An agent is a process that runs on target host and communicates with the Serena Release Automation server. Agents are integral to Serena Release Automation's client/server architecture. Agents perform the actual work of deploying components and so relieves the server from the task, making large deployments involving thousands of targets possible.

Typically, an agent runs on the same host where the resources it handles are located. A single agent can handle all resources on its host. If a host has several resources, an agent process is invoked separately for each resource. For example, a test environment might contain a single web server, a single middleware server, and a single database server all running on the same host (machine). A deployment to this environment might have one agent and three separate resources.

Depending on the number of hosts in an environment, a deployment might require a large number of agents. Agents are unobtrusive and secure. Agent communications use SSL encryption and mutual key-based authentication. For added security, agents do not listen to ports, but open direct connections to the server instead.