feature-lifecycle - SKILL.md Agent Skill

name: feature-lifecycle description: | Feature lifecycle: design, plan, implement, validate, release. Phase-gated workflow. user-invocable: false command: /feature-lifecycle allowed-tools:

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Task routing: force_route: true not_for: "small bug fixes (use quick), code reviews, refactoring single files, content writing — only for new feature work spanning design → plan → implement → validate → release" triggers:
- feature design
- design feature
- think through
- explore approaches
- design first
- feature plan
- plan feature
- break down design
- create tasks
- feature implement
- implement feature
- execute plan
- start building
- feature validate
- validate feature
- run feature quality gates
- check feature
- feature release
- release feature
- merge feature
- build feature end to end
- full feature lifecycle
- feature from scratch
- design to release
- complete feature pipeline
- feature pipeline pairs_with:
- workflow
- subagent-driven-development
- pr-workflow
- verification-before-completion
- universal-quality-gate
- adr-consultation
- planning complexity: Complex category: process

Feature Lifecycle Skill

Phase-gated feature workflow: DESIGN > PLAN > IMPLEMENT > VALIDATE > RELEASE. Each phase must pass its gate before the next begins.

Phase Routing

Determine which phase to execute based on feature state:

If .feature/ exists, check current phase:
```
python3 ~/.claude/scripts/feature-state.py status
```
Route to the phase indicated by the state machine.
If no feature state exists, determine entry point from user intent:
- "design", "think through", "explore approaches" -> DESIGN
- "plan", "break down", "create tasks" -> PLAN (requires completed design)
- "implement", "execute plan", "start building" -> IMPLEMENT (requires completed plan)
- "validate", "quality gates", "check feature" -> VALIDATE (requires completed implementation)
- "release", "merge", "ship it" -> RELEASE (requires passed validation)
- "end to end", "full lifecycle", "from scratch" -> DESIGN (start from beginning)
Load the phase reference for the current phase:
- DESIGN: Read references/design.md
- PLAN: Read references/plan.md
- IMPLEMENT: Read references/implement.md
- VALIDATE: Read references/validate.md — run quality gate commands, do not reason about whether they would pass. Paste exit codes and output.
- RELEASE: Read references/release.md
- END-TO-END: Read references/pipeline.md
Follow the loaded reference exactly. Each reference contains the full phase instructions, gates, and checkpoints.

State Conventions

Read references/shared.md for directory structure, state management commands, context loading rules, and naming conventions. All state operations go through python3 ~/.claude/scripts/feature-state.py -- never manipulate state files directly.

Phase Ordering

DESIGN -> PLAN -> IMPLEMENT -> VALIDATE -> RELEASE
  |         |         |           |          |
  v         v         v           v          v
design.md plan.md  impl.md   report.md  PR merged

Each phase produces an artifact consumed by the next. Skipping phases is not supported because downstream phases depend on artifacts from earlier phases.

Reference Loading Table

Signal	Load These Files	Why
Phase 1 DESIGN: idea to design document	`design.md`	Loads detailed guidance from `design.md`.
errors, error handling	`error-handling.md`	Loads detailed guidance from `error-handling.md`.
Phase 3 IMPLEMENT: dispatching task waves to domain agents	`implement.md`	Loads detailed guidance from `implement.md`.
running the full design-to-release pipeline	`pipeline.md`	Loads detailed guidance from `pipeline.md`.
Phase 2 PLAN: decomposing design into wave-ordered tasks	`plan.md`	Loads detailed guidance from `plan.md`.
Phase 5 RELEASE: PR merge, tagging, worktree cleanup	`release.md`	Loads detailed guidance from `release.md`.
feature state directory layout, naming, write protection	`shared.md`	Loads detailed guidance from `shared.md`.
Phase 4 VALIDATE: running quality gates	`validate.md`	Loads detailed guidance from `validate.md`.

Error Handling

Error	Cause	Solution
Phase mismatch	User requests phase N but state is at phase M	Report current state, suggest correct next phase
Missing artifact	Previous phase did not produce expected output	Route back to previous phase
Gate failure	Phase requirements not met	Report what failed, suggest fixes

References

Task Signal	Load
Phase routing (design/plan/implement/validate/release)	Phase reference (design.md, plan.md, implement.md, validate.md, release.md)
End-to-end or full pipeline	`references/pipeline.md`
State commands, directory structure, naming	`references/shared.md`
Error, failure, blocked, gate fail, retry, deviation	`references/error-handling.md`

references/design.md -- Design phase: explore requirements, discuss trade-offs
references/plan.md -- Plan phase: break design into wave-ordered tasks
references/implement.md -- Implement phase: dispatch tasks to domain agents
references/validate.md -- Validate phase: run quality gates
references/release.md -- Release phase: merge, tag, cleanup
references/pipeline.md -- End-to-end orchestration across all phases
references/shared.md -- State conventions shared across all phases
references/error-handling.md -- Recovery patterns for phase errors, gate failures, agent dispatch failures