What it does This repo holds Anthropic’s official “skills” — self-contained folders with a SKILL.md file that gives Claude structured instructions, examples, and guidelines for specific tasks. Think of them as prompt templates with metadata that Claude loads dynamically. The repo includes creative skills (art, music), technical ones (web app testing, MCP server generation), and enterprise workflows (branding, communications).

The interesting bit The document skills powering Claude’s file-creation features — docx, pdf, pptx, xlsx — are included here as source-available reference implementations. That’s unusual: you can read the exact instructions Anthropic uses in production to make Claude generate Office documents, even though you can’t freely reuse that code. The rest of the skills are Apache 2.0.

Key highlights

• Skills are dead simple to author: YAML frontmatter (name, description) plus markdown instructions in a single SKILL.md
• Installable as Claude Code plugins via /plugin marketplace add anthropics/skills
• Already live for paid Claude.ai users; also usable via API
• Includes the Agent Skills specification in ./spec and a starter template
• Partner skills emerging (Notion is the first listed)

Caveats

• Anthropic explicitly warns these are “demonstration and educational purposes only” — production Claude behavior may differ
• The document skills are source-available, not open source; the licensing split is easy to miss

Verdict Worth browsing if you write prompts for Claude or want to understand how Anthropic structures complex agent instructions. Skip if you’re looking for a general framework — this is heavily Claude-specific.