TypeScript types for script tag installation

If you're loading PostHog via a <script> tag and want TypeScript types for window.posthog, you can install the @posthog/types package.

When to use this package

You need this package if:

You're loading PostHog via a <script> tag and want TypeScript types for window.posthog:

HTML
<!-- You load PostHog like this -->
<script>
    !function(t,e){...}(document,window.posthog||[]);
    posthog.init('your-api-key', { api_host: 'https://us.i.posthog.com' })
</script>

You don't need this package if:

You're installing any Javascript/Typescript PostHog library via npm, yarn, or pnpm. The types are already included:

PackageDescription
posthog-jsBrowser SDK
posthog-js-liteLighter browser SDK (types are different)
posthog-nodeNode.js SDK
posthog-react-nativeReact Native SDK
@posthog/reactReact hooks and components
typescript
// Types are already available when you install posthog-js
import posthog from 'posthog-js'


posthog.init('your-api-key')
posthog.capture('my_event') // ✅ Fully typed

Installation

Terminal
npm install @posthog/types
# or
yarn add @posthog/types
# or
pnpm add @posthog/types

Usage

Typing window.posthog (script tag usage)

Create a type declaration file to type window.posthog:

typescript
// posthog.d.ts
import type { PostHog } from '@posthog/types'


declare global {
    interface Window {
        posthog?: PostHog
    }
}


export {}

Now you can use window.posthog with full type safety:

typescript
// Your code
window.posthog?.capture('button_clicked', { button_id: 'signup' })
window.posthog?.identify('user-123', { email: 'user@example.com' })


const flagValue = window.posthog?.getFeatureFlag('my-flag')
if (flagValue === 'variant-a') {
    // ...
}

Typing configuration objects

You can also use the types to ensure your configuration objects are correctly typed:

typescript
import type { PostHogConfig, Properties } from '@posthog/types'


// Type your configuration
const config: Partial<PostHogConfig> = {
    api_host: 'https://us.i.posthog.com',
    autocapture: true,
    capture_pageview: 'history_change',
}


// Type event properties
const eventProps: Properties = {
    button_id: 'signup',
    page: '/pricing',
}

Version synchronization

The @posthog/types package version is synchronized with posthog-js. They are always released together with matching version numbers, ensuring type definitions stay in sync with the SDK.

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