~aod Build

Implementation Checkpoint Skill

Purpose

Automatically generate standardized checkpoint reports that document implementation progress at strategic milestones. Each report includes completed tasks, remaining work, technical achievements, knowledge base entries, quality metrics, and resume instructions.

When to Use

Create a checkpoint at:

1. Complete phase finish - All tasks in a phase marked complete
2. User story completion - Entire user story implemented and tested
3. Critical milestone - Core functionality ready (e.g., MVP core)
4. Before pausing - Stopping for review, testing, or user feedback
5. After architect review - Major approval/sign-off received

How to Use

Quick Usage

# Navigate to skill directory
cd .claude/skills/~aod-build

# Generate checkpoint (interactive prompts will follow)
python scripts/generate_checkpoint.py \
  --tasks-file ../../specs/{feature-id}/tasks.md \
  --output-dir ../../specs/{feature-id} \
  --description "{Phase-Description}"

Step-by-Step Process

1. Analyze completion status

   # Script automatically:
   # - Reads tasks.md
   # - Counts [X] completed vs [ ] pending
   # - Calculates progress percentage
   # - Identifies completed phases
   # - Determines task range
   

2. Provide context when prompted

   Key achievements (3-5 bullet points):
   > - Achievement 1
   > - Achievement 2
   > - Achievement 3
   
   Knowledge base entries captured (count or 'none'):
   > 2
   
   [For each KB entry, provide: Title, Problem, Solution]
   

3. Review generated report

   # Output: CHECKPOINT-{NN}_{Description}_{TaskRange}.md
   # Location: specs/{feature-id}/
   

4. Verify index updated

   # Check: CHECKPOINTS_README.md includes new checkpoint
   

Checkpoint Naming Convention

Format: CHECKPOINT-{NN}_{Phase-Description}_{TaskRange}.md

Components:

• {NN}: Sequential checkpoint number (01, 02, 03...) - auto-detected
• {Phase-Description}: Milestone name (e.g., "Phase1-2-Complete", "US1-Complete")
• {TaskRange}: Task IDs covered (e.g., "T001-T030")

Examples:

✓ CHECKPOINT-01_Phase1-2-Complete_T001-T030.md
✓ CHECKPOINT-02_US1-Complete_T001-T039.md
✓ CHECKPOINT-03_MVP-Ready_T001-T101.md
✓ CHECKPOINT-04_ProductionReady_T001-T120.md

See references/naming_conventions.md for detailed rules.

Required Sections

Every checkpoint report includes:

1. Executive Summary - What was completed, what's next
2. Completion Status - Progress table with percentages
3. What Was Implemented - Detailed task breakdown by phase
4. Key Technical Achievements - Highlights and innovations
5. Files Created/Modified - Complete file inventory with counts
6. Knowledge Base Captured - Critical learnings documented
7. Server/Database Status - Current state of running services
8. Quality Metrics - Code quality, reviews, test coverage
9. Remaining Work - What's left and estimated time
10. Resume Instructions - How to continue implementation

Metrics Calculated Automatically

• Progress percentage: (completed / total) * 100
• Phase completion: Per-phase progress tracking
• Task range: Start and end task IDs
• Next task: First pending task to work on

See references/metrics_formulas.md for formulas and examples.

Knowledge Base Integration

When prompted for knowledge base entries, provide learnings that:

✅ DO include:

• Solved problems that took >30 minutes
• Non-obvious gotchas or edge cases
• Architectural decisions with trade-offs
• Patterns that should be reused
• Issues that could happen again

❌ DON'T include:

• Obvious facts ("we use PostgreSQL")
• Generic statements ("testing is important")
• Implementation progress ("completed task T026")
• Temporary workarounds

Output Files

The skill generates/updates:

1. Checkpoint Report: CHECKPOINT-{NN}_{Description}_{TaskRange}.md

   • Location: specs/{feature-id}/
   • Size: ~15-20 KB
   • Format: Markdown with tables and code blocks

2. Checkpoints Index: CHECKPOINTS_README.md (updated)

   • Location: specs/{feature-id}/
   • Adds new checkpoint entry
   • Updates progress tracking table

Resume Commands Generated

The checkpoint report includes auto-generated resume commands:

# For team-lead orchestration
/aod.build --resume

# For direct continuation
# Continue from task {NEXT_TASK}

Scripts Reference

analyze_tasks.py

Parse tasks.md and extract metrics.

Input: Path to tasks.md file Output: JSON with completion metrics

Usage:

python scripts/analyze_tasks.py specs/001-{{PROJECT_NAME}}/tasks.md

Output Format:

{
  "total_tasks": 120,
  "completed_tasks": 32,
  "progress_percentage": 26.67,
  "phases": [...],
  "task_range": "T001-T030",
  "next_task": "T031"
}

generate_checkpoint.py

Generate checkpoint report from template.

Usage:

python scripts/generate_checkpoint.py \
  --tasks-file specs/{feature-id}/tasks.md \
  --output-dir specs/{feature-id} \
  --description "{Phase-Description}"

Interactive Prompts:

• Key achievements summary
• Knowledge base entries (optional)
• Per-entry: title, problem, solution

Output: Complete checkpoint report file

update_index.py

Update CHECKPOINTS_README.md with new checkpoint.

Usage:

python scripts/update_index.py \
  --checkpoints-readme specs/{feature-id}/CHECKPOINTS_README.md \
  --checkpoint-file CHECKPOINT-{NN}_{Description}_{TaskRange}.md \
  --checkpoint-num {NN}

Changes Made:

• Adds checkpoint to "Active Checkpoints" section
• Updates progress tracking table
• Updates "Next Checkpoint Planned" footer

Templates Reference

checkpoint_template.md

Complete Markdown template for checkpoint reports. Contains all required sections with template variables for substitution.

Location: references/checkpoint_template.md

Key Variables:

• {CHECKPOINT_NUM}, {PHASE_DESCRIPTION}, {TASK_RANGE}
• {DATE}, {FEATURE_ID}, {TOTAL_TASKS}, {COMPLETED_TASKS}
• {PROGRESS_PERCENTAGE}, {PHASES_TABLE}, {KEY_ACHIEVEMENTS}
• {KB_ENTRIES}, {NEXT_TASK}, {RESUME_COMMAND}

CHECKPOINTS_README_template.md

Template for creating the checkpoints index file (first-time use).

Location: assets/CHECKPOINTS_README_template.md

Usage: Copy to specs/{feature-id}/CHECKPOINTS_README.md when creating first checkpoint.

Examples

Example 1: After Completing Phase 1-2

$ python scripts/generate_checkpoint.py \
    --tasks-file specs/001-{{PROJECT_NAME}}/tasks.md \
    --output-dir specs/001-{{PROJECT_NAME}} \
    --description "Phase1-2-Complete"

Analyzing tasks.md...
✓ Found 120 total tasks
✓ Found 32 completed tasks (27%)
✓ Task range: T001-T030
✓ Checkpoint #01 (auto-detected)

Key achievements (3-5 bullet points):
> - Database schema with 6 entities, 19 indexes
> - Architect review APPROVED
> - MVP core: Atomic locking with row-level locks

Knowledge base entries: 5

[... interactive prompts for KB entries ...]

✓ Generated: CHECKPOINT-01_Phase1-2-Complete_T001-T030.md
✓ Updated: CHECKPOINTS_README.md

Next: Resume with /aod.build --resume

Example 2: After Completing User Story 1

$ python scripts/generate_checkpoint.py \
    --tasks-file specs/001-{{PROJECT_NAME}}/tasks.md \
    --output-dir specs/001-{{PROJECT_NAME}} \
    --description "US1-Complete"

✓ Checkpoint #02: US1-Complete (T001-T039)
✓ Progress: 33% (39/120 tasks)

[... prompts and generation ...]

✓ Generated: CHECKPOINT-02_US1-Complete_T001-T039.md

Troubleshooting

Q: Script can't find tasks.md A: Provide absolute path or verify relative path from skill directory

Q: Checkpoint number is wrong A: Manually specify with --checkpoint-num NN flag

Q: Template variables not substituted A: Check template file exists in references/checkpoint_template.md

Q: Index file not updating A: Verify CHECKPOINTS_README.md exists in output directory

Best Practices

1. Create checkpoints proactively - Don't wait until pausing
2. Capture knowledge fresh - Document learnings immediately
3. Be specific in achievements - "Implemented X" not "Made progress"
4. Validate metrics - Review auto-calculated percentages
5. Test resume commands - Verify they work before distributing

Skill Version: 1.0.0 Last Updated: 2025-11-20 Maintainer: Team Lead Agent

Common Rationalizations

Red Flags

• Agent creates a checkpoint without running analyze_tasks.py per the metrics block (lines 162-183).
• Agent's KB entries match the DON'T list (line 128): "obvious facts," "generic statements," "implementation progress."
• Agent skips line 310 (validate metrics): publishes auto-calculated percentages without sanity-checking them.
• Agent omits the Required Sections list (line 96) — Quality Metrics, Resume Instructions, or Files Created.
• Agent uses arbitrary checkpoint numbering instead of the auto-detected {NN} from the script (line 78).
• Agent's report contains template variables like {NEXT_TASK} unsubstituted — Troubleshooting Q3 (line 298) flags this.