TanStack Start web analytics installation

Install the package

Required

Install the PostHog JavaScript library using your package manager:

npm install posthog-js
yarn add posthog-js
pnpm add posthog-js

Add environment variables

Required

Add your PostHog API key and host to your environment variables:

.env
VITE_PUBLIC_POSTHOG_KEY=<ph_project_api_key>
VITE_PUBLIC_POSTHOG_HOST=https://us.i.posthog.com

Initialize PostHog

Required

Wrap your app with the PostHogProvider component at the root of your application (such as main.tsx):

main.tsx
import { StrictMode } from 'react'
import { createRoot } from 'react-dom/client'
import './index.css'
import App from './App.jsx'
import { PostHogProvider } from 'posthog-js/react'

const options = {
  api_host: import.meta.env.VITE_PUBLIC_POSTHOG_HOST,
  defaults: '2026-01-30',
} as const

createRoot(document.getElementById('root')).render(
  <StrictMode>
    <PostHogProvider apiKey={import.meta.env.VITE_PUBLIC_POSTHOG_KEY} options={options}>
      <App />
    </PostHogProvider>
  </StrictMode>
)

defaults option

The defaults option automatically configures PostHog with recommended settings for new projects. See SDK defaults for details.

Send events

Click around and view a couple pages to generate some events. PostHog automatically captures pageviews, clicks, and other interactions for you.

If you'd like, you can also manually capture custom events:

JavaScript
posthog.capture('my_custom_event', { property: 'value' })

5
Next steps
Recommended
After installing PostHog and ensuring autocapture is enabled, head to your web analytics dashboard to see your data. And then check out our getting started guide.
PostHog tip: Web analytics works with anonymous events. This means if you are primarily using PostHog for web analytics, it can be significantly cheaper for you.

TanStack Start web analytics installation

Install the package

Add environment variables

Initialize PostHog

Send events

Next steps

Community questions

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