There are many alternatives to Node-RED as a self-hosted solution if you are looking for a replacement. The best Self-Hosted alternative is n8n.io, which is free. If that doesn't suit you, our users have ranked more than 10 alternatives to Node-RED and three of them are available as a self-hosted solution so hopefully you can find a suitable replacement. Other interesting Self-Hosted alternatives to Node-RED are ioBroker (Free, Open Source) and iot-dashboard (Free, Open Source).
ioBroker is an integration platform for the Internet of Things, focused on Smart home, Building Automation, Smart Metering, Ambient Assisted Living, Process Automation, Visualization and Data Logging. It aims to be a possible replacement or extension for software like f.e.