The following script uses Workflow’s AlambicEdit API toread the metadata from the current PDF job file and store the Keywords properties in a process variable named keywords.
var myPDF = Watch.GetPDFEditObject();
myPDF.open(Watch.GetJobFileName(),false);
var meta = myPDF.GetInfos();
Watch.SetVariable("keywords",meta.keywords);
myPDF.Close();
More information on the AlambicEdit API can be found in the online help.