Flex/AMF uses a binary packet-oriented protocol that is passed with HTTP POST requests. This packet format is called Action Message Format (AMF). The Flex/AMF application sends AMF packets to the server in the bodies of HTTP POST requests. The server responds with AMF packets in the bodies of HTTP responses. Both the HTTP requests and the responses contain the Content-Type HTTP header with the value application/x-amf.
HTTP requests that carry AMF packets are recorded with the function WebPagePost. The URL to be used is recorded as the first parameter of the function, the AMF packet to be sent is recorded as the second parameter.
In scripts, logs, and TrueLogs, Silk Performer does not display binary AMF packets in their original binary format. Instead, an XML based textual representation is used. The conversion from this textual representation to binary AMF and vice versa is done transparently by the recorder and replay. Binary AMF can only be seen in the textual log if the appropriate logging options are enabled.
The advantage of this is that AMF packets are easy to read, understand and customize. AMF packets are also rendered using the XML tree view in TrueLog Explorer, and can be customized there in the same way that all XML data can be customized.