Event Tracking with Mozilla's Telemetry Service

If there is anything in this document that is not clear, is incorrect, or that requires more detail, please file a request through a Github or Bugzilla. Also feel free to submit corrections or additional information.

NOTE: As of v3.3, the Adjust SDK is no longer used for event tracking. It is still, however, used for install tracking in Firefox Focus only (but NOT in Firefox Klar).

Firefox Focus and Firefox Klar use Mozilla's own Telemetry service for anonymous insight into usage of various app features. This event tracking is turned off by default for Firefox Klar (opt-in), but is on by default for Firefox Focus (opt-out).

The app uses Mozilla's own framework linked into Firefox Focus and Firefox Klar and a data collection service run by Mozilla. The framework is open source and MPL 2.0 licensed. It is hosted at https://github.com/mozilla-mobile/telemetry-ios. Firefox Focus and Firefox Klar pull in an unmodified copy of the framework via Carthage.

Telemetry Pings

The Telemetry framework collects and sends two types of pings to Mozilla's Telemetry backend:

• A Core Ping with basic system info and usage times.
• An Event Ping with details about user preferences and UI actions with timestamps relative to the app start time.

The messages are also documented below in more detail of what is sent in each HTTP request. All messages are posted to a secure endpoint at https://incoming.telemetry.mozilla.org. They are all application/json HTTP POST requests. Details about the HTTP edge server can be found at https://wiki.mozilla.org/CloudServices/DataPipeline/HTTPEdgeServerSpecification.

Core Ping

Request

tz:                 -240
sessions:           1
durations:          1
searches:
  suggestion.yahoo: 13
  listitem.yahoo:   7
  actionbar.yahoo:  4
clientId:           610A1520-4D47-498E-B20F-F3B46216372B
profileDate:        17326
v:                  7
device:             iPad
defaultSearch:      yahoo
locale:             en-US
seq:                1
os:                 iOS
osversion:          10.3
created:            2017-06-09
arch:               arm64

These parameters are documented at https://gecko.readthedocs.io/en/latest/toolkit/components/telemetry/telemetry/data/core-ping.html.

Response

If the ping was received successfully, the server responds with an HTTP 200 status code.

Event Ping

Request

tz:            -240
seq:           1
os:            iOS
created:       1497026730320
clientId:      2AF1A5A8-29B3-44B0-9653-346B67811E99
osversion:     10.3
settings:
  BlockAds:    true
  BlockSocial: false
},
v:             1
events:
  [ 2147, action, type_query, search_bar   ]
  [ 2213, action, type_url,   search_bar   ]
  [ 2892, action, click,      erase_button ]
locale:        en-US

These parameters are documented at http://gecko.readthedocs.io/en/latest/toolkit/components/telemetry/telemetry/collection/events.html.

You can find the full list of Event Pings sent by Focus here.

Response

If the ping was received successfully, the server responds with an HTTP 200 status code.