implement-and-verify

name	implement-and-verify
description	Implement tasks from plans with test-first approach, user-story-centric execution, and AC verification. Use proactively when executing implementation plans. Enforces quality gates, MVP-first delivery, and Article VII story-by-story implementation.
degree-of-freedom	low
allowed-tools	Read, Write, Edit, Bash, Grep, Glob

@.claude/shared-imports/constitution.md @.claude/templates/verification-report.md @.claude/templates/quality-checklist.md

Implementation & Verification Skill

Overview

This skill executes implementation plans following Specification-Driven Development (SDD) principles: quality gates, test-driven development (TDD), user-story-centric execution, and progressive delivery.

Constitutional Authority: Article III (Test-First), Article V (Template-Driven Quality), Article VII (User-Story-Centric Organization)

Core Principles:

1. Quality Gates First: Validate readiness before implementation (Article V)
2. Story-by-Story: Implement user stories in priority order (Article VII)
3. Test-First: Tests BEFORE implementation, ALL ACs verified (Article III)
4. Progressive Delivery: Each story is shippable when complete (Article VII)

Announce at start: "I'm using the implement-and-verify skill to execute this plan with SDD quality gates."

Quick Reference

Phase	Key Activities	Output	Article
0. Quality Gates	Validate spec readiness, check constitution	Gate pass/fail	Article V
1. Story Selection	Load tasks by story (P1, P2, P3)	Story tasks	Article VII
2. Progressive Delivery	Define MVP, plan incremental shipping	Delivery plan	Article VII
3. Load Tasks	Read plan, verify dependencies per story	Task selected	Article IV
4. Write Tests	Create tests from ACs (should FAIL)	Test files	Article III
5. Implement	Write code to make tests pass	Implementation	Article III
6. Verify	Run all tests, lint, build	verification-report.md	Article V
7. Update	Mark complete, handover if needed	Updated plan	Article V

Templates You Will Use

• @.claude/shared-imports/constitution.md - Architectural principles (all phases)
• @.claude/templates/quality-checklist.md - Pre-implementation gates (Phase 0)
• @.claude/templates/plan.md - Input plan with tasks and ACs (Phase 3)
• @.claude/templates/verification-report.md - Verification results (Phase 6)
• @.claude/templates/handover.md - For blocked tasks or agent transitions (Phase 7)

The Process

Copy this checklist to track progress:

SDD Implementation Progress:
- [ ] Phase 0: Quality Gates Validated (constitution check + audit PASS)
- [ ] Phase 1: Story Tasks Loaded (by priority)
- [ ] Phase 2: Progressive Delivery Planned (MVP defined)
- [ ] Phase 3: Tasks Loaded (dependencies verified)
- [ ] Phase 4: Tests Written (from ACs, should FAIL)
- [ ] Phase 5: Implementation Complete
- [ ] Phase 6: Verification Complete (ALL ACs pass)
- [ ] Phase 7: Plan Updated (story marked complete)

---

Detailed Workflows

Phase 0: Quality Gate Validation

See: @.claude/skills/implement-and-verify/workflows/quality-gates.md

Summary:

• Validate quality checklist (quality-checklist.md)
• MANDATORY: Verify /audit has passed (Article V)
  • Audit report must exist
  • Status must be PASS or PASS WITH WARNINGS
  • Critical Issues must = 0
• Block implementation if gates fail (audit blocking is non-overridable)

Phases 1-2: Story-by-Story Execution & Progressive Delivery

See: @.claude/skills/implement-and-verify/workflows/story-by-story-execution.md

Summary:

• Load tasks by story (P1, P2, P3)
• Implement each story completely
• Auto-invoke /verify --story P# after each story
• Only proceed to next story after current story verification passes
• Each story is independently shippable (MVP = P1 complete)

Phases 3-7: TDD Implementation Workflow

See: @.claude/skills/implement-and-verify/workflows/tdd-implementation.md

Summary:

• Phase 3: Load tasks, verify dependencies, extract ACs
• Phase 4: Write tests FIRST (must FAIL initially)
• Phase 5: Implement minimal code to pass tests
• Phase 6: Verify all ACs (100% coverage required)
• Phase 7: Update plan, generate verification report, create handover if needed

---

Examples & Patterns

See: @.claude/skills/implement-and-verify/examples/implementation-examples.md

Five concrete examples:

1. Successful implementation (test-first → implement → verify)
2. Failing AC → debug → fix
3. Rollback on breaking change
4. Story-level verification (P1 independent test)
5. Progressive delivery workflow (P1 → P2 → P3)

Key Patterns:

• Test-First Always: Write Test → FAIL → Implement → PASS
• Debug on Failure: AC Fails → Debug → Fix → Re-verify
• Progressive Delivery: P1 Complete → Verify → Ship or Continue

---

Enforcement & Failure Modes

See: @.claude/skills/implement-and-verify/references/enforcement-rules.md

Three Critical Rules:

1. No Completion Without Passing ACs - Status must be "blocked" if any AC fails
2. Test-First Mandatory - Tests written before implementation (must FAIL initially)
3. 100% AC Coverage - Every AC must have passing test

Common Pitfalls: Implementing before tests, skipping lint/build, marking complete with failures

11 Failure Modes with Solutions: Quality gates skipped, test-first violated, coverage incomplete, false positive tests, story verification skipped, dependency violations, over-engineering, etc.

---

Agent Integration & Related Workflows

See: @.claude/skills/implement-and-verify/references/integration.md

Executor Agent Execution:

• Triggered by: User runs /implement plan.md
• Agent: executor-implement-verify
• Receives: plan.md, tasks.md, spec.md, constitution
• Returns: Implemented code, verification reports per story, handovers if blocked

Supporting Agents:

• Code Analyzer: For understanding existing code before modification
• Debugger: For test failures (via debug-issues skill)

Handover Protocols:

• To Planner: If requirements unclear
• To Orchestrator: If blocked by external dependency

Verification Workflow:

implement-and-verify skill (completes story P1)
    ↓ auto-invokes
/verify plan.md --story P1 (SlashCommand tool)
    ↓ produces
verification-P1.md (PASS/FAIL report)

---

Prerequisites

Before using this skill:

• ✅ tasks.md exists (Article IV: tasks before implementation)
• ✅ plan.md exists with ≥2 ACs per user story
• ✅ spec.md exists with user stories and priorities
• ✅ All [NEEDS CLARIFICATION] markers resolved (or override approved)
• ✅ Audit has passed (or CRITICAL issues resolved) - MANDATORY
• ⚠️ Optional: quality-checklist.md validated (Article V quality gate)
• ⚠️ Optional: Test framework set up (for TDD)

Dependencies

Depends On:

• specify-feature skill - Provides spec.md with user stories
• create-implementation-plan skill - Provides plan.md with ACs and tech stack
• generate-tasks skill - MUST run before this skill (Article IV)
• /audit command - Should have passed before implementation starts

Integrates With:

• debug-issues skill - Use when tests fail or ACs don't pass
• analyze-code skill - Use when understanding existing code before modifying
• /verify command - Automatically invoked after each story completes

Tool Dependencies:

• Read, Write, Edit tools (code implementation)
• Bash tool (running tests, builds, linters)
• Grep, Glob tools (finding files and code patterns)

Next Steps

After implementation completes, automatic workflow progression per story:

Automatic Chain (per User Story):

implement-and-verify (implements story P1)
    ↓ (auto-invokes /verify)
/verify plan.md --story P1 (validates P1 independently)
    ↓ (if PASS)
Ready for P2 OR ship MVP
    ↓ (if user continues)
implement-and-verify (implements story P2)
    ↓ (auto-invokes /verify)
/verify plan.md --story P2 (validates P2 independently)
    ↓ (if PASS)
Ready for P3 OR ship enhancement
    ↓ (continues for all stories)

User Action Required:

• After P1 verification passes: Decision to ship MVP or continue to P2
• After any story passes: Can ship incrementally (Article VII progressive delivery)
• If verification fails: Debug with debug-issues skill, fix, re-verify

Outputs Created (per story):

• YYYYMMDD-HHMM-verification-P#.md - Story verification report
• YYYYMMDD-HHMM-handover-*.md - If blocked or transitioning agents
• Updated tasks.md with completed tasks marked
• Test files (created before implementation per Article III)

Commands:

• /verify plan.md --story P# - Automatically invoked after each story
• /bug - If tests fail and debugging needed
• /analyze - If existing code analysis needed

Related Skills & Commands

Direct Integration:

• specify-feature skill - Provides spec.md with user stories (workflow start)
• create-implementation-plan skill - Provides plan.md with ACs (workflow predecessor)
• generate-tasks skill - Provides tasks.md with task breakdown (required predecessor)
• debug-issues skill - Use when tests fail or blockers occur
• analyze-code skill - Use when existing code needs understanding
• /implement command - User-facing command that invokes this skill
• /verify command - Automatically invoked after each story (per P1, P2, P3)

Workflow Context:

• Position: Phase 4 of SDD workflow (final execution phase)
• Triggers: User runs /implement plan.md after audit passes
• Output: Implemented code + verification reports per story

Quality Gates:

• Pre-Implementation: quality-checklist.md validation (Article V)
• Per-Story: /verify --story P# automatic validation (Article VII)
• Test-First: Tests written before implementation (Article III)
• 100% AC Coverage: Every AC must have passing test

Progressive Delivery Pattern (Article VII):

P1 implemented → /verify --story P1 → PASS → Ship MVP or Continue
P2 implemented → /verify --story P2 → PASS → Ship Enhancement or Continue
P3 implemented → /verify --story P3 → PASS → Ship Complete Feature

Each story is independently shippable, enabling faster value delivery.

Success Metrics

Verification Quality:

• 100% AC coverage required
• All ACs must pass
• No task complete without verification

Implementation Quality:

• Tests written first
• Minimal implementation (YAGNI)
• Lint and build pass

When to Use This Skill

Use implement-and-verify when:

• User has a plan ready to execute
• User wants to implement tasks with TDD
• User needs AC verification
• User says "implement the plan"

Don't use when:

• No plan exists yet (use create-plan skill)
• User just wants to analyze code (use analyze-code skill)
• User wants to debug (use debugging skill)

Version

Version: 1.2.0 Last Updated: 2025-10-23 Owner: Claude Code Intelligence Toolkit

Change Log:

• v1.2.0 (2025-10-23): Refactored to progressive disclosure pattern (<500 lines)
• v1.1.0 (2025-10-23): Added Phase 0 Step 0.3 - Mandatory audit validation enforcement
• v1.0.0 (2025-10-22): Initial version with cross-skill references