4D can communicate with web various APIs if they accept HTTP requests. This can be done so using the HTTP Reqeust command. Two parameters of this command are the contents/body parameter and the response parameter. The content/body parameter is used to contain the data being sent as part of the request, and the response is an empty variable that will recieve the response data. These two parameters can be one of four types: Text, BLOB, Picture, or Object.

When working with web API or any other web server one of the potential Content-types for the body and response is application/json. The content type is typically defined as part of the :"Content-type" header. When the application/json type is used 4D can use the 4D object type variable. This can make building the body and interacting with the response easier than working with a blob or in text format