Posthog Analytics

PostHog is installed to answer growth questions—activation, retention, funnels, and feature usage—so the canonical shelf is Grow even though SDK work happens earlier. Analytics subphase matches product measurement and dashboards that inform what to ship next, which is the skill’s stated philosophy.

Also useful

Also useful

Where it fits

Example use

Install posthog-js and init with capture_pageview false before your first production deploy.

Example use

Define acquisition and activation events before you push traffic from a launch post.

Example use

Build funnels and dashboards to see where signups stall after a pricing change.

How it compares

Use as a structured PostHog implementation guide instead of scattering one-off tracking snippets across chat sessions.

Common Questions / FAQ

Who is posthog-analytics for?

Indie and solo builders adding PostHog to a web product who want events, flags, and dashboards that support real product decisions.

When should I use posthog-analytics?

During Build when integrating the SDK, at Launch when defining core events, and in Grow when tuning funnels, retention, and feature-flag rollouts.

Is posthog-analytics safe to install?

Review the Security Audits panel on this Prism page before piping production keys into your repo; the skill references network calls to PostHog hosts.

SKILL.md

READMESKILL.md - 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;
}

export { posthog };
```

```typescript
// app/providers.tsx
'use client';

import { useEffect } from 'react';
import { usePathname, useSearchParams } from 'next/navigation';
import { initPostHog, posthog } from '@/lib/posthog';

export function PostHogProvider({ children }: { children: React.ReactNode }) {
  const pathname = usePathname();
  const searchParams = useSearchParams();

  useEffect(() => {
    initPostHog();
  }, []);

  // Track pageviews
  useEffect(() => {
    if (pathname) {
      let url = window.origin + pathname;
      if (searchParams.toString()) {
        url += `?${searchParams.toString()}`;
      }
      posthog.capture('$pageview', { $current_url: url });
    }
  }, [pathname, searchParams]);

  return <>{children}</>;
}
```

```typescript
// app/layout.tsx
import { PostHogProvider } from './providers';

export default function RootLayout({ children }: { children: React.ReactNode }) {
  return (
    <html lang="en">
      <body>
        <PostHogProvider>
          {children}
        </PostHogProvider>
      </body>
    </html>
  );
}
```

### React (Vite/CRA)

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

posthog.init(import.meta.env.VITE_POSTHOG_KEY, {
  api_host: import.meta.env.VITE_POSTHOG_HOST || 'https://us.i.posthog.com',
  person_profiles: 'identified_only',
});

export { posthog };
```

```typescript
// src/main.tsx
import { PostHogProvider } from 'posthog-js/react';
import { posthog } from './posthog';

ReactDOM.createRoot(document.getElementById('root')!).render(
  <PostHogProvider client={posthog}>
    <App />
  </PostHogProvider>
);
```

### Python (FastAPI/Flask)

```bash
pip install posthog
```

```python
# analytics/posthog_client.py
import posthog
from functools import lru_cache

@lru_cache()
def get_posthog():
    posthog.project_api_key = os.environ["POSTHOG_API_KEY"]
    posthog.host = os.environ.get("POSTHOG_HOST", "https://us.i.posthog.com")
    posthog.debug = os.environ.get("ENV") == "development"
    return posthog

# Usage
def track_event(user_id: str, event: str, properties: dict = None):
    ph = get_posthog()
    ph.capture(
        distinct_id=user_id,
        event=event,
        properties=properties or {}
    )

def identify_user(user_id: str, properties: dict):
    ph = get_posthog()
    ph.identify(user_id, properti

What is this skill?

Philosophy-first guidance: measure activation, retention, funnels, and feature usage—not vanity events

Next.js App Router install pattern with posthog-js init and identified-only person profiles

Manual pageview/pageleave capture for SPA-friendly routing control

Feature flags and project dashboards tied to PostHog product analytics docs

Links to official PostHog docs for events, flags, and dashboard setup

Compatible agents: Claude Code, Cursor, Codex, any compatible agent

Adoption & trust: 655 installs on skills.sh; 691 GitHub stars; 3/3 security scanners passed (skills.sh audits).

Journey fit

Spans multiple journey phases - primary shelf plus alternate fits below.

Primary fit

Also useful

Also useful

Where it fits

Example use

Install posthog-js and init with capture_pageview false before your first production deploy.

Example use

Define acquisition and activation events before you push traffic from a launch post.

Example use