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Signals  /  capi

Server-Side Conversion API Implementation

Send conversion events from your server, not just the visitor's browser. Every platform, one framework: install the event call, gate it on consent, deduplicate against the pixel, verify it landed.

Why CAPI, Not Just A Pixel

01 / THE PROBLEM

A client-side pixel fires from the visitor's browser and depends on that browser cooperating. A growing share of them do not.

What breaks a pixel-only setup
  • ad blockers stripping the pixel request before it fires
  • Safari's Intelligent Tracking Prevention limiting cookie lifetime
  • iOS App Tracking Transparency opt-outs
  • a visitor closing the tab before the pixel loads
  • corporate networks or privacy extensions blocking third-party requests
What a Conversions API adds
  • the event fires from your server, independent of the visitor's browser
  • it can include more first-party signal (hashed email, phone, order ID) than a pixel alone
  • it can be gated on consent state before it ever leaves your server
  • paired with the pixel and deduplicated, it recovers events the pixel alone would have dropped - it does not need to replace the pixel to add value

Get A CAPI Implementation Review

Tell us which platform's conversion data looks light, and we will check whether the gap is dedupe, consent gating, or a missing server-side event entirely.

The Four Disciplines, Every Platform

02 / FRAMEWORK

1. Install

The server-side event call to the platform's Conversions/Events API, matched to the correct event schema (event name, parameters, hashed customer data where required).

2. Consent-gate

The event is checked against the visitor's recorded consent state before it is sent - not filtered after the fact. This is wired to the consent management layer (ot.webclat.com covers OneTrust specifically) rather than bolted on.

3. Dedupe

The server event and the client pixel event for the same action carry a shared event ID (or platform-equivalent) so the ad platform counts one conversion, not two. Getting this wrong is the single most common CAPI mistake - it inflates conversion counts rather than recovering lost ones.

4. Verify

Confirmed in the platform's own diagnostics tool - not assumed from a 200 response on our own endpoint. See the verification method on the homepage for the full checklist.

Platform Implementations

03 / PILLARS

Frequently Asked Questions

What is a Conversions API (CAPI)?

A Conversions API is a server-to-server connection that sends conversion events (a purchase, a lead, a sign-up) from your own server directly to an ad platform, instead of relying only on a browser-based pixel. It exists because browsers increasingly block, delay, or strip the client-side pixel calls that used to carry this data.

Do I need CAPI if I already have a pixel installed?

Yes, if you want accurate conversion counts. A pixel-only setup depends on the visitor's browser and network cooperating - ad blockers, Safari's Intelligent Tracking Prevention, iOS App Tracking Transparency opt-outs, and slow page loads before the pixel fires all cause silent data loss. CAPI runs from your server, which does not depend on the visitor's browser at all, and is meant to run alongside the pixel with deduplication, not replace it.

How long does a CAPI implementation take?

It depends on where your event data already lives. If you run server-side Google Tag Manager or a CDP with the event already centralized, a single-platform CAPI implementation is comparatively fast. If we are building event capture from scratch, it takes longer and the estimate should reflect that discovery work - we scope this per engagement rather than quoting a fixed timeline before seeing your stack.

Do you implement CAPI for platforms not listed here?

The seven covered here (Meta, TikTok, Google, LinkedIn, X, Snapchat, Pinterest) are where measurable implementation demand and CPC data point today. If you need a platform not listed, ask - the underlying engineering pattern (install, consent-gate, dedupe, verify) applies to any platform with a server-side event API.

Not Sure Which Platform To Start With?

Send us your ad spend split across platforms and we will tell you where a missing or broken CAPI implementation is costing you the most measured conversions.

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