window.openai.openExternal({ href, redirectUrl }) supports redirectUrl: false, which prevents the host from appending ?redirectUrl=... to external links.
window.openai.setOpenInAppUrl({ href }) is the supported way to override the fullscreen “Open in ” destination; if you do not call it, ChatGPT keeps opening the widget’s current iframe path.
openai/widgetDescription is honored during resource construction and takes precedence over resource.description when present.
window.openai.sendFollowUpMessage supports a scrollToBottom parameter; it defaults to true, and you can pass false to opt out.