AS4 (Applicability Statement 4) was developed for ebXML messaging services by OASIS (the Organisation for the Advancement of Structured Information Standards).

A Closer Look At AS4:

AS4 is a communication protocol that has been designed specifically to facilitate the exchange of business data over the internet which was developed for ebXML messaging services by OASIS (Organisation for the Advancement of Structured Information Standards)

AS4 is HTTP-based, with messages sent over AS4 having a specific format that is handled by AS4 software. Both successful and unsuccessful message transfers receive a receipt allowing the sender to know if the transfer has succeeded.