A discussion is provided of the large scale business-to-business (B2B) Web services environment created and used by Amazon.com and partners. The mission critical system is scaled for hundreds of partners. Through the use of eXtensible Markup Language (XML) schemas that define the structure of documents to be exchanged, with Hypertext Transport Protocol (HTTP) Secure as the transport protocol and SwA (SOAP with Attachments) as the communication protocol, critical transport requirements are handled. Amazon publishes to its third party sellers the XSD specification for each message sent and received by Amazon. The third-party seller need only implement the XSD, extract product data, transform it according to the XSD, and post it to Amazon with a Simple Object Access Protocol (SOAP) message over HTTPS. Services encapsulated in the Amazon interface give the partner substantial flexibility in integration design and allows easy incorporation of different systems. All exchanges use HTTPS and require three credentials for validation against an existing account. Such business-critical documents as order reports are exchanged because an exchange acknowledgement is included. The first operation is a service requirement for existing document IDs. Several steps may be required to complete a document exchange, at which point a return result will be the physical document represented by an ID.