Reverse engineering some updates to Claude

Anthropic recently released two undocumented features for its Claude AI model. The first allows the mobile app to create calendar events and messages, which was discovered to be implemented via new tool-use capabilities with specific JSON schemas. The author reverse-engineered these tools by prompting the model to reveal their structure. The second update enhances Claude Artifacts to handle files like PDFs and images by allowing them to call the full Claude API, a feature implemented by monkey-patching the `fetch()` function within the artifact environment to proxy API calls securely.