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posthog.com/contents/docs/libraries/angular.mdx
Edwin Lim 807c2cc77a posthog ips snippet (#13575)
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---
title: Angular
icon: >-
https://res.cloudinary.com/dmukukwp6/image/upload/posthog.com/contents/docs/integrate/frameworks/angular.svg
---
import DetailSetUpReverseProxy from "../integrate/_snippets/details/set-up-reverse-proxy.mdx"
import DetailGroupProductsInOneProject from "../integrate/_snippets/details/group-products-in-one-project.mdx"
import InstallNodePackageManagers from "../integrate/_snippets/install-node-package-managers.mdx"
import DetailPostHogIPs from "../integrate/_snippets/details/posthog-ips.mdx"
PostHog makes it easy to get data about traffic and usage of your [Angular](https://angular.dev/) app. Integrating PostHog into your site enables analytics about user behavior, custom events capture, session recordings, feature flags, and more.
This guide walks you through integrating PostHog into your Angular app using the [JavaScript Web SDK](/docs/libraries/js).
## Installation
import AngularInstall from "../integrate/_snippets/install-angular.mdx"
<AngularInstall />
> **Note:** If you're using Typescript, you might have some trouble getting your types to compile because we depend on `rrweb` but don't ship all of their types. To accommodate that, you'll need to add `@rrweb/types@2.0.0-alpha.17` and `rrweb-snapshot@2.0.0-alpha.17` as a dependency if you want your Angular compiler to typecheck correctly.
>
> Given the nature of this library, you might need to completely clear your `.npm` cache to get this to work as expected. Make sure your clear your CI's cache as well.
>
> In the rare case the versions above get out-of-date, you can check our [JavaScript SDK's `package.json`](https://github.com/PostHog/posthog-js/blob/main/package.json) to understand what's the exact version you need to depend on.
<DetailSetUpReverseProxy />
<DetailGroupProductsInOneProject />
<DetailPostHogIPs />
## Tracking pageviews
PostHog automatically tracks your pageviews by hooking up to the browser's `navigator` API as long as you initialize PostHog with the `defaults` config option set after `2025-05-24`.
## Capture custom events
To [capture custom events](/docs/product-analytics/capture-events), import `posthog` and call `posthog.capture()`. Below is an example of how to do this in a component:
```typescript file=app.component.ts
import { Component } from '@angular/core';
import posthog from 'posthog-js'
@Component({
// existing component code
})
export class AppComponent {
handleClick() {
posthog.capture(
'home_button_clicked',
)
}
}
```
## Session replay
Session replay uses change detection to record the DOM. This can clash with Angular's change detection.
The recorder tool attempts to detect when an Angular zone is present and avoid the clash but might not always succeed.
- If you followed the installation instructions for Angular v17 and above, you don't need to do anything.
- If you followed the installation instructions for Angular v16 and below and you see performance impact from recording in an Angular project, ensure that you use [`ngZone.runOutsideAngular`](https://angular.io/api/core/NgZone#runoutsideangular).
```ts file=posthog.service.ts
import { Injectable } from '@angular/core';
import posthog from 'posthog-js'
@Injectable({ providedIn: 'root' })
export class PostHogSessionRecordingService {
constructor(private ngZone: NgZone) {}
initPostHog() {
this.ngZone.runOutsideAngular(() => {
posthog.init(
/* your config */
)
})
}
}
```
## Angular with SSR
To use PostHog with Angular server-side rendering (SSR), you need to:
1. Update the PostHog web JS client to only initialize on the client-side.
2. Initialize PostHog Node on the server-side.
### 1. Update the PostHog web JS client
Update your `posthog.service.ts` to restrict the initialization of the PostHog web JS client to the client-side. The web SDK uses methods that are not available on the server side, so we need to check if we're on the client side before initializing PostHog.
```ts file=posthog.service.ts focusOnLines=5-21
import { DestroyRef, Injectable, NgZone, Inject } from "@angular/core";
import posthog from "posthog-js";
import { environment } from "../../environments/environment";
import { Router } from "@angular/router";
import { isPlatformBrowser } from "@angular/common"; // +
import { PLATFORM_ID } from "@angular/core"; // +
import { isPlatformBrowser } from "@angular/common"; // +
import { PLATFORM_ID } from "@angular/core"; // +
@Injectable({ providedIn: "root" })
export class PosthogService {
constructor(
private ngZone: NgZone,
private router: Router,
private destroyRef: DestroyRef,
@Inject(PLATFORM_ID) private platformId: Object // +
) {
// Only initialize PostHog in browser environment
if (isPlatformBrowser(this.platformId)) { // +
this.initPostHog(); //+
}
}
private initPostHog() {
this.ngZone.runOutsideAngular(() => {
posthog.init(environment.posthogKey, {
api_host: environment.posthogHost,
defaults: '<ph_posthog_js_defaults>',
debug: false,
cross_subdomain_cookie: true,
});
});
}
}
```
### 2. Add server-side initialization
Angular SSR uses a `server.ts` file to handle requests. We can add any server-side initialization code to this file.
First, install the `posthog-node` package to run on the server side.
<InstallNodePackageManagers />
Then, add the following code to the `server.ts` file:
```ts file=server.ts
// src/server.ts
import { environment } from './environments/environment';
import { PostHog } from 'posthog-node'
/**
* Extract distinct ID from PostHog cookie
*/
function getDistinctIdFromCookie(cookieHeader: string | undefined): string | null {
if (!cookieHeader) return null;
const cookieMatch = cookieHeader.match(`ph_${environment.posthogKey}_posthog=([^;]+)`);
if (cookieMatch) {
try {
const parsed = JSON.parse(decodeURIComponent(cookieMatch[1]));
return parsed?.distinct_id || null;
} catch (error) {
console.error('Error parsing PostHog cookie:', error);
return null;
}
}
return null;
}
/**
* Handle all other requests by rendering the Angular application.
*/
app.get('**', async (req, res, next) => {
const { protocol, originalUrl, baseUrl, headers } = req;
const distinctId = getDistinctIdFromCookie(headers.cookie);
let isFeatureEnabled = false;
const client = new PostHog(
const client = new PostHog(
environment.posthogKey,
{ host: environment.posthogHost }
)
)
if (distinctId) {
client.capture({
distinctId: distinctId,
event: 'test_ssr_event',
properties: {
message: 'Hello from Angular SSR!'
}
})
isFeatureEnabled = await client.isFeatureEnabled(
'your_feature_flag_key', distinctId) || false;
}
commonEngine
.render({
bootstrap,
documentFilePath: indexHtml,
url: `${protocol}://${headers.host}${originalUrl}`,
publicPath: browserDistFolder,
providers: [
{ provide: APP_BASE_HREF, useValue: baseUrl },
{ provide: 'FEATURE_FLAG_ENABLED', useValue: isFeatureEnabled }
],
})
.then((html) => res.send(html))
.catch((err) => next(err));
await client.shutdown()
});
```
This code does the following:
- Extracts the distinct ID from the cookie header. This is set by the web JS client.
- Captures an event on the server side.
- Evaluates a feature flag on the server side. This can be passed as a provider to the Angular application.
- Calls `shutdown` on the PostHog Node client to ensure all events are flushed.
<CalloutBox icon="IconInfo" title="Using PostHog in server-side code">
Angular SSR does not allow Node.js code to be bundled into client-side components. Even though resolvers and other server-side code can be written along with client-side components, you cannot use PostHog Node in those components.
</CalloutBox>
## Next steps
For any technical questions for how to integrate specific PostHog features into Angular (such as feature flags, A/B testing, surveys, etc.), have a look at our [JavaScript Web SDK docs](/docs/libraries/js/features).
Alternatively, the following tutorials can help you get started:
- [How to set up Angular analytics, feature flags, and more](/tutorials/angular-analytics)
- [How to set up A/B tests in Angular](/tutorials/angular-ab-tests)
- [How to set up surveys in Angular](/tutorials/angular-surveys)