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.
When & Why to Use This Skill
The Developer Detective skill is a high-performance code intelligence tool designed for deep structural analysis of complex codebases. By leveraging claudemem v0.3.0 and AST (Abstract Syntax Tree) parsing, it enables developers to move beyond unreliable text-based searches like grep. It provides precise tracking of function callers and callees, comprehensive data flow mapping, and transitive impact analysis, ensuring developers can navigate, understand, and modify code with surgical precision and minimal risk of regression.
Use Cases
- Refactoring & Impact Analysis: Identify all direct and transitive callers of a function before modification to prevent breaking changes in large-scale systems.
- Data Flow Tracing: Map out the execution path and dependencies of specific features by analyzing the chain of callees to understand how data is processed.
- Codebase Exploration: Quickly answer 'how does X work' by generating a structural context of symbols, definitions, and usage patterns without manual file searching.
- Integration Auditing: Locate every instance where specific APIs or library functions are implemented to ensure compliance with architectural standards and security protocols.
- Dead Code Detection: Use structural usage analysis to identify functions that have no callers, helping to clean up and optimize the codebase.
| name | developer-detective |
|---|---|
| description | "⚡ 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." |
| allowed-tools | Bash, Task, Read, AskUserQuestion |
⛔⛔⛔ 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:
callersshows only direct callers (1 level)impactshows ALL transitive callers (full tree)- 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 |
|---|---|---|
grep -r "function" |
No call relationships | claudemem --nologo callees func --raw |
| Modify without callers | Breaking changes | ALWAYS check callers first |
| Read whole files | Token waste | Read specific file:line from results |
| Guess dependencies | Miss connections | Use callees for exact deps |
Notes
callersis essential before any modification - Know your impactcalleestraces data flow - Follow the execution pathcontextgives complete picture - Symbol + callers + callees- 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)