FAQ for Python-Asyncio SDK

Check out the frequently asked questions about the PubNub Python-Asyncio SDK.

Can I use the synchronous Python client alongside Asyncio?

Yes. Use the PubNub client for synchronous workflows and PubNubAsyncio for asynchronous workflows. Keep the clients initialized separately to avoid event loop conflicts.

Why is a user ID required?

The User ID uniquely identifies the client (end user, device, or server). Set and persist a stable value for the lifetime of the user or device; without it, the client cannot connect.

How do I enable Transport Layer Security?

Set pnconfig.ssl = True during configuration. This enables Transport Layer Security (TLS) for all communications with PubNub.

How do I choose a custom HTTP request handler?

Provide custom_request_handler when initializing PubNubAsyncio. If not specified, the SDK checks the PUBNUB_ASYNC_REQUEST_HANDLER environment variable and defaults to AsyncHttpxRequestHandler if unset or invalid.

Why am I not receiving messages after subscribing?

Messages published before the subscribe() call are not delivered by default. Ensure your app subscribes before publishing, or use features like history to retrieve previous messages when applicable.

Can I subscribe to multiple channels at once?

Yes. Use a SubscriptionSet to manage multiple Subscriptions together, or use wildcard subscriptions or channel groups where supported.

How do I filter messages server-side?

Use pnconfig.filter_expression to set a filter expression. The Stream Controller add-on must be enabled for your keyset.

How do I grant access with Access Manager?

Use the secret_key only on secure server-side platforms. The client signs Access Manager messages with the secret_key. Never expose this key in client-side code.

How do I troubleshoot connection issues?

Check status events such as PNConnectionErrorCategory and PNUnexpectedDisconnectCategory. For details, refer to Status Events in the Asyncio documentation.