implement

name	implement
description	Use when user wants to implement tasks from a plan (PLN-XXX). Uses TDD internally (hidden from user), guides through task-by-task implementation with progress updates in user's preferred language. Triggered by "/implement" command or requests like "구현하고 싶어요" or "코드 작성해주세요".

Implement

Overview

This skill implements tasks from plan documents (PLN-XXX) using Test-Driven Development (TDD) internally while showing clean progress updates to the user.

Use this skill when:

• User wants to implement a plan
• User says "/implement" or "구현하고 싶어요"
• User completed planning and is ready to code
• User asks to implement specific tasks from a plan

Output: Working code in src/, tests in tests/, updated plan document

---

Workflow

Step 1: Load Context

Goal: Understand user's background and the plan to implement.

Process:

1. Read CLAUDE.md from project root:

   Read: CLAUDE.md
   

2. Extract:

   • Preferred communication language
   • Work domain
   • Technical background

3. Find plan to implement:

   • If user specified: "PLN-001을 구현하고 싶어요"
   • If not specified, list available plans:

     ls docs/plans/
     

   • Ask user which plan to implement

4. Read plan document:

   Read: docs/plans/PLN-XXX-YYYY-MM-DD-name.md
   

5. Extract from plan:

   • Requirements
   • Scenarios
   • Tasks (with acceptance criteria)
   • Verification commands

---

Step 2: Set Up Environment

Goal: Ensure project structure and dependencies are ready.

Process:

1. Check project structure exists:

   ls src/ tests/
   

   If missing:

   mkdir -p src tests
   

2. Check for virtual environment:

   ls venv/
   

   If not exist, remind user:

   • Korean: "먼저 가상 환경을 만들어주세요: python -m venv venv 그리고 활성화: source venv/bin/activate"
   • English: "Please create a virtual environment first: python -m venv venv and activate it: source venv/bin/activate"

---

Step 3: Choose Implementation Order

Goal: Determine which tasks to implement and in what order.

Process:

1. Show task list to user:

   이 계획에는 3개 태스크가 있습니다:
   - Task 1: Facebook API 연동 [미완료]
   - Task 2: Instagram API 연동 [미완료]
   - Task 3: Excel 리포트 생성 [미완료]
   
   어떤 순서로 구현할까요?
   1. 순서대로 전부 구현 (Task 1 → 2 → 3)
   2. 특정 태스크만 구현
   

2. Get user's choice

3. Create implementation checklist with TodoWrite:

   • One todo per task
   • Mark as pending initially

---

Step 4: Implement Each Task (TDD Cycle)

Goal: Implement one task at a time using TDD (hidden from user).

For each task, repeat:

4.1. Announce Task Start

AI: Task 1 시작: Facebook API 연동
    페이스북에서 좋아요, 댓글, 공유 수를 가져오는 기능을 만들겠습니다.

Update TodoWrite: Mark task as in_progress

---

4.2. TDD Cycle (Internal - Hidden from User)

Read TDD guide:

Read: references/tdd-guide.md

Process (internal):

1. Write test first in tests/test_<module>.py

   • Use pytest
   • Add @pytest.mark.scnXXX marker to map to scenarios
   • Cover acceptance criteria from plan

2. Run test → RED (should fail)

   pytest tests/test_<module>.py -v
   

3. Implement minimal code in src/<module>.py

   • Read common patterns:

     Read: references/common-patterns.md
     

   • Read library recommendations:

     Read: references/library-recommendations.md
     

   • Write clean, simple code

4. Run test → GREEN (should pass)

   pytest tests/test_<module>.py -v
   

   If test fails 3 consecutive times (same test, same error):

   • Auto-trigger debug skill:

     Skill: debug
     

   • Provide debug context: error message, test code, implementation code
   • Wait for debug result
   • If debug fixes issue → Continue with GREEN
   • If debug escalates → Inform user, wait for guidance

5. Refactor if needed

   • Clean up code
   • Add error handling
   • Add logging

DO NOT show test code to user - only show implementation code when asked.

---

4.3. Show Progress to User

After test passes:

AI: Task 1 완료 ✅
    src/facebook_client.py를 생성했습니다.
    페이스북 API에 연결하고 engagement 데이터를 가져올 수 있습니다.

    사용 방법:
    ```python
    from src.facebook_client import FacebookClient

    client = FacebookClient(api_key="...")
    data = client.fetch_engagement(page_id="우리회사")
    print(data)  # {'likes': 100, 'comments': 20, 'shares': 5}
    ```

Update TodoWrite: Mark task as completed

---

4.4. Mark Task in Plan Document

python scripts/mark_task_done.py docs/plans/PLN-XXX-... 1

This checks all acceptance criteria checkboxes for Task 1.

---

4.5. Handle Dependencies

If task requires dependencies:

1. Inform user:

   이 태스크는 facebook-sdk 라이브러리가 필요합니다.
   설치하시겠어요? `pip install facebook-sdk`
   

2. Wait for user confirmation

3. Update requirements.txt:

   # If requirements.txt doesn't exist, create it
   # Add new dependency with version
   facebook-sdk==3.1.0
   

---

Step 5: Integration and End-to-End Test

Goal: Verify all tasks work together for each scenario.

Process:

1. After all tasks for a scenario are complete, create main script:

   # src/report_generator.py
   from facebook_client import FacebookClient
   from instagram_client import InstagramClient
   from excel_generator import generate_excel
   
   def main():
       # Integrate all components
       pass
   
   if __name__ == '__main__':
       main()
   

2. Check scenario coverage (automated):

   python scripts/check_scenario_coverage.py docs/plans/PLN-XXX-...
   

   This checks:

   • All scenarios in plan have tests with @pytest.mark.scnXXX
   • Runs tests for each scenario
   • Reports coverage and results

   Output example:

   Found 3 scenario(s): SCN-001, SCN-002, SCN-003
   
   ✓ SCN-001: Tests found (2 file(s))
      ✅ PASS (5 test(s))
   
   ✓ SCN-002: Tests found (1 file(s))
      ✅ PASS (2 test(s))
   
   ⚠️  SCN-003: No tests found
   
   Summary:
   Scenario Coverage: 2/3 (67%)
   Test Results: 2/2 passing
   

   If any scenario uncovered:

   • Phase 1: Show warning, don't block
   • Ask user: "SCN-003에 테스트가 없습니다. 지금 추가할까요, 나중에 할까요?"
   • User can choose to add now or defer

3. Run scenario verification from plan document:

   python src/report_generator.py
   

4. Check expected output:

   • File created?
   • Correct content?
   • Matches scenario expectations?

5. If verification passes:

   AI: SCN-001 검증 완료 ✅
       reports/engagement-2025-10-26.xlsx 파일이 생성되었습니다.
       시나리오에 정의된 대로 작동합니다!
   

6. If verification fails → Use debug skill

7. Update plan status to completed:

   python scripts/update_plan_status.py docs/plans/PLN-XXX-... completed
   

   This updates the plan's YAML frontmatter:

   • status: completed
   • verified: true
   • verification_date: YYYY-MM-DD
   • updated: YYYY-MM-DD

---

Step 6: Documentation Update

Goal: Update docs/architecture/ with how the implementation works.

Process:

1. Create architecture document:

   Write: docs/architecture/PLN-XXX-implementation.md
   

2. Document structure:

   # PLN-XXX Implementation
   
   ## Overview
   [Brief description of what was built]
   
   ## Components
   
   ### src/facebook_client.py
   - Purpose: Connect to Facebook API and fetch engagement data
   - Key functions:
     - `fetch_engagement(page_id)`: Returns dict with likes, comments, shares
   
   ### src/excel_generator.py
   - Purpose: Generate Excel report from engagement data
   - Key functions:
     - `generate_excel(data, output_path)`: Creates formatted Excel file
   
   ## Dependencies
   - facebook-sdk==3.1.0
   - openpyxl==3.1.2
   
   ## Usage
   ```bash
   python src/report_generator.py
   

   How It Works

   1. Reads API credentials from .env
   2. Fetches data from Facebook and Instagram
   3. Calculates total engagement
   4. Generates Excel file with two sheets

3. Inform user:

   구현 문서를 작성했습니다: docs/architecture/PLN-001-implementation.md
   나중에 참고할 수 있도록 작동 방식을 기록했습니다.
   

---

Step 7: Git Commit

Goal: Create commit referencing the plan ID.

Process:

1. Show changes:

   git status
   git diff
   

2. Ask user if ready to commit:

   변경사항을 커밋할까요?
   - src/ 폴더에 새 파일 추가
   - tests/ 폴더에 테스트 추가
   - docs/plans/PLN-001-... 업데이트 (태스크 완료 체크)
   - docs/architecture/PLN-001-implementation.md 추가
   

3. If user agrees:

   git add src/ tests/ docs/
   git commit -m "Implement Tasks 1-3 from PLN-001
   
   - Add Facebook API client
   - Add Instagram API client
   - Add Excel report generator
   - Complete SCN-001: Daily engagement report
   
   Ref: PLN-001"
   

---

Step 8: Next Steps Guidance

Goal: Guide user on what to do next.

Process:

1. If all tasks complete:

   모든 태스크 구현 완료! ✅
   
   다음 단계:
   1. 실제 데이터로 테스트해보세요: `python src/report_generator.py`
   2. 문제가 생기면 [debug] 스킬 사용하기
   3. 새 기능 추가는 새 계획(PLN-002)을 먼저 작성하세요
   
   "/debug" 또는 "/plan"을 입력하세요.
   

2. If partial completion:

   Task 1-2 완료! ✅ (Task 3 남음)
   
   계속 구현할까요?
   1. 다음 태스크 구현 (Task 3)
   2. 여기서 중단하고 나중에 계속
   

---

Key Principles

TDD is Hidden from User

DO:

• Write tests first (internally)
• Run tests to verify (internally)
• Only show code to user when tests pass

DON'T:

• Show test code to user (unless they ask)
• Mention pytest in regular updates
• Explain testing process to user

User sees: "Task 1 완료 ✅"

User doesn't see: "Wrote test_facebook_client.py, ran pytest, all tests passed"

---

Progressive Implementation

One task at a time:

• Complete Task 1 fully → Show user → Mark done
• Then Task 2 → Show user → Mark done
• Don't try to do everything at once

Why: Easier to debug, user can test incrementally

---

Communication in User's Language

Adapt technical depth based on user's background (from CLAUDE.md):

• Non-technical: Simple explanations, avoid jargon
• Semi-technical: Use library names, show code examples
• Technical: Full technical details

Example (non-technical):

페이스북에 연결하는 코드를 만들었습니다.
API 키를 .env 파일에 넣으면 데이터를 가져올 수 있어요.

Example (semi-technical):

facebook-sdk 라이브러리를 사용해서 FacebookClient 클래스를 만들었습니다.
.env 파일의 FACEBOOK_API_KEY로 인증하고, fetch_engagement() 메서드로 데이터를 가져옵니다.

---

Use Common Patterns

Load references as needed:

Read: references/common-patterns.md

Find patterns for:

• CSV/Excel file I/O
• API calls
• Date/time handling
• Error handling
• Logging

Don't reinvent - use proven patterns.

---

Library Selection

Load library recommendations:

Read: references/library-recommendations.md

Based on domain (from CLAUDE.md):

• Marketing → requests, openpyxl, facebook-sdk, instagrapi
• Finance → pandas, openpyxl, pdfplumber
• Sales → requests, openpyxl
• HR → requests, openpyxl, PyYAML

Prefer built-in libraries when possible.

---

Troubleshooting

Tests Keep Failing

Symptom: Test fails after 2-3 attempts to fix

Solution:

1. Review test expectations - Are they realistic?
2. Check implementation logic - Is there a fundamental error?
3. Simplify - Break into smaller functions
4. Ask for help - External validation might reveal issue

Inform user:

Task 1을 구현하는 중 문제가 발생했습니다.
Facebook API 인증에서 오류가 나는데, API 키가 올바른지 확인해주시겠어요?

Be specific about what's needed.

---

Missing Dependencies

Symptom: Import error when running code

Solution:

1. Identify missing library
2. Install: pip install <library>
3. Add to requirements.txt
4. Re-run test

Inform user:

openpyxl 라이브러리가 필요합니다.
설치할까요? `pip install openpyxl`

---

User Wants to See Test Code

Symptom: "테스트 코드 보여주세요"

Solution:

AI: 테스트 코드는 tests/test_facebook_client.py에 있습니다.

    [Shows test code]

    pytest로 실행할 수 있습니다: `pytest tests/ -v`

It's okay to show tests when asked - just don't show them proactively.

---

Task Dependencies Are Wrong

Symptom: Task 3 needs Task 1, but they're defined independently

Solution:

1. Identify dependency
2. Implement in correct order (Task 1 → Task 3)
3. Update plan if needed to clarify dependencies

---

Resources

scripts/

• mark_task_done.py - Mark task as completed in plan document (checks all acceptance criteria)
• update_plan_status.py - Update plan status in YAML frontmatter (pending → in_progress → completed)
• check_scenario_coverage.py - Check if all scenarios have tests with pytest markers, run tests per scenario

references/

• tdd-guide.md - TDD workflow (hidden from user): RED → GREEN → REFACTOR cycle, testing patterns
• common-patterns.md - Ready-to-use code patterns for CSV, Excel, API, dates, logging, error handling
• library-recommendations.md - Domain-specific library recommendations (marketing, finance, sales, HR, data processing)

---

Example Session

User: /implement

AI: [Loads CLAUDE.md and finds plans]

AI: 어떤 계획을 구현할까요?
    1. PLN-001-2025-10-26-social-media-report.md

User: PLN-001이요

AI: [Reads plan document]

    PLN-001에는 3개 태스크가 있습니다:
    - Task 1: Facebook API 연동
    - Task 2: Instagram API 연동
    - Task 3: Excel 리포트 생성

    순서대로 전부 구현할까요?

User: 네

AI: [Creates TodoWrite todos]

    좋습니다! Task 1부터 시작하겠습니다.

AI: [Internally: writes test, implements code, runs test → GREEN]

    Task 1 완료 ✅
    src/facebook_client.py를 생성했습니다.

    [Shows usage example]

AI: [Marks task done in plan]

AI: Task 2 시작: Instagram API 연동...

    [Repeats TDD cycle]

    Task 2 완료 ✅

AI: Task 3 시작: Excel 리포트 생성...

    openpyxl 라이브러리가 필요합니다.
    설치할까요? `pip install openpyxl`

User: 네

AI: [Installs, updates requirements.txt, implements Task 3]

    Task 3 완료 ✅

AI: 모든 태스크 완료! SCN-001 검증을 시작합니다...

    [Runs: python src/report_generator.py]

    ✅ reports/engagement-2025-10-26.xlsx 생성 완료!
    시나리오대로 작동합니다.

AI: [Creates architecture doc, commits]

    구현 완료! 변경사항을 커밋했습니다.

    다음 단계:
    1. 실제 데이터로 테스트: `python src/report_generator.py`
    2. 문제 발생 시: "/debug"
    3. 새 기능 추가: "/plan"