Userflow-generated events

This page describes all the events that Userflow generates when users interact with flows/checklists. These events can be continuously streamed to other product analytics providers.

Note: Event names have not changed as part of the Adoption Agent rebrand.
In March 2026, Userflow renamed AI Assistant to Adoption Agent. Event names and attribute names for Adoption Agent events have not changed and continue to use their original identifiers (e.g., assistant_message_sent, assistant_feedback_submitted). Display names in the Userflow UI reflect the "Adoption Agent" terminology, but the underlying event names sent to your analytics provider are unchanged.

This is intentional — changing event names would break existing integrations and analytics pipelines. If event name changes are planned in a future release, this article will be updated in advance.

Event anatomy

An event consists of:

Event name: The raw name Userflow stores events with, and which will be sent to your product analytics provider.
Display name (the headers below): A user-friendly representation of the Event name.
Attributes: A dictionary of extra information about the event, such as which flow it concerns. May be referred to as “properties” in your analytics provider.

Announcement Seen

Event name: announcement_seen

A Userflow announcement was seen.

Attribute name	Display name	Description
`announcement_id`	Announcement ID	Userflow announcement
`announcement_name`	Announcement Name	Userflow announcement name
`announcement_version_id`	Announcement Version ID	Userflow announcement version
`announcement_version_number`	Announcement Version Number	Userflow announcement version number
`locale_code`	Locale Code	User’s locale when this event was tracked
`page_url`	Page URL	Page URL when the event occurred
`viewport_height`	Viewport Height	Height of the user’s viewport (browser window)
`viewport_width`	Viewport Width	Width of the user’s viewport (browser window)

Assistant Feedback Submitted

Event name: assistant_feedback_submitted

User submitted freeform feedback for an Adoption Agent’s reply.

Attribute name	Display name	Description
`assistant_conversation_id`	Assistant Conversation	Userflow Adoption Agent conversation
`assistant_id`	Assistant ID	Userflow Adoption Agent
`assistant_message_id`	Assistant Message	Userflow Adoption Agent message
`assistant_name`	Assistant Name	Userflow Adoption Agent name
`assistant_version_id`	Assistant Version ID	Userflow Adoption Agent version
`assistant_version_number`	Assistant Version Number	Userflow Adoption Agent version number
`locale_code`	Locale Code	User’s locale when this event was tracked
`page_url`	Page URL	Page URL when the event occurred
`viewport_height`	Viewport Height	Height of the user’s viewport (browser window)
`viewport_width`	Viewport Width	Width of the user’s viewport (browser window)

Assistant Message Sent

Event name: assistant_message_sent

User sent a message to an Adoption Agent.

Attribute name	Display name	Description
`assistant_conversation_id`	Assistant Conversation	Userflow Adoption Agent conversation
`assistant_id`	Assistant ID	Userflow Adoption Agent
`assistant_message_id`	Assistant Message	Userflow Adoption Agent message
`assistant_name`	Assistant Name	Userflow Adoption Agent name
`assistant_version_id`	Assistant Version ID	Userflow Adoption Agent version
`assistant_version_number`	Assistant Version Number	Userflow Adoption Agent version number
`locale_code`	Locale Code	User’s locale when this event was tracked
`page_url`	Page URL	Page URL when the event occurred
`viewport_height`	Viewport Height	Height of the user’s viewport (browser window)
`viewport_width`	Viewport Width	Width of the user’s viewport (browser window)

Assistant Rating Submitted

Event name: assistant_rating_submitted

User liked/disliked an Adoption Agent’s reply.

Attribute name	Display name	Description
`assistant_conversation_id`	Assistant Conversation	Userflow Adoption Agent conversation
`assistant_id`	Assistant ID	Userflow Adoption Agent
`assistant_message_id`	Assistant Message	Userflow Adoption Agent message
`assistant_message_rating`	Assistant Message Rating	Userflow AI message rating (like/dislike)
`assistant_message_scale_max`	Assistant Message Scale Max	Userflow AI message rating max possible value (for CSAT)
`assistant_message_scale_rating`	Assistant Message Scale Rating	Userflow AI message rating on a scale (for CSAT)
`assistant_name`	Assistant Name	Userflow Adoption Agent name
`assistant_version_id`	Assistant Version ID	Userflow Adoption Agent version
`assistant_version_number`	Assistant Version Number	Userflow Adoption Agent version number
`locale_code`	Locale Code	User’s locale when this event was tracked
`page_url`	Page URL	Page URL when the event occurred
`viewport_height`	Viewport Height	Height of the user’s viewport (browser window)
`viewport_width`	Viewport Width	Width of the user’s viewport (browser window)

Banner Dismissed

Event name: banner_dismissed

A Userflow banner was dismissed.

Attribute name	Display name	Description
`banner_id`	Banner ID	Userflow banner
`banner_name`	Banner Name	Userflow banner name
`banner_session_id`	Banner Session ID	A session of a specific user viewing a specific banner
`banner_version_id`	Banner Version ID	Userflow banner version
`banner_version_number`	Banner Version Number	Userflow banner version number
`locale_code`	Locale Code	User’s locale when this event was tracked
`page_url`	Page URL	Page URL when the event occurred
`viewport_height`	Viewport Height	Height of the user’s viewport (browser window)
`viewport_width`	Viewport Width	Width of the user’s viewport (browser window)

Banner Seen

Event name: banner_seen

A Userflow banner was seen for the first time.

Attribute name	Display name	Description
`banner_id`	Banner ID	Userflow banner
`banner_name`	Banner Name	Userflow banner name
`banner_session_id`	Banner Session ID	A session of a specific user viewing a specific banner
`banner_version_id`	Banner Version ID	Userflow banner version
`banner_version_number`	Banner Version Number	Userflow banner version number
`locale_code`	Locale Code	User’s locale when this event was tracked
`page_url`	Page URL	Page URL when the event occurred
`viewport_height`	Viewport Height	Height of the user’s viewport (browser window)
`viewport_width`	Viewport Width	Width of the user’s viewport (browser window)

Checklist Completed

Event name: checklist_completed

All of a Userflow checklist tasks were completed.

Attribute name	Display name	Description
`checklist_id`	Checklist ID	Userflow checklist
`checklist_name`	Checklist Name	Userflow checklist name
`checklist_session_id`	Checklist Session ID	A session of a specific user viewing a specific checklist
`checklist_version_id`	Checklist Version ID	Userflow checklist version
`checklist_version_number`	Checklist Version Number	Userflow checklist version number
`locale_code`	Locale Code	User’s locale when this event was tracked
`page_url`	Page URL	Page URL when the event occurred
`viewport_height`	Viewport Height	Height of the user’s viewport (browser window)
`viewport_width`	Viewport Width	Width of the user’s viewport (browser window)

Checklist Dismissed/Ended

Event name: checklist_ended

A Userflow checklist was ended/closed permanently.

Attribute name	Display name	Description
`checklist_end_reason`	Checklist End Reason	Describes why a checklist ended
`checklist_id`	Checklist ID	Userflow checklist
`checklist_name`	Checklist Name	Userflow checklist name
`checklist_session_id`	Checklist Session ID	A session of a specific user viewing a specific checklist
`checklist_version_id`	Checklist Version ID	Userflow checklist version
`checklist_version_number`	Checklist Version Number	Userflow checklist version number
`locale_code`	Locale Code	User’s locale when this event was tracked
`page_url`	Page URL	Page URL when the event occurred
`viewport_height`	Viewport Height	Height of the user’s viewport (browser window)
`viewport_width`	Viewport Width	Width of the user’s viewport (browser window)

Checklist Hidden

Event name: checklist_hidden

A Userflow checklist was hidden/minimized.

Attribute name	Display name	Description
`checklist_id`	Checklist ID	Userflow checklist
`checklist_name`	Checklist Name	Userflow checklist name
`checklist_session_id`	Checklist Session ID	A session of a specific user viewing a specific checklist
`checklist_version_id`	Checklist Version ID	Userflow checklist version
`checklist_version_number`	Checklist Version Number	Userflow checklist version number
`locale_code`	Locale Code	User’s locale when this event was tracked
`page_url`	Page URL	Page URL when the event occurred
`viewport_height`	Viewport Height	Height of the user’s viewport (browser window)
`viewport_width`	Viewport Width	Width of the user’s viewport (browser window)

Checklist Shown

Event name: checklist_shown

A Userflow checklist was shown/expanded.

Attribute name	Display name	Description
`checklist_id`	Checklist ID	Userflow checklist
`checklist_name`	Checklist Name	Userflow checklist name
`checklist_session_id`	Checklist Session ID	A session of a specific user viewing a specific checklist
`checklist_version_id`	Checklist Version ID	Userflow checklist version
`checklist_version_number`	Checklist Version Number	Userflow checklist version number
`locale_code`	Locale Code	User’s locale when this event was tracked
`page_url`	Page URL	Page URL when the event occurred
`viewport_height`	Viewport Height	Height of the user’s viewport (browser window)
`viewport_width`	Viewport Width	Width of the user’s viewport (browser window)

Checklist Started

Event name: checklist_started

A Userflow checklist was started.

Attribute name	Display name	Description
`checklist_id`	Checklist ID	Userflow checklist
`checklist_name`	Checklist Name	Userflow checklist name
`checklist_session_id`	Checklist Session ID	A session of a specific user viewing a specific checklist
`checklist_start_reason`	Checklist Start Reason	Describes why a checklist started
`checklist_version_id`	Checklist Version ID	Userflow checklist version
`checklist_version_number`	Checklist Version Number	Userflow checklist version number
`locale_code`	Locale Code	User’s locale when this event was tracked
`page_url`	Page URL	Page URL when the event occurred
`viewport_height`	Viewport Height	Height of the user’s viewport (browser window)
`viewport_width`	Viewport Width	Width of the user’s viewport (browser window)

Checklist Task Clicked

Event name: checklist_task_clicked

A Userflow checklist task was clicked.

Attribute name	Display name	Description
`checklist_id`	Checklist ID	Userflow checklist
`checklist_name`	Checklist Name	Userflow checklist name
`checklist_session_id`	Checklist Session ID	A session of a specific user viewing a specific checklist
`checklist_task_cvid`	Checklist Task CVID	Userflow checklist task Cross-Version ID (a pseudo-ID that does not change across versions)
`checklist_task_id`	Checklist Task ID	Userflow checklist task
`checklist_task_name`	Checklist Task Name	Userflow checklist task name
`checklist_version_id`	Checklist Version ID	Userflow checklist version
`checklist_version_number`	Checklist Version Number	Userflow checklist version number
`locale_code`	Locale Code	User’s locale when this event was tracked
`page_url`	Page URL	Page URL when the event occurred
`viewport_height`	Viewport Height	Height of the user’s viewport (browser window)
`viewport_width`	Viewport Width	Width of the user’s viewport (browser window)

Checklist Task Completed

Event name: checklist_task_completed

A Userflow checklist task was marked as completed.

Attribute name	Display name	Description
`checklist_id`	Checklist ID	Userflow checklist
`checklist_name`	Checklist Name	Userflow checklist name
`checklist_session_id`	Checklist Session ID	A session of a specific user viewing a specific checklist
`checklist_task_cvid`	Checklist Task CVID	Userflow checklist task Cross-Version ID (a pseudo-ID that does not change across versions)
`checklist_task_id`	Checklist Task ID	Userflow checklist task
`checklist_task_name`	Checklist Task Name	Userflow checklist task name
`checklist_version_id`	Checklist Version ID	Userflow checklist version
`checklist_version_number`	Checklist Version Number	Userflow checklist version number
`locale_code`	Locale Code	User’s locale when this event was tracked
`page_url`	Page URL	Page URL when the event occurred
`viewport_height`	Viewport Height	Height of the user’s viewport (browser window)
`viewport_width`	Viewport Width	Width of the user’s viewport (browser window)

Flow Completed

Event name: flow_completed

A Userflow flow was completed (user saw a goal step).

Attribute name	Display name	Description
`flow_id`	Flow ID	Userflow flow
`flow_name`	Flow Name	Userflow flow name
`flow_session_id`	Flow Session ID	A session of a specific user viewing a specific flow
`flow_step_cvid`	Flow Step CVID	Userflow flow step Cross-Version ID (a pseudo-ID that does not change across versions)
`flow_step_id`	Flow Step ID	Userflow flow step
`flow_step_name`	Flow Step Name	Userflow flow step name
`flow_step_number`	Flow Step Number	Userflow flow step number
`flow_step_progress`	Flow Step Progress	Userflow flow step progress (% towards goal step)
`flow_version_id`	Flow Version ID	Userflow flow version
`flow_version_number`	Flow Version Number	Userflow flow version number
`locale_code`	Locale Code	User’s locale when this event was tracked
`page_url`	Page URL	Page URL when the event occurred
`viewport_height`	Viewport Height	Height of the user’s viewport (browser window)
`viewport_width`	Viewport Width	Width of the user’s viewport (browser window)

Flow Dismissed/Ended

Event name: flow_ended

A Userflow flow was ended/closed permanently.

Attribute name	Display name	Description
`flow_end_reason`	Flow End Reason	Describes why a flow ended
`flow_id`	Flow ID	Userflow flow
`flow_name`	Flow Name	Userflow flow name
`flow_session_id`	Flow Session ID	A session of a specific user viewing a specific flow
`flow_step_cvid`	Flow Step CVID	Userflow flow step Cross-Version ID (a pseudo-ID that does not change across versions)
`flow_step_id`	Flow Step ID	Userflow flow step
`flow_step_name`	Flow Step Name	Userflow flow step name
`flow_step_number`	Flow Step Number	Userflow flow step number
`flow_step_progress`	Flow Step Progress	Userflow flow step progress (% towards goal step)
`flow_version_id`	Flow Version ID	Userflow flow version
`flow_version_number`	Flow Version Number	Userflow flow version number
`locale_code`	Locale Code	User’s locale when this event was tracked
`page_url`	Page URL	Page URL when the event occurred
`viewport_height`	Viewport Height	Height of the user’s viewport (browser window)
`viewport_width`	Viewport Width	Width of the user’s viewport (browser window)

Flow Started

Event name: flow_started

A Userflow flow was started.

Attribute name	Display name	Description
`flow_id`	Flow ID	Userflow flow
`flow_name`	Flow Name	Userflow flow name
`flow_session_id`	Flow Session ID	A session of a specific user viewing a specific flow
`flow_start_reason`	Flow Start Reason	Describes why a flow started
`flow_version_id`	Flow Version ID	Userflow flow version
`flow_version_number`	Flow Version Number	Userflow flow version number
`locale_code`	Locale Code	User’s locale when this event was tracked
`page_url`	Page URL	Page URL when the event occurred
`viewport_height`	Viewport Height	Height of the user’s viewport (browser window)
`viewport_width`	Viewport Width	Width of the user’s viewport (browser window)

Flow Step Seen

Event name: flow_step_seen

A Userflow flow step was seen.

Attribute name	Display name	Description
`flow_id`	Flow ID	Userflow flow
`flow_name`	Flow Name	Userflow flow name
`flow_session_id`	Flow Session ID	A session of a specific user viewing a specific flow
`flow_step_cvid`	Flow Step CVID	Userflow flow step Cross-Version ID (a pseudo-ID that does not change across versions)
`flow_step_id`	Flow Step ID	Userflow flow step
`flow_step_name`	Flow Step Name	Userflow flow step name
`flow_step_number`	Flow Step Number	Userflow flow step number
`flow_step_progress`	Flow Step Progress	Userflow flow step progress (% towards goal step)
`flow_version_id`	Flow Version ID	Userflow flow version
`flow_version_number`	Flow Version Number	Userflow flow version number
`locale_code`	Locale Code	User’s locale when this event was tracked
`page_url`	Page URL	Page URL when the event occurred
`viewport_height`	Viewport Height	Height of the user’s viewport (browser window)
`viewport_width`	Viewport Width	Width of the user’s viewport (browser window)

Launcher Activated

Event name: launcher_activated

A Userflow launcher was activated (e.g. clicked or hovered over).

Attribute name	Display name	Description
`launcher_id`	Launcher ID	Userflow launcher
`launcher_name`	Launcher Name	Userflow launcher name
`launcher_session_id`	Launcher Session ID	A session of a specific user viewing a specific launcher
`launcher_version_id`	Launcher Version ID	Userflow launcher version
`launcher_version_number`	Launcher Version Number	Userflow launcher version number
`locale_code`	Locale Code	User’s locale when this event was tracked
`page_url`	Page URL	Page URL when the event occurred
`viewport_height`	Viewport Height	Height of the user’s viewport (browser window)
`viewport_width`	Viewport Width	Width of the user’s viewport (browser window)

Launcher Dismissed

Event name: launcher_dismissed

A Userflow launcher was dismissed.

Attribute name	Display name	Description
`launcher_id`	Launcher ID	Userflow launcher
`launcher_name`	Launcher Name	Userflow launcher name
`launcher_session_id`	Launcher Session ID	A session of a specific user viewing a specific launcher
`launcher_version_id`	Launcher Version ID	Userflow launcher version
`launcher_version_number`	Launcher Version Number	Userflow launcher version number
`locale_code`	Locale Code	User’s locale when this event was tracked
`page_url`	Page URL	Page URL when the event occurred
`viewport_height`	Viewport Height	Height of the user’s viewport (browser window)
`viewport_width`	Viewport Width	Width of the user’s viewport (browser window)

Launcher Seen

Event name: launcher_seen

A Userflow launcher was seen for the first time.

Attribute name	Display name	Description
`launcher_id`	Launcher ID	Userflow launcher
`launcher_name`	Launcher Name	Userflow launcher name
`launcher_session_id`	Launcher Session ID	A session of a specific user viewing a specific launcher
`launcher_version_id`	Launcher Version ID	Userflow launcher version
`launcher_version_number`	Launcher Version Number	Userflow launcher version number
`locale_code`	Locale Code	User’s locale when this event was tracked
`page_url`	Page URL	Page URL when the event occurred
`viewport_height`	Viewport Height	Height of the user’s viewport (browser window)
`viewport_width`	Viewport Width	Width of the user’s viewport (browser window)

Question Answered

Event name: question_answered

A Userflow question was answered.

Attribute name	Display name	Description
`flow_id`	Flow ID	Userflow flow
`flow_name`	Flow Name	Userflow flow name
`flow_session_id`	Flow Session ID	A session of a specific user viewing a specific flow
`flow_version_id`	Flow Version ID	Userflow flow version
`flow_version_number`	Flow Version Number	Userflow flow version number
`list_answer`	List Answer	Answer for question with list input, such as multiple selection
`locale_code`	Locale Code	User’s locale when this event was tracked
`number_answer`	Number Answer	Answer for question with number input, such as NPS or a score
`page_url`	Page URL	Page URL when the event occurred
`question_cvid`	Question CVID	Cross-Version ID (a pseudo-ID that does not change across versions) of question that was answered
`question_name`	Question Name	Name of question that was answered
`text_answer`	Text Answer	Answer for question with text input, such as a free-form feedback field
`viewport_height`	Viewport Height	Height of the user’s viewport (browser window)
`viewport_width`	Viewport Width	Width of the user’s viewport (browser window)

Random A/B Assigned

Event name: random_ab_assigned

A random A/B attribute was set for the user.

Attribute name	Display name	Description
`locale_code`	Locale Code	User’s locale when this event was tracked
`page_url`	Page URL	Page URL when the event occurred
`random_ab_value`	Random A/B Value	The A or B value that was randomly assigned
`random_attribute_name`	Random Attribute Name	Name of the random attribute that was assigned
`viewport_height`	Viewport Height	Height of the user’s viewport (browser window)
`viewport_width`	Viewport Width	Width of the user’s viewport (browser window)

Random Number Assigned

Event name: random_number_assigned

A random number attribute was set for the user.

Attribute name	Display name	Description
`locale_code`	Locale Code	User’s locale when this event was tracked
`page_url`	Page URL	Page URL when the event occurred
`random_attribute_name`	Random Attribute Name	Name of the random attribute that was assigned
`random_number_value`	Random Number Value	The random number that was assigned
`viewport_height`	Viewport Height	Height of the user’s viewport (browser window)
`viewport_width`	Viewport Width	Width of the user’s viewport (browser window)

Resource Center Clicked

Event name: resource_center_clicked

A Userflow resource center block was clicked.

Attribute name	Display name	Description
`locale_code`	Locale Code	User’s locale when this event was tracked
`page_url`	Page URL	Page URL when the event occurred
`resource_center_click_description`	Resource Center Click Description	Description of the Userflow resource center element that was clicked
`resource_center_id`	Resource Center ID	Userflow resource center
`resource_center_name`	Resource Center Name	Userflow resource center name
`resource_center_session_id`	Resource Center Session ID	A session of a specific user viewing a specific resource center
`resource_center_version_id`	Resource Center Version ID	Userflow resource center version
`resource_center_version_number`	Resource Center Version Number	Userflow resource center version number
`viewport_height`	Viewport Height	Height of the user’s viewport (browser window)
`viewport_width`	Viewport Width	Width of the user’s viewport (browser window)

Resource Center Closed

Event name: resource_center_closed

A Userflow resource center was closed/minimized.

Attribute name	Display name	Description
`locale_code`	Locale Code	User’s locale when this event was tracked
`page_url`	Page URL	Page URL when the event occurred
`resource_center_id`	Resource Center ID	Userflow resource center
`resource_center_name`	Resource Center Name	Userflow resource center name
`resource_center_session_id`	Resource Center Session ID	A session of a specific user viewing a specific resource center
`resource_center_version_id`	Resource Center Version ID	Userflow resource center version
`resource_center_version_number`	Resource Center Version Number	Userflow resource center version number
`viewport_height`	Viewport Height	Height of the user’s viewport (browser window)
`viewport_width`	Viewport Width	Width of the user’s viewport (browser window)

Resource Center Hidden

Event name: resource_center_hidden

Deprecated (replaced by resource_center_closed).

Attribute name	Display name	Description
`locale_code`	Locale Code	User’s locale when this event was tracked
`page_url`	Page URL	Page URL when the event occurred
`resource_center_id`	Resource Center ID	Userflow resource center
`resource_center_name`	Resource Center Name	Userflow resource center name
`resource_center_session_id`	Resource Center Session ID	A session of a specific user viewing a specific resource center
`resource_center_version_id`	Resource Center Version ID	Userflow resource center version
`resource_center_version_number`	Resource Center Version Number	Userflow resource center version number
`viewport_height`	Viewport Height	Height of the user’s viewport (browser window)
`viewport_width`	Viewport Width	Width of the user’s viewport (browser window)

Resource Center Opened

Event name: resource_center_opened

A Userflow resource center was opened/expanded.

Attribute name	Display name	Description
`locale_code`	Locale Code	User’s locale when this event was tracked
`page_url`	Page URL	Page URL when the event occurred
`resource_center_id`	Resource Center ID	Userflow resource center
`resource_center_name`	Resource Center Name	Userflow resource center name
`resource_center_session_id`	Resource Center Session ID	A session of a specific user viewing a specific resource center
`resource_center_version_id`	Resource Center Version ID	Userflow resource center version
`resource_center_version_number`	Resource Center Version Number	Userflow resource center version number
`viewport_height`	Viewport Height	Height of the user’s viewport (browser window)
`viewport_width`	Viewport Width	Width of the user’s viewport (browser window)

Resource Center Shown

Event name: resource_center_shown

Deprecated (replaced by resource_center_opened).

Attribute name	Display name	Description
`locale_code`	Locale Code	User’s locale when this event was tracked
`page_url`	Page URL	Page URL when the event occurred
`resource_center_id`	Resource Center ID	Userflow resource center
`resource_center_name`	Resource Center Name	Userflow resource center name
`resource_center_session_id`	Resource Center Session ID	A session of a specific user viewing a specific resource center
`resource_center_version_id`	Resource Center Version ID	Userflow resource center version
`resource_center_version_number`	Resource Center Version Number	Userflow resource center version number
`viewport_height`	Viewport Height	Height of the user’s viewport (browser window)
`viewport_width`	Viewport Width	Width of the user’s viewport (browser window)

Tooltip Target Missing

Event name: tooltip_target_missing

A Userflow tooltip target element was not found on the page in time.

Attribute name	Display name	Description
`flow_id`	Flow ID	Userflow flow
`flow_name`	Flow Name	Userflow flow name
`flow_session_id`	Flow Session ID	A session of a specific user viewing a specific flow
`flow_step_cvid`	Flow Step CVID	Userflow flow step Cross-Version ID (a pseudo-ID that does not change across versions)
`flow_step_id`	Flow Step ID	Userflow flow step
`flow_step_name`	Flow Step Name	Userflow flow step name
`flow_step_number`	Flow Step Number	Userflow flow step number
`flow_step_progress`	Flow Step Progress	Userflow flow step progress (% towards goal step)
`flow_version_id`	Flow Version ID	Userflow flow version
`flow_version_number`	Flow Version Number	Userflow flow version number
`locale_code`	Locale Code	User’s locale when this event was tracked
`page_url`	Page URL	Page URL when the event occurred
`viewport_height`	Viewport Height	Height of the user’s viewport (browser window)
`viewport_width`	Viewport Width	Width of the user’s viewport (browser window)