# NEST Data source API
The NEST Data source API provides a way for NEST to interact with several data sources.
Each data source should implement the `DataSource` trait and expose the `DataSourceApi` to enable NEST to interact with it.
The data source API is built on top of the `actix-web` framework and uses the `actix-web-httpauth` middleware for authentication, with a simple authentication token.
The API can either be run as a standalone server or included in a larger `actix-web` application.
Under the hood, the data source API uses the `paas-client` to pseudonymize data between NEST and the data source.