agent-skills: 25 engineering skills from spec to ship

agent-skills packages the habits of a careful engineering team as skills an agent follows: write a spec before code, break work into small tasks, build one slice at a time, prove it with tests, review before merging and ship safely.

What’s inside: skills, slash commands, agents. Published by: a third party, addyosmani/agent-skills.

How it works

The plugin ships 25 skills grouped by phase: Define (spec-driven development, idea refinement, interviewing you), Plan (task breakdown), Build (incremental implementation, frontend UI, API design, test-driven development), Verify (debugging, browser testing with DevTools), Review (code review, security hardening, performance, code simplification) and Ship (CI/CD, git workflow, documentation and ADRs, shipping and launch). A meta-skill, using-agent-skills, maps a task to the right skill.

Every skill has the same shape: when to use it, a step-by-step process, a table of common excuses for skipping steps with rebuttals, red flags, and the evidence required before calling it done. Four agent personas (code reviewer, test engineer, security auditor, web performance auditor) run focused reviews.

Install

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

Skip the first line if you already added the addy-agent-skills marketplace. Reload the VS Code window or restart claude afterwards. New to plugins? See the install guide in this series.

How to use it

Skills activate on their own when a task matches, for example designing an API or building UI. Or drive the lifecycle with the slash commands. If another plugin defines a command with the same name, use the namespaced form, such as /agent-skills:review.

  • /spec
  • /plan
  • /build
  • /build auto
  • /test
  • /constraints
  • /review
  • /webperf
  • /code-simplify
  • /ship
  • /spec a CSV to JSON converter tool
  • /plan
  • Review this change like a staff engineer would

Good use cases

  • Starting a feature from a written spec, then a plan of small tasks
  • Running /build auto to implement an approved plan in one pass
  • Security, performance or test-coverage reviews with the matching persona

When not to use it

Quick fixes and throwaway scripts, where spec and plan steps are overhead. It also overlaps heavily with superpowers, so installing both gives Claude two sets of similar instructions.