SOAP

SOAP (Simple Object Access Protocol) is an XML-based messaging protocol used for exchanging structured information in web services over networks, typically using HTTP or SMTP. It defines a standardized format for messages, including an envelope structure with headers and a body, to enable communication between applications across different platforms and languages. SOAP is often associated with Web Services Description Language (WSDL) for service definition and Universal Description, Discovery, and Integration (UDDI) for service discovery.

Also known as: Simple Object Access Protocol, SOAP Protocol, SOAP Web Services, XML Web Services, WS-SOAP

🧊Why learn SOAP?

Developers should learn SOAP when working with enterprise-level systems, legacy applications, or scenarios requiring strict security, reliability, and transactional support, such as in financial services or healthcare. It is particularly useful for integrating heterogeneous systems where standardized, platform-independent communication is critical, and when using WS-* standards for features like encryption and message routing. However, for modern web APIs, RESTful services are often preferred due to their simplicity and lightweight nature.

See how it ranks →

Compare SOAP

SOAP vs Rest→SOAP vs Graphql→SOAP vs Grpc→

Learning Resources

W3C SOAP Specification

SOAP Tutorial on TutorialsPoint

SOAP vs REST: Understanding the Differences

SOAP Web Services in Java

Related Tools

Xml Wsdl Web Services Http Soapui

Alternatives to SOAP

Rest Graphql Grpc

Other API Protocols

Acme Protocol is a standardized communication protocol used for automated certificate management, primarily for obtaining and renewing SSL/TLS certificates from certificate authorities (CAs). It enables servers and applications to automatically request, validate, and install certificates without manual intervention, streamlining the process of securing web services with HTTPS. The protocol is widely implemented by CAs and tools like Let's Encrypt to support the ACME (Automated Certificate Management Environment) standard.

ActivityPub is an open, decentralized social networking protocol that enables servers to communicate and share social activities, such as posts, likes, and follows, across different platforms. It is a W3C standard that defines a client-to-server API for creating, updating, and deleting content, as well as a server-to-server API for federated interactions between independent servers. This allows users on different social media platforms to interact seamlessly, fostering interoperability in the fediverse.

ActivityPub is a decentralized social networking protocol that enables different social platforms to communicate with each other, allowing users to interact across independent servers. It provides a standardized way for servers to exchange social activities like posts, likes, and follows, forming a federated network where no single entity controls the entire system. This protocol underpins many modern federated social networks, promoting interoperability and user autonomy.

AMQP (Advanced Message Queuing Protocol) is an open standard application layer protocol for message-oriented middleware, enabling reliable, secure, and interoperable messaging between applications. It defines a wire-level protocol for message queuing, routing, and delivery, supporting features like publish/subscribe, request/reply, and point-to-point communication. AMQP is widely used in distributed systems, microservices architectures, and enterprise messaging to decouple components and handle asynchronous communication.

BACnet (Building Automation and Control Networks) is a communication protocol designed specifically for building automation and control systems, such as HVAC, lighting, and security. It enables interoperability between devices from different manufacturers by defining standard data objects, services, and network rules. Developed by ASHRAE, it is widely used in commercial and industrial buildings for efficient management and monitoring.

BACnet (Building Automation and Control Networks) is a communication protocol designed specifically for building automation and control systems, such as HVAC, lighting, and security. It enables interoperability between devices from different manufacturers by standardizing data exchange over various network types, including Ethernet, IP, and serial links. The protocol defines objects, services, and data structures to facilitate monitoring and control of building systems.