Hono error tracking installation

Error tracking enables you to track, investigate, and resolve exceptions your customers face. Start by installing the posthog-node package using your package manager:

npm install --save posthog-node

Hono uses app.onError to handle uncaught exceptions. You can take advantage of this for error tracking. Remember to export your project API key as an environment variable.

import { env } from 'hono/adapter'
import { PostHog } from 'posthog-node'

app.onError((err, c) => {
  const { POSTHOG_PUBLIC_KEY } = env<{ POSTHOG_PUBLIC_KEY:string }>(c)
  const posthog = new PostHog(POSTHOG_PUBLIC_KEY, { host: 'https://us.i.posthog.com' })
  
  posthog.captureException(new Error(err.message, { cause: err }), 'user_distinct_id_with_err_rethrow', {
    path: c.req.path,
    method: c.req.method,
    url: c.req.url,
    headers: c.req.header(),
    // ... other properties
  })
  posthog.shutdown() 
  // other error handling logic
  return c.text('Internal Server Error', 500)
})

Before proceeding, let's make sure exception events are being captured and sent to PostHog. You should see events appear in the activity feed.

Great, you're capturing exceptions! If you serve minified bundles, the next step is to upload source maps to generate accurate stack traces.

Let's continue to the next section.