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+# API Documentation
+
+Complete reference for Bookhoard REST API endpoints.
+
+## Quick Links
+
+- [Authentication](authentication/) - User registration, login, tokens
+- [Users](users/) - Profile management
+- [Libraries](libraries/) - Library management
+- [Media Items](media-items/) - Book/ebook operations
+- [Progress](progress/) - Reading progress tracking
+- [Notes](notes/) - User notes management
+- [Highlights](highlights/) - Book highlights
+- [Ratings](ratings/) - Book ratings
+- [Devices](devices/) - Device registration and sync
+- [Analytics](analytics/) - Usage statistics
+- [Book Matching](book-matching/) - Search and link books
+- [Collections](collections/) - See [COLLECTIONS_API.md](../COLLECTIONS_API.md)
+- [OPDS](opds/) - Open Publication Distribution
+- [Sync Protocols](sync/) - KOReader and Kobo sync
+- [WebSocket](websocket/) - Real-time sync events
+
+---
+
+## Authentication
+
+See [Authentication Endpoints](authentication/)
+
+## Users & Profiles
+
+See [User Management](users/)
+
+## Libraries
+
+See [Library Management](libraries/)
+
+## Media Items
+
+See [Media Item Operations](media-items/)
+
+## Reading Progress
+
+See [Progress Tracking](progress/)
+
+## Notes & Highlights
+
+See [Notes Management](notes/) and [Highlights Management](highlights/)
+
+## Ratings
+
+See [Ratings System](ratings/)
+
+## Device Management
+
+See [Device Registration & Sync](devices/)
+
+## Analytics
+
+See [Usage Analytics](analytics/)
+
+## Book Matching & Linking
+
+See [Book Matching](book-matching/)
+
+## Collections
+
+See [Collections API](../COLLECTIONS_API.md) or [Collections Endpoints](collections/)
+
+## OPDS
+
+See [OPDS Feeds](opds/)
+
+## Sync Protocols
+
+See [KOReader Sync](sync/) and [Kobo Sync](sync/)
+
+## WebSocket
+
+See [WebSocket Protocol](websocket/)