The "search" API parameter have the same behavior as the quick search in the PIM interface. It targets the codes and the attribute product_name.
Here is a usage example. The following API call :
GET https://{{your-instance-name}}.quable.com/api/documents?search=ABC
will try to match documents and variants that have the following codes and names :
ABC
ABCxxxxxx
xxxxABCxx
xxxxxxABC