OnStar will give selected developers access to a proprietary application program interface (API) to create mobile applications designed to interact with OnStar’s suite of services, according to a Jan. 8 press release from General Motors Corp.

OnStar services are enabled by its Advanced Telematics Operating Management System (ATOMS), which is an automotive cloud platform that connects to more than six million OnStar customers. Apps created using the API will deliver services and functionality in the same manner.

“Research shows that the amount of mobile applications for the Android and iOS platforms is likely to double in the next 12 months,” said OnStar President Linda Marshall. “Customer demand is driving a new marketplace for a variety of automotive applications. With this step we believe we can broaden our portfolio, grow our business and enable our customers to achieve additional functionality from their vehicle using their computer, smartphone, tablet or other devices.”

The first partner to use OnStar’s API will be RelayRides, the peer-to-peer car-sharing company that holds an exclusive partnership with GM. With RelayRides, millions of GM vehicle owners will soon be able to leverage OnStar to rent out their idle cars with the owner controlling the rates and availability of the car. By using the OnStar API, RelayRides will allow its renters to use remote features with their smartphones, such as unlocking GM vehicles to access a reserved car.

“Through our work with OnStar, we are jointly defining the cutting edge of smart mobility,” said RelayRides Founder and Chief Community Officer Shelby Clark. “With access to the OnStar API, car sharing has never been safer or more convenient. We are looking forward to rolling out the program in early 2012.”

Internal research of OnStar’s customer base revealed that emergency and security services are most important to customers followed by navigation, vehicle information and diagnostics. OnStar will continue to develop and expand services in these areas, but the proprietary application interface could lead to a further-customized experience for many customers.

In the past, OnStar has worked on API-based solutions with companies like MapQuest and Google to provide the company’s eNav service. An API solution was also used in the company’s beta test of Facebook Audio Updates.

OnStar will make its closed API available in the first half of 2012. Developers interested in the API should contact OnStar at developers@onstar.com.

More information about OnStar can be found at www.onstar.com.