How to integrate Buttons and RSVP Forms with Nuxt

Step 1: npm installation

Install the package from the npm registry.

npm install add-to-calendar-button

Step 2: Create a client plugin

Create plugins/add-to-calendar.client.ts in your Nuxt app directory (app/plugins/ in the default Nuxt 4 structure). The .client.ts suffix loads the core package only in the browser.

import 'add-to-calendar-button/styles/all';
import 'add-to-calendar-button/i18n/de';
import 'add-to-calendar-button';

export default defineNuxtPlugin(() => {});

Step 3: Register the custom element

Merge this compiler setting into your existing configuration so Vue recognizes the Web Component.

// nuxt.config.ts
export default defineNuxtConfig({
  vue: {
    compilerOptions: {
      isCustomElement: (tag) => tag === 'add-to-calendar-button',
    },
  },
});

Step 4: Use it

<template>
  <ClientOnly>
    <add-to-calendar-button prokey="prokey-of-your-event"></add-to-calendar-button>
  </ClientOnly>
</template>

Bring your own button

Open the button or form as a modal from a click handler. The dynamic import runs in the browser when clicked. Pass the trigger element for focus handling.

<script setup>
async function openEvent(event) {
  const trigger = event.currentTarget;
  const { atcb_action } = await import('add-to-calendar-button');
  atcb_action({ prokey: 'prokey-of-your-event' }, trigger);
}
</script>

<template>
  <button @click="openEvent">Open event</button>
</template>

Styles and languages

The npm package includes only the default style and English by default. The example mixes add-to-calendar-button/styles/all with add-to-calendar-button/i18n/de, which is valid: use add-to-calendar-button/styles/3d when your style is fixed, or add-to-calendar-button/styles/all when remote PRO configuration can change it without deployment. Import the specific language or small known set, such as add-to-calendar-button/i18n/de, by default; use add-to-calendar-button/i18n/all only when languages can change unpredictably at runtime. Both /all imports increase the bundle because they include every respective asset.

Alternatively, load styles and languages dynamically from jsDelivr by setting style-source="https://cdn.jsdelivr.net/npm/add-to-calendar-button@3/dist/styles/" on the element. Apply the same strategy to custom triggers; the option is named styleSource in atcb_action.

Optional: Server-side rendering

The package provides a separate SSR entry to pre-render a button shell. In v3.3.0, that server-rendered shell retains matching styles until the client upgrade. Use its asynchronous variant on the server for PRO data, then load required style and language modules before the main module in the client plugin. Full interaction and RSVP forms still initialize in the browser. See SSR with PRO and the Button Nuxt guide.

Do not render the generated SSR shell with v-html: Vue would replace its shadow DOM during hydration. The official Nuxt guide demonstrates a directive that preserves existing server markup.