Posthog Analytics

# PostHog Analytics Skill


For implementing product analytics with PostHog - event tracking, user identification, feature flags, and project-specific dashboards.

**Sources:** [PostHog Docs](https://posthog.com/docs) | [Product Analytics](https://posthog.com/docs/product-analytics) | [Feature Flags](https://posthog.com/docs/feature-flags)

---

## Philosophy

**Measure what matters, not everything.**

Analytics should answer specific questions:
- Are users getting value? (activation, retention)
- Where do users struggle? (funnels, drop-offs)
- What features drive engagement? (feature usage)
- Is the product growing? (acquisition, referrals)

Don't track everything. Track what informs decisions.

---

## Installation

### Next.js (App Router)

```bash
npm install posthog-js
```

```typescript
// lib/posthog.ts
import posthog from 'posthog-js';

export function initPostHog() {
  if (typeof window !== 'undefined' && !posthog.__loaded) {
    posthog.init(process.env.NEXT_PUBLIC_POSTHOG_KEY!, {
      api_host: process.env.NEXT_PUBLIC_POSTHOG_HOST || 'https://us.i.posthog.com',
      person_profiles: 'identified_only', // Only create profiles for identified users
      capture_pageview: false, // We'll handle this manually for SPA
      capture_pageleave: true,
      loaded: (posthog) => {
        if (process.env.NODE_ENV === 'development') {
          posthog.debug();
        }
      },
    });
  }
  return posthog;