Trying to use WSG to query and create new docs

Have the current WSG installed in our dev environment. We want to query documents and create list of docs and properties. We also want to be abel to create a new document and send it back to ProjectWise via WSG and our app.  We were able to query against the doc and get a ProjectWise property. We have nto been abel to find the magic required to fetch custom attributes. Finally, when we try to create a new document we get the message "The specified origin is not allowed". We have looke dhihg and low but cat a complete enough example to follow. Can we get an exaxmple of a search against a custom attribute? Can we get an exnaple of creating a new document? Any other help or documentation is appreciated. Thanks!