Consent Mode v2 with Axeptio

Axeptio is a French-origin Consent Management Platform built around CNIL guidance and popular with French, Belgian, and francophone-African publishers. It ships an IAB TCF v2.2 stub, vendor-level consent controls, and a scripted cookies:complete callback that makes Google Consent Mode v2 wiring straightforward. This playbook covers the full GTM integration.

Valid as of April 2026, Axeptio SDK v2.x / Consent Mode v2.

Overview

Axeptio communicates consent through three channels:

The _axcb callback queue — fires when the SDK is ready and again on every preference change.
The axeptio.on('cookies:complete', …) event — fires once per page with the final consent state.
An IAB TCF v2.2 API (__tcfapi) — consumed by downstream ad partners that need a TC string.

For Consent Mode v2 you only need the first two. The TCF layer handles ad-vendor chaining independently.

Prerequisites

Axeptio account with a configured project and client ID (visible in the Axeptio dashboard under Project → Settings).
Cookies configuration published (vendor list, categories, default language).
GTM container installed on the site.
The Google Tag (GA4 or Ads) configured in GTM.

Add this to your <head> before the GTM snippet and before the Axeptio loader:

<!-- Google Consent Mode v2 defaults — BEFORE GTM and Axeptio -->
<script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}

  gtag('consent', 'default', {
    ad_storage: 'denied',
    analytics_storage: 'denied',
    ad_user_data: 'denied',
    ad_personalization: 'denied',
    functionality_storage: 'denied',
    personalization_storage: 'denied',
    security_storage: 'granted',
    wait_for_update: 500
  });
</script>

Step 2 — Install the Axeptio loader

Axeptio does not publish an official GTM template at time of writing, so the SDK loads via a standard script tag. Place it in <head> after the consent defaults but before GTM:

<script type="text/javascript">
  window.axeptioSettings = {
    clientId: "YOUR_CLIENT_ID",
    cookiesVersion: "your-project-base",
    // Optional — scope the consent cookie across subdomains
    userCookiesDomain: ".example.com"
  };

  (function(d, s) {
    var t = d.getElementsByTagName(s)[0],
        e = d.createElement(s);
    e.async = true;
    e.src = "//static.axept.io/sdk.js";
    t.parentNode.insertBefore(e, t);
  })(document, "script");
</script>

Replace YOUR_CLIENT_ID and cookiesVersion with the values from your Axeptio dashboard.

Step 3 — Axeptio category mapping

Axeptio projects define their own vendor categories. The defaults from the French template are listed below. Adjust the right-hand column to match your Consent Mode signals:

Axeptio vendor category	Google Consent Signal
`google_analytics`	`analytics_storage`
`google_ads`	`ad_storage`, `ad_user_data`, `ad_personalization`
`Facebook_Pixel` / social trackers	`ad_storage`, `ad_user_data`
`functional` / preferences	`functionality_storage`, `personalization_storage`
Strictly necessary	Always granted — no mapping

Add a Custom HTML tag in GTM on the Consent Initialization — All Pages trigger with priority 10:

<script>
  window._axcb = window._axcb || [];
  window._axcb.push(function(axeptio) {

    // Fires once when Axeptio has resolved the user's consent state
    axeptio.on('cookies:complete', function(choices) {
      var analytics = !!choices.google_analytics;
      var ads = !!choices.google_ads;

      gtag('consent', 'update', {
        analytics_storage: analytics ? 'granted' : 'denied',
        ad_storage: ads ? 'granted' : 'denied',
        ad_user_data: ads ? 'granted' : 'denied',
        ad_personalization: ads ? 'granted' : 'denied',
        functionality_storage: choices.functional ? 'granted' : 'denied'
      });

      // Optional — push a dataLayer event for downstream triggers
      window.dataLayer.push({
        event: 'axeptio_consent_ready',
        axeptio_choices: choices
      });
    });

    // Fires when the user changes any single vendor preference
    axeptio.on('consent:saved', function(choices) {
      gtag('consent', 'update', {
        analytics_storage: choices.google_analytics ? 'granted' : 'denied',
        ad_storage: choices.google_ads ? 'granted' : 'denied',
        ad_user_data: choices.google_ads ? 'granted' : 'denied',
        ad_personalization: choices.google_ads ? 'granted' : 'denied'
      });
    });
  });
</script>

cookies:complete fires both for returning visitors (where consent is already stored) and for first-time visitors after they click through the banner. consent:saved handles preference-centre edits.

Step 5 — GTM configuration

Create the Custom HTML tag above. Name it CMP - Axeptio - Consent Update.
Trigger: Consent Initialization — All Pages. Priority 10 so it runs ahead of GA4 and Ads tags.
Open your Google Tag in GTM → Advanced Settings → Consent Settings and confirm analytics_storage is required.
For each Google Ads conversion tag, require ad_storage and ad_user_data.
Publish the container.

TCF v2.2 support

Axeptio exposes the standard __tcfapi interface for downstream ad vendors (Google Ad Manager, Prebid partners, header-bidding wrappers). You do not need to call it directly for Consent Mode — Google reads the TC string automatically when ad_storage is granted.

Verify the TCF stub is active:

// In browser console after the banner is interacted with
window.__tcfapi('getTCData', 2, function(tcData, success) {
  console.log('TC string:', tcData.tcString);
  console.log('Purposes:', tcData.purpose.consents);
});

Testing

GTM Preview Mode

Clear cookies, open GTM Preview, visit the site.
The Axeptio banner should appear. Before interacting, the Consent tab shows all signals denied.
Click Accept all — the CMP - Axeptio - Consent Update tag fires and the Consent tab flips to granted.
Reload the page. The tag should fire again from the stored cookie and the state should restore instantly.

GA4 DebugView

Visit the site with a ?_dbg=1 or GA Debugger extension active.
Before consent: cookieless pings appear with gcs=G100.
After accepting analytics: full events appear with gcs=G111 and a _ga cookie is set.

Console check

// After Axeptio has loaded
window._axcb.push(function(axeptio) {
  console.log('Choices:', axeptio.userPreferencesManager.choices);
});

Common gotchas

Banner appears only on the root domain. Axeptio scopes its consent cookie to the domain that served the SDK. If you serve content from both www.example.com and example.com or multiple subdomains, set axeptioSettings.userCookiesDomain = ".example.com" so the consent cookie applies across the whole property.

cookies:complete never fires for returning visitors. This happens when the cookiesVersion value has been bumped in the dashboard without your snippet being updated. Axeptio treats the stored consent as stale and waits for a fresh interaction. Keep the snippet version in sync with the dashboard.

EU-vs-non-EU traffic. Axeptio can be configured to skip the banner for non-EU visitors. If you enable that, your default consent state still applies — meaning non-EU visitors stay in denied unless you set a region-specific gtag('consent', 'default', …) block. Use geo-IP at the edge (Cloudflare Workers, CDN) to branch defaults.

Race with first pageview. Axeptio’s SDK is async. If a user lands on a page with prior consent, the restore event may arrive 200–400ms after gtm.js. The wait_for_update: 500 default covers this, but if you see occasional gcs=G100 on conversions for consented users, raise wait_for_update to 1000.

Vendor-key typos. google_analytics vs googleAnalytics vs GoogleAnalytics — Axeptio is case-sensitive. Copy the exact technical key from the project dashboard, not from documentation.

Consent Mode v2 Explained The seven consent types and why defaults must come before GTM.

CMP Integration Overview Integration patterns across all major CMPs.

Consent Initialization Timing Diagnosing and fixing timing races between CMP and GTM.

Consent Mode v2 with iubenda The same process for iubenda users.