Claude Skills Cookbook 🚀

A comprehensive guide to using Claude's Skills feature for document generation, data analysis, and business automation. This cookbook demonstrates how to leverage Claude's built-in skills for Excel, PowerPoint, and PDF creation, as well as how to build custom skills for specialized workflows.

🎯 See Skills in Action: Check out Claude Creates Files to see how these Skills power Claude's ability to create and edit documents directly in Claude.ai and the desktop app!

What are Skills?

Skills are organized packages of instructions, executable code, and resources that give Claude specialized capabilities for specific tasks. Think of them as "expertise packages" that Claude can discover and load dynamically to:

• Create professional documents (Excel, PowerPoint, PDF, Word)
• Perform complex data analysis and visualization
• Apply company-specific workflows and branding
• Automate business processes with domain expertise

📖 Read our engineering blog post on Equipping agents for the real world with Skills

Key Features

• ✨ Progressive Disclosure Architecture - Skills load only when needed, optimizing token usage
• 📊 Financial Focus - Real-world examples for finance and business analytics
• 🔧 Custom Skills Development - Learn to build and deploy your own skills
• 🎯 Production-Ready Examples - Code you can adapt for immediate use

Cookbook Structure

📚 Notebook 1: Introduction to Skills

Learn the fundamentals of Claude's Skills feature with quick-start examples.

• Understanding Skills architecture
• Setting up the API with beta headers
• Creating your first Excel spreadsheet
• Generating PowerPoint presentations
• Exporting to PDF format

💼 Notebook 2: Financial Applications

Explore powerful business use cases with real financial data.

• Building financial dashboards with charts and pivot tables
• Portfolio analysis and investment reporting
• Cross-format workflows: CSV → Excel → PowerPoint → PDF
• Token optimization strategies

🔧 Notebook 3: Custom Skills Development

Master the art of creating your own specialized skills.

• Building a financial ratio calculator
• Creating company brand guidelines skill
• Advanced: Financial modeling suite
• Best practices and security considerations

Quick Start

Prerequisites

• Python 3.8 or higher
• Anthropic API key (get one here)
• Jupyter Notebook or JupyterLab

Installation

1. Clone the repository

git clone https://github.com/anthropics/claude-cookbooks.git
cd claude-cookbooks/skills

2. Create virtual environment (recommended)

python -m venv venv
source venv/bin/activate  # On Windows: venv\\Scripts\\activate

3. Install dependencies

pip install -r requirements.txt

4. Configure API key

cp .env.example .env
# Edit .env and add your ANTHROPIC_API_KEY

5. Launch Jupyter

jupyter notebook

6. Start with Notebook 1 Open notebooks/01_skills_introduction.ipynb and follow along!

Sample Data

The cookbook includes realistic financial datasets in sample_data/:

• 📊 financial_statements.csv - Quarterly P&L, balance sheet, and cash flow data
• 💰 portfolio_holdings.json - Investment portfolio with performance metrics
• 📋 budget_template.csv - Department budget with variance analysis
• 📈 quarterly_metrics.json - KPIs and operational metrics

Project Structure

skills/
├── notebooks/                    # Jupyter notebooks
│   ├── 01_skills_introduction.ipynb
│   ├── 02_skills_financial_applications.ipynb
│   └── 03_skills_custom_development.ipynb
├── sample_data/                  # Financial datasets
│   ├── financial_statements.csv
│   ├── portfolio_holdings.json
│   ├── budget_template.csv
│   └── quarterly_metrics.json
├── custom_skills/                # Your custom skills
│   ├── financial_analyzer/
│   ├── brand_guidelines/
│   └── report_generator/
├── outputs/                      # Generated files
├── docs/                         # Documentation
├── requirements.txt             # Python dependencies
├── .env.example                 # Environment template
└── README.md                    # This file

API Configuration

Skills require specific beta headers. The notebooks handle this automatically, but here's what's happening behind the scenes:

from anthropic import Anthropic

client = Anthropic(
    api_key="your-api-key",
    default_headers={
        "anthropic-beta": "code-execution-2025-08-25,files-api-2025-04-14,skills-2025-10-02"
    }
)

Required Beta Headers:

• code-execution-2025-08-25 - Enables code execution for Skills
• files-api-2025-04-14 - Required for downloading generated files
• skills-2025-10-02 - Enables Skills feature

Working with Generated Files

When Skills create documents (Excel, PowerPoint, PDF, etc.), they return file_id attributes in the response. You must use the Files API to download these files.

How It Works

1. Skills create files during code execution
2. Response includes file_ids for each created file
3. Use Files API to download the actual file content
4. Save locally or process as needed

Example: Creating and Downloading an Excel File

from anthropic import Anthropic

client = Anthropic(api_key="your-api-key")

# Step 1: Use a skill to create a file
response = client.messages.create(
    model="claude-sonnet-4-6",
    max_tokens=4096,
    container={
        "skills": [
            {"type": "anthropic", "skill_id": "xlsx", "version": "latest"}
        ]
    },
    tools=[{"type": "code_execution_20250825", "name": "code_execution"}],
    messages=[{
        "role": "user",
        "content": "Create an Excel file with a simple budget spreadsheet"
    }]
)

# Step 2: Extract file_id from the response
file_id = None
for block in response.content:
    if block.type == "tool_result" and hasattr(block, 'output'):
        # Look for file_id in the tool output
        if 'file_id' in str(block.output):
            file_id = extract_file_id(block.output)  # Parse the file_id
            break

# Step 3: Download the file using Files API
if file_id:
    file_content = client.beta.files.download(file_id=file_id)

    # Step 4: Save to disk
    with open("outputs/budget.xlsx", "wb") as f:
        f.write(file_content.read())

    print(f"✅ File downloaded: budget.xlsx")

Files API Methods

# Download file content (binary)
content = client.beta.files.download(file_id="file_abc123...")
with open("output.xlsx", "wb") as f:
    f.write(content.read())  # Use .read() not .content

# Get file metadata
info = client.beta.files.retrieve_metadata(file_id="file_abc123...")
print(f"Filename: {info.filename}, Size: {info.size_bytes} bytes")  # Use size_bytes not size

# List all files
files = client.beta.files.list()
for file in files.data:
    print(f"{file.filename} - {file.created_at}")

# Delete a file
client.beta.files.delete(file_id="file_abc123...")

Important Notes:

• Files are stored temporarily on Anthropic's servers
• Downloaded files should be saved to your local outputs/ directory
• The Files API uses the same API key as the Messages API
• All notebooks include helper functions for file download
• Files are overwritten by default - rerunning cells will replace existing files (you'll see [overwritten] in the output)

See the Files API documentation for complete details.

Built-in Skills Reference

Claude comes with these pre-built skills:

Creating Custom Skills

Custom skills follow this structure:

my_skill/
├── SKILL.md           # Required: Instructions for Claude
├── scripts/           # Optional: Python/JS code
│   └── processor.py
└── resources/         # Optional: Templates, data
    └── template.xlsx

Learn more in Notebook 3.

Common Use Cases

Financial Reporting

• Automated quarterly reports
• Budget variance analysis
• Investment performance dashboards

Data Analysis

• Excel-based analytics with complex formulas
• Pivot table generation
• Statistical analysis and visualization

Document Automation

• Branded presentation generation
• Report compilation from multiple sources
• Cross-format document conversion

Performance Tips

1. Use Progressive Disclosure: Skills load in stages to minimize token usage
2. Batch Operations: Process multiple files in a single conversation
3. Skill Composition: Combine multiple skills for complex workflows
4. Cache Reuse: Use container IDs to reuse loaded skills

Troubleshooting

Common Issues

API Key Not Found

ValueError: ANTHROPIC_API_KEY not found

→ Make sure you've copied .env.example to .env and added your key

Skills Beta Header Missing

Error: Skills feature requires beta header

→ Ensure you're using the correct beta headers as shown in the notebooks

Token Limit Exceeded

Error: Request exceeds token limit

→ Break large operations into smaller chunks or use progressive disclosure

Resources

Documentation

• 📖 Claude API Documentation
• 🔧 Skills Documentation

Support Articles

• 📚 Teach Claude your way of working using Skills - User guide for working with Skills
• 🛠️ How to create a skill with Claude through conversation - Interactive skill creation guide

Community & Support

• 💬 Claude Support
• 🐙 GitHub Issues

Contributing

We welcome contributions! Please see CONTRIBUTING.md for guidelines.

License

This cookbook is provided under the MIT License. See LICENSE for details.

Acknowledgments

Special thanks to the Anthropic team for developing the Skills feature and providing the SDK.

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Questions? Check the FAQ or open an issue.

Ready to start? Open Notebook 1 and let's build something amazing! 🎉