmentModel
+          .findById(id)
+          .populate('courierService')
+          .lean();
+        await marketplaceIntegration.pushMarketplaceShipmentFulfillment(
+          marketplace,
+          req.user,
+          shipment
+        );
+      })
+      .catch((err) => {
+        logger.warn(`Failed to push marketplace fulfillment for shipment ${id}: ${err.message}`);
+      });
+  }
  return;
 };

--- a/src/services/management/courierservice.js
+++ b/src/services/management/courierservice.js
@ -18,6 +18,8 @@ import {
 const logger = log4js.getLogger('CourierServices');
 logger.level = config.server.logLevel;

+const COURIER_SERVICE_POPULATE = ['courier', 'costTaxRate', 'marketplaces.marketplace'];
+
 export const listCourierServicesRouteHandler = async (
  req,
  res,
@ -38,7 +40,7 @@ export const listCourierServicesRouteHandler = async (
    search,
    sort,
    order,
-    populate: ['courier', 'costTaxRate'],
+    populate: COURIER_SERVICE_POPULATE,
  });

  if (result?.error) {
@ -63,7 +65,7 @@ export const listCourierServicesByPropertiesRouteHandler = async (
    properties,
    filter,
    masterFilter,
-    populate: ['courier', 'costTaxRate'],
+    populate: COURIER_SERVICE_POPULATE,
  });

  if (result?.error) {
@ -88,6 +90,7 @@ export const searchCourierServicesRouteHandler = async (req, res, search) => {
  const result = await searchObjects({
    model: courierServiceModel,
    search,
+    populate: COURIER_SERVICE_POPULATE,
  });
  res.send(result);
 };
@ -97,7 +100,7 @@ export const getCourierServiceRouteHandler = async (req, res) => {
  const result = await getObject({
    model: courierServiceModel,
    id,
-    populate: ['courier', 'costTaxRate'],
+    populate: COURIER_SERVICE_POPULATE,
  });
  if (result?.error) {
    logger.warn(`Courier service not found with supplied id.`);
@ -128,14 +131,14 @@ export const editCourierServiceRouteHandler = async (req, res) => {
    additionalCostWithTax: req.body?.additionalCostWithTax,
    shippingCurrency: req.body?.shippingCurrency,
    international: req.body?.international,
+    marketplaces: req.body?.marketplaces,
  };
-  // Create audit log before updating
  const result = await editObject({
    model: courierServiceModel,
    id,
    updateData,
    user: req.user,
-    populate: ['courier', 'costTaxRate'],
+    populate: COURIER_SERVICE_POPULATE,
  });

  if (result.error) {
@ -166,6 +169,7 @@ export const newCourierServiceRouteHandler = async (req, res) => {
    additionalCostWithTax: req.body?.additionalCostWithTax,
    shippingCurrency: req.body?.shippingCurrency,
    international: req.body?.international,
+    marketplaces: req.body?.marketplaces,
  };
  const result = await newObject({
    model: courierServiceModel,
--- a/src/services/sales/listings.js
+++ b/src/services/sales/listings.js
@ -25,6 +25,7 @@ import {
  deleteListing as deleteExternalListing,
  publishMarketplaceOfferForSku,
  withdrawMarketplaceOfferForSku,
+  marketplaceSku,
 } from '../../integrations/marketplaceworker.js';

 const logger = log4js.getLogger('Listings');
@ -159,7 +160,9 @@ export const editListingRouteHandler = async (req, res) => {
    stockLocation: req.body.stockLocation,
    marketplace: req.body.marketplace,
    title: req.body.title,
+    description: req.body.description,
    url: req.body.url,
+    condition: req.body.condition,
    courierServices: req.body.courierServices,
  };
  const result = await editObject({
@ -193,8 +196,10 @@ export const newListingRouteHandler = async (req, res) => {
    stockLocation: req.body.stockLocation,
    marketplace: req.body.marketplace,
    title: req.body.title,
+    description: req.body.description,
    state: req.body.state || { type: 'draft' },
    url: req.body.url,
+    condition: req.body.condition,
    courierServices: req.body.courierServices,
  };
  const result = await newObject({
@ -370,7 +375,7 @@ export const publishListingRouteHandler = async (req, res) => {
      const apiResult = await publishMarketplaceOfferForSku(
        marketplace,
        req.user,
-        v._reference,
+        marketplaceSku(v),
        listing
      );
      await editObject({
@ -464,7 +469,7 @@ export const unpublishListingRouteHandler = async (req, res) => {

  try {
    for (const v of toUnpublish) {
-      await withdrawMarketplaceOfferForSku(marketplace, req.user, v._reference);
+      await withdrawMarketplaceOfferForSku(marketplace, req.user, marketplaceSku(v));
      await editObject({
        model: listingVarientModel,
        id: v._id,
@ -531,4 +536,3 @@ export const getListingNeighborsRouteHandler = async (
  logger.debug(`Retrieved listing neighbors for ID: ${id}`);
  res.send(result);
 };
-
--- a/src/services/sales/listingvarients.js
+++ b/src/services/sales/listingvarients.js
@ -21,6 +21,7 @@ import {
  hasIntegration,
  publishMarketplaceOfferForSku,
  withdrawMarketplaceOfferForSku,
+  marketplaceSku,
 } from '../../integrations/marketplaceworker.js';

 const logger = log4js.getLogger('ListingVarients');
@ -306,7 +307,7 @@ export const publishListingVarientRouteHandler = async (req, res) => {
    const apiResult = await publishMarketplaceOfferForSku(
      marketplace,
      req.user,
-      doc._reference,
+      marketplaceSku(doc),
      doc.listing
    );

@ -415,7 +416,7 @@ export const unpublishListingVarientRouteHandler = async (req, res) => {
  }

  try {
-    await withdrawMarketplaceOfferForSku(marketplace, req.user, doc._reference);
+    await withdrawMarketplaceOfferForSku(marketplace, req.user, marketplaceSku(doc));

    await editObject({
      model: listingVarientModel,
--- a/src/services/sales/marketplaces.js
+++ b/src/services/sales/marketplaces.js
@ -257,6 +257,9 @@ export const exchangeMarketplaceAuthCodeRouteHandler = async (req, res) => {
    });

    logger.info(`Marketplace authorization completed for ${marketplace.name}`);
+    marketplaceIntegration.ensureWebhookSubscriptions(result.marketplace || marketplace, req.user).catch((err) => {
+      logger.warn(`Failed to subscribe marketplace webhooks for ${marketplace.name}: ${err.message}`);
+    });
    res.send({ success: true, ...result });
  } catch (err) {
    logger.error('Error exchanging marketplace authorization code:', err.message);
@ -289,6 +292,39 @@ export const refreshMarketplaceAuthRouteHandler = async (req, res) => {
  }
 };

+export const syncMarketplaceRouteHandler = async (req, res) => {
+  const id = req.params.id;
+
+  const marketplace = await getObject({ model: marketplaceModel, id });
+  if (marketplace?.error) {
+    logger.warn('Marketplace not found for sync.');
+    return res.status(marketplace.code).send(marketplace);
+  }
+
+  if (!marketplace.active) {
+    return res.status(400).send({ error: 'Marketplace is not active.', code: 400 });
+  }
+
+  if (!marketplaceIntegration.hasIntegration(marketplace.provider)) {
+    return res.status(400).send({
+      error: `No integration available for provider: ${marketplace.provider}`,
+      code: 400,
+    });
+  }
+
+  try {
+    const syncedMarketplace = await marketplaceIntegration.syncMarketplaceMetadata(
+      marketplace,
+      req.user
+    );
+    logger.info(`Marketplace metadata synced for ${marketplace.name}`);
+    res.send({ success: true, marketplace: syncedMarketplace });
+  } catch (err) {
+    logger.error(`Error syncing marketplace ${marketplace.name}:`, err.message);
+    res.status(400).send({ error: err.message, code: 400 });
+  }
+};
+
 export const syncMarketplaceItemsRouteHandler = async (req, res) => {
  const id = req.params.id;

@ -361,27 +397,88 @@ export const marketplaceWebhookRouteHandler = async (req, res) => {
  }

  const signature =
-    req.headers['x-tts-signature'] ||
    req.headers['x-ebay-signature'] ||
+    req.headers['x-tts-signature'] ||
    req.headers['x-signature'] ||
    '';
-  const rawBody = JSON.stringify(req.body);
-
-  if (signature && marketplaceIntegration.canVerifyWebhookSignature(marketplace)) {
-    const valid = marketplaceIntegration.verifyWebhookSignature(marketplace, rawBody, signature);
-    if (!valid) {
-      logger.warn(`Invalid webhook signature for marketplace ${marketplace.name}`);
-      return res.status(401).send({ error: 'Invalid signature.', code: 401 });
-    }
-  }
+  const rawBody = req.rawBody || JSON.stringify(req.body);

  try {
-    const result = await marketplaceIntegration.handleWebhook(marketplace, req.body);
+    const result = await marketplaceIntegration.handleWebhook(marketplace, req.body, {
+      rawBody,
+      signature,
+    });
    logger.info(`Webhook processed for marketplace ${marketplace.name}: ${result.action}`);
    res.send({ success: true, ...result });
  } catch (err) {
    logger.error('Error processing marketplace webhook:', err.message);
-    res.status(500).send({ error: err.message, code: 500 });
+    res.status(err.status || 500).send({ error: err.message, code: err.status || 500 });
+  }
+};
+
+export const marketplaceWebhookChallengeRouteHandler = async (req, res) => {
+  const id = req.params.id;
+  const marketplace = await getObject({ model: marketplaceModel, id });
+  if (marketplace?.error) {
+    return res.status(404).send({ error: 'Marketplace not found.', code: 404 });
+  }
+
+  const challengeCode = req.query.challenge_code || req.query.challengeCode;
+  const endpoint =
+    marketplace.config?.webhookUrl ||
+    `${req.protocol}://${req.get('host')}/marketplaces/${id}/hook`;
+
+  try {
+    const result = marketplaceIntegration.buildWebhookChallengeResponse(marketplace, {
+      challengeCode,
+      endpoint,
+    });
+    if (!result) {
+      return res.status(400).send({ error: 'Provider does not support webhook challenges.', code: 400 });
+    }
+    res.send(result);
+  } catch (err) {
+    logger.error('Error handling webhook challenge:', err.message);
+    res.status(400).send({ error: err.message, code: 400 });
+  }
+};
+
+export const subscribeMarketplaceWebhooksRouteHandler = async (req, res) => {
+  const id = req.params.id;
+  const marketplace = await getObject({ model: marketplaceModel, id });
+  if (marketplace?.error) {
+    return res.status(marketplace.code).send(marketplace);
+  }
+  try {
+    const result = await marketplaceIntegration.ensureWebhookSubscriptions(marketplace, req.user);
+    res.send({ success: true, ...result });
+  } catch (err) {
+    logger.error('Error subscribing marketplace webhooks:', err.message);
+    res.status(400).send({ error: err.message, code: 400 });
+  }
+};
+
+export const debugEbayRouteHandler = async (req, res) => {
+  const id = req.params.id;
+  const marketplace = await getObject({ model: marketplaceModel, id });
+  if (marketplace?.error) {
+    return res.status(marketplace.code).send(marketplace);
+  }
+  if (marketplace.provider !== 'ebay') {
+    return res.status(400).send({ error: 'Debug eBay proxy is only available for eBay marketplaces.', code: 400 });
+  }
+  if (marketplace.config?.sandbox !== true) {
+    return res.status(400).send({ error: 'eBay debug proxy is sandbox-only.', code: 400 });
+  }
+  try {
+    const path = req.query.path || '/sell/inventory/v1/inventory_item';
+    const data = await marketplaceIntegration.debugMarketplaceGet(marketplace, req.user, path, {
+      limit: req.query.limit || 1,
+    });
+    res.send({ success: true, data });
+  } catch (err) {
+    logger.error('eBay debug GET failed:', err.message);
+    res.status(400).send({ error: err.message, code: 400 });
  }
 };
 export const getMarketplaceNeighborsRouteHandler = async (
--- a/src/utils.js
+++ b/src/utils.js
@ -16,6 +16,7 @@ import { Worker } from 'worker_threads';
 import path from 'path';
 import { fileURLToPath } from 'url';
 import { diffJson } from 'diff';
+import { resolveAuditOwner, actorDisplayName } from './auditOwner.js';

 const __dirname = path.dirname(fileURLToPath(import.meta.url));

@ -1064,7 +1065,7 @@ function getChangedValues(oldObj, newObj, old = false) {
  return changes;
 }

-const AUDIT_EXCLUDED_MODELS = ['notification', 'userNotifier'];
+const AUDIT_EXCLUDED_MODELS = ['notification', 'userNotifier', 'marketplaceEvent'];
 const SENSITIVE_KEYS = ['secret'];

 const DISTRIBUTE_KEYS = {
@ -1101,8 +1102,7 @@ async function newAuditLog(newValue, parentId, parentType, user) {
    },
    parent: parentId,
    parentType,
-    owner: user._id,
-    ownerType: 'user',
+    ...resolveAuditOwner(user),
    operation: 'new',
  });

@ -1130,8 +1130,7 @@ async function editAuditLog(oldValue, newValue, parentId, parentType, user) {
    },
    parent: parentId,
    parentType,
-    owner: user._id,
-    ownerType: 'user',
+    ...resolveAuditOwner(user),
    operation: 'edit',
  });

@ -1153,7 +1152,7 @@ async function editNotification(oldValue, newValue, parentId, parentType, user)
  await notfiyObjectUserNotifiers(
    parentId,
    parentType,
-    `${objectName} edited by ${user?.firstName ?? 'unknown'} ${user?.lastName ?? ''}`,
+    `${objectName} edited by ${actorDisplayName(user)}`,
    `The ${parentType} ${parentId} has been updated.`,
    'editObject',
    {
@ -1163,8 +1162,8 @@ async function editNotification(oldValue, newValue, parentId, parentType, user)
      object: { _id: String(parentId ?? '') },
      user: {
        _id: String(user?._id ?? ''),
-        firstName: user.firstName,
-        lastName: user.lastName,
+        firstName: user?.firstName ?? user?.name ?? '',
+        lastName: user?.lastName ?? '',
      },
    }
  );
@ -1179,8 +1178,7 @@ async function deleteAuditLog(deleteValue, parentId, parentType, user) {
    },
    parent: parentId,
    parentType,
-    owner: user._id,
-    ownerType: 'user',
+    ...resolveAuditOwner(user),
    operation: 'delete',
  });

@ -1195,14 +1193,18 @@ async function deleteNotification(object, parentId, parentType, user) {
  await notfiyObjectUserNotifiers(
    parentId,
    parentType,
-    `${objectName} deleted by ${user?.firstName ?? 'unknown'} ${user?.lastName ?? ''}`,
+    `${objectName} deleted by ${actorDisplayName(user)}`,
    `The ${parentType} ${parentId} has been deleted.`,
    'deleteObject',
    {
      object: omitSensitive(object),
      objectType: parentType,
      object: { _id: parentId },
-      user: { _id: user._id, firstName: user.firstName, lastName: user.lastName },
+      user: {
+        _id: user?._id,
+        firstName: user?.firstName ?? user?.name ?? '',
+        lastName: user?.lastName ?? '',
+      },
    }
  );
 }
@ -1213,7 +1215,7 @@ async function newNoteNotification(note, user) {
  await notfiyObjectUserNotifiers(
    note.parent,
    note.parentType,
-    `New note added to ${objectName.toLowerCase()} by ${user?.firstName ?? 'unknown'} ${user?.lastName ?? ''}`,
+    `New note added to ${objectName.toLowerCase()} by ${actorDisplayName(user)}`,
    `A new note has been created.`,
    'newNote',
    {
@ -1233,8 +1235,7 @@ async function subscribeAuditLog(parentId, parentType, user) {
  const auditLog = new auditLogModel({
    parent: parentId,
    parentType,
-    owner: user._id,
-    ownerType: 'user',
+    ...resolveAuditOwner(user),
    operation: 'subscribe',
  });
  await auditLog.save();
@ -1246,8 +1247,7 @@ async function unsubscribeAuditLog(parentId, parentType, user) {
  const auditLog = new auditLogModel({
    parent: parentId,
    parentType,
-    owner: user._id,
-    ownerType: 'user',
+    ...resolveAuditOwner(user),
    operation: 'unsubscribe',
  });
  await auditLog.save();
@ -1811,4 +1811,6 @@ export {
  jsonToCacheKey,
  subscribeAuditLog,
  unsubscribeAuditLog,
+  resolveAuditOwner,
+  actorDisplayName,
 };