Configuration API for Python-Asyncio SDK

The Python-Asyncio Software Development Kit (SDK) configuration reference for building real-time applications on PubNub, including basic usage and sample code.

Configuration

The PNConfiguration instance stores user-provided settings that control client behavior. The configuration includes properties for security, connectivity, and subscription features.

Method(s)

Create a configuration instance using the Python-Asyncio SDK:

pnconfig = PNConfiguration()

* required

Parameter	Description
subscribe_key * Type: String Default: n/a	The Subscribe Key from the Admin Portal.
publish_key Type: String Default: None	The Publish Key from the Admin Portal (required only for publishing).
secret_key Type: String Default: None	The secret_key (required only for configuring or revealing permissions with Access Manager).
cipher_key Type: String Default: None	If set, all communications to and from PubNub are encrypted.
user_id * Type: String Default: n/a	The User ID used to identify the client. Set a unique value per user or device. It's a UTF-8 encoded string of up to 92 alphanumeric characters. If you do not set user_id, the client cannot connect.
auth_key Type: String Default: None	If Access Manager is enabled, the client includes this auth_key in restricted requests.
ssl Type: Boolean Default: True	Use Transport Layer Security (TLS). Set to True to enable encrypted transport.
connect_timeout Type: Int Default: 5	Time in seconds to wait before giving up on establishing a connection.
subscribe_request_timeout Type: Int Default: 310	Time in seconds to keep the subscribe loop running before disconnecting.
non_subscribe_request_timeout Type: Int Default: 10	Time in seconds to wait for a server response on non-subscribe operations.
filter_expression Type: String Default: None	Enables subscribing with a custom filter expression.
heartbeat_notification_options Type: PNHeartbeatNotificationOptions Default: PNHeartbeatNotificationOptions.FAILURES	Heartbeat notifications. By default, the SDK alerts on failed heartbeats. Other options include all heartbeats or no heartbeats.
reconnect_policy Type: PNReconnectionPolicy Default: PNReconnectionPolicy.NONE	Set to linear for automatic reconnects, none to disable, or exponential for exponential backoff.
origin Type: String Default: ps.pndsn.com	Custom origin if required. To request a custom domain, contact support and follow the request process.
suppress_leave_events Type: Boolean Default: False	If True, the client does not send presence leave events during unsubscribe.
enable_subscribe Type: Boolean Default: True	Enable or disable the subscribe loop. When enabled, extra loops are started and must be stopped using pubnub.stop().
daemon Type: Boolean Default: False	If True, spawned threads do not keep the application running after SIGTERM.
disable_token_manager Type: Boolean Default: False	If True, the Token Manager System (TMS) is disabled. Requests are not authorized using tokens even if available.
use_random_initialization_vector Type: Boolean Default: True	If True, a random initialization vector (IV) is used for all requests. If False, a fixed IV is used for all requests except file upload.
uuid * Type: String Default: n/a	Deprecated. Use user_id instead.

Disabling random initialization vector

Disable random initialization vector (IV) only for backward compatibility (<5.1.0) with existing applications. Never disable random IV on new applications.

Sample code

Required User ID

Always set the user_id to uniquely identify the user or device that connects to PubNub. This user_id should be persisted, and should remain unchanged for the lifetime of the user or the device. If you don't set the user_id, you won't be able to connect to PubNub.

Reference code

This example is a self-contained code snippet ready to be run. It includes necessary imports and executes methods with console logging. Use it as a reference when working with other examples in this document.

import os
from pubnub.pnconfiguration import PNConfiguration
from pubnub.enums import PNHeartbeatNotificationOptions


# Configuration for the client instance
pn_configuration = PNConfiguration()

# Set configuration values
pn_configuration.subscribe_key = os.getenv('PUBNUB_SUBSCRIBE_KEY', 'demo')  # required
pn_configuration.publish_key = os.getenv('PUBNUB_PUBLISH_KEY', 'demo')  # only required if publishing
pn_configuration.secret_key = os.getenv('PUBNUB_SECRET_KEY', 'my_secret_key')  # optional
pn_configuration.user_id = os.getenv('PUBNUB_USER_ID', 'my_custom_user_id')  # must be set
pn_configuration.auth_key = os.getenv('PUBNUB_AUTH_KEY', 'my_auth_key')  # optional
pn_configuration.ssl = True

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Initialization

Add the SDK to your project, then initialize the client.

Description

This function initializes the client context. Call it before using any API to establish account-level credentials such as publish_key and subscribe_key.

Method(s)

Initialize with the Python-Asyncio SDK:

pubnub = PubNubAsyncio(pn_configuration, custom_event_loop, subscription_manager, *, custom_request_handler)

* required

Parameter	Description
pn_configuration * Type: PNConfiguration	See Configuration for details.
custom_event_loop Type: AbstractEventLoop	Use a custom Asyncio event loop instance.
subscription_manager Type: EventEngineSubscriptionManager	Use standardized workflows for subscribe and presence.
custom_request_handler Type: subclass of BaseRequestHandler	The custom HTTP request handler. For more information, refer to Custom request handler. Default is AsyncHttpxRequestHandler.

Environment variables

You can turn on certain features using environment variables with inline declaration:

PN_ENABLE_EVENT_ENGINE=True PN_MAINTAIN_PRESENCE_STATE=True PUBNUB_ASYNC_REQUEST_HANDLER=AsyncAiohttpRequestHandler python path/to/your/file.py 

or by exporting environment variables to your system, and then running the script:

export PN_ENABLE_EVENT_ENGINE=True
export PN_MAINTAIN_PRESENCE_STATE=True
export PUBNUB_ASYNC_REQUEST_HANDLER=AsyncAiohttpRequestHandler

python path/to/your/file.py

Flag	Description
PN_ENABLE_EVENT_ENGINE	Whether to use the recommended standardized workflows for subscribe and presence, optimizing how the SDK internally handles these operations and which statuses it emits.
PN_MAINTAIN_PRESENCE_STATE	Whether the custom presence state information set using pubnub.set_state() should be sent every time the SDK sends a subscribe call.
PUBNUB_ASYNC_REQUEST_HANDLER	The library for sending HTTP requests.

To Initialize PubNub you can use the following method(s) in the Python SDK:

pubnub = PubNub(pn_configuration, custom_request_handler)

* required

Parameter	Description
pn_configuration * Type: PNConfiguration Default: n/a	The configuration object. For more details, refer to Configuration.
custom_request_handler Type: subclass of BaseRequestHandler Default: HttpxRequestHandler	The optional custom HTTP request handler. For more information, refer to Custom request handler.

Custom request handler

The custom_request_handler option selects the library used for sending HTTP requests.

If you do not specify this parameter, the Python-Asyncio SDK first checks the value of the PUBNUB_ASYNC_REQUEST_HANDLER environment variable. If you do not set the variable or its value is not a subclass of BaseRequestHandler, the SDK defaults to AsyncHttpxRequestHandler.

Class	Description
AsyncAiohttpRequestHandler	Python SDK asynchronous requests handler based on the requests HTTP library.
AsyncHttpxRequestHandler	Python SDK asynchronous requests handler based on the httpx HTTP library.

Sample code

Initialize the client API

Required User ID

Always set the user_id to uniquely identify the user or device that connects to PubNub. This user_id should be persisted, and should remain unchanged for the lifetime of the user or the device. If you don't set the user_id, you won't be able to connect to PubNub.

from pubnub.pnconfiguration import PNConfiguration
from pubnub.pubnub_asyncio import PubNubAsyncio

pnconfig = PNConfiguration()
pnconfig.subscribe_key = "my_subkey"
pnconfig.publish_key = "my_pubkey"
pnconfig.ssl = True
pnconfig.user_id = "my_custom_user_id"
pubnub = PubNubAsyncio(pnconfig)

Returns

It returns the PubNub instance for invoking PubNub APIs like publish(), subscribe(), history(), here_now(), etc.

Other examples

Use a custom request handler

You can set a custom request handler by specifying one of the available handlers during initialization.

Required User ID

Always set the user_id to uniquely identify the user or device that connects to PubNub. This user_id should be persisted, and should remain unchanged for the lifetime of the user or the device. If you don't set the user_id, you won't be able to connect to PubNub.

from pubnub.pnconfiguration import PNConfiguration
from pubnub.pubnub_asyncio import PubNubAsyncio
from pubnub.request_handlers.async_aiohttp import AsyncAiohttpRequestHandler

pnconfig = PNConfiguration()
pnconfig.subscribe_key = "my_subkey"
pnconfig.publish_key = "my_pubkey"
pnconfig.ssl = True
pnconfig.user_id = "my_custom_user_id"
pubnub = PubNubAsyncio(pnconfig)


pubnub = PubNub(pnconfig, custom_request_handler=AsyncAiohttpRequestHandler)

Initialize a non-secure client

Required User ID

Always set the user_id to uniquely identify the user or device that connects to PubNub. This user_id should be persisted, and should remain unchanged for the lifetime of the user or the device. If you don't set the user_id, you won't be able to connect to PubNub.

from pubnub.pnconfiguration import PNConfiguration
from pubnub.pubnub_asyncio import PubNubAsyncio

pnconfig = PNConfiguration()
pnconfig.subscribe_key = "my_subkey"
pnconfig.publish_key = "my_pubkey"
pnconfig.ssl = False
pnconfig.user_id = "my_custom_user_id"
pubnub = PubNubAsyncio(pnconfig)

Initialize a read-only client

In the case where a client will only read messages and never publish to a channel, you can simply omit the publish_key when initializing the client:

Required User ID

Always set the user_id to uniquely identify the user or device that connects to PubNub. This user_id should be persisted, and should remain unchanged for the lifetime of the user or the device. If you don't set the user_id, you won't be able to connect to PubNub.

from pubnub.pnconfiguration import PNConfiguration
from pubnub.pubnub_asyncio import PubNubAsyncio

pnconfig = PNConfiguration()
pnconfig.subscribe_key = "my_subkey"

pubnub = PubNubAsyncio(pnconfig)

Use a custom user ID

Set a custom user_id to identify your users.

Required User ID

Always set the user_id to uniquely identify the user or device that connects to PubNub. This user_id should be persisted, and should remain unchanged for the lifetime of the user or the device. If you don't set the user_id, you won't be able to connect to PubNub.

from pubnub.pnconfiguration import PNConfiguration
from pubnub.pubnub import PubNub

pnconfig = PNConfiguration()

pnconfig.subscribe_key = 'mySubscribeKey'
pnconfig.publish_key = 'myPublishKey'
pnconfig.user_id = "my_custom_user_id"

pubnub = PubNub(pnconfig)

Initialize with SSL enabled

This example demonstrates how to enable Transport Layer Security (TLS) with ssl. Initialize the client with ssl set to True. The API handles encryption for you; subscribe and publish as usual.

Required User ID

Always set the user_id to uniquely identify the user or device that connects to PubNub. This user_id should be persisted, and should remain unchanged for the lifetime of the user or the device. If you don't set the user_id, you won't be able to connect to PubNub.

from pubnub.pnconfiguration import PNConfiguration
from pubnub.pubnub_asyncio import PubNubAsyncio

pnconfig = PNConfiguration()
pnconfig.subscribe_key = "my_subkey"
pnconfig.publish_key = "my_pubkey"
pnconfig.ssl = True
pnconfig.user_id = "my_custom_user_id"
pubnub = PubNubAsyncio(pnconfig)

Initialize with Access Manager

Requires Access Manager add-on

This method requires that the Access Manager add-on is enabled for your key in the Admin Portal. Read the support page on enabling add-on features on your keys.

Secure your secret_key

Anyone with the secret_key can grant and revoke permissions to your app. Never let your secret_key be discovered, and to only exchange it / deliver it securely. Only use the secret_key on secure server-side platforms.

When you init with secret_key, you get root permissions for the Access Manager. With this feature you don't have to grant access to your servers to access channel data. The servers get all access on all channels.

For applications that will administer Access Manager permissions, the API is initialized with the secret_key as in the following example:

Required User ID

Always set the user_id to uniquely identify the user or device that connects to PubNub. This user_id should be persisted, and should remain unchanged for the lifetime of the user or the device. If you don't set the user_id, you won't be able to connect to PubNub.

from pubnub.pnconfiguration import PNConfiguration
from pubnub.pubnub_asyncio import PubNubAsyncio

pnconfig = PNConfiguration()
pnconfig.subscribe_key = "my_subkey"
pnconfig.publish_key = "my_pubkey"
pnconfig.secret_key = "my_secretkey"
pnconfig.user_id = "my_custom_user_id"
pnconfig.ssl = True

pubnub = PubNubAsyncio(pnconfig)

Now that the pubnub object is instantiated, the client can access the Access Manager functions. The pubnub object uses the secret_key to sign all Access Manager messages to the PubNub network.

Initialize with a custom event loop

Required User ID

Always set the user_id to uniquely identify the user or device that connects to PubNub. This user_id should be persisted, and should remain unchanged for the lifetime of the user or the device. If you don't set the user_id, you won't be able to connect to PubNub.

from pubnub.pnconfiguration import PNConfiguration
from pubnub.pubnub_asyncio import PubNubAsyncio

pnconfig = PNConfiguration()
pnconfig.subscribe_key = "my_subkey"
pnconfig.publish_key = "my_pubkey"

pubnub = PubNubAsyncio(pnconfig, custom_event_loop=my_event_loop)

Event listeners

PubNub SDKs provide several sources for real-time updates:

• The PubNub client can receive updates from all subscriptions, including all channels, channel groups, channel metadata, and users.
• The Subscription object can receive updates only for the object for which it was created: a channel, a channel group, channel metadata, or a user.
• The SubscriptionsSet object can receive updates for all objects for which a list of subscription objects was created.

To work with these real-time update sources, PubNub SDKs provide local representations of server entities so that you can subscribe and add listeners on a per-entity basis. For more information, refer to Publish & Subscribe.

Filter expression

Requires Stream Controller add-on

This method requires that the Stream Controller add-on is enabled for your key in the Admin Portal. Read the support page on enabling add-on features on your keys.

Stream filtering allows a subscriber to apply a filter to receive only messages that meet the filter conditions. The message filter is set by the subscribing client and applied on the server to prevent unwanted messages from reaching the subscriber.

Use the filter_expression property to set or get the message filter. To learn more about filtering, refer to the Publish Messages documentation.

Method(s)

Set Filter Expression

The property accepts a string.

Get Filter Expression

The property returns a string.

Sample code

Set filter expression

Required User ID

Always set the user_id to uniquely identify the user or device that connects to PubNub. This user_id should be persisted, and should remain unchanged for the lifetime of the user or the device. If you don't set the user_id, you won't be able to connect to PubNub.

from pubnub.pnconfiguration import PNConfiguration

pnconfig = PNConfiguration()
pnconfig.filter_expression = "such=wow"

Get filter expression

filter = pnconfig.filter_expression