/dev-coding - Implementation Skill

Skill Awareness: See skills/_registry.md for all available skills.

• Before: Ensure /dev-specs completed, /dev-scout for patterns
• During: Auto-loads /dev-coding-backend, /dev-coding-frontend
• After: Suggest /dev-review for code review

Implement features based on specs. Orchestrates backend and frontend work.

When to Use

• Implement a use case from /dev-specs
• Build feature end-to-end (API + UI)
• Make changes defined in implementation plan

Usage

/dev-coding UC-AUTH-001              # Implement specific UC
/dev-coding auth                     # Implement all UCs for feature
/dev-coding UC-AUTH-001 --backend    # Backend only
/dev-coding UC-AUTH-001 --frontend   # Frontend only

Prerequisites

Before using, ensure:

1. /debrief completed → BRD exists
2. /dev-specs completed → Implementation plan exists
3. /dev-scout completed → Codebase patterns known

Output

Updates to codebase:

• New/modified files
• Tests (if required)
• Updated docs-graph

Updates to specs:

• Task status in plans/features/{feature}/specs/
• Implementation notes

Workflow

Phase 0: Load Context

1. Read UC spec
   → plans/features/{feature}/specs/{UC-ID}/README.md

2. Read scout for patterns
   → plans/features/{feature}/scout.md OR plans/scout/README.md

3. Read docs-graph for dependencies
   → plans/docs-graph.json

4. Check: Are dependencies complete?
   → If UC depends on another UC, verify it's done
   → Warn if not, let user decide to proceed

Phase 1: Determine Work Type

Based on spec, determine what's needed:

Spec Contains	Work Type	Skill to Load
API endpoints, schema	Backend	dev-coding-backend
UI components, pages	Frontend	dev-coding-frontend
Both	Full-stack	Backend first, then Frontend

Read spec → Extract:
- API changes needed?
- Schema/DB changes needed?
- UI components needed?
- Pages/routes needed?

Phase 2: Load Sub-Skills

If backend work needed:

Read: skills/dev-coding-backend/SKILL.md
Read: skills/dev-coding-backend/references/{tech}.md (if exists)

Tech detected from scout:
- directus → directus.md
- node → node.md
- prisma → prisma.md

If frontend work needed:

Read: skills/dev-coding-frontend/SKILL.md
Read: skills/dev-coding-frontend/references/{tech}.md (if exists)

Tech detected from scout:
- nextjs → nextjs.md
- vue → vue.md
- react → react.md

Phase 3: Execute Backend (if needed)

Follow dev-coding-backend workflow:

1. Schema changes (if needed)

   • Create/modify collections, tables, models
   • Run migrations
   • Verify schema

2. API implementation

   • Create endpoints per spec
   • Implement business logic
   • Add validation, error handling

3. Backend verification

   # Test API works
   curl -X POST http://localhost:3000/api/auth/login \
     -H "Content-Type: application/json" \
     -d '{"email":"test@test.com","password":"test"}'
   

4. Document what was created

   • Endpoints available
   • Request/response shapes
   • Auth requirements

Phase 4: Execute Frontend (if needed)

Follow dev-coding-frontend workflow:

1. Components (if needed)

   • Create/modify UI components
   • Follow project conventions from scout

2. Pages/Routes (if needed)

   • Create page files
   • Set up routing

3. API Integration

   • Connect to backend (use info from Phase 3)
   • Handle loading, error states

4. Frontend verification

   • Visual check (Playwright screenshot or manual)
   • Interaction test

Phase 5: Integration Test

End-to-end verification:

1. Start from UI
2. Perform user action
3. Verify API called correctly
4. Verify response handled
5. Verify UI updated

Methods:

• Playwright for automated
• Manual walkthrough
• curl + UI check

Phase 6: Quality Checks

Before marking complete:

[ ] Code follows project conventions (from scout)
[ ] No linting errors
[ ] No type errors
[ ] Tests pass (if project has tests)
[ ] No console.log / debug code left
[ ] No hardcoded secrets
[ ] Error handling in place

Phase 7: Complete

1. Update spec status

   <!-- In specs/{UC-ID}/README.md -->
   > **Status**: Complete
   > **Completed**: {date}
   

2. Document changes

   ## Implementation Notes
   
   ### Files Changed
   - `src/api/auth/login.ts` - Created login endpoint
   - `src/components/LoginForm.tsx` - Created form component
   
   ### Deviations from Spec
   - Added rate limiting (not in spec, but security best practice)
   
   ### Next Steps
   - UC-AUTH-002 can now proceed (depends on this)
   

3. Update docs-graph (automatic via hook)

Communication Protocol

When to Ask

Situation	Action
Spec unclear	Ask for clarification
Multiple valid approaches	Present options, ask preference
Stuck > 15 min	Document attempts, ask for help
Spec seems wrong	Flag it, propose alternative
Scope creep detected	Stop, suggest CR

How to Ask

**Blocker**: {What's blocking}

**Tried**:
1. {Attempt 1} → {Result}
2. {Attempt 2} → {Result}

**Options**:
A) {Option A} - {Tradeoff}
B) {Option B} - {Tradeoff}

**Recommendation**: {Your suggestion}

Scope Creep Protocol

Deviation	Action
Tiny (typo)	Fix silently
Small (edge case)	Ask + proceed
Medium (new field)	Document + ask
Large (approach wrong)	Stop + create CR

Dependency Handling

When UC depends on another:

1. Check docs-graph for dependencies
2. For each dependency:
   - Is UC marked complete? → OK
   - Is code actually there? → Check (more reliable)
3. If dependency missing:
   - Warn user
   - Ask: Proceed anyway? / Do dependency first?

Tools Used

Tool	Purpose
Read	Load specs, scout, sub-skills
Write	Create new files
Edit	Modify existing files
Bash	Run commands, curl tests
Glob	Find files
Grep	Search code
mcp__playwright__*	UI verification

Integration

Skill	Relationship
/dev-specs	Reads implementation plan from
/dev-scout	Reads patterns/conventions from
/dev-coding-backend	Loads for API/schema work
/dev-coding-frontend	Loads for UI work
/docs-graph	Auto-updates on file changes
/dev-review	Review after implementation

Example Flow

User: /dev-coding UC-AUTH-001

1. Load UC-AUTH-001 spec
   → Backend: POST /api/auth/login
   → Frontend: LoginForm component, /login page

2. Check dependencies
   → None for UC-AUTH-001 (it's first)

3. Load dev-coding-backend
   → Create login endpoint
   → Test with curl ✓

4. Load dev-coding-frontend
   → Create LoginForm component
   → Create /login page
   → Connect to API
   → Test with Playwright ✓

5. Integration test
   → Fill form → Submit → Verify redirect ✓

6. Quality checks
   → Lint ✓, Types ✓, No debug code ✓

7. Complete
   → Update spec status
   → Document changes
   → Suggest: "UC-AUTH-002 (Signup) is now unblocked"