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
AdSense Host API
The Google AdSense Management API is intended for individual developers who want to get reports on AdSense earnings and manage AdSense inventory. To familiarize yourself with the API, read the Getting Started guide or the reference pages.
The Google AdSense Host API is 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.