RESTful (Representational State Transfer) APIs allow for access of data over HTTPS. The CD3 REST API currently supports GET requests to programmatically query and retrieve program and project information as well as data for individual projects. Responses conform to JSON (JavaScript Object Notation) standards.

In addition to retrieving data stored in SFEI's Regional Data Center (RDC), you can access data uploaded to other California Environmental Data Exchange Network (CEDEN) RDCs.

The CD3 REST API is registered with the USEPA's Reusable Component Services.