Verify

Every serious project needs a scripted way to drive the real app and prove behavior: launch it, exercise a feature the way a user would, capture evidence. This skill produces that as a project-local skill at .claude/skills/verify-<app>/, then keeps it honest as the app changes.

Without it, "it works" means "it compiled". With it, "it works" means a reviewer can rerun one command and watch it work. That is the prove-it-works principle made executable.

Modes

• Generate. No verification skill exists yet, or the repo has no scripted way to prove behavior. Follow GENERATE.md.
• Maintain. One exists and may have rotted. A feature map goes stale the moment the app changes. Follow MAINTAIN.md.

Pick by what is on disk: glob .claude/skills/verify-*/. Nothing there means generate. Exactly one means maintain. More than one means ask which.

What holds in both modes

• Drive the real user path. Not internal setters, not test-only endpoints. If a user clicks it, the harness clicks it.
• Capture the action and the resulting state, not just a final screenshot. Verify side effects (files written, rows inserted, messages sent) alongside what is visible.
• Evidence outlives cleanup. Teardown removes instances and scratch state. A cleanup that eats the proof is a bug, and it is checked at the named location rather than assumed.
• Kill what you started, never by process name.
• A generated or edited skill that was never executed is a draft. Run its own instructions end to end before handing it over.

Driving surfaces here

The harness recipe depends on what the app is. Prefer a harness the repo already has (Playwright specs, expect scripts, curl-able endpoints, a debug port) before reaching for a generic recipe.

Surface	Reach for
Browser, Electron, web UI	the claude-in-chrome skill and its mcp__claude-in-chrome__* tools
CLI, TUI, server	the built-in /run skill, or a tmux/PTY harness
HTTP service	plain curl against a running dev server

Whatever it is, the generated skill records the exact commands for this repo, with real selectors and real ports. Examples are not a harness.