Consent Categories

c15t groups tracking into five categories, aligned with GDPR / ePrivacy guidance. Users toggle categories, not individual cookies — listing every _ga / _fbp name is noise that doesn't help users decide.

Category	Always enabled	Typical purpose
necessary	Yes — cannot be disabled	Session, CSRF, cart, auth — things the site literally can't function without.
functionality	No	Preferences, remembered settings, language, theme.
experience	No	Quality-of-life improvements — soft analytics, feature flags tied to consent.
measurement	No	Analytics and telemetry — GA4, Mixpanel, PostHog.
marketing	No	Ads, retargeting, social embeds.

necessary is enforced internally. Toggling it off from the UI is not possible — c15t treats it as permanently granted.

Choosing which to show

List the categories you actually use:

c15t: {
  consentCategories: ['necessary', 'measurement', 'marketing'],
}

Unlisted categories don't appear in the banner or dialog but still exist in the consent state (default false). You can check them in code regardless:

const { has } = useC15t()
const hasExperience = has('experience') // always false if not listed and not granted

Mapping categories to real cookies

consentCategories controls the UI toggles. The cookie policy table lists individual cookies and maps them back to categories — users see a summary grouped by category, with the underlying vendor cookies visible if they want the detail.

c15t: {
  consentCategories: ['necessary', 'measurement', 'marketing'],
  cookiePolicy: {
    vendors: ['google-analytics', 'meta-pixel'],
    cookies: [
      { name: 'session_id', vendor: 'This website', category: 'necessary', /* ... */ },
    ],
  },
}

How categories flow through your code

• Category check — useC15t().has('measurement') returns a reactive boolean.
• Compound check — pass { and: ['measurement', 'marketing'] } or { or: [...] } for multi-category conditions.
• Script gate — useC15tScriptTrigger returns a Promise for @nuxt/scripts.
• Iframe gate — <C15tIframe category="marketing"> or raw <iframe data-category="marketing" data-src="...">.
• Network gate — network blocker rules with { category: 'measurement' }.
• Arbitrary gate — <C15tConsentGate category="experience"> for any slot content.

The whole module treats category as the unit of consent — adding a new one is a single string in consentCategories.