Tuna Marketplace Integration: How to Keep Stock, Orders and Prices in Sync
If you sell on Amazon, Etsy or other marketplaces alongside your own online store, you probably spend part of every day doing the same work over and over: reducing stock on one channel after a sale on another, copying orders into your shipping panel one by one, and updating prices separately on every channel during a campaign. As sales grow, this manual work turns into lost time and costly mistakes.
In this post we explain what marketplace integration is, which data needs to be synced and what to watch for in a healthy setup.
What does marketplace integration mean?
Most marketplaces offer sellers an API (application programming interface). Integration means your store or stock software talks to that API automatically. Product data, stock, prices and orders move between channels without anyone touching them.
The goal is simple: manage everything from one place. You define a product once, keep stock in one place and see all orders on one screen.
Which data should be synced?
- Stock: The most critical data. When a product sells on one channel, stock must drop on the others immediately; otherwise you sell items you no longer have and must cancel orders. Cancellations hurt both customer satisfaction and your seller rating.
- Price: You can set channel-specific price rules, for example keeping the marketplace price a certain percentage above your store price to cover commission.
- Orders: Marketplace orders land in your panel; shipping labels and invoicing run from one place.
- Product data: Title, description, images, variants (size, color) and category mapping. Every marketplace has its own category tree and required fields; this mapping must be done right once.
- Shipping and invoice status: Tracking numbers and invoice details are reported back to the marketplace.
The hidden cost of doing it by hand
With a few orders a day, manual syncing seems manageable. During campaigns, especially when the same product sells on several channels at once, stock differences grow fast. The cost is not just hours: oversell cancellations, orders at the wrong price and late shipments directly hit revenue and store ratings.
5 steps to a healthy integration
- Pick a single source of stock. Will stock live in your store or in your accounting/ERP software? The right answer is one place.
- Clean up product codes (SKU/barcode). The backbone of integration is every product and variant being recognized by the same code on all channels.
- Map categories and attributes. Filling in the marketplace's required fields up front prevents rejected listings.
- Write price rules. Set channel rules that account for commission, shipping and campaign discounts.
- Set up errors and alerts. What happens when an API is temporarily unavailable? A good integration logs the error, retries and alerts you when needed.
Off-the-shelf connector or custom integration?
There are subscription-based connector tools that can be a good start for standard needs. But if you have a specific stock structure, a custom-built store, or a flow that must also talk to your accounting software, an integration built for your needs is more flexible and often more economical in the long run.
Conclusion
Marketplace integration is the essential infrastructure of multi-channel selling. Set up correctly, it eliminates stock errors, speeds up orders and frees your team to focus on selling. If you would like us to review your setup and find the right path together, see our E-commerce & Marketplace and API Integrations services or check our packages.
