Welcome to the Grand Central Message Broker 👋
The Grand Central Message Broker (or GCMB for short) is a hub for live data. It allows you to share data streams with others, and to subscribe to data streams shared by others. It uses the MQTT protocol, which is a lightweight and efficient pub/sub protocol.
Open Data is especially welcome here, and we encourage you to share your live data with the world (Private data is also supported, and you can control who has access).
GCMB is in beta. To get notified of new features, subscribe to our newsletter.
Projects
ADS-B location data from flights around the world
Live currency and stock exchange index data
Firehose of new blog posts on medium.com
Data about open and used parking spaces
Open data from the energy market in Germany, Austria and Luxembourg
Stream of Wikipedia Events
Water levels of German waterways
Data from my house
Grand Central Message Broker © huditech 2026. All rights reserved