Marketplace waterfall-development

Enforces strict waterfall development workflow with phase gates. Use when (1) features.yml exists in project root, (2) user asks to implement/develop/build a feature, (3) user explicitly requests waterfall workflow. Creates features.yml if missing when invoked.

install

source · Clone the upstream repo

git clone https://github.com/aiskillstore/marketplace

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/aiskillstore/marketplace "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills/chemiseblanc/waterfall-development" ~/.claude/skills/aiskillstore-marketplace-waterfall-development && rm -rf "$T"

manifest: skills/chemiseblanc/waterfall-development/SKILL.md

Waterfall Development

Strict phase gate enforcement for waterfall workflow. Requires the

feature-file

skill for artifact management.

Phases

Requirements → Design → Implementation → Testing → Complete

Activation

Condition	Action
features.yml exists	Activate, validate gates
User invokes skill, no features.yml	Create features.yml via feature-file skill, then activate
No features.yml, not invoked	Do not activate

Workflow

Run
```
./scripts/validate-gates.py
```
If errors: Print errors, STOP
Identify target feature and current phase
Block work that doesn't match current phase
Before phase transitions: Re-validate target phase gates

Gates

See references/phase-gates.md for fix instructions.

Gate	Transition	Criteria
G1	→ Design	Feature has ≥1 requirement
G2	→ Design	All requirements have descriptions
G3	→ Implementation	decisions field exists
G4	→ Testing	All requirements In-Progress or Complete
G5	→ Complete	All requirements Complete + tested-by + all tests passing

Agent Usage

Use sub-agents for verification tasks that require codebase exploration:

Before Design phase: Verify requirements are complete by examining codebase and user request for implicit requirements.

Before Complete phase: Verify test coverage by checking all requirements have corresponding tests and tested-by references.

Error Handling

Gate failures print terse errors. No bypass mechanism.