# SOAP SOAP is a standard protocol that was first designed so that applications built with different languages and on different platforms could communicate. Because it is a protocol, it imposes built-in rules that increase its complexity and overhead, which can lead to longer page load times. However, these standards also offer built-in compliances that can make it preferable for enterprise scenarios. The built-in compliance standards include security, atomicity, consistency, isolation, and durability (ACID), which is a set of properties for ensuring reliable database transactions. Common web service specifications include: * **Web services security (WS-security)**: Standardizes how messages are secured and transferred through unique identifiers called tokens. * **WS-ReliableMessaging**: Standardizes error handling between messages transferred across unreliable IT infrastructure. * **Web services addressing (WS-addressing)**: Packages routing information as metadata within SOAP headers, instead of maintaining such information deeper within the network. * **Web services description language (WSDL)**: Describes what a web service does, and where that service begins and ends. When a request for data is sent to a SOAP API, it can be handled through any of the application layer protocols: HTTP (for web browsers), SMTP (for email), TCP, and others. However, once a request is received, return SOAP messages must be returned as XML documents—a markup language that is both human- and machine-readable. A completed request to a SOAP API is not cacheable by a browser, so it cannot be accessed later without resending to the API. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://dailyjournal.gitbook.io/notes/topics/api/soap.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.