Sync Gateway is the synchronization server in a Couchbase Mobile deployment. It is designed to provide data synchronization for large-scale interactive web, mobile, and IoT applications — see: Figure 1.
As you can see from Figure 1 Sync Gateway synchronizes changes made by web clients through its REST API, Couchbase Lite mobile-device applications, and Couchbase Server buckets.
You can read more about the Data Synchronization process in Sync with Couchbase Server. Some of its most central, and commonly used features, are those used to ensure secure Access Control.
Sync Gateway assures secure access control using:
Data Routing, which ensures that authorized users can only access documents in those Channels assigned to them and only in accordance with their assigned privileges. You can set those privileges to confer Read Access and-or Write Access as required.
The business logic behind the validation and authorization of document access is provided by the customizable Sync Function.