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Reserved Properties

Reserved Properties: Properties used for system features

Mixpanel reserves certain property names for special processing or for specific system features. These properties, when populated, will affect the way Mixpanel processes your data.

Reserved Profile Properties

Note: Also refer to the list of Mixpanel Default Properties indicated in our documentation.

Raw NameDisplay NameDescription
$distinct_idDistinct IDMixpanel's internal unique identifier for a profile. See Identifying Users and Group Profiles
$name,
$first_name,
$last_name
Name,
First Name,
Last Name
The user's / group's general name, as well as, first and last names. These are primarily useful because they are used, if available, in various Mixpanel UI / reports. For user Cohort Syncs, only $first_name and $last_name is exported.
$emailEmailThe user's / group's email address. You must set this property if you want to send emails to users via partners receiving cohorts from our Cohort Syncs.
$phonePhoneThe user's / group's phone number. You must set this property if you want to send SMS to users via partners receiving cohorts from our Cohort Syncs. Note that a '+' needs to precede international phone numbers. If the user does not import a phone number with the '+' sign in front, the country code will be prefixed to the front of the number based on the $country_code default property, resulting in a phone number with two country codes.
$avatarAvatar URLSet this property to a URL resource of a gif, jpg, jpeg, or png to update the profile picture in a profile. This property will override a profile picture pulled from Gravatar (opens in a new tab).
$createdCreatedThe time that the profile was created. Note that this is not auto-populated.
$mp_first_event_timeFirst SeenMixpanel calculated property that represents the time of the user's (or group's) very first event in Mixpanel. This can be used to filter/segment reports by users (or groups) who were "new" in a particular timeframe.

Reserved Event Properties

Note: Also refer to the list of Mixpanel Default Properties indicated in our documentation.

Raw NameDisplay NameDescription
token-The project's token when sending data via /track API (opens in a new tab). Not visible via Mixpanel UI reports.
ip-The ip event property is the value to be used for geo-location parsing (i.e. $city, $region, and mp_country_code) if ip as param to the /track endpoint (opens in a new tab) has not been set to 1. Our client-side libraries, by default, will set the ip param to 1 so geo location is parsed from the incoming request, but this can be disabled or, if you're implementing from the server-side, you can include the ip event property so it's parsed from it instead of the IP of the incoming request. The ip event property is not stored in Mixpanel.
$bucket / bucket-A reserved property that is hidden from the Mixpanel interface, and will cause other events to not appear in the interface. Do not name any property bucket or $bucket.
$distinct_id / distinct_idDistinct IDMixpanel's internal unique identifier for a user. See Identifying Users.
$device_idDevice IDIn Simplified ID Merge: unique identifier used to track a device while the user is in anynymous state.
$user_idUser IDIn Simplified ID Merge: unique identifier used to track a user across devices when user is in identified state.
$event_nameEvent NameName of the tracked event used in the Mixpanel UI.
$time / timeTime or DateA unix time epoch that is used to determine the time of an event. If no time property is provided, we will use the time when the event arrives at our servers.
$insert_idInsert IDA unique identifier for the event, used to deduplicate events that are accidentally sent multiple times. More details here (opens in a new tab).
$identified_idIdentified IDIn Original ID Merge: Internal Mixpanel property to track the identifier passed into the $identify (opens in a new tab) event.
$anon_idAnonymous IDIn Original ID Merge: Internal Mixpanel property to track the anonymous ID passed into the $identify (opens in a new tab) event.
aliasAliasIn Original ID Merge: Internal Mixpanel property to track the alias passed into the $create_alias (opens in a new tab) event.
$distinct_idsDistinct IdsIn Original ID Merge: Internal Mixpanel property to track the distinct IDs passed into the $merge (opens in a new tab) event.
$distinct_id_before_identityDistinct ID Before IdentityInternal Mixpanel property to track an event's original $distinct_id before it was updated due to identity merging. Used in Original ID Merge and Simplified ID Merge.
$is_reshuffledIs ReshuffledInternal Mixpanel property to denote an event was reshuffled (sets to true if original $distinct_id was updated) due to identity merging. Used in Original ID Merge and Simplified ID Merge.
$failure_descriptionFailure DescriptionIn Original ID Merge: Mixpanel property explaining in detail why identity merging was not executed.
$failure_reasonFailure ReasonIn Original ID Merge: Mixpanel property summarizing why identity merging was not executed.
$identity_failure_reasonIdentity Failure ReasonIn Simplified ID Merge: Mixpanel property summarizing why identity merging was not executed.
mp_original_distinct_idHotshard Original Distinct IDOriginal $distinct_id for an event that was identified as contributing to a hot shard (opens in a new tab).
mp_original_event_nameHotshard Original Event NameOriginal $event_name for an event that was identified as contributing to hot shard (opens in a new tab).
$sourceSourceHidden property used by certain integration partners to denote events were sent by them. Refer to the respective partners under Cohort Sync -> Integrations.
$partner_idPartner IdHidden property used by certain integration partners to denote events were sent by them. Refer to the respective partners under Cohort Sync -> Integrations.
$warehouse_typeWarehouse TypeThe type of the warehouse sync setup to send the event. See Supported Warehouses.
$warehouse_import_idWarehouse Import IDThe ID of the warehouse sync setup to send this event. See Data Warehouse.
$warehouse_import_job_idWarehouse Import Job IDThe internal Mixpanel Job ID of the warehouse sync setup to send this event. See Data Warehouse.
$warehouse_import_run_idWarehouse Import Run IDThe internal Mixpanel Run ID of the warehouse sync setup to send this event. See Data Warehouse.
$duration_sSession Duration (Seconds)The duration between Session Start and Session End events in seconds. See How Sessions Work.
$event_countSession Event CountThe number of events during a session (i.e. Session Start and Session End). This does not include Excluded Events and Hidden Events in Lexicon. See How Sessions Work.
$origin_startSession Start Event NameThe original event name that triggered Session Start event. See How Sessions Work.
$origin_endSession End Event NameThe original event name that triggered Session End event. See How Sessions Work.

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