eCAP is a software interface that allows a network application, such as an HTTP proxy or an ICAP server, to outsource content analysis and adaptation to a loadable module. For each applicable protocol message being processed, an eCAP-enabled host application supplies the message details to the adaptation module and gets back an adapted message, a "not interested" response, or a "block this message now!" instruction. These exchanges often include message bodies. The adaptation module can also exchange meta-information with the host application to supply additional details such as configuration options, a reason behind the decision to ignore a message, or a detected virus name. If you are familiar with the ICAP protocol , then you may think of eCAP as an "embedded ICAP", where network interactions with an ICAP server are replaced with function calls to an adaptation module.