--- source_url: https://www.pubnub.com/docs/sdks/cocoa-objective-c/api-reference/configuration title: Configuration API for Cocoa Objective-C SDK updated_at: 2026-05-25T11:27:27.120Z --- > Documentation Index > For a curated overview of PubNub documentation, see: https://www.pubnub.com/docs/llms.txt > For the full list of all documentation pages, see: https://www.pubnub.com/docs/llms-full.txt # Configuration API for Cocoa Objective-C SDK Cocoa complete API reference for building real-time applications on PubNub, including basic usage and sample code. ## Configuration `PNConfiguration` stores user-provided settings that define how the client behaves. The configuration includes properties to fine-tune the PubNub client. ### Method(s) To create `configuration` instance you can use the following function in the Cocoa SDK: ```objectivec + (instancetype)configurationWithPublishKey:(NSString *)publishKey subscribeKey:(NSString *)subscribeKey; ``` | Parameter | Type | Required | Default | Description | | --- | --- | --- | --- | --- | | publishKey | NSString | Yes | | Key which allow client to use data push API. | | subscribeKey | NSString | Yes | | Key which allow client to subscribe on live feeds pushed from PubNub service. | | heartbeatNotificationOptions | PNHeartbeatNotificationOptions | Optional | | These are bitmask options, they can be combined. When client instances are notified about heartbeat operations, this happens through the `PNObjectEventListener` callback for statuses. `PNHeartbeatNotifySuccess`: explicitly tells client to notify on successful heartbeat operations. `PNHeartbeatNotifyFailure`: explicitly tells client to notify on failed heartbeat operations (default is only this option) `PNHeartbeatNotifyAll`: This is a combination of `PNHeartbeatNotifySuccess` and `PNHeartbeatNotifyFailure` `PNHeartbeatNotifyNone`: This means the client will not provide any callback notifications for heartbeat operations. | | stripMobilePayload | BOOL | Optional | | Stores whether client should strip out received messages (real-time and history) from data which has been appended by client (like mobile payload for mobile push notifications). | | cipherKey | NSString | Optional | | `Key` which is used to encrypt `messages` pushed to `PubNub` service and decrypt `messages` received from live feeds on which client subscribed at this moment. | | subscribeMaximumIdleTime | NSTimeInterval | Optional | | Maximum number of seconds which client should wait for events from live feed. Default `310`. | | nonSubscribeRequestTimeout | NSTimeInterval | Optional | | Number of seconds which is used by client during non-subscription operations to check whether response potentially failed with `timeout` or not. Default `10`. | | presenceHeartbeatValue | NSInteger | Optional | | 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](https://www.pubnub.com/docs/general/presence/overview). | | presenceHeartbeatInterval | NSInteger | Optional | | Specifies how often the client will send heartbeat signals to the server. This property offers more granular control over client activity tracking than `presenceHeartbeatValue`. Configure this property to achieve a shorter presence timeout if needed, with the interval typically recommended to be `(presenceHeartbeatValue / 2) - 1`. Due to server constraints, don't set the value below `3`. | | keepTimeTokenOnListChange | BOOL | Optional | | Whether client should keep previous timetoken when subscribe on new set of remote data objects live feeds. Default `YES`. | | catchUpOnSubscriptionRestore | BOOL | Optional | | Whether client should try to catch up for events which occurred on previously subscribed remote data objects feed while client was off-line. Default `YES`. | | applicationExtensionSharedGroupIdentifier | NSString | Optional | | Reference on group identifier which is used to share request cache between application extension and it's containing application. This property should be set to valid registered group only if `PubNub` client is used inside of application's extension (iOS 8.0+, macOS 10.10+). | | requestMessageCountThreshold | NSUInteger | Optional | | Number of maximum expected messages from `PubNub` service in single response. | | maximumMessagesCacheSize | NSUInteger | Optional | | Messages de-duplication cache size Default `100`. | | completeRequestsBeforeSuspension | BOOL | Optional | | Whether client should try complete all API call which is done before application will be completely suspended. Default `YES`. | | suppressLeaveEvents | BOOL | Optional | | If `YES`, the client shouldn't send presence leave events during the unsubscribe process. | | origin | NSString | Optional | | If a custom domain is required, SDK accepts it here. To request a custom domain, contact support and follow the [request process](https://www.pubnub.com/docs/general/setup/data-security#request-process). | ### Sample code :::note Required UUID Always set the `UUID` to uniquely identify the user or device that connects to PubNub. This `UUID` should be persisted, and should remain unchanged for the lifetime of the user or the device. If you don't set the `UUID`, you won't be able to connect to PubNub. ::: ```objectivec PNConfiguration *config = [PNConfiguration configurationWithPublishKey:@"demo" subscribeKey:@"demo"]; config.uuid = @"myUniqueUUID"; self.client = [PubNub clientWithConfiguration:config]; [self.client addListener:self]; ``` ### Returns Configured and ready to use client configuration instance. ### Other examples #### Configure heartbeat notifications ##### PNConfiguration ```objectivec PNConfiguration *config = [PNConfiguration configurationWithPublishKey:@"" subscribeKey:@""]; /** This is where you need to adjust the PNConfiguration object for the types of heartbeat notifications you want. This is a bitmask of options located at https://github.com/pubnub/objective-c/blob/1f1c7a41a3bd8c32b644a6ad98fe179d45397c2b/PubNub/Misc/PNStructures.h#L24 */ config.heartbeatNotificationOptions = PNHeartbeatNotifyAll; self.client = [PubNub clientWithConfiguration:config]; [self.client addListener:self]; ``` ##### Listener ```objectivec - (void)client:(PubNub *)client didReceiveStatus:(PNStatus *)status { if (status.operation == PNHeartbeatOperation) { /** Heartbeat operations can in fact have errors, so it is important to check first for an error. For more information on how to configure heartbeat notifications through the status PNObjectEventListener callback, consult http://www.pubnub.com/docs/sdks/objective-c/api-reference/configuration#configuration_basic_usage */ if (!status.isError) { /* Heartbeat operation was successful. */ } else { /* There was an error with the heartbeat operation, handle here. */ } } } ``` ## Initialization #### Include the SDK with CocoaPods Install the CocoaPods gem by following the procedure in the [Getting Started guide](https://www.pubnub.com/docs/sdks/cocoa-objective-c). To add the PubNub SDK to your project with CocoaPods, complete these tasks: 1. Create new Xcode project. 2. Create Podfile in new Xcode project root folder 1touch Podfile 3. The PubNub client can be added as module (only with a deployment target of OS X 10.9 and above): 1source 'https://github.com/CocoaPods/Specs.git'2platform :osx, "10.9"3use_frameworks!4 5target 'application-target-name' do6 pod "PubNub", "~> 4.1"7end If you have other pods to include, or other targets to add (like a test target), add those entries to this Podfile as well. See the CocoaPods documentation for more details on Podfile configuration. 4. Install your pods by running pod install via the command line from the directory that contains your Podfile. :::note Work within the workspace After installing your Pods, you should only be working within the workspace generated by CocoaPods or specified by you in Podfile. Always open the newly generated workspace file, not the original project file! ::: To be able to use PubNub SDK within your application code you need to import it. Import PubNub SDK headers in implementation files for classes where you need to use it using this import statement: ```objectivec #import ``` #### Complete application delegate configuration Add the PNObjectEventListener protocol to AppDelegate in implementation file to anonymous category: :::note Required UUID Always set the `UUID` to uniquely identify the user or device that connects to PubNub. This `UUID` should be persisted, and should remain unchanged for the lifetime of the user or the device. If you don't set the `UUID`, you won't be able to connect to PubNub. ::: ```objectivec #import @interface AppDelegate () // Stores reference on PubNub client to make sure what it won't be released. @property (nonatomic, strong) PubNub *client; @end ``` ### Description This function is used for initializing the PubNub Client API context. This function must be called before attempting to utilize any API functionality in order to establish account level credentials such as `publishKey` and `subscribeKey`. ### Method(s) To `Initialize` PubNub you can use the following method(s) in the Cocoa SDK: #### Initialize PubNub ```objectivec + (instancetype)clientWithConfiguration:(PNConfiguration *)configuration; ``` | Parameter | Description | | --- | --- | | `configuration` *Type: PNConfiguration | Reference on instance which store all user-provided information about how client should operate and handle events. | #### Initialize PubNub with callback queue ```objectivec + (instancetype)clientWithConfiguration:(PNConfiguration *)configuration callbackQueue:(dispatch_queue_t)callbackQueue; ``` | Parameter | Description | | --- | --- | | `configuration` *Type: PNConfiguration | Reference on instance which store all user-provided information about how client should operate and handle events. | | `callbackQueue`Type: dispatch_queue_t | Reference on queue which should be used by client for completion block and delegate calls. | ### Sample code #### Initialize the PubNub client API :::note Required UUID Always set the `UUID` to uniquely identify the user or device that connects to PubNub. This `UUID` should be persisted, and should remain unchanged for the lifetime of the user or the device. If you don't set the `UUID`, you won't be able to connect to PubNub. ::: ```objectivec PNConfiguration *configuration = [PNConfiguration configurationWithPublishKey:@"demo" subscribeKey:@"demo"]; configuration.TLSEnabled = YES; configuration.uuid = @"myUniqueUUID"; self.client = [PubNub clientWithConfiguration:configuration]; ``` ### Returns It returns the PubNub instance for invoking PubNub APIs like `publish`, `subscribeToChannels`, `historyForChannel`, `hereNowForChannel`, etc. ### Other examples #### Initialize the client :::note Required UUID Always set the `UUID` to uniquely identify the user or device that connects to PubNub. This `UUID` should be persisted, and should remain unchanged for the lifetime of the user or the device. If you don't set the `UUID`, you won't be able to connect to PubNub. ::: ```objectivec PNConfiguration *configuration = [PNConfiguration configurationWithPublishKey:@"demo" subscribeKey:@"demo"]; configuration.uuid = @"myUniqueUUID"; self.client = [PubNub clientWithConfiguration:configuration]; ``` #### Initialization for 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 `publishKey` when initializing the client: :::note Required UUID Always set the `UUID` to uniquely identify the user or device that connects to PubNub. This `UUID` should be persisted, and should remain unchanged for the lifetime of the user or the device. If you don't set the `UUID`, you won't be able to connect to PubNub. ::: ```objectivec PNConfiguration *configuration = [PNConfiguration configurationWithPublishKey:@"" subscribeKey:@"demo"]; self.client = [PubNub clientWithConfiguration:configuration]; ``` #### Use a custom UUID Set a custom `UUID` to identify your users. :::note Required UUID Always set the `UUID` to uniquely identify the user or device that connects to PubNub. This `UUID` should be persisted, and should remain unchanged for the lifetime of the user or the device. If you don't set the `UUID`, you won't be able to connect to PubNub. ::: ```objectivec PNConfiguration *configuration = [PNConfiguration configurationWithPublishKey:@"myPublishKey" subscribeKey:@"mySubscribeKey"]; configuration.uuid = @"myUniqueUUID"; self.client = [PubNub clientWithConfiguration:configuration]; ``` ## UUID This function is used to set a user ID on the fly. ### Method(s) To set `UUID` you can use the following method(s) in Cocoa SDK: ```objectivec @property (nonatomic, copy, setter = setUUID:) NSString *uuid; ``` ### Sample code :::note Required UUID Always set the `UUID` to uniquely identify the user or device that connects to PubNub. This `UUID` should be persisted, and should remain unchanged for the lifetime of the user or the device. If you don't set the `UUID`, you won't be able to connect to PubNub. ::: ```objectivec // User authorized and we need to update used UUID PNConfiguration *configuration = self.client.currentConfiguration; configuration.uuid = @"myUniqueUUID"; __weak __typeof(self) weakSelf = self; [self.client copyWithConfiguration:configuration completion:^(PubNub *client) { weakSelf.client = client; }]; ``` ### Other examples #### Creating a function to subscribe a unique channel name ```objectivec /** Subscription process results arrive to listener which should adopt to PNObjectEventListener protocol and registered using: */ [self.client addListener:self]; [self.client subscribeToChannels:@[[NSUUID UUID].UUIDString] withPresence:NO]; // Handle new message from one of channels on which client has been subscribed. - (void)client:(PubNub *)client didReceiveMessage:(PNMessageResult *)message { // Handle new message stored in message.data.message if (![message.data.channel isEqualToString:message.data.subscription]) { // Message has been received on channel group stored in message.data.subscription. } else { // Message has been received on channel stored in message.data.channel. } NSLog(@"Received message: %@ on channel %@ at %@", message.data.message, message.data.channel, message.data.timetoken); } // Handle subscription status change. - (void)client:(PubNub *)client didReceiveStatus:(PNStatus *)status { if (status.operation == PNSubscribeOperation) { // Check whether received information about successful subscription or restore. if (status.category == PNConnectedCategory || status.category == PNReconnectedCategory) { // Status object for those categories can be casted to `PNSubscribeStatus` for use below. PNSubscribeStatus *subscribeStatus = (PNSubscribeStatus *)status; if (subscribeStatus.category == PNConnectedCategory) { // This is expected for a subscribe, this means there is no error or issue whatsoever. } else { /** This usually occurs if subscribe temporarily fails but reconnects. This means there was an error but there is no longer any issue. */ } } else if (status.category == PNUnexpectedDisconnectCategory) { /** This is usually an issue with the internet connection, this is an error, handle appropriately retry will be called automatically. */ } // Looks like some kind of issues happened while client tried to subscribe or disconnected from // network. else { PNErrorStatus *errorStatus = (PNErrorStatus *)status; if (errorStatus.category == PNAccessDeniedCategory) { /** This means that Access Manager does allow this client to subscribe to this channel and channel group configuration. This is another explicit error. */ } else { /** More errors can be directly specified by creating explicit cases for other error categories of `PNStatusCategory` such as: `PNDecryptionErrorCategory`, `PNMalformedFilterExpressionCategory`, `PNMalformedResponseCategory`, `PNTimeoutCategory` or `PNNetworkIssuesCategory` */ } } } } ``` #### Initializing with a custom uuid :::note Required UUID Always set the `UUID` to uniquely identify the user or device that connects to PubNub. This `UUID` should be persisted, and should remain unchanged for the lifetime of the user or the device. If you don't set the `UUID`, you won't be able to connect to PubNub. ::: ```objectivec PNConfiguration *configuration = self.client.currentConfiguration; configuration.uuid = @"myUniqueUUID"; __weak __typeof(self) weakSelf = self; [self.client copyWithConfiguration:configuration completion:^(PubNub *client) { // Store reference on new client with updated configuration. weakSelf.client = client; }]; ``` #### Creating a unique auth_key for Access Manager on initialization ```objectivec PNConfiguration *configuration = self.client.currentConfiguration; configuration.authKey = [NSUUID UUID].UUIDString.lowercaseString; __weak __typeof(self) weakSelf = self; [self.client copyWithConfiguration:configuration completion:^(PubNub *client) { // Store reference on new client with updated configuration. weakSelf.client = client; }]; ``` ## Authentication key Setter and getter for users auth key. ### Method(s) #### Auth key ```objectivec @property (nonatomic, nullable, copy) NSString *authKey; ``` #### UUID ```objectivec @property (nonatomic, copy, setter = setUUID:) NSString *uuid; ``` ### Sample code #### Set auth key ```objectivec PNConfiguration *configuration = self.client.currentConfiguration; configuration.authKey = @"my_new_authkey"; __weak __typeof(self) weakSelf = self; [self.client copyWithConfiguration:configuration completion:^(PubNub *client) { // Store reference on new client with updated configuration. weakSelf.client = client; }]; ``` #### Get auth key ```objectivec // Request current client configuration and pull out authorisation key from it. NSString *authorizationKey = self.client.currentConfiguration.authKey; ``` ### Returns `Get Auth key` returns the `current authentication key`. ## Filter expression :::note Requires Stream Controller add-on This method requires that the *Stream Controller* add-on is enabled for your key in the [Admin Portal](https://admin.pubnub.com/). Read the [support page](https://support.pubnub.com/hc/en-us/articles/360051974791-How-do-I-enable-add-on-features-for-my-keys-) on enabling add-on features on your keys. ::: Stream filtering allows a subscriber to apply a filter to only receive messages that satisfy the conditions of the filter. The message filter is set by the subscribing client(s) but it is applied on the server side thus preventing unwanted messages (those that do not meet the conditions of the filter) from reaching the subscriber. To set or get message filters, you can use the following property. To learn more about filtering, refer to the [Publish Messages](https://www.pubnub.com/docs/general/messages/publish) documentation. ### Method(s) ```objectivec @property (nonatomic, nullable, copy) NSString *filterExpression; ``` ### Sample code #### Set filter expression :::note Required UUID Always set the `UUID` to uniquely identify the user or device that connects to PubNub. This `UUID` should be persisted, and should remain unchanged for the lifetime of the user or the device. If you don't set the `UUID`, you won't be able to connect to PubNub. ::: ```objectivec PNConfiguration *configuration = [PNConfiguration configurationWithPublishKey:@"demo" subscribeKey:@"demo"]; self.client = [PubNub clientWithConfiguration:configuration]; self.client.filterExpression = @"(senderID=='PubNub')"; ``` #### Get filter expression ```objectivec NSLog(@"Filtering expression: %@", self.client.filterExpression); ``` ### Returns `Get Filter Expression` returns the `Current filtering expression`. :::warning Malformed filter expression If filter expression is malformed, `PNObjectEventListener` won't receive any messages and presence events from service (only error status). ::: ## Terms in this document * **PubNub** - PubNub is a real-time messaging platform that provides APIs and SDKs for building scalable applications. It handles the complex infrastructure of real-time communication, including: Message delivery and persistence, Presence detection, Access control, Push notifications, File sharing, Serverless processing with Functions and Events & Actions, Analytics and monitoring with BizOps Workspace, AI-powered insights with Illuminate.