Posthog Analytics

What the source does

• FilesystemNone observedNo reads or writes in the source
• NetworkNone observedNo outbound calls in the source
• ShellNone observedNo commands run in the source
• DependenciesPinnedNothing floats
• SecretsNone foundNo keys in source

Five audit layers

Gates applied: no behavioural pass.

Audit 0.4.1 · source sha ea59a0c53d79 · 14 Oct 2026Report an issue or request a re-scan

• Publisheralinaqi GitHub userOwner of the repository this skill is read from
• Source folderalinaqi/claude-bootstrap/skills/posthog-analyticsThe exact folder we audited
• LicenceMITAs the repository states it
• Commit pinned for this verdictea59a0c53d79A new audit runs when the source changes
• Repository statusNot archivedPushed today
• Sandboxed runNot runSkills are read, not executed; layer L4 is skipped

Its description: PostHog analytics, event tracking, feature flags, dashboards

---
name: posthog-analytics
description: PostHog analytics, event tracking, feature flags, dashboards
when-to-use: When adding analytics, feature flags, or event tracking with PostHog
user-invocable: false
effort: medium
---

# 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, properties)
```

### Node.js (Express/Hono)

```bash
npm install posthog-node
```

```typescript
// lib/posthog.ts
import { PostHog } from 'posthog-node';

const posthog = new PostHog(process.env.POSTHOG_API_KEY!, {
  host: process.env.POSTHOG_HOST || 'https://us.i.posthog.com',
});

// Flush on shutdown
process.on('SIGTERM', () => posthog.shutdown());

export { posthog };

// Usage
export function trackEvent(userId: string, event: string, properties?: Record<string, any>) {
  posthog.capture({
    distinctId: userId,
    event,
    properties,
  });
}

export function identifyUser(userId: string, properties: Record<string, any>) {
  posthog.identify({
    distinctId: userId,
    properties,
  });
}
```

---

## Environment Variables

```bash
# .env.local (Next.js) - SAFE: These are meant to be public
NEXT_PUBLIC_POSTHOG_KEY=phc_xxxxxxxxxxxxxxxxxxxx
NEXT_PUBLIC_POSTHOG_HOST=https://us.i.posthog.com

# .env (Backend) - Keep private
POSTHOG_API_KEY=phc_xxxxxxxxxxxxxxxxxxxx
POSTHOG_HOST=https://us.i.posthog.com
```

Add to `credentials.md` patterns:
```python
'POSTHOG_API_KEY': r'phc_[A-Za-z0-9]+',
```

---

## User Identification

### When to Identify

```typescript
// Identify on signup
async function handleSignup(email: string, name: string) {
  const user = await createUser(email, name);

  posthog.identify(user.id, {
    email: user.email,
    name: user.name,
    created_at: user.createdAt,
    plan: 'free',
  });

  posthog.capture('user_signed_up', {
    signup_method: 'email',
  });
}

// Identify on login
async function handleLogin(email: string) {
  const user = await authenticateUser(email);

  posthog.identify(user.id, {
    email: user.email,
    name: user.name,
    plan: user.plan,
    last_login: new Date().toISOString(),
  });

  posthog.capture('user_logged_in');
}

// Reset on logout
function handleLogout() {
  posthog.capture('user_logged_out');
  posthog.reset(); // Clears identity
}
```

### User Properties

```typescript
// Standard properties to track

Excerpt, first 6,000 characters of SKILL.md, verbatim from the audited commit. It is text from someone else’s repository, quoted so you can judge it before your agent reads it.

npm install posthog-js
pip install posthog
npm install posthog-node

git clone https://github.com/alinaqi/claude-bootstrap
git -C claude-bootstrap checkout ea59a0c53d79

Works in

1. 2026-10-14
   ✓SAFE B 89 / 100

   first audit · source ea59a0c53d79

Questions about Posthog Analytics

• github.com/alinaqi/claude-bootstrap/tree/main/skills/posthog-ana — the audited source at commit ea59a0c53d79 and every finding aboveObserved · 14 Oct 2026

Spotted something wrong? Report a correction · Methodology