Agent Agent is shorthand for database agent. A database Agent is the only database-specific component in OpenLink's Multi-Tier architecture. In fact, these agents are built against a database's CLI. When the OpenLink Request Broker receives a connection request, it spawns the appropriate agent. Then, the agent retrieves data from the database and returns it to the calling client.Note: Agents connect directly to the database in a standard Two-Tier or "Client/Server" configuration. However, most agents connect to the database via the database native libraries in a Three-Tier or "Application Server" configuration. MS SQLServer, MySQL, and PostgreSQL agents are the exception. They connect directly to the database in both Client/Server and Application Server configurations.