Chapter 160 · Omnibus Instrument Integration
Subchapter 160.9
references/EXAMPLE-astro-static.mdMarkdown19 KBView on GitHub
Repository: https://github.com/PostHog/context-mill Path: basics/astro-static
This is an Astro (opens in a new tab) static site (SSG) example demonstrating PostHog integration with product analytics, session replay, and error tracking.
It uses the PostHog web snippet directly and shows how to:
posthog.captureException()npm install
# or
pnpm installCreate a .env file in the project root:
PUBLIC_POSTHOG_PROJECT_TOKEN=your_posthog_project_token
PUBLIC_POSTHOG_HOST=https://us.i.posthog.comGet your PostHog project token from your project settings in PostHog.
npm run dev
# or
pnpm devOpen http://localhost:4321 in your browser.
src/
components/
posthog.astro # PostHog snippet with is:inline directive
Header.astro # Navigation + logout, calls posthog.reset()
layouts/
PostHogLayout.astro # Root layout that includes PostHog + Header
lib/
auth.ts # Auth utilities (localStorage-based)
pages/
index.astro # Login form, identifies user + captures 'user_logged_in'
burrito.astro # Burrito consideration demo, captures 'burrito_considered'
profile.astro # Profile + error tracking demo
styles/
global.css # Global stylesThe PostHog snippet is included as an inline script to prevent Astro from processing it:
<script is:inline>
!function(t,e){...}(document,window.posthog||[]);
posthog.init('<ph_project_token>', {
api_host: 'https://us.i.posthog.com',
defaults: '2026-01-30'
})
</script>The is:inline directive is required to prevent TypeScript errors about window.posthog.
After a successful “login”, the app identifies the user and captures a login event:
window.posthog?.identify(username);
window.posthog?.capture("user_logged_in");Identification happens only on login, all further requests will automatically use the same distinct ID.
The burrito page tracks a custom event when a user “considers” the burrito:
window.posthog?.capture("burrito_considered", {
total_considerations: newCount,
username: currentUser,
});This shows how to attach useful properties to events (e.g. counts, usernames).
The profile page includes a button to trigger a test error:
try {
throw new Error("Test error for PostHog error tracking");
} catch (err) {
window.posthog?.captureException(err);
}On logout, both the local auth state and PostHog state are cleared:
window.posthog?.capture("user_logged_out");
localStorage.removeItem("currentUser");
window.posthog?.reset();posthog.reset() clears the current distinct ID and session so the next login starts a fresh identity.
# Run dev server
npm run dev
# Build for production
npm run build
# Preview production build
npm run previewPUBLIC_POSTHOG_PROJECT_TOKEN=your_posthog_project_token_here
PUBLIC_POSTHOG_HOST=https://us.i.posthog.com
import { defineConfig } from "astro/config";
export default defineConfig({});
---
// Header component with navigation and logout functionality
---
<header class="header">
<div class="header-container">
<nav>
<a href="/">Home</a>
<a href="/burrito" class="auth-link" style="display: none;">Burrito Consideration</a
---
// PostHog analytics snippet
// Uses is:inline to prevent Astro from processing the script
---
<script is:inline define:vars={{ apiKey: import.meta.env.PUBLIC_POSTHOG_PROJECT_TOKEN, apiHost: import.meta.env.PUBLIC_POSTHOG_HOST }}>
!function(t,e){var o,n,p,r;e.__SV||(window.posthog=e,e._i=[],e.init=function(i,s,a){function g(t,e){var o=e.split(".");2==o.length&&(t=
posthog.init(apiKey || '', {
api_host: apiHost || 'https://us.i.posthog.com',
defaults: '2026-01-30'
})
</script>
---
import PostHog from '../components/posthog.astro';
import Header from '../components/Header.astro';
import '../styles/global.css';
interface Props {
title: string;
}
const { title } = Astro.props;
---
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<meta name="description" content="Astro PostHog Integration Example" />
<link rel="icon" type="image/svg+xml" href="/favicon.svg" />
<title>{title}</title>
<PostHog />
</head>
<body>
<Header />
<main>
<slot />
</main>
</body>
</html>
// Client-side auth utilities for localStorage-based authentication
export interface User {
username: string;
burritoConsiderations: number;
}
export function getCurrentUser(): User | null {
if (typeof window === "undefined") return null;
const username = localStorage.getItem("currentUser");
if (!username) return null;
const considerations = parseInt(
localStorage.getItem("burritoConsiderations") || "0",
10,
);
return {
username,
burritoConsiderations: considerations,
};
}
export function login(username: string, password: string): boolean {
if (!username || !password) return false;
localStorage.setItem("currentUser", username);
// Initialize burrito considerations if not set
if (!localStorage.getItem("burritoConsiderations")) {
localStorage.setItem("burritoConsiderations", "0");
}
return true;
}
export function logout(): void {
localStorage.removeItem("currentUser");
localStorage.removeItem("burritoConsiderations");
}
export function incrementBurritoConsiderations(): number {
const current = parseInt(
localStorage.getItem("burritoConsiderations") || "0",
10,
);
const newCount = current + 1;
localStorage.setItem("burritoConsiderations", newCount.toString());
return newCount;
}
---
import PostHogLayout from '../layouts/PostHogLayout.astro';
---
<PostHogLayout title="Burrito Consideration - Astro PostHog Example">
<div class="container">
<h1>Burrito consideration zone</h1>
<p>Take a moment to truly consider the potential of burritos.</p>
<div style="text-align: center;">
<button id="consider-btn" class="btn-burrito">
I have considered the burrito potential
</button>
<p id="success-message" class="success" style="display: none;">
Thank you for your consideration! Count: <span id="consideration-count"></span>
</p>
</div>
<div class="stats">
<h3>Consideration stats</h3>
<p>Total considerations: <span id="total-considerations">0</span></p>
</div>
</div>
</PostHogLayout>
<script is:inline>
function checkAuth() {
const currentUser = localStorage.getItem('currentUser');
if (!currentUser) {
window.location.href = '/';
return false;
}
return true;
}
function updateStats() {
const count = localStorage.getItem('burritoConsiderations') || '0';
document.getElementById('total-considerations').textContent = count;
}
function handleConsideration() {
const currentUser = localStorage.getItem('currentUser');
if (!currentUser) return;
// Increment the count
const currentCount = parseInt(localStorage.getItem('burritoConsiderations') || '0', 10);
const newCount = currentCount + 1;
localStorage.setItem('burritoConsiderations', newCount.toString());
// Update the UI
updateStats();
const successMessage = document.getElementById('success-message');
const considerationCount = document.getElementById('consideration-count');
considerationCount.textContent = newCount;
successMessage.style.display = 'block';
// Hide success message after 2 seconds
setTimeout(() => {
successMessage.style.display = 'none';
}, 2000);
// Capture burrito consideration event in PostHog
window.posthog?.capture('burrito_considered', {
total_considerations: newCount,
username: currentUser
});
}
document.addEventListener('DOMContentLoaded', () => {
if (!checkAuth()) return;
updateStats();
document.getElementById('consider-btn')?.addEventListener('click', handleConsideration);
});
</script>
---
import PostHogLayout from '../layouts/PostHogLayout.astro';
---
<PostHogLayout title="Home - Astro PostHog Example">
<div class="container">
<div id="logged-in-view" style="display: none;">
<h1>Welcome back, <span id="welcome-username"></span>!</h1>
---
import PostHogLayout from '../layouts/PostHogLayout.astro';
---
<PostHogLayout title="Profile - Astro PostHog Example">
<div class="container">
<h1>User Profile</h1>
<div class="stats">
<h2>Your Information</h2>
<p><strong>Username:</strong> <span id="profile-username"></span></p>
<p><strong>Burrito Considerations:</strong> <span id="profile-considerations">0</span></p>
</div>
<div style="margin-top: 2rem;">
<h3>Your Burrito Journey</h3>
<p id="journey-message"></p>
</div>
<div style="margin-top: 2rem;">
<h3>Error Tracking Demo</h3>
<p>Click the button below to trigger a test error and send it to PostHog:</p>
<button id="error-btn" class="btn-error">
Trigger Test Error
</button>
<p id="error-feedback" class="success" style="display: none;">
Error captured and sent to PostHog!
</p>
</div>
</div>
</PostHogLayout>
<script is:inline>
function checkAuth() {
const currentUser = localStorage.getItem('currentUser');
if (!currentUser) {
window.location.href = '/';
return false;
}
return true;
}
function updateProfile() {
const username = localStorage.getItem('currentUser') || '';
const considerations = parseInt(localStorage.getItem('burritoConsiderations') || '0', 10);
document.getElementById('profile-username').textContent = username;
document.getElementById('profile-considerations').textContent = considerations;
// Update journey message based on consideration count
const journeyMessage = document.getElementById('journey-message');
if (considerations === 0) {
journeyMessage.textContent = "You haven't considered any burritos yet. Visit the Burrito Consideration page to start!";
} else if (considerations === 1) {
journeyMessage.textContent = "You've considered the burrito potential once. Keep going!";
} else if (considerations < 5) {
journeyMessage.textContent = "You're getting the hang of burrito consideration!";
} else if (considerations < 10) {
journeyMessage.textContent = "You're becoming a burrito consideration expert!";
} else {
journeyMessage.textContent = "You are a true burrito consideration master!";
}
}
function triggerTestError() {
try {
throw new Error('Test error for PostHog error tracking');
} catch (err) {
// Capture the error in PostHog
window.posthog?.captureException(err);
console.error('Captured error:', err);
// Show feedback to user
const feedback = document.getElementById('error-feedback');
feedback.style.display = 'block';
setTimeout(() => {
feedback.style.display = 'none';
}, 3000);
}
}
document.addEventListener('DOMContentLoaded', () => {
if (!checkAuth()) return;
updateProfile();
document.getElementById('error-btn')?.addEventListener('click', triggerTestError);
});
</script>