---
name: dev-lifecycle
description: Structured SDLC workflow with 8 phases — requirements, design review, planning, implementation, testing, and code review. Use when the user wants to build a feature end-to-end, or run any individual phase (new requirement, review requirements, review design, execute plan, update planning, check implementation, write tests, code review).
---

# Dev Lifecycle

Sequential phases producing docs in `docs/ai/`. Flow: 1→2→3→4→(5 after each task)→6→7→8.

## Prerequisite

Before starting any phase, run `npx ai-devkit@latest lint` to verify the base `docs/ai/` structure exists and is valid.

If working on a specific feature, also run `npx ai-devkit@latest lint --feature <name>` to validate feature-scoped docs.

If lint fails because project docs are not initialized, run `npx ai-devkit@latest init`, then rerun lint. Do not proceed until checks pass.

For a **new feature start** (Phase 1 or `/new-requirement`), apply the shared worktree setup in [references/worktree-setup.md](references/worktree-setup.md) before phase work. This setup is worktree-first by default and includes explicit no-worktree fallback, context verification, and dependency bootstrap.

## Phases

| # | Phase | Reference | When |
|---|-------|-----------|------|
| 1 | New Requirement | [references/new-requirement.md](references/new-requirement.md) | User wants to add a feature |
| 2 | Review Requirements | [references/review-requirements.md](references/review-requirements.md) | Requirements doc needs validation |
| 3 | Review Design | [references/review-design.md](references/review-design.md) | Design doc needs validation against requirements |
| 4 | Execute Plan | [references/execute-plan.md](references/execute-plan.md) | Ready to implement tasks from planning doc |
| 5 | Update Planning | [references/update-planning.md](references/update-planning.md) | Auto-trigger after completing any task in Phase 4 |
| 6 | Check Implementation | [references/check-implementation.md](references/check-implementation.md) | Verify code matches design |
| 7 | Write Tests | [references/writing-test.md](references/writing-test.md) | Add test coverage (100% target) |
| 8 | Code Review | [references/code-review.md](references/code-review.md) | Final pre-push review |

Load only the reference file for the current phase. For Phase 1, also load [references/worktree-setup.md](references/worktree-setup.md).

## Resuming Work

If the user wants to continue work on an existing feature:

1. Check branch and worktree state before phase work:
   - Branch check: `git branch --show-current`
   - Worktree check: `git worktree list`
2. Determine target context for `<feature-name>` (all `.worktrees/` paths are relative to the **project root** — the directory containing `.git`):
   - Prefer worktree `<project-root>/.worktrees/feature-<name>` when it exists.
   - Otherwise use branch `feature-<name>` in the current repository.
3. Before switching, explicitly confirm target with the user (branch or worktree path).
4. After user confirmation, switch to the confirmed context first:
   - Worktree: run phase commands with `workdir=<project-root>/.worktrees/feature-<name>`.
   - Branch: checkout `feature-<name>` in current repo.
5. After switching, run `npx ai-devkit@latest lint --feature <feature-name>` in the active branch/worktree context.
6. Then run the phase detector using the installed skill directory (same resolution rule as reference docs), not a workspace-relative `skills/...` path:
   - Resolve `<skill-dir>` as the directory containing this `SKILL.md`.
   - Run `<skill-dir>/scripts/check-status.sh <feature-name>` (or `cd <skill-dir> && scripts/check-status.sh <feature-name>`).
   Use the suggested phase from this script based on doc state and planning progress.

## Backward Transitions

Not every phase moves forward. When a phase reveals problems, loop back:

- Phase 2 finds fundamental gaps → back to **Phase 1** to revise requirements
- Phase 3 finds requirements gaps → back to **Phase 2**; design doesn't fit → revise design in place
- Phase 6 finds major deviations → back to **Phase 3** (design wrong) or **Phase 4** (implementation wrong)
- Phase 7 tests reveal design flaws → back to **Phase 3**
- Phase 8 finds blocking issues → back to **Phase 4** (fix code) or **Phase 7** (add tests)

## Doc Convention

Feature docs: `docs/ai/{phase}/feature-{name}.md` (copy from `README.md` template in each directory, preserve frontmatter). Keep `<name>` aligned with the worktree/branch name `feature-<name>`.

Phases: `requirements/`, `design/`, `planning/`, `implementation/`, `testing/`.

## Memory Integration

In phases with clarification questions (typically 1-3), run these CLI commands (see the `memory` skill for full options):

1. **Before asking** — search first, only ask about uncovered gaps: `npx ai-devkit@latest memory search --query "<topic>"`
2. **After clarification** — store for future sessions: `npx ai-devkit@latest memory store --title "<title>" --content "<insight>" --tags "<tags>"`

## Red Flags and Rationalizations

| Rationalization | Why It's Wrong | Do Instead |
|---|---|---|
| "Skip to coding, requirements are clear" | Ambiguity hides in assumptions | Run Phase 1-3 first |
| "Design hasn't changed, skip Phase 6" | Code drifts from design during implementation | Check implementation against design |
| "Tests slow us down, ship first" | Bugs in production are slower | Write tests in Phase 4 and 7 |
| "Just a small change, no review needed" | Small changes cause big outages | Phase 8 applies to all changes |

## Rules

- Read existing `docs/ai/` before changes. Keep diffs minimal.
- Use mermaid diagrams for architecture visuals.
- After each phase, summarize output and suggest next phase.
- Apply the `verify` skill before completing Phase 4 tasks, Phase 6 checks, Phase 7 coverage claims, and Phase 8 review items. No phase transition without fresh evidence.