Anthropic Skills - Claude AI Skill System

Project Overview

Anthropic Skills is an open skill repository officially maintained by Anthropic, designed to showcase the capabilities of Claude AI's skill system. Skills are an innovative mechanism that allows Claude to dynamically load and enhance its performance on specialized tasks, through folders containing instructions, scripts, and resources.

Project Address: https://github.com/anthropics/skills

Core Concepts

What are Skills?

Skills are specialized capability packages that Claude can dynamically load. Each Skill includes:

• Instruction document (SKILL.md)
• Executable scripts
• Related resource files

Claude automatically identifies and loads relevant Skills based on task requirements, accessing only the minimal information needed to complete the task, thus maintaining efficient operation.

Characteristics of Skills

1. Progressive Disclosure: Claude initially only sees the skill name and a brief description, then autonomously decides which skills to load based on the task.
2. Composable: Multiple Skills can automatically layer and work together.
3. Cross-platform: Usable in Claude.ai, API, and Claude Code.
4. Easy to Create: Requires only a Markdown file containing YAML frontmatter.

Repository Structure

Example Skills

This repository contains a diverse range of example skills, showcasing various capabilities:

Creative & Design

• algorithmic-art: Creates generative art using p5.js, supporting seed randomness, flow fields, and particle systems.
• canvas-design: Creates aesthetically pleasing visual art in .png and .pdf formats using design philosophies.
• slack-gif-creator: Creates animated GIFs optimized for Slack's size limitations.
• theme-factory: Applies 10 preset professional themes to artifacts or generates custom themes on the fly.

Technical Development

• artifacts-builder: Builds complex claude.ai HTML artifacts using React, Tailwind CSS, and shadcn/ui components.
• mcp-server: A guide to creating high-quality MCP servers for integrating external APIs and services.
• webapp-testing: Tests local web applications using Playwright for UI validation and debugging.

Enterprise Workflows

• brand-guidelines: Applies Anthropic's official brand colors and typography within artifacts.
• internal-comms: Writes internal communication documents such as status reports, newsletters, and FAQs.

Tools & Templates

• skill-creator: A guide to creating effective skills to extend Claude's capabilities.
• template-skill: A foundational template to use as a starting point for new skills.

Document Skills

The document-skills/ subdirectory contains document file format processing skills developed by Anthropic, showcasing advanced patterns for handling complex file formats and binary data:

• docx: Creates, edits, and analyzes Word documents, supporting track changes, comments, format preservation, and text extraction.
• pdf: A comprehensive PDF manipulation toolkit for extracting text and tables, creating new PDFs, merging/splitting documents, and processing forms.
• pptx: Creates, edits, and analyzes PowerPoint presentations, supporting layouts, templates, charts, and automatic slide generation.
• xlsx: Creates, edits, and analyzes Excel spreadsheets, supporting formulas, formatting, data analysis, and visualization.

Important Note: These document skills are point-in-time snapshots and are not actively maintained or updated. Versions of these skills are pre-installed in Claude and primarily serve as reference examples.

How to Create a Custom Skill

Creating a Skill is straightforward, requiring only a SKILL.md file containing YAML frontmatter and instructions:

---
name: my-skill-name
description: A clear description of what this skill does and when to use it
---

# My Skill Name

[Add your instructions here that Claude will follow when this skill is active]

## Examples
- Example usage 1
- Example usage 2

## Guidelines
- Guideline 1
- Guideline 2

Required Fields

• name: The skill's unique identifier (lowercase, hyphen-separated words).
• description: A complete description of what the skill does and when to use it.

Usage

Using in Claude Code

Skills can be installed via plugins from the anthropics/skills marketplace:

/plugin install document-skills@anthropic-agent-skills
/plugin install example-skills@anthropic-agent-skills

Once installed, simply mention the skill to use it, for example:

"Use the PDF skill to extract the form fields from path/to/some-file.pdf"

Using in Claude.ai

All these example skills are available for free in paid plans (Max, Pro, Teams, and Enterprise) at no additional cost.

Using via API

Anthropic's pre-built skills can be used and custom skills can be uploaded via the Claude API. See the Skills API Quickstart for details.

Technical Advantages

1. Distinction from RAG: Skills do not rely on Retrieval Augmented Generation; instead, they use simple tools to allow Claude to manage and read files from the file system.
2. Infinite Context: Skills can contain an unlimited amount of context to teach Claude how to complete a task or a series of tasks.
3. Autonomous Navigation: Based on the premise that agents can autonomously and intelligently navigate the file system and execute code.
4. Speed and Efficiency: Through progressive disclosure, only necessary information is loaded when needed, maintaining fast responsiveness.

Partner Examples

Some partners have already created excellent example skills:

• Notion: Notion Skills for Claude

Disclaimer

These skills are provided for demonstration and educational purposes only. While some functionalities may be available in Claude, the actual implementation and behavior might differ from these examples. These examples are intended to illustrate patterns and possibilities. Always thoroughly test skills in your own environment before using them for critical tasks.

Resource Links

• What are Skills?
• Using Skills in Claude
• How to Create Custom Skills
• Equipping Agents for the Real World with Agent Skills

Summary

Anthropic Skills represent a new paradigm for AI capability expansion. By packaging specialized knowledge into reusable, composable modules, Skills enable Claude to perform exceptionally well in specific domains. Whether for document processing, creative design, or enterprise workflows, Skills offer a simple yet powerful way to customize Claude's behavior.