Automatic Form Capture - Upstack Data

Upstack automatically detects and captures form submissions from popular email and SMS platforms. When a visitor submits a form on one of these platforms, we capture their email and/or phone number and fire appropriate tracking events.

Works on any website — these integrations work on Shopify stores, headless storefronts, and custom websites. As long as the Upstack pixel and the third-party tool are both installed, form capture is automatic.

No configuration required — these integrations work automatically when both Upstack and the third-party tool are installed on your site.

How It Works

When a visitor submits a signup form from a supported platform:

Upstack detects the submission automatically when both apps are installed
Captures email and/or phone from the form data
Fires a Lead event with the captured information
Associates the session with the captured identity
Forwards to destinations (Meta, TikTok, Klaviyo, etc.)

Supported Platforms

Upstack automatically captures signups from the following platforms:

Platform	Supported Forms
Klaviyo	Popups, embedded forms, flyouts
Postscript	SMS opt-in popups and forms
Attentive	Two-tap creative, email capture
Omnisend	Popups, signup boxes, wheels
Sendlane	Popups and embedded forms
Recart	Opt-in popups and tools
Listrak	Email and SMS capture forms
Justuno	Popups and embedded forms
Alia	Signup popups
Octane AI	Quiz lead capture
Loop Subscriptions	Subscription management events

Events Fired

When a visitor interacts with a supported form, the following events may fire:

Event	When It Fires
`email_opt_in_form_displayed`	Popup or form becomes visible to visitor
`Lead`	Visitor submits email and/or phone
`email_opt_in_form_submitted`	Same as Lead — fired alongside for compatibility
`email_opt_in_form_declined`	Visitor dismisses the form without submitting

All events include captured email/phone for identity resolution when available.

Platform Details

Recart

Upstack automatically captures leads from Recart opt-in tools. Events Captured:

recart:optin-tool:email-captured
recart:optin-tool:phone-number-captured

Data Captured:

Email address
Phone number
Opt-in tool ID
Opt-in tool name

Upstack Event Fired: Lead

Listrak

Upstack automatically captures leads from Listrak forms. Events Captured:

ltkEmailIdentityEvent
ltkPhoneIdentityEvent

Data Captured:

Email address
Phone number

Upstack Event Fired: Lead

Justuno

Upstack automatically captures leads from Justuno popups and forms. Detection Method: Monitors form field changes for ju_hidden_email and ju_hidden_sms fields. Data Captured:

Email address (from ju_hidden_email field)
Phone number (from ju_hidden_sms field)

Upstack Event Fired: Lead

Alia

Upstack automatically captures leads from Alia signup popups. Events Captured:

alia:signup

Data Captured:

Email address
Phone number
Popup ID

Upstack Event Fired: Lead

Octane AI Quiz

Upstack automatically tracks quiz interactions from Octane AI, including question responses, quiz completion, and lead capture. Events Captured:

Octane Event	Upstack Event
`octane.quiz.questionAnswered`	`quiz_question_answered`
`octane.quiz.completed`	`quiz_completed` + `Lead` (if email/phone captured)
`octane.quiz.accessed`	`view_quiz_results`

Data Captured:

Quiz answer details
Email address (from lead capture step)
Phone number (from lead capture step)
Quiz completion status

The Lead event fires automatically when email or phone is captured during quiz completion.

Loop Subscriptions

Upstack tracks subscription management events from Loop Subscriptions, enabling attribution for subscription-related cart actions. Events Captured:

Loop Event	Upstack Event
`loopAddAsOneTime`	`add_to_cart`
`loopAddAsSubscription`	`add_to_cart`
`loopBundleAddAsOneTime`	`add_to_cart`
`loopBundleAddAsSubscription`	`add_to_cart`
`loopItemAddToBundleSuccessEvent`	`add_to_cart`
`loopByobAddToCartSuccessEvent`	`add_to_cart`
`loopPresetAddToCartSuccessEvent`	`add_to_cart`
`loopRemoveForOneTime`	`product_removed_from_cart`
`loopRemoveFromSubscription`	`product_removed_from_cart`
`loopBundleRemoveForOneTime`	`product_removed_from_cart`
`loopBundleRemoveFromSubscription`	`product_removed_from_cart`

Data Captured:

Product ID
Variant ID
Product title
Price
Quantity

Loop also fires additional subscription management events (pause, resume, cancel, etc.) that are tracked for analytics but not mapped to standard e-commerce events.

What Destinations Receive

When a form submission is detected, Upstack automatically forwards the event to your connected destinations:

// Destination wire format (what Meta CAPI receives)
{
  "event_name": "Lead",
  "event_time": "2026-02-18T14:39:00.000Z",
  "event_source_url": "https://example-store.com/",
  "user_data": {
    "em": "a1b2c3d4e5f6...hashed",
    "ph": "f6e5d4c3b2a1...hashed",
    "client_ip_address": "203.0.113.42",
    "client_user_agent": "Mozilla/5.0..."
  },
  "custom_data": {
    "content_name": "Newsletter Signup"
  }
}

You don’t need to write any code for form capture integrations — Upstack detects and processes these automatically.

Destination Forwarding

Form submissions are automatically forwarded to your enabled destinations:

Destination	Event Received	Lead Data
Meta CAPI	`Lead`	Email (hashed), phone (hashed)
TikTok Events API	`SubmitForm`	Email (hashed), phone (hashed)
Google Ads	`generate_lead`	Enhanced conversions data
Klaviyo	Profile created/updated	Full PII
Attentive	Subscriber created	Phone, email

Lead events are valuable for building audiences and measuring top-of-funnel performance, even if you don’t optimize directly for leads.

Identity Resolution

When a form is submitted:

Email is captured and used as primary identifier
Phone is captured if provided (E.164 format)
Session is associated with the captured identity
Cross-device matching becomes possible for repeat visitors

This means when a visitor who previously submitted a form returns to your site, Upstack can recognize them and attribute their behavior to the original touchpoint — even if they’re on a different device.

Identity resolution works across all form capture integrations and connects with data from checkout identity capture.

Troubleshooting

Form submissions not tracking

Verify both apps are installed:

Confirm Upstack is installed and active (check for events in the dashboard)
Confirm the third-party tool (Klaviyo, Postscript, etc.) is installed on your storefront
Test by submitting a form and checking the Live Event Stream in your Upstack dashboard

Check browser console:Open browser DevTools (F12) and look for JavaScript errors that might prevent form detection.Contact support:If the form is from a supported platform but not tracking, contact support with the form URL for investigation.

Identity not resolving

Verify data format:

Email must be a valid email format
Phone should be in E.164 format (e.g., +14155551234)

Check consent settings:If the visitor hasn’t granted analytics consent, identity resolution may be limited.Allow time for resolution:Identity stitching happens asynchronously. Check back in a few minutes if the identity doesn’t appear immediately.

Events not forwarding to destinations

Check destination configuration:

Go to Integrations → Destinations in your Upstack dashboard
Verify the destination is connected and active
Check that Lead events are enabled for that destination

Review event mapping:Some destinations may map Lead events to different event names. Check the destination-specific documentation for details.

Standard Events

Full reference for Lead and other standard events.

Shopify Automatic Tracking

How checkout and storefront events are captured.

Identity Resolution

How Upstack connects visitor sessions across devices.

Meta CAPI

Configure Lead event forwarding to Meta.

​How It Works

​Supported Platforms

​Events Fired

​Platform Details

​Recart

​Listrak

​Justuno

​Alia

​Octane AI Quiz

​Loop Subscriptions

​What Destinations Receive

​Destination Forwarding

​Identity Resolution

​Troubleshooting

​Related

Standard Events

Shopify Automatic Tracking

Identity Resolution

Meta CAPI

How It Works

Supported Platforms

Events Fired

Platform Details

Recart

Listrak

Justuno

Alia

Octane AI Quiz

Loop Subscriptions

What Destinations Receive

Destination Forwarding

Identity Resolution

Troubleshooting

Related