from app import app from flask import make_response @app.route("/assert-header") def assert_header(): resp = make_response() resp.headers["Header1"] = "value1" resp.headers["ETag"] = '"33a64df551425fcc55e4d42a148795d9f25f89d4"' resp.set_cookie("cookie1", "value1") resp.set_cookie("cookie2", "value2") resp.set_cookie("cookie3", "value3") return resp