Agent Skills

Overview

addyosmani/agent-skills is a curated bundle of production-grade engineering skills for AI coding agents — MIT-licensed, distributed via a shell-script installer, and authored by Addy Osmani, one of the most visible figures in mainstream web developer experience. As of May 6, 2026 the repo sits at 31,051 stars (+629 in 24h), placing it among the highest-starred agent-skills directories on GitHub. The repo’s GitHub topics — claude-code, cursor, antigravity, antigravity-ide, skills, agent-skills — cover the four leading agent harnesses simultaneously.

Key Capabilities

The bundle ships SKILL.md-formatted instruction files that load at runtime into any agent harness following the skills convention: Claude Code, Cursor, Anthropic’s Antigravity IDE, and SKILL.md-aware tools like Codex CLI. Each skill encapsulates a repeatable engineering workflow — patterns refined for production codebases rather than toy examples. Installation is a single shell command that drops the skills into the harness’s expected location. There is no proprietary runtime — every skill is auditable markdown.

Why It Matters

When Addy Osmani — a mainstream web-platform DevRel voice — publishes a curated skills bundle and tags it explicitly for antigravity-ide, that’s a legitimacy signal for the SKILL.md format itself. The skills convergence has been visible since late 2025, but as of May 2026 every credible runtime-skills directory ships in the same format and targets the same four harnesses. Vendor-specific skills bundles are no longer competitive against the cross-harness pattern. addyosmani/agent-skills is the highest-profile example of that convergence in mainstream web DX, alongside ComposioHQ/awesome-codex-skills (Codex-side) and mattpocock/skills (Claude Code-side).

Use Cases

Useful for engineering teams adopting any SKILL.md-aware agent harness who want a curated baseline of production-quality skills without authoring them from scratch. Particularly valuable for teams running Antigravity IDE, where the bundled skills have been validated against the newest entrant in the agent-IDE space. Pairs naturally with mattpocock/skills (TypeScript/Claude Code emphasis) and ComposioHQ/awesome-codex-skills (Codex-CLI emphasis) — installing all three together gives an agent harness very strong default capability across the modern coding workflow.

Considerations

The skills directory is opinionated — Addy’s preferences for engineering style and tooling are embedded in the prompts. Teams with strongly differing conventions should fork and adapt rather than ship the bundle as-is. As an open-source skills directory there is no SLA, hosted runtime, or vendor support; if you need that, the relevant agent harness vendor (Anthropic, Cursor, Google Antigravity) is the support contract — addyosmani/agent-skills is the content, not the infrastructure.

Who It’s For

agent-skills fits engineering teams adopting Claude Code, Cursor, Antigravity, or Codex who want a credible, mainstream-DX-validated baseline of skills before authoring their own. It’s also useful for SKILL.md authors studying high-quality production examples — the repo is small enough to read fully and large enough to demonstrate the breadth the format supports. If you’re not yet using a SKILL.md-aware harness, this directory is also one of the cleanest arguments for starting.