--- source_url: https://www.pubnub.com/docs/sdks/cocoa-objective-c/api-reference/channel-groups title: Channel Groups API for Cocoa Objective-C SDK updated_at: 2026-05-25T11:27:26.757Z --- > 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 # Channel Groups API for Cocoa Objective-C SDK [Channel groups](https://www.pubnub.com/docs/general/channels/subscribe#channel-groups) allow PubNub developers to bundle thousands of [channels](https://www.pubnub.com/docs/general/channels/overview) into a group that can be identified by a name. These channel groups can then be subscribed to, receiving data from the many back-end channels the channel group contains. :::note Channel group operations You can't publish to a channel group. You can only subscribe to it. To publish within the channel group, you need to publish to each channel individually. ::: ## Add channels to a channel group :::note Requires Stream Controller add-on This method requires that the *Stream Controller* add-on is enabled for your key in the PubNub [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. ::: This function adds channels to a channel group. ### Method(s) Use the following method in the Cocoa SDK: ```objectivec - (void)addChannels:(NSArray *)channels toGroup:(NSString *)group withCompletion:(nullable PNChannelGroupChangeCompletionBlock)block; ``` | Parameter | Type | Required | Default | Description | | --- | --- | --- | --- | --- | | channels | NSArray | Yes | | The channels to add to the channel group. | | group | NSString | Yes | | The channel group to add the channels to. | | block | PNChannelGroupChangeCompletionBlock | Optional | | `Channels` addition process completion block which pass only one argument - request processing status to report about how data pushing was successful or not. | ### Sample code #### Add channels ```objectivec NSString *channelGroup = @"family"; ``` ```objectivec [self.client addChannels: @[@"wife"] toGroup:channelGroup withCompletion:^(PNAcknowledgmentStatus *status) { if (!status.isError) { // Handle successful channels list modification for group. } else { /** Handle channels list modification for group error. Check 'category' property to find out possible reason because of which request did fail. Review 'errorData' property (which has PNErrorData data type) of status object to get additional information about issue. Request can be resent using: [status retry]; */ } }]; ``` ### Response Response objects which is returned by client when Add Channels to Group API is used: ```objectivec @interface PNAcknowledgmentStatus : PNErrorStatus @end ``` ## List channels in a channel group :::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. ::: This function lists all channels in a channel group. ### Method(s) Use the following method in the Cocoa SDK: ```objectivec - (void)channelsForGroup:(NSString *)group withCompletion:(PNGroupChannelsAuditCompletionBlock)block; ``` | Parameter | Description | | --- | --- | | `group` *Type: NSString | The channel group for which to list channels. | | `block` *Type: PNClientChannelsForGroupRequestHandlingBlock | `Channels` audition process completion `block` which pass two arguments: result - in case of successful request processing data field will contain results of channel groups `channels` audition operation; status - in case if error occurred during request processing. | ### Sample code #### List channels ```objectivec NSString *channelGroup = @"family"; ``` ```objectivec [self.client channelsForGroup:channelGroup withCompletion:^(PNChannelGroupChannelsResult *result, PNErrorStatus *status) { if (!status) { // Handle downloaded list of chanels using: result.data.channels } else { /** Handle channels for group audition error. Check 'category' property to find out possible reason because of which request did fail. Review 'errorData' property (which has PNErrorData data type) of status object to get additional information about issue. Request can be resent using: [status retry]; */ } }]; ``` ### Response Response objects which is returned by client when Add Channels to Group API is used: ```objectivec @interface PNChannelGroupChannelsData : PNServiceData // Registered channels within channel group. @property (nonatomic, readonly, strong) NSArray *channels; @end @interface PNChannelGroupChannelsResult : PNResult // Stores reference on channel group's channels list audit request processing information. @property (nonatomic, nonnull, readonly, strong) PNChannelGroupChannelsData *data; @end ``` ## Remove channels from a channel group :::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. ::: This function removes channels from a channel group. ### Method(s) Use the following method in the Cocoa SDK: ```objectivec - (void)removeChannels:(NSArray *)channels fromGroup:(NSString *)group withCompletion:(nullable PNChannelGroupChangeCompletionBlock)block; ``` | Parameter | Description | | --- | --- | | `channels` *Type: NSArray | The channels to remove from the channel group. | | `group` *Type: NSString | The channel group from which to remove the channels. | | `block`Type: PNChannelGroupChangeCompletionBlock | Channels removal process completion block which pass only one argument - request processing status to report about how data pushing was successful or not. | ### Sample code #### Remove channels ```objectivec NSString *channelGroup = @"family"; ``` ```objectivec [self.client removeChannels:@[@"son"] fromGroup:channelGroup withCompletion:^(PNAcknowledgmentStatus *status) { if (!status.isError) { // Handle successful channels list modification for group. } else { /** Handle channels list modification for group error. Check 'category' property to find out possible reason because of which request did fail. Review 'errorData' property (which has PNErrorData data type) of status object to get additional information about issue. Request can be resent using: [status retry]; */ } }]; ``` ### Response Response objects which is returned by client when Remove Channels to Group API is used: ```objectivec @interface PNAcknowledgmentStatus : PNErrorStatus @end ``` ## Delete a channel group :::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. ::: This function deletes a channel group. ### Method(s) Use the following method in the Cocoa SDK: ```objectivec - (void)removeChannelsFromGroup:(NSString *)group withCompletion:(nullable PNChannelGroupChangeCompletionBlock)block; ``` | Parameter | Description | | --- | --- | | `group` *Type: NSString | The channel group to delete. | | `block`Type: PNChannelGroupChangeCompletionBlock | Channel group removal process completion `block` which pass only one argument - request processing status to report about how data pushing was successful or not. | ### Sample code Deleting Channel Group: ```objectivec NSString *channelGroup = @"family"; ``` ```objectivec [self.client removeChannelsFromGroup:channelGroup withCompletion:^(PNAcknowledgmentStatus *status) { if (!status.isError) { // Handle successful channel group removal. } else { /** Handle channel group removal error. Check 'category' property to find out possible reason because of which request did fail. Review 'errorData' property (which has PNErrorData data type) of status object to get additional information about issue. Request can be resent using: [status retry]; */ } }]; ``` ### Response Response objects which is returned by client when Remove Channel Group API is used: ```objectivec @interface PNAcknowledgmentStatus : PNErrorStatus @end ``` ## Terms in this document * **Channel** - A pathway for sending and receiving messages between devices, created automatically when you first use it, that can handle any number of users and messages for different communication needs, like 1-1 text chats, group conversations, and other data streaming. * **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.