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Pixel installation: 5 minutes (copy-paste) First event: 10 minutes Full implementation: Days to weeks depending on your architecture

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1. Install the Fidero Pixel

Copy this snippet into your website’s <head> tag. Replace YOUR_PROJECT_ID with your ID from the Fidero dashboard. 
<!-- Paste in your <head> tag -->
<!-- Replace YOUR_PROJECT_ID with your actual ID -->
<script>
  // prettier-ignore
  !function(){let e=window.fidero=window.fidero??{};if(e.initialised)return;if(e.invoked)return console.error("[Fidero] Snippet included multiple times");e.invoked=!0;let t={};e.ready=new Promise((e,r)=>{t.resolve=e,t.reject=r}),e.ready.resolve=t.resolve,e.ready.reject=t.reject,e.buffered=[],e.initArgs=null,e.init=function(){return e.initArgs=Array.prototype.slice.call(arguments),e.ready},["updateConsent","updateIdentity","page","track","reset"].forEach(t=>{e[t]=function(){let r=Array.prototype.slice.call(arguments);r.unshift(t),e.buffered.push(r)}}),e.load=t=>{let r=(t=t||"https://cdn.datahappy.co/sdk/v0.9/fidero.js").match(/.+sdk\/v?(.+)\/fidero.js/);null!==r&&r.length>=2&&(e.version=r[1]);let i=document.createElement("script");i.type="text/javascript",i.async=!0,i.src=t,(document.head||document.body).appendChild(i)}}()

  fidero.load()
  fidero.init("YOUR_PROJECT_ID") // 👈 Add your Project ID here
  fidero.page() // Tracks first page view, captures click IDs immediately
</script>
Place the pixel in the <head>, not the <body>. We capture attribution data in the first milliseconds – including click IDs that disappear after redirects. Missing this first-page data means lost conversions.
Done! The pixel is now capturing page views, click IDs and attribution context automatically. Check your Fidero dashboard – you should see page views arriving in real-time.

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2. Send a test event

Verify everything works. Open your browser console and paste: 
fidero.track({
  event: "test_event",
  properties: {
    message: "Fidero is working! 🎉",
  },
})
Check your dashboard – the event should arrive within seconds.

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3. Track your first conversion

Now track something that matters for your business: 
// Signup event - creates unified user profile
fidero.track({
  event: "signup_completed",
  userId: "user_abc123", // Links all previous anonymous browsing to this user
  traits: {
    email: "alex@example.com",
    plan: "free_trial",
  },
})

// Subscription event - the conversion you want to attribute
fidero.track({
  event: "subscription_started",
  userId: "user_abc123",
  properties: {
    transaction_id: "sub_xyz789", // CRITICAL: Enables 98% deduplication
    value: 29.99,
    currency: "GBP",
  },
})
Correctly implementing transaction_id is the key to achieving a Duplicate-Block Rate of ≥98%. Use your unique subscription ID or payment transaction ID.
That’s it. Within 24 hours, click IDs are preserved through redirects and campaign context flows to all your destinations.

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Next steps

Choose the implementation pattern that matches your architecture:

Stripe Hosted Checkout

Preserve attribution across checkout redirects

Web-to-app flows

Unify web signup with in-app engagement

Offline conversions

Track webhook events with full attribution

Pixel API reference

Complete SDK method reference
Want to understand how the architecture works? See Server-first architecture for technical details on Browser State Capture, identity resolution and consent enforcement.