X-Analytics

X-Analytics is an HTTP header used for measurement purposes, including in cache log format and the webrequest data stream.

Generally, values are added to the header on the server side; the only keys accepted from the client side are preview and pageview.

Format

The X-Analytics header is formatted as a list of key=value pairs separated by semicolons, like mf-m=b or zero=123-45;mf-m=b. If a key occurs more than once, it is undefined which one takes precedence.

The special value - must be interpreted as the empty string.

Keys

Looks like X-Analytics extension might be adding these values if used: [1]

Key	Value	Origin	Since	Until	Team	Contact	Use case
mf-m	b, amc, b,amc, or not set	appserver	?	Current	Readers Web	Phuedx	If set, then the value b indicates that the user is opted into the beta mode (of the mobile site) (mf-m=b), the value amc indicates Advanced Mobile Contributions (mf-m=amc), and b,amc indicates both (mf-m=b,amc). See MobileContext.php.
max-snippet	1, 0, or not set	appserver (WikimediaEvents)	Mar 2022	Current	Readers Web	cjming	If set, the value 1 indicates the page's robots meta tag contains the max-snippet directive. The value 0 indicates the page's robots meta tag does not contain the max-snippet directive. If set, both 1 and 0 indicate that the page is part of an A/B test in the treatment and control groups respectively. Added in T301584.
proxy	Proxy name, e.g. Opera	varnish	?	Current	Wikipedia Zero	Yurik	If set, indicates that this request has been received via one of the trusted proxies such as Opera Mini servers. Currently, the following proxies can be expected: Value Description Opera Opera mini proxy Nokiaprod Nokia Xpress Production Proxy Servers Nokiaqa Nokia Xpress QA Lab Proxy Servers IORG Internet.org (set by analytics.inc.vcl in puppet)
https	1	varnish	?	Current	SRE Traffic	BBlack	If set, will be equal to "1", indicating HTTPS protocol. Currently set for the vast majority of requests, including all that are served with content from canonical WMF domains. If it is missing and the HTTP status is 301, the request was sent using HTTP and met with a HTTP redirect response, most likely to the corresponding HTTPS URL. For other response codes <400 (non-errors), it is assumed that the absence of this field also indicates a HTTP request. For some rare cases involving response codes >= 400, it may be possible that this field is not set even though the request was over HTTPS. (More details)
wmfuuid	UUID v4 value	varnish	?	Current	Mobile apps	dr0ptp4kt	If set, will be equal to a hyphen separated value, and indicates a unique app installation. The ID may span multiple requests, as it is generated once, at app install time, using an appropriate library (Java, Objective C), and conforms to RFC 4122 version 4. Older versions of the app may contain an appInstallID parameter in the request URL instead, or may contain both the appInstallID parameter in the URL as well as the wmfuuid X-Analytics value. Later versions of the software should only contain the wmfuuid X-Analytics value and not the appInstallID parameter in the URL. Requests from the app will not contain this header if the user has turned off "Send usage reports" in the settings menu of the app.
WMF-Last-Access	dd-MMM-yyyy, e.g. 06-May-2015	varnish	?	Current	Analytics (Infrastructure)	Milimetric	Date of site last access. If set will be equal to the latest date when a device issued a request to the specific host in dd-MMM-yyyy format(Eg: 06-May-2015) and an expiration date set to ~31 days in the future. More explanation at Analytics/Unique_clients/Last_access_solution.
preview	1	client	?		Analytics (Infrastructure)	Milimetric	Whether this is a preview request (not present if not). At the time of this writing, preview requests by mobile apps are not consider pageviews. Expected value is preview=1. Not actively used as of Dec 2021 (task T297172#7567161).
pageview	1	client	?	Current	Analytics (Infrastructure)	Milimetric	If set it will count the request in question as a pageview regardless of other attributes of request.
nocookies	1	varnish	?	Current	Analytics (Infrastructure)	Madhuvishy or Nuria	If set it will tag the request in question as a nocookie request. This means that either this is a fresh browser session, a user browsing with cookies disabled or possibly a bot request. We expect that the majority of requests tagged with nocookies will belong to bots. Please see: change 244626.
loggedIn	1	appserver (WikimediaEvents)	?		WMDE-Analytics	Addshore	If set, will be equal to "1", and indicates that the request came from a logged in user (see also code).
page_id	Page ID	appserver (WikimediaEvents)	?		WMDE-Analytics	Addshore, Ori.livneh	If set, will be a string of a positive integer.
ns	Namespace ID	appserver (WikimediaEvents)	?		WMDE-Analytics	Addshore, Ori.livneh	If set, will be a string integer (can be negative for negative namespace IDs)
special	Special page name	appserver (WikimediaEvents)	?		WMDE-Analytics	Addshore	Set for special pages only. This will be the base name of the special page, so if the user is browsing a page via an alias the actual page name will be here.
translationengine	Identifier, e.g. GT	varnish	Nov 2018	Current	Product	ABaso	If set, indicates request served through a known intermediary service for machine translations. "GT" stands for Google Translate. Added in T208795.
wprov	<3_char_feature> <1_char_platform><major_version> e.g. srpw1 for SRP, Web, v1.	client or varnish	?	Current	?	?	see Provenance
debug	1	varnish	Jan 2021	Current	Analytics (Infrastructure)	Milimetric	Added in T263683.
client_port	medium-size int	varnish	Jan 2021	Current	Analytics (Infrastructure)	JAllemandou	Added in T271953.
public_cloud	1	varnish	May 2021	Current	SRE	CDanis	Added in T279380.
sessioncookie	1	varnish	November 2022	Current	SRE	Vgutierrez	Added in T319324.

Former keys

Key	Value	Origin	Since	Until	Team	Contact	Use case
php	zend, or hhvm	appserver	?	Jan 2015	SRE	_joe_	If set, marks the used PHP implementation. This tag was only set between September 2014 and January 2015 during the migration from Zend to HHVM. (See I46ff99, and I75b30b)
zero	MCC-MNC of a zero carrier, e.g. 404‑01.	varnish	?	July 2019	Wikipedia Zero	Yurik	If set, indicates that this request has been associated with the given carrier. It does not mean that the request qualifies as page view. zero.inc.vcl.erb. mobile-frontend.inc.vcl.erb. Removal in T213769.
zeronet	Subdivision of a carrier, e.g. b	varnish	?	July 2019	Wikipedia Zero	Yurik	Used of disambiguate between different parts/configurations of a single carrier. Like broadband vs. special access points. Removal in T213769.

Code

https://github.com/wikimedia/mediawiki-extensions-XAnalytics

Extension documentation

mw:Extension:XAnalytics

Tasks and Bugs

https://phabricator.wikimedia.org/tag/xanalytics/

See also

• The wprov URL parameter documented under Provenance is likewise logged in the x_analytics_map field of the webrequest table.