"I'll help you generate a burndown chart. Which sprint?

A) Current active sprint: {SPRINT_NAME}
B) Specific sprint: {SPRINT_ID or SPRINT_NAME}
C) Last completed sprint: {SPRINT_NAME}
D) All active sprints

[If user doesn't specify, default to current sprint]"

{
  "sprintId": "{SPRINT_ID}"
}

{
  "sprintId": "{SPRINT_ID}"
}

{
  "sprintId": "{SPRINT_ID}",
  "projectId": "{PROJECT_ID}"
}

def calculate_burndown(sprint, items):
    # Sprint dates
    start_date = sprint['startDate']
    end_date = sprint['endDate']
    total_days = (end_date - start_date).days
    
    # Initial points
    initial_points = sum(item['estimate'] for item in items)
    
    # Daily data points
    burndown_data = []
    for day in range(total_days + 1):
        current_date = start_date + timedelta(days=day)
        
        # Calculate remaining points
        completed_items = [
            item for item in items 
            if item['status'] == 'Done' and item['completedAt'] <= current_date
        ]
        completed_points = sum(item['estimate'] for item in completed_items)
        remaining_points = initial_points - completed_points
        
        # Ideal burndown (linear)
        ideal_remaining = initial_points * (1 - day / total_days)
        
        burndown_data.append({
            'date': current_date,
            'remaining': remaining_points,
            'ideal': ideal_remaining,
            'completed': completed_points
        })
    
    return burndown_data

{
  "sprint": {
    "id": "{SPRINT_ID}",
    "name": "{SPRINT_NAME}",
    "startDate": "{START_DATE}",
    "endDate": "{END_DATE}",
    "totalPoints": {TOTAL_POINTS}
  },
  "burndown": [
    {
      "date": "{DATE_1}",
      "remaining": {REMAINING_POINTS},
      "ideal": {IDEAL_POINTS},
      "completed": {COMPLETED_POINTS}
    },
    {
      "date": "{DATE_2}",
      "remaining": {REMAINING_POINTS},
      "ideal": {IDEAL_POINTS},
      "completed": {COMPLETED_POINTS}
    }
  ],
  "summary": {
    "currentRemaining": {CURRENT_REMAINING},
    "idealRemaining": {IDEAL_REMAINING},
    "variance": {VARIANCE},
    "onTrack": true/false,
    "completionRate": {PERCENTAGE}
  }
}

Date,Remaining Points,Ideal Points,Completed Points,Variance
2026-02-03,25,25,0,0
2026-02-04,23,23.3,2,-0.3
2026-02-05,21,21.6,4,-0.6
...

| Date | Remaining | Ideal | Completed | Variance | Status |
|------|-----------|-------|-----------|----------|--------|
| 2026-02-03 | 25 | 25.0 | 0 | 0.0 | ✅ On Track |
| 2026-02-04 | 23 | 23.3 | 2 | -0.3 | ✅ On Track |
| 2026-02-05 | 21 | 21.6 | 4 | -0.6 | ✅ On Track |
| ... | ... | ... | ... | ... | ... |

"📊 **Burndown Analysis: {SPRINT_NAME}**

**Sprint Details:**
- **Dates:** {START_DATE} to {END_DATE}
- **Total Points:** {TOTAL_POINTS} pts
- **Days Elapsed:** {DAYS_ELAPSED} / {TOTAL_DAYS}
- **Days Remaining:** {DAYS_REMAINING}

**Current Status:**
- **Remaining Points:** {REMAINING_POINTS} pts
- **Ideal Remaining:** {IDEAL_REMAINING} pts
- **Variance:** {VARIANCE} pts ({PERCENTAGE}%)
- **On Track:** {ON_TRACK_STATUS}

**Progress:**
- **Completed:** {COMPLETED_POINTS} pts ({PERCENTAGE}%)
- **Remaining:** {REMAINING_POINTS} pts ({PERCENTAGE}%)
- **Completion Rate:** {COMPLETION_RATE} pts/day
- **Required Rate:** {REQUIRED_RATE} pts/day

**Trend Analysis:**
- {TREND_DESCRIPTION}
- {TREND_INSIGHT}

**Recommendations:**
- {RECOMMENDATION_1}
- {RECOMMENDATION_2}
"

"**Burndown Chart Visualization:**

**Chart Interpretation:**
- **Ideal Line:** Expected progress (linear burndown)
- **Actual Line:** Real progress (may vary)
- **Above Ideal:** Behind schedule ⚠️
- **Below Ideal:** Ahead of schedule ✅
- **On Ideal:** On track ✅
"

"✅ Burndown chart data generated!

**Sprint:** {SPRINT_NAME}
**Format:** {FORMAT} (JSON/CSV/Markdown)

**Chart Data:**
{CHART_DATA}

**Summary:**
- Total Points: {TOTAL_POINTS} pts
- Current Remaining: {REMAINING_POINTS} pts
- On Track: {ON_TRACK_STATUS}

**Next Steps:**
1. Visualize data using your preferred tool
2. Share with team during standup
3. Use for sprint review
4. Track trends over multiple sprints

**Visualization Tools:**
- Excel/Google Sheets (import CSV)
- Chart.js (use JSON data)
- Python matplotlib (use JSON data)
- Online chart tools

Burndown data is ready!"

✅ Burndown chart data generated!

**Sprint:** Sprint 6 - Payment Integration Phase 2
**Format:** JSON

**Chart Data:**
```json
{
  "sprint": {
    "id": "SPRINT-789",
    "name": "Sprint 6 - Payment Integration Phase 2",
    "startDate": "2026-02-03",
    "endDate": "2026-02-14",
    "totalPoints": 25
  },
  "burndown": [
    {"date": "2026-02-03", "remaining": 25, "ideal": 25.0, "completed": 0},
    {"date": "2026-02-04", "remaining": 23, "ideal": 23.3, "completed": 2},
    {"date": "2026-02-05", "remaining": 21, "ideal": 21.6, "completed": 4},
    {"date": "2026-02-06", "remaining": 18, "ideal": 20.0, "completed": 7},
    {"date": "2026-02-07", "remaining": 15, "ideal": 18.3, "completed": 10},
    {"date": "2026-02-10", "remaining": 12, "ideal": 15.0, "completed": 13},
    {"date": "2026-02-11", "remaining": 8, "ideal": 13.3, "completed": 17},
    {"date": "2026-02-12", "remaining": 5, "ideal": 11.6, "completed": 20},
    {"date": "2026-02-13", "remaining": 2, "ideal": 10.0, "completed": 23},
    {"date": "2026-02-14", "remaining": 0, "ideal": 8.3, "completed": 25}
  ],
  "summary": {
    "currentRemaining": 0,
    "idealRemaining": 8.3,
    "variance": -8.3,
    "onTrack": true,
    "completionRate": 100
  }
}

### Example 2: Burndown Analysis

**User:** "Show burndown analysis for SPRINT-790"

**Agent:** [Generates burndown with analysis]

**Output:**

### Example 3: CSV Format Burndown

**User:** "Generate burndown CSV for current sprint"

**Agent:** [Generates CSV format]

**Output:**

Date,Remaining Points,Ideal Points,Completed Points,Variance,Status
2026-03-03,25,25.0,0,0.0,On Track
2026-03-04,23,23.3,2,-0.3,On Track
2026-03-05,20,21.6,5,-1.6,Ahead
2026-03-06,18,20.0,7,-2.0,Ahead
2026-03-07,15,18.3,10,-3.3,Ahead
2026-03-10,12,15.0,13,-3.0,Ahead
2026-03-11,8,13.3,17,-5.3,Ahead
2026-03-12,5,11.6,20,-6.6,Ahead
2026-03-13,2,10.0,23,-8.0,Ahead
2026-03-14,0,8.3,25,-8.3,Ahead

## Backend Operations Reference

### Required Operations

| Operation | Interface | Purpose |
|-----------|-----------|---------|
| `getSprint` | `planning.getSprint` | Get sprint details |
| `getBurndown` | `metrics.getBurndown` | Get burndown data (if backend supports) |
| `listItems` | `workItems.listItems` | Query sprint items (for manual calculation) |

### Operation Details

**getSprint:**
- **Parameters:** `sprintId` (required)
- **Returns:** Sprint details with dates, items
- **Error Handling:** Validate sprintId exists

**getBurndown:**
- **Parameters:** `sprintId` (required)
- **Returns:** Burndown data points
- **Error Handling:** Handle if backend doesn't support, fall back to manual calculation

**listItems:**
- **Parameters:** `sprintId` (required), `projectId`
- **Returns:** List of items with estimates and completion dates
- **Error Handling:** Handle empty sprints, unestimated items

## Burndown Calculation Details

### Ideal Burndown

Linear burndown assumes constant velocity:

### Actual Burndown

Based on completed work:

### Variance

Difference between ideal and actual:

### On Track Assessment

- **On Track:** Variance within ±10%
- **Ahead:** Variance < -10%
- **Behind:** Variance > +10%

## Fallback Procedures

| Condition | Action |
|-----------|--------|
| PM backend not configured | Guide user to run `pm-configuration` skill first |
| Sprint not found | List available sprints, ask user to select |
| Sprint hasn't started | Warn user, show planned burndown instead |
| No items in sprint | Show empty burndown, suggest adding items |
| Items unestimated | Warn user, use count instead of points |
| Backend doesn't support getBurndown | Calculate manually from sprint items |
| Incomplete data | Use available data, note missing dates |

## Integration with Other Skills

### Integration with plan-sprint Skill

After planning:

### Integration with run-standup Skill

During sprint:

### Integration with close-sprint Skill

After closure:

## Important Rules

1. **Calculate accurately** - Use actual completion dates, not estimates
2. **Handle unestimated items** - Warn if items lack estimates
3. **Support multiple formats** - JSON, CSV, Markdown for flexibility
4. **Provide analysis** - Include progress insights and recommendations
5. **Visualize when possible** - Generate charts if tools available
6. **Track trends** - Compare across sprints for patterns
7. **Ground in reality** - Use actual data, not projections
8. **Make it actionable** - Provide recommendations based on burndown

## CLI Quick Reference

```bash
# Generate burndown via CLI (if implemented)
python cli/factory_cli.py --generate-burndown \
  --sprint-id "SPRINT-789" \
  --format "json" \
  --output "burndown.json"

# Generate CSV burndown
python cli/factory_cli.py --generate-burndown \
  --sprint-id "SPRINT-789" \
  --format "csv" \
  --output "burndown.csv"

# Show burndown analysis
python cli/factory_cli.py --burndown-analysis --sprint-id "SPRINT-789"