The vSphere check is packaged with the Agent, so simply install the Agent on your vCenter server, or configure it to point to a vCenter server on the network. This check collects resource usage metrics from your vSphere cluster—CPU, disk, memory, and network usage. It also watches your vCenter server for events and emits them to Datadog.
You will be charged for each agent installed on a vCenter server.
For more on monitoring vSphere, please see our blog post.