A cache server receives content and an instruction indicating an event associated with the content that causes a processor to invoke a call out to an adjunct device. The instruction further indicates an operation that the adjunct device is to perform. The cache server detects the event associated with the content, halts a flow of the content in response to detecting the event associated with the content, passes via the call out the content to the adjunct device to perform the operation, receives from the adjunct device a response and resulting data from the operation, and performs an additional operation on the resulting data based on the response from the adjunct device.