Platform Integration

Relevant source files

• .gitignore
• README.md
• spec/agent-skills-spec.md

Skills from the anthropics/skills repository are delivered across three Claude surfaces: Claude Code (via the plugin marketplace), Claude.ai (pre-integrated for paid plans), and the Claude API (via the Skills API). Each surface has a distinct installation mechanism, but all three load the same SKILL.md file format at runtime.

For details on the SKILL.md format, see page 2.2. For how skills are packaged into plugins, see page 2.3.

Platform Comparison

Platform	Access Method	Pre-installed	Custom Skills	Activation
Claude Code	/plugin commands + marketplace	No (manual install required)	Yes (local repo files)	Natural language mention
Claude.ai	Web interface	Yes (paid plans)	Yes (upload via UI)	Auto-available after upload
Claude API	Skills API endpoints	Yes (Anthropic pre-built)	Yes (upload via API)	API parameter / natural language

Sources: README.md29-59

Claude Code Integration

Claude Code accesses skills through a plugin marketplace system that requires explicit registration and installation steps.

Marketplace Registration

Register the repository as a plugin marketplace source:

/plugin marketplace add anthropics/skills

This registers .claude-plugin/marketplace.json as an available plugin source under the name anthropic-agent-skills.

Sources: README.md32-35

Plugin Installation Methods

After marketplace registration, install a plugin bundle using either method:

Interactive:

1. Select Browse and install plugins
2. Select anthropic-agent-skills
3. Choose document-skills or example-skills
4. Select Install now

Direct command:

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

The syntax is /plugin install <plugin-name>@<marketplace-name>.

Sources: README.md37-47

Skill Activation

Once installed, invoke a skill by mentioning it in natural language:

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

Claude Code matches the mention against loaded SKILL.md description fields and injects the matching skill's instructions into context.

Sources: README.md49

Diagram: Claude Code installation flow — from /plugin command to SKILL.md execution

Sources: README.md31-49 .claude-plugin/marketplace.json

Claude.ai Integration

Pre-integrated Skills

All skills from this repository are pre-integrated and available to paid plan users on Claude.ai without any installation step.

Sources: README.md51-53

Custom Skill Upload

Paid users can also upload additional skills (including custom-authored ones) through the Claude.ai web interface. The upload accepts a SKILL.md file and any supporting assets. Instructions are in the Claude support article "Using skills in Claude" linked from README.md55

Sources: README.md54-55

Claude API Integration

Pre-built Skills

The Skills API exposes Anthropic's pre-built skills (the four document skills and example skills) directly. No repository setup is required.

Custom Skill Upload

Developers can upload custom SKILL.md-based skills to the API for use in production applications. See the Skills API Quickstart at docs.claude.com (linked from README.md59) for the upload endpoint and request format.

Sources: README.md57-59

Plugin Packaging (Claude Code)

The .claude-plugin/marketplace.json file defines the two plugin bundles available in Claude Code. This is only relevant to the Claude Code surface; Claude.ai and the API do not use this file.

Plugin Name	Skills included	License
document-skills	skills/xlsx, skills/docx, skills/pptx, skills/pdf	Source-available
example-skills	12 example skill folders	Apache 2.0

Each bundle entry in marketplace.json contains: name, description, skills (array of folder paths), strict (validation mode), and source (base path, set to ./).

For full details on the marketplace.json schema, see page 2.3.

Sources: .claude-plugin/marketplace.json README.md37-47

Cross-Platform Execution Model

All three platforms share a common execution model despite different integration methods:

Unified Skill Loading

Sources: README.md1-88

Platform-Specific Features

Feature	Claude Code	claude.ai	Claude API
Installation method	/plugin commands	Pre-integrated + upload	API endpoint
Skill discovery	Marketplace browse UI	Web interface	Programmatic query
Custom skills	Local repository files	Upload interface	API upload
Activation	Natural language mention	Automatic	API parameter
Skill updates	Re-install plugin	Re-upload	Re-upload via API

Skill Path Resolution

All platforms resolve skill paths relative to the source directory specified in the plugin configuration:

• Base path: source: ./ in marketplace.json
• Skill path format: skills/<skill-name>/SKILL.md
• Full resolution: ./<skills>/<skill-name>/SKILL.md

For example, the PDF skill resolves to: ./skills/pdf/SKILL.md

Sources: README.md29-59 .claude-plugin/marketplace.json

Platform Integration Summary

The three platforms provide different developer experiences while maintaining compatibility with the same skill format:

• Claude Code requires explicit marketplace registration and plugin installation, offering fine-grained control over which skills are available
• claude.ai provides immediate access to example skills for paid users and supports custom uploads through a web interface
• Claude API enables programmatic skill management and execution, suitable for production applications

All platforms load SKILL.md files dynamically at skill activation time, ensuring that skill updates are immediately available without requiring application restarts or redeployments.

Sources: README.md29-59