This presentation will discuss the implementation of the CSW endpoint using pycsw within the Data.gov infrastructure (architecture/enhancements/testing/deployment) and CKAN, which powers Data.gov.CSW (Catalogue Service for the Web) is an OGC (Open Geospatial Consortium) specification that defines common interfaces to discover, browse, and query metadata about data, services, and other potential resources.Data.gov provides access to its catalog via the CSW standard for both first-order and all metadata for harvested data, services and applications. Data may be referenced from federal, state, local, tribal, academic, commercial, or non-profit organizations. The first-order CSW endpoint provides collection level filtering of all metadata records. The all metadata CSW endpoint provides all levels of metadata at varying levels of granularity.Any client supporting CSW (desktop, GIS, web application, client library, etc.) can integrate the Data.gov CSW endpoints.