Metrics Track

/metrics-track

Set up a metrics tracking plan for a project. Defines PostHog event funnel, KPI benchmarks, and kill/iterate/scale decision thresholds based on lean startup principles.

MCP Tools (use if available)

kb_search(query) — find PostHog methodology, analytics patterns If MCP tools are not available, fall back to Grep + Read.

Methodology Reference

This skill implements metrics tracking based on lean startup principles: Relative metrics vs niche benchmarks — compare against your own trajectory, not vanity averages Kill/iterate/scale decision rules — data-driven thresholds for product decisions (see step 7 below)

Steps

• Parse project from $ARGUMENTS.
• Read PRD for features, ICP, monetization model.
• Read CLAUDE.md for stack (iOS/Web/both).
• If empty: ask via AskUserQuestion.
• Detect platform:
• iOS app → PostHog iOS SDK events
• Web app → PostHog JS SDK events
• Both → cross-platform identity (shared user ID across platforms)
• Load PostHog methodology:
• If MCP available: kb_search("PostHog analytics events funnel identity")
• Otherwise: check project docs for existing analytics configuration
• Extract: event naming conventions, identity resolution, funnel pattern
• Define event funnel based on PRD features:
• Standard funnel stages (adapt per product):
• Awareness → Acquisition → Activation → Revenue → Retention → Referral
• Map to concrete events:
• StageEvent NameTriggerPropertiesAwarenesspage_viewedLanding page visitsource, utm_*Acquisitionapp_installed or signed_upFirst install/signupplatform, sourceActivationcore_action_completedFirst key actionfeature, duration_msRevenuepurchase_completedFirst paymentplan, amount, currencyRetentionsession_startedReturn visit (D1/D7/D30)session_number, days_since_installReferralinvite_sentShared or referredchannel, referral_code
• Forced reasoning — metrics selection:
• Before defining KPIs, write out:
• North Star Metric: The ONE number that matters most (e.g., "weekly active users who completed core action")
• Leading indicators: What predicts the North Star? (e.g., "activation rate D1")
• Lagging indicators: What confirms success? (e.g., "MRR", "retention D30")
• Vanity metrics to AVOID: (e.g., total downloads without activation)
• Set KPI benchmarks per stage:
• KPITargetKill ThresholdScale ThresholdSourceLanding → Signup3-5%< 1%> 8%Industry avgSignup → Activation20-40%< 10%> 50%Product benchmarkD1 Retention25-40%< 15%> 50%Mobile avgD7 Retention10-20%< 5%> 25%Mobile avgD30 Retention5-10%< 2%> 15%Mobile avgTrial → Paid2-5%< 1%> 8%SaaS avg
• Adjust based on product type (B2C vs B2B, free vs paid, mobile vs web).
• Define decision rules (lean startup kill/iterate/scale):
• ## Decision Framework
• **Review cadence:** Weekly (Fridays)
• ### KILL signals (any 2 = kill)
• [ ] Activation rate < {kill_threshold} after 2 weeks
• [ ] D7 retention < {kill_threshold} after 1 month
• [ ] Zero organic signups after 2 weeks of distribution
• [ ] CAC > 3x LTV estimate
• ### ITERATE signals
• [ ] Metrics between kill and scale thresholds
• [ ] Qualitative feedback suggests product-market fit issues
• [ ] One stage of funnel is dramatically worse than others
• ### SCALE signals (all 3 = scale)
• [ ] Activation rate > {scale_threshold}
• [ ] D7 retention > {scale_threshold}
• [ ] Organic growth > 10% week-over-week
• Generate PostHog implementation snippets:
• For iOS (Swift):
• // Event tracking examples
• PostHogSDK.shared.capture("core_action_completed", properties: [
• "feature": "scan_receipt",
• "duration_ms": elapsed
• ])
• For Web (TypeScript):
• // Event tracking examples
• posthog.capture('signed_up', {
• source: searchParams.get('utm_source') ?? 'direct',
• plan: 'free'
• })
• Write metrics plan to docs/metrics-plan.md:
• # Metrics Plan: {Project Name}
• **Generated:** {YYYY-MM-DD}
• **Platform:** {iOS / Web / Both}
• **North Star:** {north star metric}
• ## Event Funnel
• | Stage | Event | Properties |
• |-------|-------|------------|
• {event table from step 4}
• ## KPIs & Thresholds
• | KPI | Target | Kill | Scale |
• |-----|--------|------|-------|
• {benchmark table from step 6}
• ## Decision Rules
• {framework from step 7}
• ## Implementation
• ### PostHog Setup
• Project: {project name} (EU region)
• SDK: {posthog-ios / posthog-js}
• Identity: {anonymous → identified on signup}
• ### Code Snippets
• {snippets from step 8}
• ## Dashboard Template
• Funnel: {stage1} → {stage2} → ... → {stageN}
• Retention: D1 / D7 / D30 cohort chart
• Revenue: MRR trend + trial conversion
• ---
• *Generated by /metrics-track. Implement events, then review weekly.*
• Output summary — North Star metric, key thresholds, first event to implement.

For iOS (Swift):

// Event tracking examples PostHogSDK.shared.capture("core_action_completed", properties: [ "feature": "scan_receipt", "duration_ms": elapsed ])

For Web (TypeScript):

// Event tracking examples posthog.capture('signed_up', { source: searchParams.get('utm_source') ?? 'direct', plan: 'free' })

Notes

PostHog EU hosting for privacy compliance Use $set for user properties, capture for events Identity: start anonymous, identify() on signup with user ID Cross-platform: same PostHog project, same user ID → unified journey Review dashboard weekly, make kill/iterate/scale decision monthly

Wrong platform detected

Cause: Project has both web and iOS indicators. Fix: Skill checks package manifests. If both exist, it generates cross-platform identity setup. Verify the detected platform in the output.

KPI thresholds too aggressive

Cause: Default thresholds are industry averages. Fix: Adjust thresholds in docs/metrics-plan.md based on your niche. B2B typically has lower volume but higher conversion.

PostHog SDK not in project

Cause: Metrics plan generated but SDK not installed. Fix: This skill generates the PLAN only. Install PostHog SDK separately: pnpm add posthog-js (web) or add posthog-ios via SPM (iOS).