Install Addy Osmani's 25 engineering skills with one command

Addy Osmani (ex-Google, now writing Claude Code guides on claude.dev) packaged his engineering workflow as 25 skills. They're grouped Define → Plan → Build → Verify → Review → Ship, and each one states when to use it, the steps, the excuses agents use to skip steps with a rebuttal for each, and the evidence required before it can call the job done.

# install all (works with 70+ agents: Claude Code, Cursor, Codex...)
npx skills add addyosmani/agent-skills

# pick and choose
npx skills add addyosmani/agent-skills --list
npx skills add addyosmani/agent-skills --skill test-driven-development

As a Claude Code plugin it updates itself.

/plugin marketplace add addyosmani/agent-skills
/plugin install agent-skills@addy-agent-skills

For Codex: codex plugin marketplace add addyosmani/agent-skills, then codex plugin add agent-skills@agent-skills. Every skill's name and description costs context on each turn, so don't leave all 25 on; use /skill-doctor to turn off the ones you don't use.