Runway 7


satellite is a global messaging service that's tuned to publish small messages to a large number of subscribers. It allows message broadcasting to browsers and mobile devices based on the Server Sent Events (SSE) / EventSource protocol.

why we built it

Broadcasting messages to browsers and devices using topics is incredibly useful, but equally hard to do. satellite is perfect for applications which need to send soft-realtime updates to many of their users, like scoreboards, live tickers, social media, and any application that handles streams of information visible to multiple users.

how it works

satellite lets you create a realm for each application, and publish at will to topics in that realm. Topics do not need to be created before they are used - they are created on demand when you attempt to use them. For example:

For Example:

1000 users subscribing for 1 hour:
1000 people X 60 minutes = 60,000 minutes
60,000 minutes X USD $1 / 1,000,000 minutes = USD $0.06

100 messages published to 1000 users:
100 publishes X USD $1 / 100,000 publishes = USD $0.001
100 messages X 1000 users = 100,000 deliveries
100,000 deliveries X USD $1 / 1,000,000 deliveries = USD $0.10


In order to achieve high scalability at low costs, satellite sacrifices a certain amount of speed by design. This isn't to say that delivery is slow - messages can reach millions of subscribers within a few seconds. But sub-second delivery simply isn't a goal at all. signs focuses more on distributing widely than it does on distributing quickly. If your use case is 1 to 1 messaging, or 1 to few, signs may not be your best bet. The optimal use case is at 1 to many publishing.