SimpleHub is a self-hosted API aggregation monitoring and management system designed for AI relay services. It allows users to manage multiple API sites (NewAPI, Veloera, DoneHub, VOAPI, and OpenAI-compatible) from a single dashboard. The system monitors model lists for changes, tracks account balances and usage, and supports automatic daily check-in for supported platforms. It sends email notifications via Resend when model changes are detected, either individually or aggregated in scheduled batch checks. The architecture is a monolithic Node.js application using Fastify for the backend and React (with Vite) for the frontend. The backend serves the built frontend statically and exposes a RESTful API under /api. Authentication is handled via JWT tokens. Data persistence uses SQLite via Prisma ORM. The system includes a cron-based scheduler for periodic checks, with support for per-site proxy configuration (HTTP, HTTPS, SOCKS5) and automatic BunkerWeb challenge solving through proxies. External dependencies include Fastify, Prisma, Resend, node-cron, bcryptjs, and various proxy agent libraries. Key entry points are the Fastify server (port 3000), the API routes defined in routes.js, and the scheduler that manages global and per-site cron jobs. The frontend provides a modern Ant Design-based UI for managing sites, viewing model lists, checking balances, and configuring notifications. The system is designed for easy deployment via Docker or direct installation scripts, with support for alwaysdata and systemd services.