APIs let programmers build amazing tools and Apps even with different environments. For those who may not be familiar with API, What’s API? According to Wikipedia, An application programming interface (API) is a set of subroutine definitions, protocols, and tools for building application software. In general terms, it’s a set of clearly defined methods of communication between various software components. The Server-side Interface of API usually consists of a standardized request-response System, typically referred to as Web Services. For developing an API, you should follow one of the design models like: Rest SOAP JavaScript XML-RPC The two most dominant design models for API are SOAP and REST. SOAP used to be a popular choice for making specific use of API(s). But, now you can see a paradigm shift from SOAP to REST. REST design model has gained enormous popularity, due to its simplicity and awesomeness. As a developer, you can follow anyone as per your requirements. Let’s have a look at them: SOAP: In short, SOAP(Simple Object Access Protocol) is a protocol specification for information transfer. It provides a strongly type message format for API and relies on the XML format. Example Request: POST /url HTTP/1.1 Host: HostServerName Content-type: text/xml; charset=utf-8 Content-length: 350 SoapAction: http://tempUri.org/GetUserInfo ... <?xml version="1.0" encoding="utf-8" ?> <soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"> <soap:Body> <GetUserInfo xmlns="http://tempUri.org/"> <UserID>1</UserID> <OutputParam /> </GetUserInfo> </soap:Body> </soap:Envelope> 123456789101112131415 POST /url HTTP/1.1Host: HostServerNameContent-type: text/xml; charset=utf-8Content-length: 350SoapAction: http://tempUri.org/GetUserInfo...<?xml version="1.0" encoding="utf-8" ?><soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"> <soap:Body> <GetUserInfo xmlns="http://tempUri.org/"> <UserID>1</UserID> <OutputParam /> </GetUserInfo> </soap:Body></soap:Envelope> Example Response: <?xml version="1.0" encoding="utf-8" ?> <SOAP-ENV:Envelope xmlns:xsd="http://www.w3.org/2001/XMLSchema" ...> <SOAP-ENV:Body> <method:MethodNameResponse> <method:MethodNameResult xmlns="" xsi:type="sqlresultstream:SqlResultStream"> <!-- the results are returned here --> </method:MethodNameResult> <method:OutputParam>Value</method:OutputParam> </method:MethodNameResponse> </SOAP-ENV:Body> </SOAP-ENV:Envelope> 1234567891011 <?xml version="1.0" encoding="utf-8" ?><SOAP-ENV:Envelope xmlns:xsd="http://www.w3.org/2001/XMLSchema" ...> <SOAP-ENV:Body> <method:MethodNameResponse> <method:MethodNameResult xmlns="" xsi:type="sqlresultstream:SqlResultStream"> <!-- the results are returned here --> </method:MethodNameResult> <method:OutputParam>Value</method:OutputParam> </method:MethodNameResponse> </SOAP-ENV:Body></SOAP-ENV:Envelope> Rest: REST is an architectural style, unlike SOAP which is a standardized protocol, it makes use of HTTP and uses HTTP methods explicitly. It can structure API data into JSON, XML, YAML, HTML, or any other format. JSON is the preferred format. Unlike SOAP, you don’t need to use the verb for action but corresponding HTTP Methods like GET, PUT, DELETE, POST, PATCH. Example Request: GET /ticket Accept: application/json Content-Type: application 123 GET /ticketAccept: application/jsonContent-Type: application Example Response: 200 OK Content-Type: application/json { "ticket": { "id": 11174, "incrementId": 82, "subject": "ticket subject", "isStarred": null, "isAgentView": true, "isTrashed": false, "source": "website", "group": null, "priority": { "id": 1, "name": "Low", "description": "Low", "color": "#5cb85c" }, "formatedCreatedAt": "21-Dec 10:36am", "totalThreads": "0", "agent": { "id": 1724, "name": "agent name" }, "customer": { "id": 193, "name": "customer name" }, "hasAttachments": 0 } } 12345678910111213141516171819202122232425262728293031 200 OKContent-Type: application/json{ "ticket": { "id": 11174, "incrementId": 82, "subject": "ticket subject", "isStarred": null, "isAgentView": true, "isTrashed": false, "source": "website", "group": null, "priority": { "id": 1, "name": "Low", "description": "Low", "color": "#5cb85c" }, "formatedCreatedAt": "21-Dec 10:36am", "totalThreads": "0", "agent": { "id": 1724, "name": "agent name" }, "customer": { "id": 193, "name": "customer name" }, "hasAttachments": 0 }} More and more sites like UV desk are following REST design pattern. Because REST have many advantages over SOAP like ReST leverages HTTP, so everything is simple. In ReST metadata and URI are nouns, actions are specified by HTTP Methods like GET, PUT, POST, DELETE, PATCH, HEAD. Rest API(s) are more suitable for mobile devices. so, if you may use your API for mobile Apps then ReST API is the right choice for you. multiple data formats can be supported like JSON, YAML, XML, while SOAP provides only XML format. ReST services are cacheable. Normally, ReST is faster than SOAP. Since it uses JSON format rather than XML. Rest following community is quite big. so, You can easily find a suitable library for ReST implementation PHP: PHP-crud-API Symfony: fosrest WordPress: wp-api java: Resteasy What’s Next? If you have selected a suitable Design Model. Then, Stay connected for upcoming API category blogs. In Upcoming blogs, You can have a look at our full journey of API development. Furthermore, there will all sorts of tricks, tweaks, and key points that we learned while developing REST API. Tag(s) api rest soap Category(s) API UVdesk