Configuration API for Swift Native SDK

Use this configuration object to define how a PubNub instance behaves.

Initializer(s)

Create a configuration with your Publish and Subscribe Keys.

Privacy

MAU billing tracks users (Device and MAU) for analytics and billing. PubNub does not track customers using transactions with random UUIDs/UserIDs.

Method(s)

To initialize PubNub, use:

PubNubConfiguration(
  publishKey: String?,
  subscribeKey: String,
  userId: String,
  cryptoModule: CryptoModule? = nil,
  authKey: String? = nil,
  authToken: String? = nil,
  useSecureConnections: Bool = true,
  origin: String = "ps.pndsn.com",
  useInstanceId: Bool = false,
  useRequestId: Bool = false,
  automaticRetry: AutomaticRetry? = .default,
  durationUntilTimeout: UInt = 300,
  heartbeatInterval: UInt = 0,
  supressLeaveEvents: Bool = false,

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* required

Parameter	Description
publishKey Type: String? Default: nil	Specifies the PubNub Publish Key to be used when publishing messages to a channel.
subscribeKey * Type: String Default: nil	Specifies the PubNub Subscribe Key to be used when subscribing to a channel.
userId * Type: String Default: n/a	userId to use. You should set a unique identifier for the user or the device that connects to PubNub. It's a UTF-8 encoded string of up to 92 alphanumeric characters. If you don't set the userId, you won't be able to connect to PubNub.
cryptoModule Type: CryptoModule? Default: nil	The cryptography module used for encryption and decryption of messages and files. Takes the cipherKey parameter as argument. For more information, refer to the cryptoModule section.
authKey Type: String? Default: nil	If Access Manager is enabled, client will use authKey on all requests.
authToken Type: String? Default: nil	If Access Manager is enabled, client will use authToken instead of authKey on all requests.
useSecureConnections Type: Bool Default: true	If true, requests will be made over HTTPS; otherwise they will use HTTP (for cases when HTTPS might not be necessary or feasible, like development or testing purposes). You will still need to disable ATS for the system to allow insecure network traffic. See Apple's documentation for further details.
origin Type: String Default: "ps.pndsn.com"	Domain name used for requests. To request a custom domain, contact support and follow the request process.
useInstanceId Type: Bool Default: false	Whether a PubNub object instanceId should be included on outgoing requests.
useRequestId Type: Bool Default: false	Whether a request identifier should be included on outgoing requests.
automaticRetry Type: AutomaticRetry? Default: ReconnectionPolicy.exponential (subscribe only)	Custom reconnection configuration parameters. For more information, refer to the automaticRetry section.
durationUntilTimeout Type: Int Default: 300	Defines how long the server considers the client alive for presence. This property works similarly to the concept of long polling by sending periodic requests to the PubNub server every 300 seconds by default. These requests ensure the client remains active on subscribed channels. If no heartbeat is received within the timeout period, the client is marked inactive, triggering a "timeout" event on the presence channel. Minimum value is 20.
heartbeatInterval Type: UInt Default: 0	Specifies how often the client will send heartbeat signals to the server. This property offers more granular control over client activity tracking than durationUntilTimeout. Configure this property to achieve a shorter presence timeout if needed, with the interval typically recommended to be (durationUntilTimeout / 2) - 1. The default value is 0 and it means that the SDK doesn't send explicit heartbeat messages to the server. Due to server constraints, don't set the value below 3 when configuring this parameter.
suppressLeaveEvents Type: Bool Default: false	Whether to send out the leave requests.
requestMessageCountThreshold Type: UInt Default: 100	The number of messages into the payload before emitting RequestMessageCountExceeded.
filterExpression Type: String? Default: nil	PSV2 feature to subscribe with a custom filter expression.
enableEventEngine Type: Bool Default: true	Whether to use the recommended standardized workflows for subscribe and presence, optimizing how the SDK internally handles these operations and which statuses it emits.
maintainPresenceState Type: Bool Default: true	This option works only when enableEventEngine is set to true. Whether the custom presence state information set using pubnub.setPresence() should be sent every time the SDK sends a subscribe call.
cipherKey Type: Crypto? Default: nil	This way of setting this parameter is deprecated, pass it to cryptoModule instead. If set, all communication will be encrypted with this key.
uuid * Type: String Default: n/a	This parameter is deprecated, use userId instead. UUID to use. You should set a unique UUID to identify the user or the device that connects to PubNub. If you don't set the UUID, you won't be able to connect to PubNub.

cryptoModule

cryptoModule encrypts and decrypts messages and files. From 6.1.0, you can choose the algorithms.

Each SDK includes two options: legacy 128-bit encryption and recommended 256-bit AES-CBC. For background, see Message Encryption and File Encryption.

If you don't set cryptoModule and have cipherKey in PubNub config, the client uses legacy encryption.

For configuration details, utilities, and examples, see Encryption.

Legacy encryption with 128-bit cipher key entropy

You don't have to change your encryption configuration if you want to keep using the legacy encryption. If you want to use the recommended 256-bit AES-CBC encryption, you must explicitly set that in PubNub config.

automaticRetry

automaticRetry lets the client retry requests automatically. It has these parameters:

Parameter	Description
retryLimit Type: UInt	Maximum number of times a request can be retried before failing.
policy Type: ReconnectionPolicy	The policy to be used. Available values include: ReconnectionPolicy.linear(delay) ReconnectionPolicy.exponential(minDelay, maxDelay) ReconnectionPolicy.exponential is the default value for subscribe connections.
retryableHTTPStatusCodes Type: Set<Int>	One or more HTTP status codes for which the retry policy will be applied.
retryableURLErrorCode Type: Set<URLError.Code>	One or more URL error codes for which the retry policy will be applied.
excluded Type: [AutomaticRetry.Endpoint]	One or more endpoints for which the retry policy won't be applied.

For more information, refer to SDK connection lifecycle.

Request configuration

Use PubNub.RequestConfiguration to customize one request without changing global settings.

* required

Parameter	Description
customSession Type: SessionReplaceable? Default: nil	A custom network session that implements the SessionReplaceable protocol, which provides session management capabilities including request routing, task execution, and session lifecycle control.
customConfiguration Type: RouterConfiguration? Default: nil	The endpoint configuration used by the request.
responseQueue Type: DispatchQueue Default: n/a	The queue that will be used for dispatching a response.

SessionReplaceable

SessionReplaceable defines a custom network session interface. It manages routing, task execution, and the session lifecycle.

Property	Description
sessionID Type: UUID	The unique identifier for the session object
session Type: URLSessionReplaceable	The underlying URLSession used to execute network tasks
sessionQueue Type: DispatchQueue	The dispatch queue used to execute session operations
defaultRequestOperator Type: RequestOperator?	The default request operator attached to every request (settable)
sessionStream Type: SessionStream?	Optional session stream for real-time communication (settable)

RouterConfiguration

RouterConfiguration defines the base settings for PubNub endpoints. It includes authentication, connection security, encryption, and other behavior used to build and execute HTTP requests.

* required

Property	Description
publishKey Type: String?	Refer to the publishKey section.
subscribeKey Type: String	Refer to the subscribeKey section.
uuid Type: String	Unique device identifier for the client (equivalent to userId in Configuration)
useSecureConnections Type: Bool	Refer to the useSecureConnections section.
origin Type: String	Refer to the origin section. To request a custom domain, contact support and follow the request process.
authKey Type: String?	Refer to the authKey section.
authToken Type: String?	Refer to the authToken section.
cryptoModule Type: CryptoModule?	Refer to the cryptoModule section.
useRequestId Type: Bool	Refer to the useRequestId section.
consumerIdentifiers Type: [String: String]	Key-value pairs identifying various consumers for request tracking
enableEventEngine Type: Bool	Refer to the enableEventEngine section.
maintainPresenceState Type: Bool	Refer to the maintainPresenceState section.
urlScheme Type: String	URL scheme derived from useSecureConnections ("https" or "http").
subscribeKeyExists Type: Bool	Whether subscribeKey is valid and not empty.
publishKeyExists Type: Bool	Whether publishKey is valid and not empty.

DispatchQueue

DispatchQueue specifies which queue handles response callbacks.

Method	Description
currentLabel Type: String	Returns the label of the current DispatchQueue or "Unknown Queue" if no label was set

Official Apple Documentation

For standard DispatchQueue properties and methods, refer to Apple's DispatchQueue documentation.

Sample code

Initialize the PubNub client API

Required User ID

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

Other examples

Initialization for a read-only client

If the client only reads and never publishes, set publishKey to nil:

Required User ID

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

Event listeners

PubNub SDKs provide several sources for real-time updates:

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

To work with these sources, the SDK provides local representations of server entities, so you can subscribe and add handlers per entity. For details, see Publish & Subscribe.

Overriding PubNub configuration

You can change PubNubConfiguration properties until you set the configuration on a PubNub instance. After that, the settings are locked. To change them, create a new PubNub instance.

Filter

Update the filter expression without creating a new instance: