Hemlock

Makes your AI agent think like the skeptic who kills your project on day one, so day fifty doesn't have to. The cheapest code is the project you never started. Use this BEFORE any new project, product, feature, or "I have an idea" moment — whenever someone is about to build something and the riskiest thing is the premise, not the code. Triggers include "I want to build X", "should I build X", "is this idea worth it", "validate this idea", "does this beat what already exists", "new project idea", "let's start on", "kick off", any plan that schedules construction before validation, and mid-build "should I keep going or kill it". Trigger even on enthusiasm ("I have a great idea for…"), not just doubt — enthusiasm is when this skill earns its keep. Runs a 6-rung kill ladder (incumbent → riskiest assumption → cheapest decisive test → pre-registered kill bar → run → verdict) and refuses to authorize building until every rung is climbed. Bundled linter fails any verdict with an unnamed incumbent, unranked assumptions, or a kill bar written after the result. Supersedes idea-validator. Distinct from reality-check (verifies an existing plan for hallucinations), experiment-designer (designs one test), and derisk-sequencer (orders many tests) — hemlock decides whether the project deserves any tests at all.

mkdir -p ~/.claude/skills/hemlock
curl -L https://claudskills.com/skills/hemlock/SKILL.md \
  -o ~/.claude/skills/hemlock/SKILL.md

@misc{hemlock-2026,
  author    = {scoobydrew83},
  title     = {Hemlock [Claude Code skill]},
  year      = {2026},
  publisher = {ClaudSkills},
  url       = {https://claudskills.com/skills/hemlock/}
}