posthog-cost-tuningClaude Skill

PostHog Cost Tuning

Overview

Optimize PostHog costs through smart tier selection, sampling, and usage monitoring.

Prerequisites

• Access to PostHog billing dashboard
• Understanding of current usage patterns
• Database for usage tracking (optional)
• Alerting system configured (optional)

Pricing Tiers

Tier	Monthly Cost	Included	Overage
Free	$0	1,000 requests	N/A
Pro	$99	100,000 requests	$0.001/request
Enterprise	Custom	Unlimited	Volume discounts

Cost Estimation

interface UsageEstimate {
  requestsPerMonth: number;
  tier: string;
  estimatedCost: number;
  recommendation?: string;
}

function estimatePostHogCost(requestsPerMonth: number): UsageEstimate {
  if (requestsPerMonth <= 1000) {
    return { requestsPerMonth, tier: 'Free', estimatedCost: 0 };
  }

  if (requestsPerMonth <= 100000) {
    return { requestsPerMonth, tier: 'Pro', estimatedCost: 99 };
  }

  const proOverage = (requestsPerMonth - 100000) * 0.001;
  const proCost = 99 + proOverage;

  return {
    requestsPerMonth,
    tier: 'Pro (with overage)',
    estimatedCost: proCost,
    recommendation: proCost > 500
      ? 'Consider Enterprise tier for volume discounts'
      : undefined,
  };
}

Usage Monitoring

class PostHogUsageMonitor {
  private requestCount = 0;
  private bytesTransferred = 0;
  private alertThreshold: number;

  constructor(monthlyBudget: number) {
    this.alertThreshold = monthlyBudget * 0.8; // 80% warning
  }

  track(request: { bytes: number }) {
    this.requestCount++;
    this.bytesTransferred += request.bytes;

    if (this.estimatedCost() > this.alertThreshold) {
      this.sendAlert('Approaching PostHog budget limit');
    }
  }

  estimatedCost(): number {
    return estimatePostHogCost(this.requestCount).estimatedCost;
  }

  private sendAlert(message: string) {
    // Send to Slack, email, PagerDuty, etc.
  }
}

Cost Reduction Strategies

Step 1: Request Sampling

function shouldSample(samplingRate = 0.1): boolean {
  return Math.random() < samplingRate;
}

// Use for non-critical telemetry
if (shouldSample(0.1)) { // 10% sample
  await posthogClient.trackEvent(event);
}

Step 2: Batching Requests

// Instead of N individual calls
await Promise.all(ids.map(id => posthogClient.get(id)));

// Use batch endpoint (1 call)
await posthogClient.batchGet(ids);

Step 3: Caching (from P16)

• Cache frequently accessed data
• Use cache invalidation webhooks
• Set appropriate TTLs

Step 4: Compression

const client = new PostHogClient({
  compression: true, // Enable gzip
});

Budget Alerts

# Set up billing alerts in PostHog dashboard
# Or use API if available:
# Check PostHog documentation for billing APIs

Cost Dashboard Query

-- If tracking usage in your database
SELECT
  DATE_TRUNC('day', created_at) as date,
  COUNT(*) as requests,
  SUM(response_bytes) as bytes,
  COUNT(*) * 0.001 as estimated_cost
FROM posthog_api_logs
WHERE created_at >= NOW() - INTERVAL '30 days'
GROUP BY 1
ORDER BY 1;

Instructions

Step 1: Analyze Current Usage

Review PostHog dashboard for usage patterns and costs.

Step 2: Select Optimal Tier

Use the cost estimation function to find the right tier.

Step 3: Implement Monitoring

Add usage tracking to catch budget overruns early.

Step 4: Apply Optimizations

Enable batching, caching, and sampling where appropriate.

Output

• Optimized tier selection
• Usage monitoring implemented
• Budget alerts configured
• Cost reduction strategies applied

Error Handling

Issue	Cause	Solution
Unexpected charges	Untracked usage	Implement monitoring
Overage fees	Wrong tier	Upgrade tier
Budget exceeded	No alerts	Set up alerts
Inefficient usage	No batching	Enable batch requests

Examples

Quick Cost Check

// Estimate monthly cost for your usage
const estimate = estimatePostHogCost(yourMonthlyRequests);
console.log(`Tier: ${estimate.tier}, Cost: $${estimate.estimatedCost}`);
if (estimate.recommendation) {
  console.log(`💡 ${estimate.recommendation}`);
}

Resources

• PostHog Pricing
• PostHog Billing Dashboard

Next Steps

For architecture patterns, see posthog-reference-architecture.