servicemodel

A service model is a conceptual framework for describing and organizing services in software architectures such as service-oriented architecture (SOA), web services, and microservices. It defines how services are described, published, discovered, invoked, and governed, including the contracts that define their behavior and the mechanisms used to exchange messages.

Core elements commonly included are: service contracts (the interface listing operations or resources), data contracts or resource representations (the shapes of messages and resources), messages, endpoints (addresses at which a service can be reached), bindings or transport/encoding specifics, and metadata that describes the service. Policies and versioning frameworks govern compatibility and security, while service governance covers lifecycle management, composition, and monitoring.

In different ecosystems, the term takes slightly different emphases. In web services that use SOAP, the service model is closely tied to WSDL definitions, SOAP envelopes, and XML schemas; in RESTful and modern API designs the model centers on resources and representations, usually described by OpenAPI specifications. In Microsoft .NET, the phrase "service model" is associated with Windows Communication Foundation (WCF) and the System.ServiceModel namespace, which gathers contracts, bindings, and behaviors used to build, host, and consume services. In microservices, the service model often emphasizes autonomous deployment, API gateways, and strong emphasis on contract-first design and versioning.

The service model evolves with security, discovery, and observability requirements, enabling interoperability across platforms and enabling evolution without breaking clients. Related topics include service-oriented architecture, web services, REST, WCF, and OpenAPI.