{"mdn_url":"https://developer.mozilla.org/docs/Mozilla/Add-ons/WebExtensions/API/webRequest/onBeforeRequest","source_file":"webextensions/api/webRequest.json","support":{"chrome":{"notes":"Asynchronous event listeners are not supported.","version_added":true},"edge":{"notes":"Asynchronous event listeners are not supported.","version_added":"14"},"firefox":{"notes":"Asynchronous event listeners are supported from version 52.","version_added":"46"},"firefox_android":{"notes":"Asynchronous event listeners are supported from version 52.","version_added":"48"},"opera":{"notes":"Asynchronous event listeners are not supported.","version_added":true},"safari":{"notes":"<code>extraInfoSpec</code> options are not supported.","version_added":"14"},"safari_ios":{"version_added":false}}}