GrepAI Trace Callees

This skill covers using grepai trace callees to find all functions called by a specific function.

When to Use This Skill

• Understanding function dependencies
• Mapping function behavior
• Finding deeply nested dependencies
• Code comprehension and documentation

What is Trace Callees?

grepai trace callees answers: "What does this function call?"

func ProcessOrder(order) {
    validateOrder(order)
    calculateTotal(order)
    sendConfirmation(order.email)
}
        │
        ↓
┌───────┴───────────────────┐
│  What does ProcessOrder   │
│  call?                    │
├───────────────────────────┤
│ • validateOrder           │
│ • calculateTotal          │
│ • sendConfirmation        │
└───────────────────────────┘

Basic Usage

grepai trace callees "FunctionName"

Example

grepai trace callees "ProcessOrder"

Output:

🔍 Callees of "ProcessOrder"

Found 4 callees:

1. validateOrder
   File: services/order.go:45
   Context: validateOrder(order)

2. calculateTotal
   File: services/order.go:48
   Context: total := calculateTotal(order.Items)

3. applyDiscount
   File: services/order.go:51
   Context: total = applyDiscount(total, order.Coupon)

4. sendConfirmation
   File: services/order.go:55
   Context: sendConfirmation(order.Email, total)

JSON Output

grepai trace callees "ProcessOrder" --json

Output:

{
  "query": "ProcessOrder",
  "mode": "callees",
  "count": 4,
  "results": [
    {
      "file": "services/order.go",
      "line": 45,
      "callee": "validateOrder",
      "context": "validateOrder(order)"
    },
    {
      "file": "services/order.go",
      "line": 48,
      "callee": "calculateTotal",
      "context": "total := calculateTotal(order.Items)"
    },
    {
      "file": "services/order.go",
      "line": 51,
      "callee": "applyDiscount",
      "context": "total = applyDiscount(total, order.Coupon)"
    },
    {
      "file": "services/order.go",
      "line": 55,
      "callee": "sendConfirmation",
      "context": "sendConfirmation(order.Email, total)"
    }
  ]
}

Compact JSON (AI Optimized)

grepai trace callees "ProcessOrder" --json --compact

Output:

{
  "q": "ProcessOrder",
  "m": "callees",
  "c": 4,
  "r": [
    {"f": "services/order.go", "l": 45, "fn": "validateOrder"},
    {"f": "services/order.go", "l": 48, "fn": "calculateTotal"},
    {"f": "services/order.go", "l": 51, "fn": "applyDiscount"},
    {"f": "services/order.go", "l": 55, "fn": "sendConfirmation"}
  ]
}

TOON Output (v0.26.0+)

TOON format offers ~50% fewer tokens than JSON:

grepai trace callees "ProcessOrder" --toon

Note: --json and --toon are mutually exclusive.

Extraction Modes

Fast Mode (Default)

grepai trace callees "ProcessOrder" --mode fast

Precise Mode

grepai trace callees "ProcessOrder" --mode precise

Mode	Speed	Accuracy	Dependencies
fast	⚡⚡⚡	Good	None
precise	⚡⚡	Excellent	tree-sitter

Use Cases

Understanding Function Behavior

# What does this complex function do?
grepai trace callees "handleRequest"

# Map the data flow
grepai trace callees "processPayment"

Finding Dependencies

# What external services does this call?
grepai trace callees "syncData"

# What database operations happen?
grepai trace callees "saveUser"

Code Review

# What side effects does this function have?
grepai trace callees "updateProfile"

# Is this function doing too much?
grepai trace callees "doEverything"  # Lots of callees = code smell

Documentation

# Generate dependency list for docs
grepai trace callees "initialize" --json | jq '.results[].callee'

Callers vs Callees

Command	Question	Use Case
trace callers	Who calls me?	Impact analysis
trace callees	What do I call?	Behavior analysis

# Combined analysis
grepai trace callers "processOrder"   # Who uses this?
grepai trace callees "processOrder"   # What does it do?

Filtering Results

By File Type

# Get callees and filter to only .go files
grepai trace callees "main" --json | jq '.results[] | select(.file | endswith(".go"))'

Exclude Test Functions

grepai trace callees "Login" --json | jq '.results[] | select(.callee | startswith("Test") | not)'

Count by Category

# Count how many database vs. API calls
grepai trace callees "processOrder" --json | jq '.results[].callee' | grep -c "db"

What Callees Includes

The trace finds:

• Direct function calls
• Method calls
• Built-in function calls (depending on mode)

Example

func ProcessOrder(order Order) error {
    // Direct call
    validateOrder(order)

    // Method call
    order.Validate()

    // Package function
    utils.Log("processing")

    // Built-in (may or may not be captured)
    fmt.Println("done")

    return nil
}

Callees found:

• validateOrder
• Validate (method)
• Log (from utils)
• Println (depending on mode)

Limitations

What Callees Might Miss

• Dynamic/runtime calls
• Callbacks and closures
• Interface method calls (may show interface, not implementation)
• Reflection-based calls

Example of Undetected Call

func process(fn func()) {
    fn()  // Callee is unknown at static analysis time
}

Combining with Trace Graph

For recursive dependency analysis, use trace graph:

# Direct callees only
grepai trace callees "main"

# Full dependency tree (recursive)
grepai trace graph "main" --depth 3

Scripting Examples

List All Callees

grepai trace callees "main" --json | jq -r '.results[].callee' | sort -u

Check for Specific Callee

# Does processOrder call sendEmail?
grepai trace callees "processOrder" --json | jq -e '.results[] | select(.callee == "sendEmail")' && echo "Yes" || echo "No"

Generate Dependency Report

#!/bin/bash
echo "# Function Dependencies Report"
echo ""
for fn in main initialize processOrder; do
    echo "## $fn"
    grepai trace callees "$fn" --json | jq -r '.results[].callee' | sed 's/^/- /'
    echo ""
done

Common Issues

❌ Problem: Function not found
✅ Solution: Check spelling and ensure function exists in indexed files

❌ Problem: No callees found (but function has calls)
✅ Solutions:

• Try --mode precise
• Check language is in enabled_languages
• Ensure symbols.gob is up to date (grepai watch)

❌ Problem: Missing some callees
✅ Solution: Use --mode precise for better accuracy

Best Practices

1. Use for understanding: Great for learning new codebases
2. Combine with callers: Full dependency picture
3. Use graph for deep analysis: When you need recursion
4. Filter results: Focus on relevant callees
5. Document findings: Export to markdown for docs

Output Format

Trace callees result:

🔍 Callees of "ProcessOrder"

Mode: fast
Function found in: services/order.go:40

Found 4 callees:

1. validateOrder
   File: services/order.go:45
   Context: validateOrder(order)

2. calculateTotal
   File: services/order.go:48
   Context: total := calculateTotal(order.Items)

3. applyDiscount
   File: services/order.go:51
   Context: total = applyDiscount(total, order.Coupon)

4. sendConfirmation
   File: services/order.go:55
   Context: sendConfirmation(order.Email, total)

Tip: Use 'grepai trace graph ProcessOrder' for recursive analysis