A Cargo Service Agent (CSA) is a person or company that acts as a representative for an airline or other cargo carrier. They are responsible for handling all aspects of cargo operations for the carrier at a specific airport or location, including cargo sales, handling, warehousing, and transportation.

CSA's typically represent the cargo carrier at an airport and provides a full range of cargo services to shippers and consignees, including air freight forwarding, warehousing, documentation, and handling of special cargo. They also help with the coordination of cargo flights and the handling of freight at the airport, including the loading and unloading of cargo onto aircrafts.

In general, the main role of a CSA is to act as a link between the carrier and its customers, by facilitating the movement of goods and providing necessary information to the parties involved in the cargo operations. This includes but not limited to booking cargo space, arranging for the necessary documents, customs clearance, and arranging transportation.

Some Cargo Service Agents (CSA) also offer additional services such as freight forwarding, warehousing, and logistics management, making it easier for customers to handle all aspects of their shipping needs through one point of contact.