---

name: posthog-security-basics description: | Apply PostHog security best practices for secrets and access control. Use when securing API keys, implementing least privilege access, or auditing PostHog security configuration. Trigger with phrases like "posthog security", "posthog secrets", "secure posthog", "posthog API key security". allowed-tools: Read, Write, Grep version: 1.0.0 license: MIT author: Jeremy Longshore jeremy@intentsolutions.io

PostHog Security Basics

Overview

Security best practices for PostHog API keys, tokens, and access control.

Prerequisites

• PostHog SDK installed
• Understanding of environment variables
• Access to PostHog dashboard

Instructions

Step 1: Configure Environment Variables

Copy# .env (NEVER commit to git)
POSTHOG_API_KEY=sk_live_***
POSTHOG_SECRET=***

# .gitignore
.env
.env.local
.env.*.local

Step 2: Implement Secret Rotation

Copy# 1. Generate new key in PostHog dashboard
# 2. Update environment variable
export POSTHOG_API_KEY="new_key_here"

# 3. Verify new key works
curl -H "Authorization: Bearer ${POSTHOG_API_KEY}" \
  https://api.posthog.com/health

# 4. Revoke old key in dashboard

Step 3: Apply Least Privilege

Output

• Secure API key storage
• Environment-specific access controls
• Audit logging enabled

Error Handling

Examples

Service Account Pattern

Copyconst clients = {
  reader: new PostHogClient({
    apiKey: process.env.POSTHOG_READ_KEY,
  }),
  writer: new PostHogClient({
    apiKey: process.env.POSTHOG_WRITE_KEY,
  }),
};

Webhook Signature Verification

Copyimport crypto from 'crypto';

function verifyWebhookSignature(
  payload: string, signature: string, secret: string
): boolean {
  const expected = crypto.createHmac('sha256', secret).update(payload).digest('hex');
  return crypto.timingSafeEqual(Buffer.from(signature), Buffer.from(expected));
}

Security Checklist

• API keys in environment variables
• .env files in .gitignore
• Different keys for dev/staging/prod
• Minimal scopes per environment
• Webhook signatures validated
• Audit logging enabled

Audit Logging

Copyinterface AuditEntry {
  timestamp: Date;
  action: string;
  userId: string;
  resource: string;
  result: 'success' | 'failure';
  metadata?: Record<string, any>;
}

async function auditLog(entry: Omit<AuditEntry, 'timestamp'>): Promise<void> {
  const log: AuditEntry = { ...entry, timestamp: new Date() };

  // Log to PostHog analytics
  await posthogClient.track('audit', log);

  // Also log locally for compliance
  console.log('[AUDIT]', JSON.stringify(log));
}

// Usage
await auditLog({
  action: 'posthog.api.call',
  userId: currentUser.id,
  resource: '/v1/resource',
  result: 'success',
});

Resources

• PostHog Security Guide
• PostHog API Scopes

Next Steps

For production deployment, see posthog-prod-checklist.