npx skills add nutlope/hallmark -g

-g installs for every project; leave it off to install into the current one. Needs Node 18 or later. The browser checks (sloplint --render, screenshots) also need npm i -g puppeteer-core and Chrome; without them the static checks still run.

| Harness | Lands in | Invoke | | --- | --- | --- | | Claude Code | ~/.claude/skills/hallmark | /hallmark <prompt> or describe a new build | | Codex CLI | ~/.agents/skills/hallmark | $hallmark <prompt> or describe a new build | | Cursor | finds the copies above | /hallmark <prompt> or describe a new build | | OpenCode | finds the copies above | /hallmark <prompt> or describe a new build |

• One harness only: npx skills add nutlope/hallmark -g --agent claude-code (or codex, opencode, cursor, github-copilot).
• As a Claude Code plugin: /plugin marketplace add nutlope/hallmark, then /plugin install hallmark@hallmark (invoked as /hallmark:hallmark).
• From a clone: node skills/hallmark/scripts/install.mjs validates every theme and reference before it copies; install-hook.mjs adds an edit-time Floor check to Claude Code.
• Lint any page: node skills/hallmark/scripts/sloplint.mjs <file-or-dir> --render.
• If it does not fire on its own, name it: use hallmark to build ....