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

1. Use roles to limit client permissions
2. Use groups for targeted messaging
3. Generate short-lived tokens for security
4. Use user IDs to send to users across connections
5. Handle reconnection in client applications
6. Use JSON content type for structured data
7. Close connections gracefully with reasons