The Endeca Assembler API enables an application to query external data sources and retrieve content based on a user's navigation state or other triggers. By default, it includes functionality for querying an MDEX Engine and returning query results as well as a content item object that encapsulates the page configuration specified by the content administrator. All the content for a page, including the results of any additional queries needed for spotlighting or merchandising, are wrapped in the content item object, simplifying the logic in the front-end application by reducing the need to manage sub-queries in the application layer.

The Endeca Assembler API also incorporates the URL Optimization API which enables you to create application URLs that are optimized for internet search engines. In particular, the API provides the capability to shorten and canonicalize URLs and add search and navigation keywords to URLs. The resulting URLs are more optimized for internet search engines and more understandable to front-end application users.

The core cartridges and the Discover Electronics reference application use the URL Optimization API in conjunction with the Endeca Assembler to produce search-engine optimized URLs. In this scenario, the reference application uses a configuration file to both enable the URL Optimization API and to produce search-engine optimized URLs. By default, the reference application does not use the URL Optimization API. You have to explicitly enable it.