---

name: gap-analysis description: Route-aware gap analysis. For Brownfield - uses /speckit.analyze to compare specs against implementation. For Greenfield - validates spec completeness and asks about target tech stack for new implementation. This is Step 4 of 6 in the reverse engineering process.

Gap Analysis (Route-Aware)

Step 4 of 6 in the Reverse Engineering to Spec-Driven Development process.

Estimated Time: 15 minutes Prerequisites: Step 3 completed (.specify/ directory exists with specifications) Output: Route-specific analysis and implementation roadmap

---

Configuration Check (FIRST STEP!)

CRITICAL: Check detection type and route:

Copy# Load state file
DETECTION_TYPE=$(cat .stackshift-state.json | jq -r '.detection_type // .path')
ROUTE=$(cat .stackshift-state.json | jq -r '.route // .path')

echo "Detection: $DETECTION_TYPE (what kind of app)"
echo "Route: $ROUTE (how to spec it)"

Routes:

• greenfield → Building NEW app (tech-agnostic specs)
• brownfield → Managing EXISTING app (tech-prescriptive specs)

Detection Types:

• generic → Standard application
• monorepo-service → Service in a monorepo
• nx-app → Nx workspace application
• turborepo-package → Turborepo package
• lerna-package → Lerna package

Based on route, this skill behaves differently!

Examples:

• Monorepo Service + Greenfield → Analyze spec completeness for platform migration
• Monorepo Service + Brownfield → Compare specs vs current implementation
• Nx App + Greenfield → Validate specs for rebuild (framework-agnostic)
• Nx App + Brownfield → Find gaps in current Nx/Angular implementation

---

Greenfield Route: Spec Completeness Analysis

Goal: Validate specs are complete enough to build NEW application

NOT analyzing: Old codebase (we're not fixing it, we're building new) YES analyzing: Spec quality, completeness, readiness

Step 1: Review Spec Completeness

For each specification:

Copy# Check each spec
for spec in .specify/memory/specifications/*.md; do
  echo "Analyzing: $(basename $spec)"

  # Look for ambiguities
  grep "\[NEEDS CLARIFICATION\]" "$spec" || echo "No clarifications needed"

  # Check for acceptance criteria
  grep -A 10 "Acceptance Criteria" "$spec" || echo "⚠️ No acceptance criteria"

  # Check for user stories
  grep -A 5 "User Stories" "$spec" || echo "⚠️ No user stories"
done

Step 2: Identify Clarification Needs

Common ambiguities in Greenfield specs:

• UI/UX details missing (what should it look like?)
• Business rules unclear (what happens when...?)
• Data relationships ambiguous (how do entities relate?)
• Non-functional requirements vague (how fast? how secure?)

Mark with [NEEDS CLARIFICATION]:

Copy### Photo Upload Feature
- Users can upload photos [NEEDS CLARIFICATION: drag-drop or click-browse?]
- Photos stored in cloud [NEEDS CLARIFICATION: S3, Cloudinary, or Vercel Blob?]
- Max 10 photos [NEEDS CLARIFICATION: per fish or per tank?]

Step 3: Ask About Target Tech Stack

For Greenfield, you're building NEW - need to choose stack!

CopyI've extracted the business logic into tech-agnostic specifications.
Now we need to decide what to build the NEW application in.

What tech stack would you like to use for the new implementation?

Examples:
A) Next.js 15 + React 19 + Prisma + PostgreSQL + Vercel
B) Python FastAPI + SQLAlchemy + PostgreSQL + AWS ECS
C) Ruby on Rails 7 + PostgreSQL + Heroku
D) Your choice: [describe your preferred stack]

Document choice in Constitution for consistency.

Step 4: Create Implementation Roadmap

Greenfield roadmap focuses on BUILD ORDER:

Copy# Greenfield Implementation Roadmap

## Tech Stack Selected
- Frontend: Next.js 15 + React 19
- Backend: Next.js API Routes
- Database: PostgreSQL + Prisma
- Auth: NextAuth.js
- Hosting: Vercel

## Build Phases

### Phase 1: Foundation (Week 1)
- Set up Next.js project
- Database schema with Prisma
- Authentication system
- Base UI components

### Phase 2: Core Features (Week 2-3)
- User management
- Fish tracking
- Tank management
- Water quality logging

### Phase 3: Advanced Features (Week 4)
- Photo upload
- Analytics dashboard
- Notifications
- Social features

## All Features are ❌ MISSING
(Greenfield = building from scratch)

Ready to proceed to:
- Step 5: Resolve clarifications
- Step 6: Implement features in new stack

---

Brownfield Route: Implementation Gap Analysis

Goal: Identify gaps in EXISTING codebase implementation

YES analyzing: Old codebase vs specs Using: AST-powered analysis with fallback to /speckit.analyze

IMPORTANT: You MUST run the AST analysis tool - don't just read the instructions!

Step 1: Verify GitHub Spec Kit Scripts Exist

CRITICAL: Check if prerequisite scripts are installed:

Copy# Check for scripts
if [ ! -f .specify/scripts/bash/check-prerequisites.sh ]; then
  echo "⚠️  GitHub Spec Kit scripts not found!"
  echo ""
  echo "The /speckit.analyze command requires prerequisite scripts."
  echo "These should have been installed during Gear 3."
  echo ""
  echo "Fix options:"
  echo "1. Run the installer:"
  echo "   ~/stackshift/scripts/install-speckit-scripts.sh ."
  echo ""
  echo "2. Download directly from GitHub:"
  echo "   mkdir -p .specify/scripts/bash"
  echo "   curl -sSL https://raw.githubusercontent.com/github/spec-kit/main/scripts/bash/check-prerequisites.sh -o .specify/scripts/bash/check-prerequisites.sh"
  echo "   # ... download other scripts ..."
  echo ""
  echo "3. Skip /speckit.analyze and do manual gap analysis (see Step 2b below)"
  echo ""

  # Offer to download now
  read -p "Download scripts now? (y/n) " -n 1 -r
  echo
  if [[ $REPLY =~ ^[Yy]$ ]]; then
    ~/stackshift/scripts/install-speckit-scripts.sh . || {
      echo "❌ Installer not found, downloading directly..."
      mkdir -p .specify/scripts/bash
      BASE_URL="https://raw.githubusercontent.com/github/spec-kit/main/scripts"
      curl -sSL "$BASE_URL/bash/check-prerequisites.sh" -o .specify/scripts/bash/check-prerequisites.sh
      curl -sSL "$BASE_URL/bash/setup-plan.sh" -o .specify/scripts/bash/setup-plan.sh
      curl -sSL "$BASE_URL/bash/create-new-feature.sh" -o .specify/scripts/bash/create-new-feature.sh
      curl -sSL "$BASE_URL/bash/update-agent-context.sh" -o .specify/scripts/bash/update-agent-context.sh
      curl -sSL "$BASE_URL/bash/common.sh" -o .specify/scripts/bash/common.sh
      chmod +x .specify/scripts/bash/*.sh
      echo "✅ Scripts downloaded!"
    }
  else
    echo "Skipping /speckit.analyze - will do manual gap analysis instead"
  fi
fi

Step 2a: Run AST-Powered Analysis (PRIMARY METHOD - RUN THIS!)

ACTION REQUIRED: Execute the AST analysis command now:

Copy# Run AST-powered roadmap generation (includes gap analysis)
~/stackshift/scripts/run-ast-analysis.mjs roadmap . --format=markdown

What this provides (far superior to /speckit.analyze):

• ✅ Function signature verification (not just "exists")
• ✅ Stub detection (functions returning placeholder text)
• ✅ Missing parameters detection
• ✅ Business logic pattern analysis
• ✅ Test coverage gaps
• ✅ Confidence scoring (0-100%)
• ✅ Detailed roadmap with phases, priorities, and effort estimates

If this command fails (script not found, Node.js issue, etc.), proceed to Step 2b.

Otherwise: Use the AST analysis output and skip Step 2b/2c entirely.

---

Step 2b: Run /speckit.analyze (FALLBACK ONLY)

If AST analysis unavailable, use GitHub Spec Kit's validation:

Copy> /speckit.analyze

What it checks:

• Specifications marked ✅ COMPLETE but implementation missing
• Implementation exists but not documented in specs
• Inconsistencies between related specifications
• Conflicting requirements across specs
• Outdated implementation status

Note: This is less thorough than AST analysis (checks existence only, not correctness)

If this command fails with "Script not found", the scripts weren't installed. Use Step 2c instead.

Step 2c: Manual Gap Analysis (last resort if scripts missing)

If /speckit.analyze can't run, do manual analysis:

Copy# For each spec, check implementation status
for spec in .specify/specs/*/spec.md; do
  feature=$(dirname "$spec" | xargs basename)
  echo "Analyzing: $feature"

  # Extract status from spec
  status=$(grep "^## Status" "$spec" -A 1 | tail -1)
  echo "  Status: $status"

  # Look for [NEEDS CLARIFICATION] markers
  clarifications=$(grep -c "\[NEEDS CLARIFICATION\]" "$spec" 2>/dev/null || echo "0")
  echo "  Clarifications needed: $clarifications"

  echo ""
done

This is less thorough than /speckit.analyze but will identify the basics.

---

Process Overview

Step 1: Verify Scripts

Check that GitHub Spec Kit scripts are installed (see above).

Step 2: Run Analysis

Try /speckit.analyze first. If it fails, fall back to manual analysis.

Output example:

CopyAnalyzing specifications vs implementation...

Issues Found:

1. user-authentication.md marked PARTIAL
   - Spec says: Frontend login UI required
   - Reality: No login components found in codebase

2. analytics-dashboard.md marked MISSING
   - Spec exists but no implementation

3. Inconsistency detected:
   - fish-management.md requires photo-upload feature
   - photo-upload.md marked PARTIAL (upload API missing)

4. Orphaned implementation:
   - src/api/notifications.ts exists
   - No specification found for notifications feature

Summary:
- 3 COMPLETE features
- 4 PARTIAL features
- 5 MISSING features
- 2 inconsistencies
- 1 orphaned implementation

See operations/run-speckit-analyze.md

Step 2: Detailed Gap Analysis

Expand on /speckit.analyze findings with deeper analysis:

A. Review PARTIAL Features

For each ⚠️ PARTIAL feature:

• What exists? (backend, frontend, tests, docs)
• What's missing? (specific components, endpoints, UI)
• Why incomplete? (was it deprioritized? ran out of time?)
• Effort to complete? (hours estimate)
• Blockers? (dependencies, unclear requirements)

B. Review MISSING Features

For each ❌ MISSING feature:

• Is it actually needed? (or can it be deprioritized?)
• User impact if missing? (critical, important, nice-to-have)
• Implementation complexity? (simple, moderate, complex)
• Dependencies? (what must be done first)

C. Technical Debt Assessment

From docs/reverse-engineering/technical-debt-analysis.md:

• Code quality issues
• Missing tests (unit, integration, E2E)
• Documentation gaps
• Security vulnerabilities
• Performance bottlenecks

D. Identify Clarification Needs

Mark ambiguous areas with [NEEDS CLARIFICATION]:

• Unclear requirements
• Missing UX/UI details
• Undefined behavior
• Unspecified constraints

See operations/detailed-gap-analysis.md

Step 3: Prioritize Implementation

Classify gaps by priority:

P0 - Critical

• Blocking major use cases
• Security vulnerabilities
• Data integrity issues
• Broken core functionality

P1 - High Priority

• Important for core user value
• High user impact
• Competitive differentiation
• Technical debt causing problems

P2 - Medium Priority

• Nice-to-have features
• Improvements to existing features
• Minor technical debt
• Edge cases

P3 - Low Priority

• Future enhancements
• Polish and refinements
• Non-critical optimizations

See operations/prioritization.md

Step 4: Create Implementation Roadmap

Phase the work into manageable chunks:

Phase 1: P0 Items (~X hours)

• Complete critical features
• Fix security issues
• Unblock major workflows

Phase 2: P1 Features (~X hours)

• Build high-value features
• Address important technical debt
• Improve test coverage

Phase 3: P2/P3 Enhancements (~X hours or defer)

• Nice-to-have features
• Polish and refinements
• Optional improvements

---

Output Format

Create docs/gap-analysis-report.md (supplementing Spec Kit's output):

Copy# Gap Analysis Report

**Date:** [Current Date]
**Based on:** /speckit.analyze + manual review

---

## Executive Summary

- **Overall Completion:** ~66%
- **Complete Features:** 3 (25%)
- **Partial Features:** 4 (33%)
- **Missing Features:** 5 (42%)
- **Critical Issues:** 2
- **Clarifications Needed:** 8

---

## Spec Kit Analysis Results

### Inconsistencies Detected by /speckit.analyze

1. **user-authentication.md** (PARTIAL)
   - Spec: Frontend login UI required
   - Reality: No login components exist
   - Impact: Users cannot authenticate

2. **photo-upload.md → fish-management.md**
   - fish-management depends on photo-upload
   - photo-upload.md is PARTIAL (API incomplete)
   - Impact: Fish photos cannot be uploaded

3. **Orphaned Code: notifications.ts**
   - Implementation exists without specification
   - Action: Create specification or remove code

---

## Gap Details

### Missing Features (❌ 5 features)

#### F003: Analytics Dashboard [P1]
**Specification:** `specs/analytics-dashboard.md`
**Status:** ❌ MISSING (not started)
**Impact:** Users cannot track metrics over time
**Effort:** ~8 hours
**Dependencies:** None

**Needs Clarification:**
- [NEEDS CLARIFICATION] What metrics to display?
- [NEEDS CLARIFICATION] Chart types (line, bar, pie)?
- [NEEDS CLARIFICATION] Real-time or daily aggregates?

#### F005: Social Features [P2]
...

### Partial Features (⚠️ 4 features)

#### F002: Fish Management [P0]
**Specification:** `specs/fish-management.md`
**Status:** ⚠️ PARTIAL

**Implemented:**
- ✅ Backend API (all CRUD endpoints)
- ✅ Fish list page
- ✅ Fish detail view

**Missing:**
- ❌ Fish profile edit page
- ❌ Photo upload UI (blocked by photo-upload.md)
- ❌ Bulk import feature

**Effort to Complete:** ~4 hours
**Blockers:** Photo upload API must be completed first

**Needs Clarification:**
- [NEEDS CLARIFICATION] Photo upload: drag-drop or click-browse?
- [NEEDS CLARIFICATION] Max photos per fish?

---

## Technical Debt

### High Priority (Blocking)
- Missing integration tests (0 tests, blocks deployment)
- No error handling in 8 API endpoints (causes crashes)
- Hardcoded AWS region (prevents multi-region)

### Medium Priority
- Frontend components lack TypeScript types
- No loading states in UI (poor UX)
- Missing rate limiting on API (security risk)

### Low Priority
- Inconsistent code formatting
- No dark mode support
- Missing accessibility labels

---

## Prioritized Roadmap

### Phase 1: P0 Critical (~12 hours)

**Goals:**
- Unblock core user workflows
- Fix security issues
- Complete essential features

**Tasks:**
1. Complete F002: Fish Management UI (~4h)
   - Implement photo upload API
   - Build fish edit page
   - Connect to backend

2. Add error handling to all APIs (~3h)

3. Implement integration tests (~5h)

### Phase 2: P1 High Value (~20 hours)

**Goals:**
- Build analytics dashboard
- Implement notifications
- Improve test coverage

**Tasks:**
1. F003: Analytics Dashboard (~8h)
2. F006: Notification System (~6h)
3. Add rate limiting (~2h)
4. Improve TypeScript coverage (~4h)

### Phase 3: P2/P3 Enhancements (~TBD)

**Goals:**
- Add nice-to-have features
- Polish and refinements

**Tasks:**
1. F005: Social Features (~12h)
2. F007: Dark Mode (~6h)
3. F008: Admin Panel (~10h)

---

## Clarifications Needed (8 total)

### Critical (P0) - 2 items
1. **F002 - Photo Upload:** Drag-drop, click-browse, or both?
2. **F004 - Offline Sync:** Full data or metadata only?

### Important (P1) - 4 items
3. **F003 - Analytics:** Which chart types and metrics?
4. **F006 - Notifications:** Email, push, or both?
5. **F003 - Data Refresh:** Real-time or daily aggregates?
6. **F006 - Alert Frequency:** Per event or digest?

### Nice-to-Have (P2) - 2 items
7. **F007 - Dark Mode:** Full theme or toggle only?
8. **F005 - Social:** Which social features (share, comment, like)?

---

## Recommendations

1. **Resolve P0 clarifications first** (Step 5: complete-spec)
2. **Focus on Phase 1** before expanding scope
3. **Use /speckit.implement** for systematic implementation
4. **Update specs as you go** to keep them accurate
5. **Run /speckit.analyze regularly** to catch drift

---

## Next Steps

1. Run complete-spec skill to resolve clarifications
2. Begin Phase 1 implementation
3. Use `/speckit.implement` for each feature
4. Update implementation status in specs
5. Re-run `/speckit.analyze` to validate progress

---

GitHub Spec Kit Integration

After gap analysis, leverage Spec Kit commands:

Validate Continuously

Copy# Re-run after making changes
> /speckit.analyze

# Should show fewer issues as you implement

Implement Systematically

Copy# Generate tasks for a feature
> /speckit.tasks user-authentication

# Implement step-by-step
> /speckit.implement user-authentication

# Updates spec status automatically

Clarify Ambiguities

Copy# Before implementing unclear features
> /speckit.clarify analytics-dashboard

# Interactive Q&A to fill gaps

---

Success Criteria

After running this skill, you should have:

• ✅ /speckit.analyze results reviewed
• ✅ All inconsistencies documented
• ✅ PARTIAL features analyzed (what exists vs missing)
• ✅ MISSING features categorized
• ✅ Technical debt cataloged
• ✅ [NEEDS CLARIFICATION] markers added
• ✅ Priorities assigned (P0/P1/P2/P3)
• ✅ Phased implementation roadmap
• ✅ docs/gap-analysis-report.md created
• ✅ Ready to proceed to Step 5 (Complete Specification)

---

Next Step

Once gap analysis is complete, proceed to:

Step 5: Complete Specification - Use the complete-spec skill to resolve all [NEEDS CLARIFICATION] markers interactively.

---

Technical Notes

• /speckit.analyze is run first for automated checks
• Manual analysis supplements with deeper insights
• Gap report complements Spec Kit's output
• Keep both .specify/memory/ specs and gap report updated
• Re-run /speckit.analyze frequently to track progress

---

Route Comparison: What Gap Analysis Means

Key Insight:

• Greenfield: Specs describe WHAT to build (old code doesn't matter) - Same for ALL detection types
• Brownfield: Specs describe current reality (validate against old code) - Same for ALL detection types

Detection type doesn't change gap analysis approach - it only affects what patterns were analyzed in Gear 2

---

Remember: Check route first! Greenfield analyzes SPECS, Brownfield analyzes IMPLEMENTATION.