---
description: Debugging command. Activates DEBUG mode for systematic problem investigation.
ai_support: qwen, claude, gemini, opencode
---

# /debug - Systematic Problem Investigation

$ARGUMENTS

---

## Purpose

This command activates DEBUG mode for systematic investigation of issues, errors, or unexpected behavior.

---

## Behavior

When `/debug` is triggered:

1. **Gather information**
   - Error message
   - Reproduction steps
   - Expected vs actual behavior
   - Recent changes

2. **Form hypotheses**
   - List possible causes
   - Order by likelihood

3. **Investigate systematically**
   - Test each hypothesis
   - Check logs, data flow
   - Use elimination method

4. **Fix and prevent**
   - Apply fix
   - Explain root cause
   - Add prevention measures

---

## Output Format

```markdown
## 🔍 Debug: [Issue]

### 1. Symptom
[What's happening]

### 2. Information Gathered
- Error: `[error message]`
- File: `[filepath]`
- Line: [line number]

### 3. Hypotheses
1. ❓ [Most likely cause]
2. ❓ [Second possibility]
3. ❓ [Less likely cause]

### 4. Investigation

**Testing hypothesis 1:**
[What I checked] → [Result]

**Testing hypothesis 2:**
[What I checked] → [Result]

### 5. Root Cause
🎯 **[Explanation of why this happened]**

### 6. Fix
```[language]
// Before
[broken code]

// After
[fixed code]
```

### 7. Prevention
🛡️ [How to prevent this in the future]
```

---

## Examples

```
/debug login not working
/debug API returns 500
/debug form doesn't submit
/debug data not saving
```

---

## Key Principles

- **Ask before assuming** - get full error context
- **Test hypotheses** - don't guess randomly
- **Explain why** - not just what to fix
- **Prevent recurrence** - add tests, validation

---

## AI-Specific Notes

| AI | Strength |
|----|----------|
| **Qwen** | Multi-language debugging, code analysis |
| **Claude** | Deep reasoning, complex bug chains |
| **Gemini** | Google ecosystem, Firebase issues |