Abstract: Various exemplary embodiments relate to method performed by a router. The method may include: receiving a HTTP GET request from a user device; forwarding the HTTP GET request; receiving a response to the HTTP GET request; determining whether to intercept the response based on flow selection criteria; and replacing the response with a modified response. Various exemplary embodiments relate to a router including a plurality of line cards interconnected by a backplane, the plurality of line cards receiving communication packets; and an application assurance card connected to the backplane and configured to detect application traffic flows among the communication packets, identify a HTTP session including a HTTP GET request and a matching response from among the packets; determine whether the HTTP session meets selection criteria; and modify the response to include a command to execute a script located on a notification server responsive to the HTTP session meeting the criteria.