Adding a Claude config file

Author: mikecousins

CLAUDE.md

@@ -0,0 +1,54 @@
+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Project Overview
+
+This is a monorepo for `@mikecousins/react-pdf`, a React component library that provides an easy way to render PDF documents using PDF.js. The repository uses pnpm workspaces with Turborepo for build orchestration.
+
+## Repository Structure
+
+- `packages/react-pdf-js/` - Main React PDF component library
+- `apps/demo/` - Demo application showcasing the component
+- `apps/demo-react-router/` - React Router demo application  
+- `apps/docs/` - Documentation site built with Next.js
+
+## Development Commands
+
+### Root Level Commands (use these for most tasks)
+- `pnpm build` - Build all packages and apps via Turborepo
+- `pnpm lint` - Lint all packages and apps via Turborepo
+- `pnpm test` - Run tests for all packages via Turborepo
+- `pnpm format` - Format all code using Prettier
+
+### Package-Specific Commands
+For the main library (`packages/react-pdf-js/`):
+- `pnpm build` - Build using tsup (outputs ESM and CJS formats)
+- `pnpm lint` - Run ESLint
+
+### Package Manager
+This project uses `pnpm` as the package manager (version 10.7.0). Always use `pnpm` instead of npm or yarn.
+
+## Core Architecture
+
+The main library exports a single React hook called `usePdf` that:
+
+1. **PDF Document Loading**: Uses PDF.js `getDocument()` to load PDF files from URLs
+2. **Canvas Rendering**: Renders PDF pages to HTML5 canvas elements with support for:
+   - Scaling and rotation
+   - High DPI displays (devicePixelRatio handling)
+   - Render task cancellation for performance
+3. **Lifecycle Callbacks**: Provides optional callbacks for document/page load and render events
+4. **Configuration**: Supports PDF.js worker configuration, cMap settings, and credential handling
+
+### Key Files
+- `packages/react-pdf-js/src/index.tsx` - Main hook implementation and TypeScript types
+- `packages/react-pdf-js/package.json` - Library configuration with peer dependencies on React 19+ and pdfjs-dist 5+
+
+## Testing
+
+Tests are located in `packages/react-pdf-js/test/` and use Jest with React Testing Library. The project includes canvas mocking for PDF rendering tests.
+
+## Build Output
+
+The library builds to both ESM and CommonJS formats in the `dist/` directory with full TypeScript declarations.