Product analytics and campaign attribution

Overview

The web app records product analytics (usage and conversion events) and first-touch campaign data from query parameters. Attribution runs in the browser via UtmAttribution.svelte on the root layout; no extra page wiring is required for basic UTM storage.

This is separate from platform analytics (followers, impressions, per-post metrics from social providers). See Analytics APIs for channel and post insights.

Environment variables

More detail on Vite keys: Configuration — Vite (SvelteKit).

Where to get credentials

• PostHog — posthog.com → Project settings → Project token (phc_…) and API host.
• Meta Pixel — Meta Events Manager → your Pixel → Pixel ID; Conversions API → Generate access token (backend only).
• Google Analytics — Google Analytics → Admin → Data streams → Measurement ID.

UTM and campaign capture

On every visit, the app can persist:

localStorage key	Set when	Meaning
utm	First matching query param	Campaign source string (first-touch)
landingUrl	First visit only	Full URL of the first page loaded
referrer	First visit only	document.referrer on that first visit

Supported query parameters

The first non-empty value wins and is stored once (later visits do not overwrite utm):

• utm_source
• utm
• ref

Example marketing links

Newsletter

https://web-production-ce4be0.up.railway.app/sign-up?utm_source=newsletter&utm_medium=email&utm_campaign=march

Stored value: newsletter (only utm_source is read into utm; medium and campaign are not saved unless you extend utm.ts).

Partner or affiliate

https://web-production-ce4be0.up.railway.app/?ref=partner_acme

Stored value: partner_acme.

Paid social

https://web-production-ce4be0.up.railway.app/?utm_source=meta&utm_campaign=prospecting

Stored value: meta.

Verify in the browser

1. Open your site with a tagged URL, e.g. https://localhost:5173/?utm_source=test_dev.
2. DevTools → Application → Local Storage → your origin.
3. Confirm utm, landingUrl, and referrer.
4. Navigate to another route without query params — utm should still be test_dev.

Post-checkout return (check)

If the user lands with ?check=1 (or any truthy check query), the layout fires:

• PostHog event purchase (when Stripe + PostHog are configured)
• Meta conversion StartTrial (when Pixel + CAPI token are configured)

Example:

https://web-production-ce4be0.up.railway.app/account/billing?check=1

Use this on return URLs after Stripe Checkout or trial confirmation flows you control.

Reading stored UTM in app code

Export readStoredUtm() from $lib/product-analytics returns the stored campaign string. You can attach it to checkout payloads or analytics event properties, for example:

import { readStoredUtm, fireProductEvent } from '$lib/product-analytics';

const utm = readStoredUtm();
fireProductEvent('initiate_checkout', { utm });

Event map (hosted product)

When billing is enabled (VITE_PUBLIC_STRIPE_PUBLISHABLE_KEY set), common events include:

User action	PostHog (approx.)	Meta conversion
Sign-up success	register	CompleteRegistration
Subscribe click	—	InitiateCheckout
Checkout return with check	purchase	StartTrial
Billing poll after checkout	purchase	Purchase
Channel connected (added query)	channel_added	—

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