title: fragment/analytics/web_identifiers
description: >
  Standard identifiers for Wikimedia product/feature analytics on
  MediaWiki-powered mobile and desktop websites.

  NOTE: Unlike the fields in the related app_identifiers fragment -- which are
        filled in automatically by the Event Platform Client libraries for
        Android and iOS -- these fields are (currently) *not* automatically set
        by EventLogging's `mw.eventLog.submit()` and must be set by
        instrumentation code when it is putting together the event data.
$id: /fragment/analytics/web_identifiers/1.0.0
$schema: https://json-schema.org/draft-07/schema#
type: object
properties:
  web_session_id:
    type: string
    minLength: 20
    maxLength: 20
    pattern: ^[0-9a-z]{20}$
    description: >
      Identifies a web session: a cluster of actions taken by the user on a
      website within a limited period of time. A session ID is generated the
      first time it is requested by the instrumentation code, which is usually
      the first time the user visits the website.

      In the current implementation, this ID is shared across windows, tabs, and
      page views in the same browser. The ID is normally regenerated after the
      browser is shut down; however, if the browser's "restore previous session"
      feature is used when it restarts, the previous ID is retained.

      Interactions across multiple pages in the same web session may be linked
      together via this identifier.

      Instrumentation code should assign this with mw.user.sessionId()
  web_pageview_id:
    type: string
    minLength: 20
    maxLength: 20
    pattern: ^[0-9a-z]{20}$
    description: >
      Identifies a single web page view (visit). This identifier is randomly
      generated the first time it is requested by the instrumentation code on
      any page view and persists for the lifetime of the page. When the user
      navigates to another page or refreshes/reloads the page, this identifier
      disappears and a new one is regenerated (when needed). Different visits
      to the same page will yield different pageview IDs (also called tokens).

      Interactions with multiple features (instrumented separately) on the same
      web page may be linked together via this identifier.

      Instrumentation code should assign this with mw.user.getPageviewToken()