The SITA FlightFollower API streams live map images of routes for progressing flights. It allows users to search information on the basis of departure or arrival airports, flight number, or airline number. Developers must request API keys to be able to access this API. Its success is currently restricted to invited developers; contact Ashish.Kapoor@sita.aero to request access. The API that returns images in GIF format passes authentication key in HTTP header.