Agent Skills

Production-grade engineering skills for AI coding agents.

Skills encode the workflows, quality gates, and best practices that senior engineers use when building software. These ones are packaged so AI agents follow them consistently across every phase of development.

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  DEFINE          PLAN           BUILD          VERIFY         REVIEW          SHIP
 ┌──────┐      ┌──────┐      ┌──────┐      ┌──────┐      ┌──────┐      ┌──────┐
 │ Idea │ ───▶ │ Spec │ ───▶ │ Code │ ───▶ │ Test │ ───▶ │  QA  │ ───▶ │  Go  │
 │Refine│      │  PRD │      │ Impl │      │Debug │      │ Gate │      │ Live │
 └──────┘      └──────┘      └──────┘      └──────┘      └──────┘      └──────┘
  /spec          /plan          /build        /test         /review       /ship

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Commands

8 slash commands that map to the development lifecycle. Each one activates the right skills automatically.

| What you're doing | Command | Key principle | |-------------------|---------|---------------| | Define what to build | /spec | Spec before code | | Plan how to build it | /plan | Small, atomic tasks | | Build incrementally | /build | One slice at a time | | Prove it works | /test | Tests are proof | | Review before merge | /review | Improve code health | | Audit web performance | /webperf | Measure before you optimize | | Simplify the code | /code-simplify | Clarity over cleverness | | Ship to production | /ship | Faster is safer |

Want fewer manual steps once the spec exists? /build auto generates the plan and implements every task in a single approved pass — you approve the plan once, then it runs autonomously. It removes the human stepping between tasks, not the verification: every task is still test-driven and committed individually, and it pauses on failures or risky steps.

Skills also activate automatically based on what you're doing — designing an API triggers api-and-interface-design, building UI triggers frontend-ui-engineering, and so on.

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Quick Start

Fastest path — any agent, one command. The open skills CLI installs into 70+ agents (Claude Code, Cursor, Codex, Copilot, Cline, and more):

npx skills add addyosmani/agent-skills            # install all 24 skills
npx skills add addyosmani/agent-skills --list     # browse before installing

Or grab individual skills:

npx skills add addyosmani/agent-skills --skill code-review-and-quality   # five-axis review before merge
npx skills add addyosmani/agent-skills --skill interview-me              # requirements interrogation, one question at a time
npx skills add addyosmani/agent-skills --skill test-driven-development   # red-green-refactor, enforced

Installing one skill? A per-skill npx install copies only skills/<name>/, not the repo-level references/ directory. The skill still works, but paths to supplementary shared checklists are unavailable. Use a whole-repo integration, clone the repository, or copy the needed checklist into a references/ directory inside the installed skill. This portability gap is tracked in #361.

Prefer a native integration? Pick your tool below.

<details> <summary><b>Claude Code (recommended)</b></summary>

Marketplace install:

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

SSH errors? The marketplace clones repos via SSH. If you don't have SSH keys set up on GitHub, either add your SSH key or use the full HTTPS URL to force HTTPS cloning during the marketplace-add step:

/plugin marketplace add https://github.com/addyosmani/agent-skills.git
/plugin install agent-skills@addy-agent-skills

If /plugin install still fails with git@github.com: Permission denied (publickey) on Windows or macOS, the recommended workaround is to configure Git once to rewrite GitHub SSH URLs to HTTPS for subprocess clones:

git config --global url."https://github.com/".insteadOf git@github.com:

Local / development:

git clone https://github.com/addyosmani/agent-skills.git
claude --plugin-dir /path/to/agent-skills

</details> <details> <summary><b>Cursor</b></summary>

Put workflow skills under .cursor/skills/ (sync from agent-skills/skills/) and short policies in .cursor/rules/*.mdc — do not paste full skills into rules. See docs/cursor-setup.md.

</details> <details> <summary><b>Antigravity CLI</b></summary>

Install as a native plugin for skills, subagents, and slash commands. See docs/antigravity-setup.md.

Install from the repo:

agy plugin install https://github.com/addyosmani/agent-skills.git

Install from a local clone:

git clone https://github.com/addyosmani/agent-skills.git
agy plugin install ./agent-skills

</details> <details> <summary><b>Gemini CLI</b></summary>

Install as native skills for auto-discovery, or add to GEMINI.md for persistent context. See docs/gemini-cli-setup.md.

Install from the repo:

gemini skills install https://github.com/addyosmani/agent-skills.git --path skills

Install from a local clone:

gemini skills install ./agent-skills/skills/

</details> <details> <summary><b>Windsurf</b></summary>

Add skill contents to your Windsurf rules configuration. See docs/windsurf-setup.md.

</details> <details> <summary><b>OpenCode</b></summary>

Uses agent-driven skill execution via AGENTS.md and the skill tool.

See docs/opencode-setup.md.

</details> <details> <summary><b>GitHub Copilot</b></summary>

Use agent definitions from agents/ as Copilot personas and skill content in .github/copilot-instructions.md. See docs/copilot-setup.md.

</details> <details> <summary><b>Kiro IDE & CLI </b></summary> Skills for Kiro reside under ".kiro/skills/" and can be stored under Project or Global level. Kiro also supports Agents.md. See Kiro docs at https://kiro.dev/docs/skills/ </details> <details> <summary><b>Codex</b></summary>

Install as a native Codex plugin (Codex CLI v0.122+):

codex plugin marketplace add addyosmani/agent-skills
codex plugin add agent-skills@agent-skills

The first command registers the marketplace; the second installs the plugin. Codex reads the root skills/ directory directly through .codex-plugin/plugin.json. Once installed, invoke skills in chat using @ (e.g., @spec-driven-development). See docs/codex-setup.md for local installation and troubleshooting.

</details> <details> <summary><b>Command Code</b></summary>

Install natively with the built-in cmd skills command. Command Code clones the repo, discovers every SKILL.md, and installs into .commandcode/skills/:

cmd skills add addyosmani/agent-skills            # pick skills to install (project)
cmd skills add addyosmani/agent-skills --global   # install for all projects (~/.commandcode/skills/)
cmd skills add addyosmani/agent-skills -s spec-driven-development  # install a specific skill

Installed skills show up in the TUI slash menu, e.g. /spec-driven-development. See docs/commandcode-setup.md.

</details> <details> <summary><b>Other Agents</b></summary>

Skills are plain Markdown - they work with any agent that accepts system prompts or instruction files. See docs/getting-started.md.

</details>

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Adoption

Already installed? How you roll the pack out depends on your codebase. The Adoption Guide covers two paths: the full lifecycle from day one for a greenfield project, or an incremental, verification-first rollout for an established codebase.

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All 24 Skills

The commands above are entry points. The pack includes 24 skills total — 23 lifecycle skills plus the using-agent-skills meta-skill. Each skill is a structured workflow with steps, verification gates, and anti-rationalization tables. You can also reference any skill directly.

Meta - Discover which skill applies

| Skill | What It Does | Use When | |-------|-------------|----------| | using-agent-skills | Maps incoming work to the right skill workflow and defines shared operating rules | Starting a session or deciding which skill applies |

Define - Clarify what to build

| Skill | What It Does | Use When | |-------|-------------|----------| | interview-me | One-question-at-a-time interview that extracts what the user actually wants instead of what they think they should want, until ~95% confidence | The ask is underspecified, or the user invokes "interview me" / "grill me" | | idea-refine | Structured divergent/convergent thinking to turn vague ideas into concrete proposals | You have a rough concept that needs exploration | | spec-driven-development | Write a PRD covering objectives, commands, structure, code style, testing, and boundaries before any code | Starting a new project, feature, or significant change |

Plan - Break it down

| Skill | What It Does | Use When | |-------|-------------|----------| | planning-and-task-breakdown | Decompose specs into small, verifiable tasks with acceptance criteria and dependency ordering | You have a spec and need implementable units |

Build - Write the code

| Skill | What It Does | Use When | |-------|-------------|----------| | incremental-implementation | Thin vertical slices - implement, test, verify, commit. Feature flags, safe defaults, rollback-friendly changes | Any change touching more than one file | | test-driven-development | Red-Green-Refactor, test pyramid (80/15/5), test sizes, DAMP over DRY, Beyonce Rule, browser testing | Implementing logic, fixing bugs, or changing behavior | | context-engineering | Feed agents the right information at the right time - rules files, context packing, MCP integrations | Starting a session, switching tasks, or when output quality drops | | source-driven-development | Ground every framework decision in official documentation - verify, cite sources, flag what's unverified | You want authoritative, source-cited code for any framework or library | | doubt-driven-development | Adversarial fresh-context review of every non-trivial decision in-flight - CLAIM → EXTRACT → DOUBT → RECONCILE → STOP, with optional user-authorized cross-model escalation | Stakes are high (production, security, irreversible), working in unfamiliar code, or a confident output is cheaper to verify now than to debug later | | frontend-ui-engineering | Component architecture, design systems, state management, responsive design, WCAG 2.1 AA accessibility | Building or modifying user-facing interfaces | | api-and-interface-design | Contract-first design, Hyrum's Law, One-Version Rule, error semantics, boundary validation | Designing APIs, module boundar