Azure Web PubSub Service SDK for Python

Real-time messaging with WebSocket connections at scale.

Installation

Service SDK (server-side)

pip install azure-messaging-webpubsubservice

Client SDK (for Python WebSocket clients)

pip install azure-messaging-webpubsubclient

Environment Variables

AZURE_WEBPUBSUB_CONNECTION_STRING=Endpoint=https://<name>.webpubsub.azure.com;AccessKey=... AZURE_WEBPUBSUB_HUB=my-hub

Service Client (Server-Side)

Authentication

from azure.messaging.webpubsubservice import WebPubSubServiceClient

Connection string

client = WebPubSubServiceClient.from_connection_string( connection_string=os.environ["AZURE_WEBPUBSUB_CONNECTION_STRING"], hub="my-hub" )

Entra ID

from azure.identity import DefaultAzureCredential

client = WebPubSubServiceClient( endpoint="https://<name>.webpubsub.azure.com", hub="my-hub", credential=DefaultAzureCredential() )

Generate Client Access Token

Token for anonymous user

token = client.get_client_access_token() print(f"URL: {token['url']}")

Token with user ID

token = client.get_client_access_token( user_id="user123", roles=["webpubsub.sendToGroup", "webpubsub.joinLeaveGroup"] )

Token with groups

token = client.get_client_access_token( user_id="user123", groups=["group1", "group2"] )

Send to All Clients

Send text

client.send_to_all(message="Hello everyone!", content_type="text/plain")

Send JSON

client.send_to_all( message={"type": "notification", "data": "Hello"}, content_type="application/json" )

Send to User

client.send_to_user( user_id="user123", message="Hello user!", content_type="text/plain" )

Send to Group

client.send_to_group( group="my-group", message="Hello group!", content_type="text/plain" )

Send to Connection

client.send_to_connection( connection_id="abc123", message="Hello connection!", content_type="text/plain" )

Group Management

Add user to group

client.add_user_to_group(group="my-group", user_id="user123")

Remove user from group

client.remove_user_from_group(group="my-group", user_id="user123")

Add connection to group

client.add_connection_to_group(group="my-group", connection_id="abc123")

Remove connection from group

client.remove_connection_from_group(group="my-group", connection_id="abc123")

Connection Management

Check if connection exists

exists = client.connection_exists(connection_id="abc123")

Check if user has connections

exists = client.user_exists(user_id="user123")

Check if group has connections

exists = client.group_exists(group="my-group")

Close connection

client.close_connection(connection_id="abc123", reason="Session ended")

Close all connections for user

client.close_all_connections(user_id="user123")

Grant/Revoke Permissions

from azure.messaging.webpubsubservice import WebPubSubServiceClient

Grant permission

client.grant_permission( permission="joinLeaveGroup", connection_id="abc123", target_name="my-group" )

Revoke permission

client.revoke_permission( permission="joinLeaveGroup", connection_id="abc123", target_name="my-group" )

Check permission

has_permission = client.check_permission( permission="joinLeaveGroup", connection_id="abc123", target_name="my-group" )

Client SDK (Python WebSocket Client)

from azure.messaging.webpubsubclient import WebPubSubClient

client = WebPubSubClient(credential=token["url"])

Event handlers

@client.on("connected") def on_connected(e): print(f"Connected: {e.connection_id}")

@client.on("server-message") def on_message(e): print(f"Message: {e.data}")

@client.on("group-message") def on_group_message(e): print(f"Group {e.group}: {e.data}")

Connect and send

client.open() client.send_to_group("my-group", "Hello from Python!")

Async Service Client

from azure.messaging.webpubsubservice.aio import WebPubSubServiceClient from azure.identity.aio import DefaultAzureCredential

async def broadcast(): credential = DefaultAzureCredential() client = WebPubSubServiceClient( endpoint="https://<name>.webpubsub.azure.com", hub="my-hub", credential=credential )

await client.send_to_all("Hello async!", content_type="text/plain")

await client.close()
await credential.close()

Client Operations

Operation Description

get_client_access_token

Generate WebSocket connection URL

send_to_all

Broadcast to all connections

send_to_user

Send to specific user

send_to_group

Send to group members

send_to_connection

Send to specific connection

add_user_to_group

Add user to group

remove_user_from_group

Remove user from group

close_connection

Disconnect client

connection_exists

Check connection status

Best Practices

• Use roles to limit client permissions

• Use groups for targeted messaging

• Generate short-lived tokens for security

• Use user IDs to send to users across connections

• Handle reconnection in client applications

• Use JSON content type for structured data

• Close connections gracefully with reasons