SOAP (Simple Object Access Protocol) is a messaging specification for exchanging information between systems and applications. It is a secure way to build APIs that works by encoding data in the XML format. SOAP APIs are developed in a more structured and formalized way than other types of APIs. SOAP is often compared to REST (Representational State Transfer), another type of API. While SOAP is more established and dependable, it can be slower than REST.
Some key features of SOAP APIs include:
- WSDL: The Web Service Description Language is a contract between the provider and the consumer of the service. It can be thought of as a method signature for the web service.
- XML: SOAP relies heavily on XML, and together with schemas, defines a very strict communication contract between systems.
- Independence: SOAP APIs are independent of programming language and even underlying transport protocol. The sender can use one language, while the recipients stack relies on another.
To call a SOAP API, youll most likely need to include a SOAP library with your programming language. SOAP is ideal for enterprise solutions and stateful operations. While SOAP is more popular in large enterprises, organizations of all sizes produce and consume SOAP APIs.
