---
title: "Google Tag Manager data layer"
description: "Read CookieBeam consent state and use the data-layer events emitted by the core runtime."
url: "https://cookiebeam.com/docs/integrations/gtm-datalayer"
lang: "en"
---

# Google Tag Manager data layer

Read CookieBeam consent state and use the data-layer events emitted by the core runtime.

The core runtime publishes `window.CookieBeamGTM` for scripts and GTM templates. For installation, see [Install with Google Tag Manager](https://cookiebeam.com/docs/install/google-tag-manager).

## The `window.CookieBeamGTM` bridge

| Method | Returns or action |
| ------ | ----------------- |
| `getConsent()` | `{ categories, consentId, timestamp, isValid }` |
| `hasConsent(category)` | Whether one category is accepted |
| `getConsentDetails()` | Booleans for `necessary`, `preferences`, `analytics`, and `marketing`; `functionality` and `statistics` remain aliases |
| `updateConsent(categories)` | Accept one category, an array, `'all'`, or `'necessary'` |
| `isBannerVisible()` | Whether the consent or preferences view is visible |
| `showBanner()` | Open the consent banner |
| `showPreferences()` | Open preferences |
| `getConfig()` | The running mode, auto-show value, revision, and GTM-enabled value |

Check the bridge after the banner bundle has loaded:

```js
window.CookieBeamGTM
window.CookieBeamGTM?.getConsent()
window.CookieBeamGTM?.getConsentDetails()
```

## dataLayer events

When Google Consent Mode processes a valid consent change, the runtime pushes `cookie_consent_update`. It also pushes category events for accepted groups:

- `cookie_consent_marketing`
- `cookie_consent_statistics`
- `cookie_consent_preferences`

The live core runtime does not currently subscribe the GTM bridge to modal lifecycle events. Do not create triggers for `cookiebeam_modal_shown` or `cookiebeam_modal_hidden`; those events are not emitted by the shipped core path.

Inspect the current entries with:

```js
window.dataLayer?.filter((entry) => entry && typeof entry === 'object' && entry.event)
```

Test with a clean browser profile. Make a consent choice and confirm the expected consent event appears before relying on it as a GTM trigger.

If `window.CookieBeamGTM` is undefined, confirm that the banner bundle loaded successfully before checking GTM triggers. If the bridge exists but no consent event appears, confirm the visitor produced a valid consent change.