Product Sync

This guide covers how product and offer listings flow from JTL-Wawi to your channel, how to report listing status back to sellers, and how to keep stock levels synchronized.

Listing Sync Flow

Listings are transmitted by the Seller:Offer.New and Seller:Offer.Update events. Each time listing data changes, JTL-Wawi transmits the entire listing again.

Essential Properties

It is generally not necessary to provide attributes for essential data, as each listing already implements a set of essential properties by default, including title, description, GTIN, quantity, and price.

Pictures and Images

Product or listing images are transmitted as a link along with the listing event.

Image links have a lifetime of 7 days after the listing event was triggered. Make sure to download and store images if you need them beyond that period.

The filename is generated based on the file content, so each separate image will have a unique filename derived from its content.

Listing State

We recommend informing the seller about the processing status of their listings. Most marketplaces use an asynchronous listing process during which the listing data is curated in a semi-automated process that may take some time. The three states are reported through their own endpoints.

In-Progress
Successful
Failed

Send this state to inform the seller that the listing process is now in progress:

// POST /v1/channel/offer/in-progress
{
  "offerList": [
    {
      "offerId": 1,
      "sellerId": "1",
      "startedAt": "2022-11-28T01:00:13+00"
    }
  ]
}

Inform the seller once a listing is successfully listed on the connected marketplace. The optional listingUrl allows the seller to visit and directly check the listing.

// POST /v1/channel/offer/listed
{
  "offerList": [
    {
      "sellerId": "1",
      "offerId": 1,
      "listedAt": "2022-11-28T01:00:13+00",
      "listingUrl": "https://marketplace.de/offer1",
      "channelOfferId": "AFGHDHDFH"
    }
  ]
}

You need to inform the seller if the listing process for a listing failed:

// POST /v1/channel/offer/listing-failed
{
  "offerList": [
    {
      "sellerId": "1",
      "offerId": 1,
      "errorList": [
        {
          "code": "123",
          "message": "A listing error occurred",
          "longMessage": "A serious listing error occurred."
        }
      ],
      "failedAt": "2019-02-09T05:33:12+00:00"
    }
  ]
}

Stock Updates

The Stock Updates API enables channels to keep their inventory synchronized with seller stock levels.

Available Methods

There are multiple ways to synchronize stock:

Method	Endpoint	Use Case
Per-seller	`GET /v1/channel/offer/stock-updates`	Parallel per-seller processing. Higher rate limit.
All sellers	`GET /v1/channel/offer/stock-updates/all`	Get stock changes for all active sellers in a single call.
Event-based	`Seller:Offer.StockUpdate` event	Consuming the seller event directly.

Use the stock update endpoints rather than the Seller:Offer.StockUpdate event. The event remains available, but the dedicated endpoints are the supported path for stock synchronization.

Example Request and Response

The following request retrieves stock changes for all active sellers since a given timestamp.

// GET /v1/channel/offer/stock-updates/all?updatedAfter=2025-12-29T00:00:00+00:00
{
  "stockUpdateList": [
    {
      "channel": "MYCHANNEL",
      "sellerId": "SELLER001",
      "offerId": 4711,
      "channelOfferId": "SKU-WIDGET-001",
      "quantity": 25,
      "updatedAt": "2025-12-29T10:15:30+00:00"
    },
    {
      "channel": "MYCHANNEL",
      "sellerId": "SELLER002",
      "offerId": 8822,
      "channelOfferId": "SKU-GADGET-042",
      "quantity": 0,
      "updatedAt": "2025-12-29T11:22:45+00:00"
    }
  ],
  "lastUpdatedAt": "2025-12-29T11:22:45+00:00"
}

Incremental Sync Pattern

Use the lastUpdatedAt cursor from each response to fetch only the changes since your last call.

For efficient synchronization, use the lastUpdatedAt value from the response as the updatedAfter parameter in your next request.

1. First call:    GET /v1/channel/offer/stock-updates/all?updatedAfter=2025-12-01T00:00:00Z
   Response:      lastUpdatedAt = "2025-12-29T11:22:45+00:00"

2. Next call:     GET /v1/channel/offer/stock-updates/all?updatedAfter=2025-12-29T11:22:45+00:00
   Response:      lastUpdatedAt = "2025-12-29T14:30:00+00:00"

3. Continue...

What’s Next?

Order Management

Handle orders, cancellations, returns, and refunds.

Channel API Overview

Review events, metadata, and media content handling.

Seller Management

Seller sign-up, update, and unlink flows.

Rate Limits

Per-endpoint quotas and 429 handling.

Channel API Reference

Endpoint-level reference for the Channel API.

Postman Collection

Try the API with ready-made requests.

Essentials

Cloud Apps

Marketplace Channels

ERP Integration

Vouchers API

Listing Sync Flow

Essential Properties

Pictures and Images

Listing State

Stock Updates

Available Methods

Example Request and Response

Incremental Sync Pattern

What’s Next?

Order Management

Channel API Overview

Seller Management

Rate Limits

Channel API Reference

Postman Collection

​Listing Sync Flow

​Essential Properties

​Pictures and Images

​Listing State

​Stock Updates

​Available Methods

​Example Request and Response

​Incremental Sync Pattern

​What’s Next?

Order Management

Channel API Overview

Seller Management

Rate Limits

Channel API Reference

Postman Collection

Listing Sync Flow

Essential Properties

Pictures and Images

Listing State

Stock Updates

Available Methods

Example Request and Response

Incremental Sync Pattern

What’s Next?