from mitmproxy import ctx class AddHeader: def __init__(self): self.num = 0 def load(self, loader): loader.add_option( name = "addheader", typespec = bool, default = False, help = "Add a count header to responses", ) def response(self, flow): if ctx.options.addheader: self.num = self.num + 1 flow.response.headers["count"] = str(self.num) addons = [ AddHeader() ]