GitHub - addyosmani/agent-skills: Production-grade engineering skills for AI coding agents. · GitHub

Author: Addy Osmani | Published: Unknown | Generated: 2026-05-07 | Domain: github.com
Tags: ‘#ai-agents’ ‘#coding-agents’ ‘#engineering-workflows’ ‘#developer-tools’ ‘#claude-code’ ‘#agent-skills’

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TLDR

Agent Skills packages senior-engineering practices as 25 portable Markdown workflows for AI coding agents, spanning requirement definition through production launch. The pack adds nine lifecycle commands, 24 specialized lifecycle skills plus a routing meta-skill, four reviewer personas, and seven checklists—all designed around explicit process steps, anti-rationalization safeguards, and verifiable evidence rather than generic prompting. It supports 70+ agents through the Skills CLI and native integrations for tools including Claude Code, Codex, Gemini CLI, Cursor, Copilot, and OpenCode.

Key Takeaways

• Full development lifecycle: Nine commands—/spec, /plan, /build, /test, /constraints, /review, /webperf, /code-simplify, and /ship—map to define, plan, build, verify, review, and deployment stages; /build auto generates and executes an approved plan while preserving per-task testing, commits, and failure pauses.
• Structured, evidence-driven skills: Each SKILL.md includes triggering conditions, a step-by-step workflow, rationalization rebuttals, red flags, and verification requirements; “seems right” is explicitly not accepted as evidence.
• 25 skills and specialist reviews: The repository provides 24 lifecycle skills plus using-agent-skills for routing, alongside four targeted personas: code reviewer, test engineer, security auditor, and web-performance auditor.
• Cross-tool portability: npx skills add addyosmani/agent-skills installs all 25 skills into 70+ agent environments. Native installation guidance is included for Claude Code, Codex CLI v0.122+, Gemini CLI, Antigravity, Cursor, Windsurf, OpenCode, GitHub Copilot, Kiro, and Command Code.
• Quality practices encoded directly: Workflows incorporate concepts such as test-driven development and an 80/15/5 test pyramid, WCAG 2.1 AA accessibility, OWASP Top 10 prevention, Core Web Vitals measurement, trunk-based development, feature flags, and staged rollouts.
• Repository signals: At capture time, the project reports 94.4k stars, 10k forks, 67 contributors, 512 commits, 11 releases, and latest release 0.6.9 dated 2026-09-05.

Images & Media

• Addy’s Agent Skills overview graphic — Promotional illustration for the Agent Skills pack.
• Development lifecycle diagram — Inline ASCII workflow depicting Define → Plan → Build → Verify → Review → Ship, with corresponding slash commands.
• Skill anatomy diagram — Inline ASCII diagram showing a SKILL.md structure: frontmatter, overview, triggers, process, rationalizations, red flags, and verification.

Referenced Links

• Skills CLI — Open CLI used to install the pack into 70+ supported agents.
• Adoption Guide — Rollout guidance for greenfield projects and incremental adoption in established codebases.
• Software Engineering at Google — Source for engineering principles reflected in the workflows.
• Google Engineering Practices — Google’s engineering-practice guidance referenced by the project.
• Comparison with Superpowers and Matt Pocock’s skills — Side-by-side comparison of the skill packs and intended use cases.
• Controlled head-to-head experiment — Linked experiment comparing Agent Skills and Superpowers.
• Portability gap issue #361 — Tracks missing shared references/ files when a single skill is installed via npx.
• Claude Code setup — Universal getting-started guidance for agents that accept prompts or instruction files.