WebSocket channel between a single client and a hub on the Web
PubSub service instance. Each connection belongs to exactly one
hub. Messages on this channel are JSON frames defined by the
`json.webpubsub.azure.v1` or `json.reliable.webpubsub.azure.v1`
subprotocol. Simple WebSocket clients (no subprotocol) exchange
raw text/binary frames instead and are NOT modeled here — refer
to the user event ha
Provider:Azure Web PubSubAsyncAPI: v2.6.0Spec: Azure Web PubSubOperations: 2Messages: 12
Channel address
/client/hubs/{hub}
Parameters
hub — Hub name. Hubs provide logical isolation within an instance.
Operations
publish
clientSend
Messages a client sends to the service over the JSON pub/sub subprotocol.
subscribe
clientReceive
Messages the service sends back to the client.
Messages
joinGroup
Client asks the service to add the connection to a group.
Content-Type: application/json
leaveGroup
Client asks the service to remove the connection from a group.
Content-Type: application/json
sendToGroup
Client publishes a message to all connections in a group.
Content-Type: application/json
event
Client sends a custom user event that the service forwards to
the upstream event handler as a CloudEvents request with
`ce-type: azure.webpubsub.user.`.
Content-Type: application/json
ping
Client liveness check.
Content-Type: application/json
sequenceAck
Acknowledgement of a `sequenceId` delivered on an inbound
message. Required for the `json.reliable.webpubsub.azure.v1`
subprotocol so the service can release in-flight messages.
Content-Type: application/json
ack
Service response to a client request that carried `ackId`.
Clients should inspect `success` before reading `error`.
Content-Type: application/json
messageFromGroup
Data message delivered to the client because a publisher (REST
API, server SDK, or another subprotocol client) sent it to a
group the client has joined.
Content-Type: application/json
messageFromServer
Data message delivered to the client because the server (REST
API or server SDK) targeted this connection, the user, or all
connections.
Content-Type: application/json
systemConnected
Service notifies the client that the WebSocket handshake
succeeded. Reliable subprotocol additionally carries
`reconnectionToken` for use on session recovery.
Content-Type: application/json
systemDisconnected
Service notifies the client that the connection was closed by
the server or declined by the service.
Content-Type: application/json
pong
Service response to a `ping` request.
Content-Type: application/json
About AsyncAPI
The AsyncAPI specification describes event-driven APIs the way OpenAPI describes request/response APIs. A channel is the named pipe — a webhook URL, a Kafka topic, a WebSocket route, an MQTT subject — that producers and consumers publish or subscribe to. Each channel carries one or more messages with structured payloads, and an operation declares whether a given party sends or receives on that channel.