The Sync API lets you connect to the Sell synchronization layer, in the same way our mobile devices do, which allows them to keep their local data up to date with Sell.

There is no need to track data changes on your side, nor to download all the data every time you want to carry out analysis. You can use the Sync API as a single point for all your data, and to sync with changes that occur in Sell.

The Sync service is optimized for getting fresh data as fast as possible. The service favors availability over consistency and provides eventual consistency guarantees. It means it does not guarantee order of data, but you can be sure the data will eventually arrive and the communication protocol is designed in such a way that you can't lose the data.

By allowing multiple simultaneous connections, the Sync API allows for fast, multithreaded and multiprocess download of data that cuts heavily on polling and time needed to download the data from our servers.

The API provides a single entry point for all your data, and exposes a simple, HTTP-based, stateful, JSON-formatted interface you can interact with.

For authorization and authentication we embrace OAuth 2 protocol across all our APIs. The Sync API is no exception. You can reuse the same access token across all of them.

The Sync API is a premium Sell API. Check out pricing and rate limits to get pricing details.

The Protocol

This section gives you an overview of how the Sync communication protocol works and how you can leverage the protocol to keep up with changes.


In this section you will learn everything required to build integration on top of the Sync API. You will learn how to make a full synchronization flow.


The reference library of resources and actions that are exposed via the Sync API.


Learn the ins and outs of the API.


Use the following endpoint to communicate with the Sync API.