windchill API which gives all cad documents url in output

Are you looking for the details page or the content link? I have written JSP page that returns the content WTDocs via parameters, very similar. APIs should be similar. A word of caution on directly accessing the content in this manner. Workspaces are able to handle things like rename events dynamically. For example, you know in Creo that the assembly and drawing call for their dependents by their filename. I am able to change the filename in PDMLink at any time. The binary content of the assembly and drawing are not touched where they sit in the vaults. They are dynamically altered when they enter a workspace. This means if you directly access those files in this manner, that rename adjustment will not occur and they will be looking for the old filename.