# Use of the API by data users
The use of the NADA API for catalog administration has been documented in multiple sections of the Administrator's Guide. Some API functions are also accessible to the public. This section describes the public-facing functionalities of the API.
When a NADA catalog is published, a web page must provide all necessary documentation (technical and legal) to users.
[restrictions apply?]
# Getting metadata via API
How to query the catalog to extract metadata
# Getting data via API
Catalog administrators may decide to make some data accessible to users via API. In such case, the data are stored in the web server in a MongoDB database. Visitors to the catalog can query and access the data using the API as described below. Note that access restrictions may apply.