Yandex is the largest search engine in Russia and develops a number of Internet-based services and products. Yandex offers owners of websites and blogs tools with which they can apply the functional services of Yandex in their projects.
The Yandex Direct API allows developers to create applications which directly interact with the Yandex contextual advertising service. These applications allow advertising agencies as well as direct advertisers to run complex large-scaled advertising campaigns. It uses SOAP protocol and responses are formatted in JSON.