Auto-Captured Fields

These fields are captured automatically by the Upstack Pixel and edge API. Do not include them in your track() calls.

Click IDs

Click IDs are captured automatically from URL parameters and browser cookies. Each platform’s click ID is stored along with a timestamp indicating when it was collected.

Meta (Facebook/Instagram)

Field	Source	Description
`fbc`	`_fbc` cookie	Meta click ID cookie (contains `fbclid` from ad click URL)
`fbp`	`_fbp` cookie	Meta browser ID (first-party cookie for user identification)
`fbclid`	URL parameter	Meta click ID from ad click URL (raw parameter value)

Google Ads

Field	Source	Description
`gclid`	URL parameter	Google click ID (standard web campaigns)
`gbraid`	URL parameter	Google click ID for iOS App campaigns (privacy-safe)
`wbraid`	URL parameter	Google click ID for web-to-app measurement

TikTok

Field	Source	Description
`ttclid`	URL parameter	TikTok click ID from ad click URL
`ttp`	`_ttp` cookie	TikTok browser ID cookie (first-party pixel cookie)

Snapchat

Field	Source	Description
`snapchatSCCid`	URL parameter	Snapchat click ID (`ScCid` parameter)
`snapchatSCCookie`	`_scid` cookie	Snapchat browser ID cookie

Field	Source	Description
`pinterestEpik`	`_epik` cookie	Pinterest click ID cookie (Enhanced Match)

AppLovin

Field	Source	Description
`applovinAxwrt`	URL parameter	AppLovin attribution token (`axwrt` parameter)
`aleid`	URL parameter	AppLovin click ID

Klaviyo

Field	Source	Description
`kx`	URL parameter	Klaviyo click ID from email links
`klaviyoCid`	URL parameter	Klaviyo campaign ID

Sendlane

Field	Source	Description
`sendlaneCid`	URL parameter	Sendlane click ID from email links

Omnisend

Field	Source	Description
`omnisendCid`	URL parameter	Omnisend click ID from email links

Field	Source	Description
`redditCid`	URL parameter	Reddit click ID from ad clicks
`redditUuid`	`_rdt_uuid` cookie	Reddit browser ID cookie

Taboola

Field	Source	Description
`tblci`	URL parameter	Taboola click ID from native ad clicks

Outbrain

Field	Source	Description
`obclid`	URL parameter	Outbrain click ID from native ad clicks

NewsBreak

Field	Source	Description
`nbclid`	URL parameter	NewsBreak click ID from ad clicks

Field	Source	Description
`liFatId`	URL parameter	LinkedIn First-Party Ad Tracking ID (`li_fat_id` parameter)

Microsoft Advertising (Bing)

Field	Source	Description
`msclkid`	URL parameter	Microsoft Advertising click ID

UTM Parameters

Captured automatically from URL query string parameters:

Field	Description
`utm_source`	Traffic source (e.g., `google`, `facebook`, `newsletter`)
`utm_medium`	Marketing medium (e.g., `cpc`, `email`, `social`)
`utm_campaign`	Campaign name or identifier
`utm_content`	Ad or link variant for A/B testing
`utm_term`	Paid search keyword

Page Context

Captured automatically from the browser on every event:

Field	Description
`host`	Hostname of the page (e.g., `www.example.com`)
`path`	URL path (e.g., `/products/widget`)
`referrer`	Full referrer URL
`search`	Query string (e.g., `?utm_source=google`)
`title`	Page title from `document.title`
`url`	Full page URL where the event fired

Viewport & Device

Captured from the browser at page load:

Field	Description
`viewportWidth`	Browser viewport width in CSS pixels
`viewportHeight`	Browser viewport height in CSS pixels
`pageHeight`	Total scrollable page height in CSS pixels
`devicePixelRatio`	Device pixel ratio (e.g., `2` for Retina displays)
`device_type`	Detected device type: `"mobile"`, `"desktop"`, or `"tablet"`
`client_user_agent`	Browser user agent string

Browser Settings

Field	Description
`locale`	Browser locale (e.g., `en-US`)
`timezone`	Browser timezone (e.g., `America/New_York`)
`adBlockDetected`	`true` if an ad blocker was detected

Geographic Data (from Cloudflare)

Captured server-side from Cloudflare’s edge network:

Field	Description
`country`	ISO 3166-1 alpha-2 country code (e.g., `US`, `GB`)
`region`	State/province name (e.g., `Texas`, `California`)
`regionCode`	ISO 3166-2 region code (e.g., `TX`, `CA`)
`city`	City name (e.g., `Austin`, `San Francisco`)
`postalCode`	Postal/zip code (e.g., `78701`)
`latitude`	Latitude coordinate
`longitude`	Longitude coordinate
`continent`	Continent code (e.g., `NA`, `EU`, `AS`)
`isEUCountry`	`"1"` if the country is in the EU
`timezone`	IANA timezone (e.g., `America/Chicago`)

Network Info (from Cloudflare)

Field	Description
`asn`	Autonomous System Number
`asOrganization`	Organization that owns the ASN (e.g., `Google Cloud`)
`isBot`	`true` if Cloudflare detects the request as a bot
`client_ip_address`	Visitor’s IP address (captured server-side)

Session & Event Metadata

Field	Description
`event_id`	Unique event ID for deduplication
`event_time`	Timestamp (ISO 8601, UTC)
`event_source_url`	Full URL where the event fired
`session_id`	Upstack session identifier
`pixel_id`	Your Upstack Pixel ID

SDK

PIXEL EVENTS

IDENTITY

AUTOMATIC TRACKING

Click IDs

Meta (Facebook/Instagram)

Google Ads

TikTok

Snapchat

Pinterest

AppLovin

Klaviyo

Sendlane

Omnisend

Reddit

Taboola

Outbrain

NewsBreak

LinkedIn

Microsoft Advertising (Bing)

UTM Parameters

Page Context

Viewport & Device

Browser Settings

Geographic Data (from Cloudflare)

Network Info (from Cloudflare)

Session & Event Metadata

​Click IDs

​Meta (Facebook/Instagram)

​Google Ads

​TikTok

​Snapchat

​Pinterest

​AppLovin

​Klaviyo

​Sendlane

​Omnisend

​Reddit

​Taboola

​Outbrain

​NewsBreak

​LinkedIn

​Microsoft Advertising (Bing)

​UTM Parameters

​Page Context

​Viewport & Device

​Browser Settings

​Geographic Data (from Cloudflare)

​Network Info (from Cloudflare)

​Session & Event Metadata

Click IDs

Meta (Facebook/Instagram)

Google Ads

TikTok

Snapchat

Pinterest

AppLovin

Klaviyo

Sendlane

Omnisend

Reddit

Taboola

Outbrain

NewsBreak

LinkedIn

Microsoft Advertising (Bing)

UTM Parameters

Page Context

Viewport & Device

Browser Settings

Geographic Data (from Cloudflare)

Network Info (from Cloudflare)

Session & Event Metadata