Hi, My reporting class return a pdf document :
class MyReport(Report): __name__ = 'mymodule.myreport' @classmethod def execute(cls, ids, data): # code to create myfile.pdf ... pdf_buffer = None with open('myfile.pdf', 'rb') as pdf: pdf_buffer = pdf.read() return ('pdf', pdf_buffer, False, 'myreport' ) The problem is that json won't encode binary stuff. I'm trying to understand how it's done for images in odt, or odt itself since its a zip file, but it's a bit tedious and I'd be grateful for some help. V.