Claude-skill-registry developer-detective
⚡ PRIMARY TOOL for: 'how does X work', 'find implementation of', 'trace data flow', 'where is X defined', 'audit integrations', 'find all usages'. Uses claudemem v0.3.0 AST with callers/callees analysis. GREP/FIND/GLOB ARE FORBIDDEN.
git clone https://github.com/majiayu000/claude-skill-registry
T=$(mktemp -d) && git clone --depth=1 https://github.com/majiayu000/claude-skill-registry "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills/data/developer-detective" ~/.claude/skills/majiayu000-claude-skill-registry-developer-detective && rm -rf "$T"
skills/data/developer-detective/SKILL.md⛔⛔⛔ CRITICAL: AST STRUCTURAL ANALYSIS ONLY ⛔⛔⛔
╔══════════════════════════════════════════════════════════════════════════════╗ ║ ║ ║ 🧠 THIS SKILL USES claudemem v0.3.0 AST ANALYSIS EXCLUSIVELY ║ ║ ║ ║ ❌ GREP IS FORBIDDEN ║ ║ ❌ FIND IS FORBIDDEN ║ ║ ❌ GLOB IS FORBIDDEN ║ ║ ║ ║ ✅ claudemem --nologo callers <name> --raw FOR USAGE ANALYSIS ║ ║ ✅ claudemem --nologo callees <name> --raw FOR DEPENDENCY TRACING ║ ║ ✅ claudemem --nologo context <name> --raw FOR FULL UNDERSTANDING ║ ║ ║ ║ ⭐ v0.3.0: callers/callees show exact data flow and dependencies ║ ║ ║ ╚══════════════════════════════════════════════════════════════════════════════╝
Developer Detective Skill
Version: 3.3.0 Role: Software Developer Purpose: Implementation investigation using AST callers/callees and impact analysis
Role Context
You are investigating this codebase as a Software Developer. Your focus is on:
- Implementation details - How code actually works
- Data flow - How data moves through the system (via callees)
- Usage patterns - How code is used (via callers)
- Dependencies - What a function needs to work
- Impact analysis - What breaks if you change something
Why callers/callees is Perfect for Development
The
callers and callees commands show you:
- callers = Every place that calls this code (impact of changes)
- callees = Every function this code calls (its dependencies)
- Exact file:line = Precise locations for reading/editing
- Call kinds = call, import, extends, implements
Developer-Focused Commands (v0.3.0)
Find Implementation
# Find where a function is defined claudemem --nologo symbol processPayment --raw # Get full context with callers and callees claudemem --nologo context processPayment --raw
Trace Data Flow
# What does this function call? (data flows OUT) claudemem --nologo callees processPayment --raw # Follow the chain claudemem --nologo callees validateCard --raw claudemem --nologo callees chargeStripe --raw
Find All Usages
# Who calls this function? (usage patterns) claudemem --nologo callers processPayment --raw # This shows EVERY place that uses this code
Impact Analysis (v0.4.0+ Required)
# Before modifying ANY code, check full impact claudemem --nologo impact functionToChange --raw # Output shows ALL transitive callers: # direct_callers: # - LoginController.authenticate:34 # - SessionMiddleware.validate:12 # transitive_callers (depth 2): # - AppRouter.handleRequest:45 # - TestSuite.runAuth:89
Why impact matters:
shows only direct callers (1 level)callers
shows ALL transitive callers (full tree)impact- Critical for refactoring decisions
Handling Empty Results:
IMPACT=$(claudemem --nologo impact functionToChange --raw) if echo "$IMPACT" | grep -q "No callers"; then echo "No callers found. This is either:" echo " 1. An entry point (API handler, main function) - expected" echo " 2. Dead code - verify with: claudemem dead-code" echo " 3. Dynamically called - check for import(), reflection" fi
Impact Analysis (BEFORE Modifying)
# Quick check - direct callers only (v0.3.0) claudemem --nologo callers functionToChange --raw # Deep check - ALL transitive callers (v0.4.0+ Required) IMPACT=$(claudemem --nologo impact functionToChange --raw) # Handle results if [ -z "$IMPACT" ] || echo "$IMPACT" | grep -q "No callers"; then echo "No static callers found - verify dynamic usage patterns" else echo "$IMPACT" echo "" echo "This tells you:" echo "- Direct callers (immediate impact)" echo "- Transitive callers (ripple effects)" echo "- Grouped by file (for systematic updates)" fi
Understanding Complex Code
# Get full picture: definition + callers + callees claudemem --nologo context complexFunction --raw
PHASE 0: MANDATORY SETUP
Step 1: Verify claudemem v0.3.0
which claudemem && claudemem --version # Must be 0.3.0+
Step 2: If Not Installed → STOP
Use AskUserQuestion (see ultrathink-detective for template)
Step 3: Check Index Status
# Check claudemem installation and index claudemem --version && ls -la .claudemem/index.db 2>/dev/null
Step 3.5: Check Index Freshness
Before proceeding with investigation, verify the index is current:
# First check if index exists if [ ! -d ".claudemem" ] || [ ! -f ".claudemem/index.db" ]; then # Use AskUserQuestion to prompt for index creation # Options: [1] Create index now (Recommended), [2] Cancel investigation exit 1 fi # Count files modified since last index STALE_COUNT=$(find . -type f \( -name "*.ts" -o -name "*.tsx" -o -name "*.js" -o -name "*.jsx" -o -name "*.py" -o -name "*.go" -o -name "*.rs" \) \ -newer .claudemem/index.db 2>/dev/null | grep -v "node_modules" | grep -v ".git" | grep -v "dist" | grep -v "build" | wc -l) STALE_COUNT=$((STALE_COUNT + 0)) # Normalize to integer if [ "$STALE_COUNT" -gt 0 ]; then # Get index time with explicit platform detection if [[ "$OSTYPE" == "darwin"* ]]; then INDEX_TIME=$(stat -f "%Sm" -t "%Y-%m-%d %H:%M" .claudemem/index.db 2>/dev/null) else INDEX_TIME=$(stat -c "%y" .claudemem/index.db 2>/dev/null | cut -d'.' -f1) fi INDEX_TIME=${INDEX_TIME:-"unknown time"} # Get sample of stale files STALE_SAMPLE=$(find . -type f \( -name "*.ts" -o -name "*.tsx" \) \ -newer .claudemem/index.db 2>/dev/null | grep -v "node_modules" | grep -v ".git" | head -5) # Use AskUserQuestion (see template in ultrathink-detective) fi
Step 4: Index if Needed
claudemem index
Workflow: Implementation Investigation (v0.3.0)
Phase 1: Map the Area
# Get overview of the feature area claudemem --nologo map "payment processing" --raw
Phase 2: Find the Entry Point
# Locate the main function (highest PageRank in area) claudemem --nologo symbol PaymentService --raw
Phase 3: Trace the Flow
# What does PaymentService call? claudemem --nologo callees PaymentService --raw # For each major callee, trace further claudemem --nologo callees validatePayment --raw claudemem --nologo callees processCharge --raw claudemem --nologo callees saveTransaction --raw
Phase 4: Understand Usage
# Who uses PaymentService? claudemem --nologo callers PaymentService --raw # This shows the entry points
Phase 5: Read Specific Code
# Now read ONLY the relevant file:line ranges from results # DON'T read whole files
Output Format: Implementation Report
1. Symbol Overview
┌─────────────────────────────────────────────────────────┐ │ IMPLEMENTATION ANALYSIS │ ├─────────────────────────────────────────────────────────┤ │ Symbol: processPayment │ │ Location: src/services/payment.ts:45-89 │ │ Kind: function │ │ PageRank: 0.034 │ │ Search Method: claudemem v0.3.0 (AST analysis) │ └─────────────────────────────────────────────────────────┘
2. Data Flow (Callees)
processPayment ├── validateCard (src/validators/card.ts:12) ├── getCustomer (src/services/customer.ts:34) ├── chargeStripe (src/integrations/stripe.ts:56) │ └── stripe.charges.create (external) └── saveTransaction (src/repositories/transaction.ts:78) └── database.insert (src/db/index.ts:23)
3. Usage (Callers)
processPayment is called by: ├── CheckoutController.submit (src/controllers/checkout.ts:45) ├── SubscriptionService.renew (src/services/subscription.ts:89) └── RetryQueue.processPayment (src/workers/retry.ts:23)
4. Impact Analysis
⚠️ IMPACT: Changing processPayment will affect: - 3 direct callers (shown above) - Checkout flow (user-facing) - Subscription renewals (automated) - Payment retry logic (background)
Scenarios
Scenario: "How does X work?"
# Step 1: Find X claudemem --nologo symbol X --raw # Step 2: See what X does claudemem --nologo callees X --raw # Step 3: See how X is used claudemem --nologo callers X --raw # Step 4: Read the specific code # Use Read tool on exact file:line from results
Scenario: Refactoring
# Step 1: Find ALL usages (callers) claudemem --nologo callers oldFunction --raw # Step 2: Document each caller location # Step 3: Update each caller systematically
Scenario: Adding to Existing Code
# Step 1: Find where to add claudemem --nologo symbol targetModule --raw # Step 2: Understand dependencies claudemem --nologo callees targetModule --raw # Step 3: Check existing patterns claudemem --nologo callers targetModule --raw
Result Validation Pattern
After EVERY claudemem command, validate results:
Symbol/Callers Validation
When tracing implementation:
# Find symbol SYMBOL=$(claudemem --nologo symbol PaymentService --raw) EXIT_CODE=$? if [ "$EXIT_CODE" -ne 0 ] || [ -z "$SYMBOL" ] || echo "$SYMBOL" | grep -qi "not found\|error"; then # Symbol doesn't exist, typo, or index issue # Diagnose index health DIAGNOSIS=$(claudemem --version && ls -la .claudemem/index.db 2>&1) # Use AskUserQuestion with suggestions: # [1] Reindex, [2] Try different name, [3] Cancel fi # Check callers CALLERS=$(claudemem --nologo callers PaymentService --raw) # 0 callers is valid (entry point or unused) # But error message is not if echo "$CALLERS" | grep -qi "error\|failed"; then # Use AskUserQuestion fi
Empty/Irrelevant Results
RESULTS=$(claudemem --nologo callees FunctionName --raw) # Validate relevance # Extract keywords from the user's investigation query # Example: QUERY="how does auth work" → KEYWORDS="auth work authentication" # The orchestrating agent must populate KEYWORDS before this check MATCH_COUNT=0 for kw in $KEYWORDS; do if echo "$RESULTS" | grep -qi "$kw"; then MATCH_COUNT=$((MATCH_COUNT + 1)) fi done if [ "$MATCH_COUNT" -eq 0 ]; then # Results don't match expected dependencies # Use AskUserQuestion: Reindex, Different query, or Cancel fi
FALLBACK PROTOCOL
CRITICAL: Never use grep/find/Glob without explicit user approval.
If claudemem fails or returns irrelevant results:
- STOP - Do not silently switch tools
- DIAGNOSE - Run
claudemem status - REPORT - Tell user what happened
- ASK - Use AskUserQuestion for next steps
// Fallback options (in order of preference) AskUserQuestion({ questions: [{ question: "claudemem [command] failed or returned no relevant results. How should I proceed?", header: "Investigation Issue", multiSelect: false, options: [ { label: "Reindex codebase", description: "Run claudemem index (~1-2 min)" }, { label: "Try different query", description: "Rephrase the search" }, { label: "Use grep (not recommended)", description: "Traditional search - loses call graph analysis" }, { label: "Cancel", description: "Stop investigation" } ] }] })
See ultrathink-detective skill for complete Fallback Protocol documentation.
Anti-Patterns
| Anti-Pattern | Why Wrong | Correct Approach |
|---|---|---|
| No call relationships | |
| Modify without callers | Breaking changes | ALWAYS check first |
| Read whole files | Token waste | Read specific file:line from results |
| Guess dependencies | Miss connections | Use for exact deps |
Notes
is essential before any modification - Know your impactcallers
traces data flow - Follow the execution pathcallees
gives complete picture - Symbol + callers + calleescontext- Always read specific file:line ranges, not whole files
- Works best with TypeScript, Go, Python, Rust codebases
Maintained by: MadAppGang Plugin: code-analysis v2.7.0 Last Updated: December 2025 (v3.3.0 - Cross-platform compatibility, inline templates, improved validation)