Developer Detective Skill

Name: developer-detective
Rating: 92
Author: MadAppGang

This skill uses claudemem's callers/callees analysis for implementation investigation.

Why Claudemem Works Better for Development

Task	claudemem	Native Tools
Find usages	`callers` shows all call sites	Grep (text match)
Trace dependencies	`callees` shows called functions	Manual reading
Understand context	`context` gives full picture	Multiple reads
Impact analysis	Caller chain reveals risk	Unknown

Primary commands:

•claudemem --agent callers <name> - What calls this code
•claudemem --agent callees <name> - What this code calls
•claudemem --agent context <name> - Full understanding

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

bash

# Find where a function is defined
claudemem --agent symbol processPayment
# Get full context with callers and callees
claudemem --agent context processPayment```

### Trace Data Flow

```bash
# What does this function call? (data flows OUT)
claudemem --agent callees processPayment
# Follow the chain
claudemem --agent callees validateCardclaudemem --agent callees chargeStripe```

### Find All Usages

```bash
# Who calls this function? (usage patterns)
claudemem --agent callers processPayment
# This shows EVERY place that uses this code

Impact Analysis (v0.4.0+ Required)

bash

# Before modifying ANY code, check full impact
claudemem --agent impact functionToChange
# 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:

•callers shows only direct callers (1 level)
•impact shows ALL transitive callers (full tree)
•Critical for refactoring decisions

Handling Empty Results:

bash

IMPACT=$(claudemem --agent impact functionToChange)
if echo "$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)

bash

# Quick check - direct callers only (v0.3.0)
claudemem --agent callers functionToChange
# Deep check - ALL transitive callers (v0.4.0+ Required)
IMPACT=$(claudemem --agent impact functionToChange)

# 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

bash

# Get full picture: definition + callers + callees
claudemem --agent context complexFunction```

## PHASE 0: MANDATORY SETUP

### Step 1: Verify claudemem v0.3.0

```bash
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

bash

# 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:

bash

# 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

bash

claudemem index

Workflow: Implementation Investigation (v0.3.0)

Phase 1: Map the Area

bash

# Get overview of the feature area
claudemem --agent map "payment processing"```

### Phase 2: Find the Entry Point

```bash
# Locate the main function (highest PageRank in area)
claudemem --agent symbol PaymentService```

### Phase 3: Trace the Flow

```bash
# What does PaymentService call?
claudemem --agent callees PaymentService
# For each major callee, trace further
claudemem --agent callees validatePaymentclaudemem --agent callees processChargeclaudemem --agent callees saveTransaction```

### Phase 4: Understand Usage

```bash
# Who uses PaymentService?
claudemem --agent callers PaymentService
# This shows the entry points

Phase 5: Read Specific Code

bash

# Now read ONLY the relevant file:line ranges from results
# DON'T read whole files

Output Format: Implementation Report

1. Symbol Overview

code

┌─────────────────────────────────────────────────────────┐
│              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)

code

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)

code

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

code

⚠️ 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?"

bash

# Step 1: Find X
claudemem --agent symbol X
# Step 2: See what X does
claudemem --agent callees X
# Step 3: See how X is used
claudemem --agent callers X
# Step 4: Read the specific code
# Use Read tool on exact file:line from results

Scenario: Refactoring

bash

# Step 1: Find ALL usages (callers)
claudemem --agent callers oldFunction
# Step 2: Document each caller location
# Step 3: Update each caller systematically

Scenario: Adding to Existing Code

bash

# Step 1: Find where to add
claudemem --agent symbol targetModule
# Step 2: Understand dependencies
claudemem --agent callees targetModule
# Step 3: Check existing patterns
claudemem --agent callers targetModule```

## Result Validation Pattern

After EVERY claudemem command, validate results:

### Symbol/Callers Validation

When tracing implementation:

```bash
# Find symbol
SYMBOL=$(claudemem --agent symbol PaymentService)
EXIT_CODE=$?

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=$(claudemem --agent callers PaymentService)
# 0 callers is valid (entry point or unused)
# But error message is not
if echo "$CALLERS" | grep -qi "error\|failed"; then
  # Use AskUserQuestion
fi

Empty/Irrelevant Results

bash

RESULTS=$(claudemem --agent callees FunctionName)

# 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

typescript

// 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 --agent callees func`
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
`cmd \| head/tail`	Hides callers/callees	Use full output or `--tokens`

Output Truncation Warning

╔══════════════════════════════════════════════════════════════════════════════╗ ║ ║ ║ ❌ Anti-Pattern 7: Truncating Claudemem Output ║ ║ ║ ║ FORBIDDEN (any form of output truncation): ║ ║ → BAD: claudemem --agent map "query" | head -80 ║ ║ → BAD: claudemem --agent callers X | tail -50 ║ ║ → BAD: claudemem --agent search "x" | grep -m 10 "y" ║ ║ → BAD: claudemem --agent map "q" | awk 'NR <= 50' ║ ║ → BAD: claudemem --agent callers X | sed '50q' ║ ║ → BAD: claudemem --agent search "x" | sort | head -20 ║ ║ → BAD: claudemem --agent map "q" | grep "pattern" | head -20 ║ ║ ║ ║ CORRECT (use full output or built-in limits): ║ ║ → GOOD: claudemem --agent map "query" ║ ║ → GOOD: claudemem --agent search "x" -n 10 ║ ║ → GOOD: claudemem --agent map "q" --tokens 2000 ║ ║ → GOOD: claudemem --agent search "x" --page-size 20 --page 1 ║ ║ → GOOD: claudemem --agent context Func --max-depth 3 ║ ║ ║ ║ WHY: Output is pre-optimized; truncation hides critical results ║ ║ ║ ╚══════════════════════════════════════════════════════════════════════════════╝

Feedback Reporting (v0.8.0+)

After completing investigation, report search feedback to improve future results.

When to Report

Report feedback ONLY if you used the search command during investigation:

Result Type	Mark As	Reason
Read and used	Helpful	Contributed to investigation
Read but irrelevant	Unhelpful	False positive
Skipped after preview	Unhelpful	Not relevant to query
Never read	(Don't track)	Can't evaluate

Feedback Pattern

bash

# Track during investigation
SEARCH_QUERY="your original query"
HELPFUL_IDS=""
UNHELPFUL_IDS=""

# When reading a helpful result
HELPFUL_IDS="$HELPFUL_IDS,$result_id"

# When reading an unhelpful result
UNHELPFUL_IDS="$UNHELPFUL_IDS,$result_id"

# Report at end of investigation (v0.8.0+ only)
if claudemem feedback --help 2>&1 | grep -qi "feedback"; then
  timeout 5 claudemem feedback \
    --query "$SEARCH_QUERY" \
    --helpful "${HELPFUL_IDS#,}" \
    --unhelpful "${UNHELPFUL_IDS#,}" 2>/dev/null || true
fi

Output Update

Include in investigation report:

code

Search Feedback: [X helpful, Y unhelpful] - Submitted (v0.8.0+)

Notes

•callers is essential before any modification - Know your impact
•callees traces data flow - Follow the execution path
•context gives 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)