Google AdSense provides a free, flexible way to earn money from your websites, mobile sites, and site search results with relevant and engaging ads.

AdSense Management API

Intended for individual developers who want to get reports on AdSense earnings and manage AdSense inventory.

AdSense Host API

Intended for developers whose users create their own content through blogging, web publishing, forum/wiki/community creation, or any other application where substantial web content is generated. This API is only available to Host partners.