I usually use posthog for all my analytics needs, it is a great solution to track all the web analytics and also the product analytics. I also really like the ability to easily make custom dashboards.

For this reason when I want to track errors in the backend API of one of my projects I turned also to posthog. There is no information on how to integrate these two so that is why I wrote this guide.

Usually posthog is run on the client side. And for the server side, the posthog team has created posthog-node for nodejs, hence the name. This github project is an easy way to create a client and send events from your node.js server.

However since I was running my nuxt site on cloudflare this does not work. Because cloudflare does not run your code on nodejs. It instead runs your code with cloudflare workers, cloudflare’s own javascript runtime.

So in this article we will see how to make a simple client for posthog from scratch which runs like a well oiled machine on cloudflare.

The Solution

Create a new file server/utils/posthog.ts.

Then we can create a server composable called usePosthog(). The only critical API request is sending events to posthog.

interface Payload {
  api_key: string;
  event: string;
  timestamp?: string;
  distinct_id: string;
  properties?: any;
}

export async function usePosthog() {

}