I'm building something that should do exactly what you want. It is free for any databases you create before I add payment options (middle of 2022).

I don't offer a self-hosted option (sorry), but otherwise I think you'll like it:

• No sign up required
• Super fast
• Real-time sync between devices
• Web-only, but very nice on mobile (no app to install)
• Custom fields
• Checkout/check-in to track where things are or who has them
• Tagging via QR codes, which you can print yourself

I'd be happy to shoot you a link when it goes public in late January. The product is called Assetbots. My name is Chad if you have any questions or want to chat about it further.