/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

1. Parse project from $ARGUMENTS.
• Read PRD for features, ICP, monetization model.
• Read CLAUDE.md for stack (iOS/Web/both).
• If empty: ask via AskUserQuestion.

1. Detect platform:
• iOS app → PostHog iOS SDK events
• Web app → PostHog JS SDK events
• Both → cross-platform identity (shared user ID across platforms)

1. 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

1. Define event funnel based on PRD features:

Standard funnel stages (adapt per product):

```

Awareness → Acquisition → Activation → Revenue → Retention → Referral

```

Map to concrete events:

| Stage | Event Name | Trigger | Properties |

|-------|-----------|---------|------------|

| Awareness | page_viewed | Landing page visit | source, utm_* |

| Acquisition | app_installed or signed_up | First install/signup | platform, source |

| Activation | core_action_completed | First key action | feature, duration_ms |

| Revenue | purchase_completed | First payment | plan, amount, currency |

| Retention | session_started | Return visit (D1/D7/D30) | session_number, days_since_install |

| Referral | invite_sent | Shared or referred | channel, referral_code |

1. 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)

1. Set KPI benchmarks per stage:

| KPI | Target | Kill Threshold | Scale Threshold | Source |

|-----|--------|---------------|-----------------|--------|

| Landing → Signup | 3-5% | < 1% | > 8% | Industry avg |

| Signup → Activation | 20-40% | < 10% | > 50% | Product benchmark |

| D1 Retention | 25-40% | < 15% | > 50% | Mobile avg |

| D7 Retention | 10-20% | < 5% | > 25% | Mobile avg |

| D30 Retention | 5-10% | < 2% | > 15% | Mobile avg |

| Trial → Paid | 2-5% | < 1% | > 8% | SaaS avg |

Adjust based on product type (B2C vs B2B, free vs paid, mobile vs web).

1. Define decision rules (lean startup kill/iterate/scale):

```markdown

## 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

```

1. Generate PostHog implementation snippets:

### For iOS (Swift):

```swift

// Event tracking examples

PostHogSDK.shared.capture("core_action_completed", properties: [

"feature": "scan_receipt",

"duration_ms": elapsed

])

```

### For Web (TypeScript):

```typescript

// Event tracking examples

posthog.capture('signed_up', {

source: searchParams.get('utm_source') ?? 'direct',

plan: 'free'

})

```

1. Write metrics plan to docs/metrics-plan.md:

```markdown

# 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.

```

1. Output summary — North Star metric, key thresholds, first event to implement.

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

Common Issues

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).