This is a guide of selected resources that have API's and bulk downloading. It focuses on primarily federal and some very selected state data and includes some resources to which the library does not subscribe (noted with $$$). Government data and legal information at the federal, state and local level is becoming increasingly available as API's and in bulk downloadable formats. When visiting websites, information about bulk downloading and API's often appears on a "developer's" or "API" page.
Licenses sometimes have limitations regarding programming around their interfaces. Some completely prohibit or have limits on large downloads and some offer services for an additional negotiated fee/access. See particular vendors and their licenses for restrictions.
For data resources generally, see our guide Statistical and Data-Related Resources.