---
title: Pendo
description: Load Pendo after measurement consent, configure its tracking
  settings, and verify loading and withdrawal with c15t.
seoTitle: Pendo cookie consent with c15t
seoDescription: Load and initialize Pendo only after measurement consent. The
  c15t pendo helper stops and resumes event sending and keeps the visitor's
  identity.
icon: chart-line
group: integrations
lastModified: "2026-10-26T22:16:35Z"
lastAuthor: Kaylee
---
Pendo records product usage and shows in-app guides. The c15t `pendo` helper
waits until the `measurement` category is allowed before it downloads the
Pendo agent, and it calls `pendo.initialize()` only once the agent has loaded
and consent is still granted. Until then, c15t defines no `pendo` global.

When the visitor withdraws, the helper calls `pendo.stopSendingEvents()`. If
consent comes back on the same page, it calls `startSendingEvents()` and keeps
the same visitor identity. c15t still reloads the page by default.

## Configure Pendo

Copy the web agent API key from Pendo. Then delete Pendo's install snippet from
your app, and any tag manager copy, so Pendo can't load outside c15t. Pass
visitor and account metadata only when your app has permission to identify the
visitor.

|Package manager|Command|
|:--|:--|
|npm|`npm install @c15t/integrations`|
|pnpm|`pnpm add @c15t/integrations`|
|yarn|`yarn add @c15t/integrations`|
|bun|`bun add @c15t/integrations`|

```ts title="src/consent-scripts.ts"
import { pendo } from '@c15t/integrations/pendo';

export const scripts = [pendo({ apiKey: 'YOUR_API_KEY' })];
```

## Register the scripts

Complete your [framework quickstart](/docs/frameworks) first. Keep its Inth
endpoint, policy, styles and consent UI. Remove the vendor's original script,
SDK initializer or tag-manager entry, so the vendor loads only through c15t.

The vendor pages put the helper in `src/consent-scripts.ts`. If your framework
quickstart already has a `scripts` array, such as the one in `c15t.config.ts`
in the Next.js guide, add the helper to that array instead of creating a
second file.
The `scripts` export is a configuration, not an initializer. Add it to the c15t provider you already have, at the registration
point for your framework below. These are edits to that provider, not a second
provider.

**Next.js**

Add the configuration to `scripts` in `c15t.config.ts`, next to
`next.config.ts`:

```ts title="c15t.config.ts"
import { defineConsentConfig } from 'c15t/next';
import { scripts } from './src/consent-scripts';

export default defineConsentConfig({ scripts });
```

Keep the rest of your config, such as `mode` and `routePrefix`, in the
same call. `ConsentRoot` reads the config in the browser, so the layout
keeps passing only `state`. App Router, Pages Router and static export all
read the same file. See
[Next.js scripts and embeds](/docs/frameworks/next/scripts).

**TanStack Start**

Import the configuration into your root route and pass it to the existing
`ConsentRoot` as a top-level prop. Keep the loader from the
[TanStack Start quickstart](/docs/frameworks/tanstack-start/quickstart):

```tsx title="src/routes/__root.tsx"
import { scripts } from '../consent-scripts';

<ConsentRoot state={consent} scripts={scripts}>
```

Import vendor helpers in the root route module, not in a server function.
A server function's return value must be serializable, and script
configurations carry callbacks. See
[TanStack Start scripts](/docs/frameworks/tanstack-start/scripts).

**React**

Add the configuration to the existing `ConsentProvider` options, next to
`mode`:

```tsx title="src/consent.tsx"
import { scripts } from './consent-scripts';

<ConsentProvider options={{ mode, scripts }}>
```

`mode` is the `manifest()` value from the
[React quickstart](/docs/frameworks/react/quickstart). Keep the banner,
dialog and preferences link inside the provider. See
[React scripts and embeds](/docs/frameworks/react/scripts).

**Nuxt**

Register the scripts under the `c15t` key in `app/app.config.ts`. Adjust the
relative import to where you created `consent-scripts.ts`:

```ts title="app/app.config.ts"
import { scripts } from '../src/consent-scripts';

export default defineAppConfig({
  c15t: { scripts },
});
```

The Nuxt module merges this over its options in `nuxt.config.ts` and starts
one script loader in the browser after hydration, once it has applied the
visitor's stored choice and privacy signals. Keep `scripts` out of
`nuxt.config.ts`, which reaches the browser as JSON and drops the vendor
callbacks. Write the vendor IDs into `consent-scripts.ts`. See
[Nuxt scripts and embeds](/docs/frameworks/nuxt/scripts).

**Vue**

Pass the scripts to the existing `c15tVue` plugin call in `src/main.ts`:

```ts title="src/main.ts"
import { c15tVue, manifest } from 'c15t/vue/vue-plugin';
import { scripts } from './consent-scripts';

app.use(c15tVue, {
  mode: manifest(),
  scripts,
});
```

Keep your existing `mode` and other options. The plugin starts one
script loader when the app mounts, after it has applied the visitor's stored
choice. Do not also call `createScriptLoader` from a component. See
[Vue scripts and embeds](/docs/frameworks/vue/scripts).

**Astro**

Add the scripts to the client entrypoint from the
[Astro quickstart](/docs/frameworks/astro/quickstart), `src/c15t.client.ts`,
which the integration finds on its own. Keep `astro.config.mjs` as it is.
If the module already exports scripts, combine the two arrays.

```ts title="src/c15t.client.ts"
import type { C15tClientOptionsExtension } from 'c15t/astro';
import { scripts } from './consent-scripts';

export default { scripts } satisfies C15tClientOptionsExtension;
```

Vendor helpers contain callbacks, and the integration options in
`astro.config.mjs` are serialized into the page, so do not put helpers in
the integration's `scripts` option. The integration passes the client
entrypoint to the one runtime every page shares, including across
`ClientRouter` navigation.

**Svelte**

Import the scripts in the component that owns your existing provider and
pass them as a top-level prop:

```svelte title="src/App.svelte"
<script lang="ts">
  import { ConsentProvider, manifest } from 'c15t/svelte';
  import { scripts } from './consent-scripts';
</script>

<ConsentProvider mode={manifest()} {scripts}>
  <!-- Keep your application, consent UI and preferences link here. -->
</ConsentProvider>
```

Retain the styles and consent UI from the [Svelte quickstart](/docs/frameworks/svelte/quickstart).
The provider owns the loader and disposes it on unmount.

**SvelteKit**

Add the scripts to the existing `ConsentRoot` in the root layout. Keep the
handle and the layout load from the [SvelteKit quickstart](/docs/frameworks/sveltekit/quickstart).

```svelte title="src/routes/+layout.svelte"
<script lang="ts">
  import { ConsentRoot } from 'c15t/svelte';
  import { scripts } from '../consent-scripts';

  let { children, data } = $props();
</script>

<ConsentRoot state={data.consent} {scripts}>
  {@render children()}
  <!-- Keep your consent UI and preferences link here. -->
</ConsentRoot>
```

Import vendor helpers in the layout component, not in `+layout.server.ts`:
a server load cannot send functions to the browser. Prerendered, static and
SPA-mode pages use the same `scripts` prop. If you pass an externally owned
`runtime` to the provider, register scripts when creating that runtime instead.

**HTML**

The helpers in `@c15t/integrations` are ES modules that need a bundler. On a
page that loads the c15t script tag, paste the vendor's own snippet instead
and keep it inert until its category is allowed:

```html
<script type="text/plain" data-c15t-category="measurement">
  // The vendor's snippet, unchanged
</script>
```

Use the category this guide names for the vendor. c15t runs the snippet
once that category is allowed, and reloads the page when the visitor
withdraws it. Helper options on this page, such as `loadMode`, do not apply
to a pasted snippet. See [HTML scripts](/docs/frameworks/html/scripts).

**JavaScript**

Pass the scripts to `init()` from `@c15t/browser`, next to your mode:

```ts
import { init, manifest } from '@c15t/browser';
import { scripts } from './consent-scripts';

const consent = init({
  mode: manifest(),
  scripts,
});
```

Keep the mode from your quickstart. With
`createConsentRuntime` from `c15t/runtime`, pass `scripts` to it instead.
A kernel you create yourself needs a loader from
`c15t/modules/script-loader`. Attach one loader per kernel. See
[JavaScript scripts](/docs/frameworks/javascript/scripts).

## Options

|Option|Default|Behavior|
|--|--|--|
|`apiKey`|Required|Web agent API key. Trimmed and URL-encoded into the default loader URL. If it's missing or blank, c15t logs an error and never loads Pendo.|
|`visitor`|Unset|Visitor metadata passed to `pendo.initialize()`. Replaces any `visitor` in `initializeOptions`.|
|`account`|Unset|Account metadata passed to `pendo.initialize()`. Replaces any `account` in `initializeOptions`.|
|`initializeOptions`|Unset|Other `initialize()` options, such as `disableCookies`, `localStorageOnly`, `excludeAllText` and `cookieDomain`.|
|`category`|`measurement`|Consent category or condition that must be allowed before the agent loads.|
|`scriptUrl`|`https://cdn.pendo.io/agent/static/<apiKey>/pendo.js`|Custom, regional or proxied agent URL. A blank value uses the default.|

## Loading and revocation

When the category is allowed, the helper adds the agent as an async script. It
doesn't queue calls before the agent loads. After the script loads, it checks
consent again and calls `initialize()` with your options. If the visitor
withdrew while the agent was downloading, the helper doesn't initialize. It
initializes on the next grant instead. Calling `pendo()` again with equal
options, such as on a rerender, returns the same script, so Pendo initializes
only once per page.

If the loaded script doesn't define `window.pendo`, for example because the API
key or `scriptUrl` is wrong, the helper logs
`pendo: loader did not install the Pendo API` and does nothing else. It doesn't
throw.

On withdrawal, the helper keeps the agent on the page and calls
`stopSendingEvents()`. On a later grant it calls `startSendingEvents()` and
doesn't initialize a second time. This keeps the visitor's identity across
reversible consent changes.

The helper never calls `clearSession()`, because that starts a new anonymous
visitor and can send identification events. If a visitor signs out while Pendo
is loaded and consent is granted, call `pendo.clearSession()` yourself before
you identify the next visitor. Don't call it to withdraw consent, or while
consent is denied. To remove data Pendo already collected, use your account's
data deletion or Do Not Process controls.

Stopping events doesn't delete Pendo's cookies or local storage, and guides
already on the page stay there. Keep `reloadOnConsentRevoked` enabled if the
next page must run without Pendo loaded.

## Cookies and storage

Pendo storage keys usually start with `_pendo_` and include the app ID. Cookie
behavior depends on `initialize()` options such as `disableCookies`,
`localStorageOnly` and `cookieDomain`.

## Verify Pendo

Filter the DevTools Network panel by `pendo.io`. Before consent, and with only
an unrelated category allowed, check that no Pendo request, `pendo` global,
cookie or storage entry appears. Allow measurement and confirm that the agent
loads and initializes once. Withdraw consent and confirm the page reloads with
Pendo blocked.

If you set `reloadOnConsentRevoked: false`, withdraw consent and check that
`pendo.isSendingEvents()` returns `false`. Grant again and confirm that event
sending resumes without a new anonymous visitor. Test guide behavior with your
own account.

If the console shows `pendo: loader did not install the Pendo API`, check the
API key and `scriptUrl`.

Sources: [installation](https://support.pendo.io/hc/en-us/articles/360031862272-Install-Pendo-on-a-single-page-web-application),
[collection prevention](https://support.pendo.io/hc/en-us/articles/17541315915035-Data-collection-prevention-strategies),
[event controls](https://web-sdk.pendo.io/public/events) and
[cookies](https://web-sdk.pendo.io/cookies/).

Test in a private window with an opt-in policy. Open DevTools Network, disable
the cache and filter by the vendor's domain:

1. Load the page. No request goes to the vendor before you choose.
2. Click Reject, then reload. There is still no vendor request.
3. Open Privacy settings and allow the helper's category. The vendor script
   loads without a page reload.
4. Turn the category off again and save. c15t reloads the page, and the new
   page makes no vendor request.

c15t reloads on revocation because removing a script element does not stop
code that already ran. The vendor's listeners, timers and queued events stay
alive until the page unloads. If you set `reloadOnConsentRevoked: false`, stop
the vendor yourself. Register a callback-only script whose `onConsentChange`
calls the vendor's opt-out API, as shown in
[custom integrations](/docs/integrations/building-integrations), and check the
permission before each of your own event calls. The reload does not delete
cookies the vendor already set; see
[clear on revocation for your framework](/docs/integrations/overview#vendor-switches-and-cookie-cleanup).

The helper lists its vendor by name in the preference dialog, so a visitor can
turn it off inside an allowed category. See
[vendor consent for your framework](/docs/integrations/overview#vendor-switches-and-cookie-cleanup). The
[consent verification guide](/docs/guides/verify-consent) covers navigation,
expiry and hosting checks.