You should document your APIs using the OpenAPI specification as much as possible - so make full use of descriptions for all operations, parameters, attributes etc.
But, in some cases this is not enough and you need a higher level of documentation - or your API might not be OpenAPI spec, but might be WSDL/SOAP or plain HTTP.
For these cases, you can write documentation for an API using Ceptor's built-in HTML editor.
Simply navigate to the Documentation tab for an API version, and begin editing your HTML - you can either use the built-in editor, or switch to html source mode and write the HTML source code directly.
Anything you write in this documentation can be viewed by your API Partners and developers within the Ceptor API Developer Portal.