Concepts
This page explains how channels, segments, permissions, payloads, ordering, and reconnection fit together.
Celeris carries live updates between your backend, browsers, and other services that receive them. Your application decides who can connect, what each message means, and where it stores important data.
Start with the message path
A channel reference names a communication space. In the SDK, one channel handle owns one WebSocket connection. Segments are named streams inside that connection. A segment is not a separate socket.
When you connect to a channel, you automatically join its default segment. That membership does not need a separate subscription. You can start with default for one stream and add named segments to separate topics or permissions. The application still needs a listener and read permission to receive messages.
The payload is the content of a message, encoded as bytes. Text, JSON, MessagePack, and Protobuf are all possible choices. Celeris does not automatically convert between them.
Follow the concepts
- Channels and Segments explains where messages belong and how membership operates.
- Binary Messaging explains how to encode the content and how to select a format.
- Message Ordering explains the order of delivered messages and the message IDs.
- Reconnection and Recovery explains interruptions, replay, and reconciliation.
- Permissions explains read access, write access, and how to plan them.
Example: an order dashboard
Your backend saves an order status to its database. It then publishes a message to a segment that the customer can read. The browser receives the message and refreshes its interface.
After an interruption, the browser fetches the order from your backend again. That database record remains authoritative when a live message does not arrive or arrives twice.
Next: Follow the Quickstart.