Agent Skills Open Standard

The Agent Skills format is an open standard for extending AI agent capabilities with specialized knowledge and workflows. Originally developed by Anthropic, adopted by 25+ agent products.

Source: https://agentskills.io

When to use this skill: Before creating any skill that should be portable across multiple agent products. For Claude Code-specific features (hooks, context fork, model selection, invocation control), see claude-skills-overview-2026 instead.

SKILL.md Format

Every skill is a directory containing a SKILL.md file with YAML frontmatter and Markdown body: