Addy Osmani agent-skills: 25 Production Workflows for Coding Agents Addy Osmani published agent-skills on GitHub, a production-grade skill library for coding agents containing 25 skills, nine lifecycle commands, four review personas and seven reference checklists, installable in Claude Code, Cursor, Codex, Gemini CLI, Copilot and 70+ agents via the open `npx skills` CLI. The repository, released under the MIT license, trended with hundreds of new stars on November 10, 2026 and organizes work around a DEFINE → PLAN → BUILD → VERIFY → REVIEW → SHIP lifecycle with commands including /spec, /plan, /build, /test, /constraints, /review, /webperf, /code-simplify and /ship. The README warns that skills are executable policy and should be pinned and audited like any agent dependency. Addy Osmani published agent-skills on GitHub https://github.com/addyosmani/agent-skills?ref=explainx as a production-grade skill library for coding agents: 25 skills , nine lifecycle commands , four review personas , and install paths for Claude Code, Cursor, Codex, Gemini CLI, Copilot , and 70+ agents via the open npx skills CLI. The repo trended with hundreds of new stars on November 10, 2026 because it encodes how senior engineers actually ship — not just how models autocomplete. If you already use Matt Pocock's engineering skills https://explainx.ai/blog/matt-pocock-agent-skills-real-engineers or Janestreet's Socratic tutor pack https://explainx.ai/blog/janestreet-agent-skills-socratic-tutor-github-2026 , this is a different editorial bet : a full DEFINE → PLAN → BUILD → VERIFY → REVIEW → SHIP belt with explicit anti-rationalization tables in each skill. TL;DR | Question | Answer | |---|---| | What ships? | 25 skills plus using-agent-skills meta skill; 9 commands ; 4 personas ; 7 reference checklists | | Fastest install? | npx skills add addyosmani/agent-skills per README | | Claude Code path? | /plugin marketplace add addyosmani/agent-skills then /plugin install agent-skills@addy-agent-skills | | License? | MIT per repository LICENSE file | | Stars Nov 10 ? | 114k+ on GitHub trending snapshot; verify live count on the repo | | Vs Matt Pocock? | Broader lifecycle; README points to docs/comparisons | | Risk? | Skills are executable policy — pin and audit like any agent dependency | What the repository contains Spec-through-ship workflow diagram beside assembled structure for Addy Osmani agent-skills lifecycle commands The README https://github.com/addyosmani/agent-skills?ref=explainx frames skills as workflows, quality gates, and best practices senior engineers use, packaged so agents follow them consistently. ASCII art in the repo maps: DEFINE → PLAN → BUILD → VERIFY → REVIEW → SHIP with commands /spec , /plan , /build , /test , /constraints , /review , /webperf , /code-simplify , /ship . The 25 skills grouped Meta: using-agent-skills routes work to the right workflow. Define: interview-me , idea-refine , spec-driven-development , constraints-and-standards . Plan: planning-and-task-breakdown . Build: incremental-implementation , test-driven-development , context-engineering , source-driven-development , doubt-driven-development , frontend-ui-engineering , api-and-interface-design . Verify: browser-testing-with-devtools , debugging-and-error-recovery . Review: code-review-and-quality , code-simplification , security-and-hardening , performance-optimization . Ship: git-workflow-and-versioning , ci-cd-and-automation , deprecation-and-migration , documentation-and-adrs , observability-and-instrumentation , shipping-and-launch . Each skill's SKILL.md follows a consistent anatomy: overview, when-to-use, process steps, rationalization tables, red flags, and verification evidence — the same anti-rationalization pattern we highlighted in teardown posts on offline HTML skills https://explainx.ai/blog/teardown-claude-code-skill-3d-simulator-offline-html-github-trending-2026 . Commands vs skills Commands are entry points that activate skills automatically. Claude Code installs them as plugin commands; where a built-in /review collides, the README says to use /agent-skills:review . Notable product detail: /build auto mode generates a plan and implements every task in one approved pass — still test-driven per task , still commits per task , but fewer human clicks between tasks. How to install without breaking your repo layout The README is explicit that hosts use different folders : | Tool | Location | |---|---| | Cursor | Copy under .cursor/skills/ ; keep short policies in .cursor/rules/ .mdc — see docs/cursor-setup.md | | OpenCode | .opencode/skills/ plus optional AGENTS.md | | Gemini CLI | gemini skills install with --path skills | | Codex | codex plugin marketplace add / codex plugin add | | Copilot | Personas in agents/ , prose in .github/copilot-instructions.md ; slash commands are Claude-only | Portability caveat issue 361 in README : installing a single skill via npx skills add … --skill name copies only that skill folder, not repo-level references/ checklists. Whole-repo install, clone, or manual copy fixes that. Personas for multi-angle review Under agents/ , the pack ships: - code-reviewer — five-axis staff-engineer bar - test-engineer — coverage and prove-it framing - security-auditor — OWASP-style pass - web-performance-auditor — Core Web Vitals with metric-honesty rules docs/agents.md covers orchestration, including the rule that personas do not spawn personas — relevant if you chain multi-agent orchestration benchmarks https://explainx.ai/blog/workflowarena-multi-agent-orchestration-benchmark-einsia-2026 in production. How this compares to other skill libraries | Pack | Emphasis | explainx.ai coverage | |---|---|---| | Addy Osmani agent-skills | Full SDLC, Google-flavored practices cited in README | This post | | Matt Pocock skills | TypeScript / real-engineer TDD & planning | Skills guide https://explainx.ai/blog/matt-pocock-agent-skills-real-engineers | | ECC affaan-m | Huge agent + skill count, install risk | ECC harness guide https://explainx.ai/blog/ecc-affaan-m-agent-harness-71-agents-311-skills-install-risks-github-trending-guide-2026 | | Anthropic / AAIF | Standard format donation | Agent Skills explainer https://explainx.ai/blog/what-are-agent-skills-complete-guide | Osmani's README links docs/comparisons.md for Superpowers and Matt Pocock — read that file in-repo for his stated deltas. We do not treat comparisons as independent benchmarks. Context: Osmani moved to Anthropic to work on Claude Code in September, covered in our Addy Osmani hire post https://explainx.ai/blog/addy-osmani-joins-anthropic-claude-code-2026 . This repo is personal open source , not an Anthropic product release — still worth watching because it influences how Claude Code power users structure repos. Security and supply-chain hygiene Supply-chain audit metaphor for vetting third-party agent skill packs before production install Skills are not passive docs. They can instruct agents to run scripts under scripts/ , edit CONSTRAINTS.md , or call browser tools. Before you npx skills add : 1. Read the SKILL.md files you will enable — same bar as agent skills security threats https://explainx.ai/blog/agent-skills-security-threat-explainx-verification . 2. Pin with skills-lock.json patterns https://explainx.ai/blog/skills-lock-json-reproducible-agent-skills-2026 where your harness supports them. 3. Separate "marketing skills" from repo-specific skills — our stack-diagram skill post https://explainx.ai/blog/stack-diagram-agent-skill-architecture-diagrams-github-trending-2026 shows narrow skills that do one job well. 4. Check the format spec — the open Agent Skills specification https://agentskills.io/?ref=explainx describes the SKILL.md folder layout and how agents load skills on demand, so you know what a skill can bundle before you enable it. The repo includes evals/ with 25 case files and CI under .github/workflows/ — a sign the maintainer expects regression testing on skill routing, similar in spirit to scenario-labs game-art skills https://explainx.ai/blog/scenario-labs-skills-agent-skills-scenario-mcp-game-art-blender-unity-install-github-trending-2026 . Adoption: greenfield vs legacy codebases docs/adoption.md linked from README splits rollout: - Greenfield: run the full /spec → /ship chain from day one. - Legacy: incremental, verification-first — align with incremental implementation https://explainx.ai/blog/beneath-the-surface-agent-harness-evolution-evoaudit-2026 themes in harness evolution posts. For teams standardized on MCP instead of skills, pair this pack with MCP comparison guides https://explainx.ai/blog/what-is-mcp-model-context-protocol-guide — skills instruct procedure ; MCP exposes tools . Osmani's browser-testing-with-devtools skill assumes Chrome DevTools MCP-style workflows. What developers are saying The older Hacker News thread on related agent-skills discourse id 47670950 on the candidate feed had low engagement when we checked. Trending stars on GitHub are the stronger signal for this repo — treat social proof as install interest , not a security audit. Reference checklists and shared artifacts The references/ directory holds seven checklists skills pull on demand: definition-of-done , testing-patterns , security-checklist , performance-checklist , accessibility-checklist , observability-checklist , and orchestration-patterns . Keeping them at repo root is why the README warns that per-skill npx installs skip shared files — your agent might reference paths that were never copied. CONSTRAINTS.md is another standing artifact: the constraints-and-standards skill helps teams write it once so agents stop renegotiating lint rules every session. That mirrors how Microsoft Copilot managed runtime templates https://explainx.ai/blog/microsoft-copilot-managed-runtime-github-repo-vite8-template-claude-code-plugin-ms-cli-guide-2026 bake policy into repo scaffolding. Hooks, scripts, and CI The repository ships hooks/ for lifecycle automation and scripts/ 13 utilities per README used in contributor workflows. .github/workflows/ runs validation on skill routing using the evals/ corpus 25 case files . If you fork the pack for a company monorepo, treat those evals as a template for regression tests on skill selection — the same mindset as EVOAudit harness evolution https://explainx.ai/blog/beneath-the-surface-agent-harness-evolution-evoaudit-2026 research. Google engineering culture embedded in prose The README explicitly cites practices from Software Engineering at Google and Google's engineering practices guide: Hyrum's Law in API design, the Beyonce Rule in testing, change-sizing norms in review, Chesterton's Fence in simplification, trunk-based git workflow, Shift Left in CI/CD, and treating deprecation as liability. None of that replaces your team's written standards, but it explains why the skills read opinionated rather than generic. If you are standardizing agent behavior across Cursor and Codex in the same repo, align this pack with Claude Code command reference https://explainx.ai/blog/claude-code-commands-complete-reference-guide-2026 habits so humans and agents share vocabulary for /review and /test . When not to install the full pack Skip the entire marketplace install if you only need one narrow skill for example browser-testing-with-devtools and you are token-sensitive. Copy that skills/