Open-source developer and product skills for Claude Code, Cursor, Codex and any agent that reads SKILL.md files.
Browse them at il.ly/skills. Looking for SEO and copywriting skills? See Illyism/seo-skills.
# Install a specific skill
npx skills add Illyism/dev-skills --skill eval
# Install all skills
npx skills add Illyism/dev-skills
# List available skills
npx skills add Illyism/dev-skills --list| Skill | Category | What it does |
|---|---|---|
| eval | Code | Minimal 1-file AI evals for prompts, models and production functions |
| benchmarking | Code | Micro-benchmark hot paths with a baseline, 3 hypotheses, ship gates and lock-in checkpoints |
| cleanup | Code | Delete unused exports, variables, functions and files, from smallest to largest |
| optimize | Code | Slim queries, components and APIs to what the UI actually uses |
| elon | Product | Apply the Elon Musk first-principles algorithm to code, product, SaaS and design |
| extension-store-assets | Product | Chrome extension icons, store promo tiles, benefit slides and listing copy |
Each skill is a folder with a SKILL.md that follows the Agent Skills spec:
<category>/<skill-name>/SKILL.md
MIT, by Ilias Ism