WebSocket Protobuf is the realtime companion for typed ConnectRPC and SDK integrations. It uses binary Protobuf payloads over WebSocket while ConnectRPC continues to handle request-response calls.
This is not ConnectRPC streaming
The payloads use Protobuf message types, but connection tokens, subscriptions, and reconnects follow
the WebSocket session model.
When to use Protobuf channels
Choose WebSocket Protobuf when:
- you use an official SDK realtime client
- your application already uses generated Protobuf message types
- compact typed payloads matter more than direct inspection
- the required stream is available only as Protobuf
Encoding support is channel-specific. A Protobuf channel does not guarantee an equivalent JSON channel.
Channel implementation
Choose a Protobuf channel
Use the official SDK product method or identify the exact channel and published message type for a custom client.
Decode with generated types
Decode each binary publication with the message type assigned to that channel. Apply the integer and identifier conventions defined by the field contract.
Protobuf is not SBE
Do not decode realtime Protobuf frames with the SBE WebSocket schema. SBE WebSocket is a
separate binary order-entry session.
