REST-based APIs are great for modeling your domain (that is, resources or entities), making CRUD (create, read, update, delete) available for all of your data. RPC-based APIs are great for actions (that is, procedures or commands). Seeing as XML is not everyone’s cup of tea, an RPC API could use the JSON-RPC protocol, or you could roll a custom JSON-based API, as Slack has done with its Web API. The “RPC” part stands for “remote procedure call,” and it’s essentially the same as calling a function in JavaScript, PHP, Python and so on, taking a method name and arguments. XML-RPC and SOAP, along with custom homegrown solutions, dominated the API landscape for a long time and were all RPC-based HTTP APIs.

This became part of the basis for SOAP (Simple Object Access Protocol). In XML, a lot of things are just strings, so you need to layer meta data on top in order to describe things such as which fields correspond to which data types. XML-RPC was problematic, because ensuring data types of XML payloads is tough. These constraints (plus a few more) allow the REST architecture to help APIs last for decades, not just years.īefore REST became popular (after companies such as Twitter and Facebook labeled their APIs as REST), most APIs were built using an XML-RPC or SOAP.

REST focuses on uniformity: if you’re using HTTP you should utilize HTTP features whenever possible, instead of inventing conventions.

Responses should declare cacheablility: helps your API scale if clients respect the rules.

REST must be stateless: not persisting sessions between requests.

Hypermedia is fundamental to REST, and is essentially just the concept of providing links to other resources.īeyond hypermedia there are a few other constraints, such as: These representations for resources, or collections of resources, which are then potentially modifiable, with actions and relationships being made discoverable via a method known as hypermedia.

REST is all about a client-server relationship, where server-side data are made available through representations of data in simple formats, often JSON and XML. Sadly, that dissertation is not widely read, and so many people have their own idea of what REST is, leading to a lot of confusion and disagreement. REST stands for “ representational state transfer,” described by Roy Fielding in his dissertation. RPC and REST can both be used via other transportation protocols, such as AMQP, but that is another topic entirely. This article discusses these two approaches in the context of building HTTP APIs, because that is how they are most commonly used. REST is made out by many to be ultimately superior to the other “RPC-based” approaches, which is a bit misleading because they are just different. Or use both and have the best of both worlds!įor the last few years, whenever somebody wants to start building an HTTP API, they pretty much exclusively use REST as the go-to architectural style, over alternative approaches such as XML-RPC, SOAP and JSON-RPC. Use REST when it makes sense, or use RPC if it is more appropriate. It’s best not to mix styles in a single API, because this could be confusing both to consumers of your API as well as to any tools that expect one set of conventions (REST, for example) and that fall over when it instead sees a different set of conventions (RPC). Knowing the differences between REST and RPC can be incredibly useful when you are planning a new API, and it can really help when you are working on features for existing APIs.

Soap vs rest vs rmi