Galactic City Authority was the government of Galactic City, Coruscant during the time of the Galactic Alliance. They were in charge of all the public works operations and other government agencies on Coruscant and presumably collected taxes to fund other planetary organizations such as the Coruscant Police and Coruscant Fire and Rescue. They also had an incident command room deep under the Senate Building where emergencies affecting Galactic City could be dealt with.