Reactions - CometChat Docs

Quick Reference for AI Agents & Developers

Add reaction: CometChat.addReaction(messageId:reaction:onSuccess:onError:)
Remove reaction: CometChat.removeReaction(messageId:reaction:onSuccess:onError:)
Fetch reactions: ReactionsRequestBuilder().setMessageId(messageId:).build() → fetchNext(onSuccess:onError:)
Listen for reactions: onMessageReactionAdded(_:), onMessageReactionRemoved(_:) in message listener
Related: Send Message · Messaging Overview

Enhance user engagement in your chat application with message reactions. Users can express their emotions using reactions to messages. This feature allows users to add or remove reactions, and to fetch all reactions on a message.

Add a Reaction

Users can add a reaction to a message by calling addReaction with the message ID and the reaction emoji.

Swift

CometChat.addReaction(messageId: 148, reaction: "😴") { message in
    print("Reactions: \(message.getReactions())")
} onError: { error in
    print("Error: \(error?.errorDescription)")
}

Sample Payloads - Add Reaction

Request
Success Response
Error Response

Method: CometChat.addReaction(messageId:reaction:)

Parameter	Type	Value
messageId	`Int`	`38230`
reaction	`String`	`"👍"`

Message Properties:

Parameter	Type	Value
id	`Int`	`38230`
reactionAdded	`String`	`"👍"`

Reactions List (message.reactions):

Reaction	Count	ReactedByMe
👍	`1`	`true`

Object Type: CometChatException

Parameter	Type	Value
errorCode	`String`	`"ERR_MESSAGE_NOT_FOUND"`
errorDescription	`String`	`"Message does not exist"`

More Sample Payloads - Multiple Reactions

Add Heart Reaction
Add Laugh Reaction

Request:

Parameter	Type	Value
messageId	`Int`	`38230`
reaction	`String`	`"❤️"`

Updated Reactions List:

Reaction	Count	ReactedByMe
👍	`1`	`true`
❤️	`1`	`true`

Request:

Parameter	Type	Value
messageId	`Int`	`38230`
reaction	`String`	`"😂"`

Updated Reactions List:

Reaction	Count	ReactedByMe
👍	`1`	`true`
❤️	`1`	`true`
😂	`1`	`true`

You can react on Text, Media and Custom messages.

Remove a Reaction

Removing a reaction from a message can be done using the removeReaction method.

Swift

CometChat.removeReaction(messageId: 148, reaction: "😴") { message in
    print("Reactions: \(message.getReactions())")
} onError: { error in
    print("Error: \(error?.errorDescription)")
}

Sample Payloads - Remove Reaction

Request
Success Response
Error Response

Method: CometChat.removeReaction(messageId:reaction:)

Parameter	Type	Value
messageId	`Int`	`38230`
reaction	`String`	`"👍"`

Message Properties:

Parameter	Type	Value
id	`Int`	`38230`
reactionRemoved	`String`	`"👍"`

Updated Reactions List:

Reaction	Count	ReactedByMe
❤️	`1`	`true`
😂	`1`	`true`

Object Type: CometChatException

Parameter	Type	Value
errorCode	`String`	`"ERR_REACTION_NOT_FOUND"`
errorDescription	`String`	`"Reaction not found on message"`

Fetch Reactions for a Message

To get all reactions for a specific message, create a ReactionsRequest using ReactionsRequestBuilder.

Method	Description
`setMessageId(messageId: Int)`	Specifies the message ID (required)
`setReaction(reaction: String)`	Filter by specific emoji (optional)
`setLimit(limit: Int)`	Number of reactions to fetch (max 100)

Fetch Next Reactions

Swift

let reactionsRequest = ReactionsRequestBuilder()
    .setLimit(limit: 30)
    .setMessageId(messageId: 148)
    .build()

reactionsRequest.fetchNext { reactions in
    for reaction in reactions {
        print("Reaction: \(reaction.reaction)")
        print("Reacted by: \(reaction.reactedBy?.name ?? "")")
    }
} onError: { error in
    print("Error: \(error?.errorDescription)")
}

Sample Payloads - Fetch Reactions

Request
Success Response
Error Response

Method: ReactionsRequest.fetchNext()

Parameter	Type	Value
messageId	`Int`	`38230`
limit	`Int`	`30`
reaction	`String?`	`nil` (optional - filter by emoji)

Reactions Array:

Reaction	Reacted By UID	Reacted By Name	Reacted At
😴	`"cometchat-uid-1"`	`"John Doe"`	`1697025960`
👍	`"cometchat-uid-2"`	`"Jane Smith"`	`1697025950`

Object Type: CometChatException

Parameter	Type	Value
errorCode	`String`	`"ERROR_LIMIT_EXCEEDED"`
errorDescription	`String`	`"Limit Exceeded Max limit of 100"`

Fetch Reactions for Specific Emoji

Swift

let reactionsRequest = ReactionsRequestBuilder()
    .setLimit(limit: 30)
    .setMessageId(messageId: 148)
    .setReaction(reaction: "👍")
    .build()

reactionsRequest.fetchNext { reactions in
    // Only returns 👍 reactions
} onError: { error in
    print("Error: \(error?.errorDescription)")
}

Fetch Previous Reactions

Swift

reactionsRequest.fetchPrevious { reactions in
    for reaction in reactions {
        print("Reaction: \(reaction.stringValue())")
    }
} onError: { error in
    print("Error: \(error?.errorDescription)")
}

Real-time Reaction Events

Keep the chat interactive with real-time updates for reactions.

Swift

let listenerID = "UNIQUE_LISTENER_ID"
CometChat.addMessageListener(listenerID, self)

extension YourViewController: CometChatMessageDelegate {
    
    func onMessageReactionAdded(reactionEvent: ReactionEvent) {
        print("Reaction Added")
        print("Reaction: \(reactionEvent.reaction)")
        print("Message ID: \(reactionEvent.reaction.messageId)")
        print("Reacted By: \(reactionEvent.reaction.reactedBy?.name ?? "")")
    }
    
    func onMessageReactionRemoved(reactionEvent: ReactionEvent) {
        print("Reaction Removed")
        print("Reaction: \(reactionEvent.reaction)")
    }
}

// Remove listener when done:
CometChat.removeMessageListener(listenerID)

Sample Payloads - Reaction Events

onMessageReactionAdded
onMessageReactionRemoved

Method: onMessageReactionAdded(reactionEvent: ReactionEvent)ReactionEvent Object:

Parameter	Type	Description
reaction	`Reaction`	The reaction details
receiverId	`String`	ID of the receiver
receiverType	`ReceiverType`	`.user` or `.group`
conversationId	`String`	ID of the conversation
parentMessageId	`Int`	Parent message ID (for threads)

Method: onMessageReactionRemoved(reactionEvent: ReactionEvent)ReactionEvent Object:

Parameter	Type	Description
reaction	`Reaction`	The reaction details
receiverId	`String`	ID of the receiver
receiverType	`ReceiverType`	`.user` or `.group`

Get Reactions List

To retrieve the list of reactions on a particular message:

Swift

let reactions = message.reactions  // Returns [ReactionCount]

Check if Logged-in User Has Reacted

Swift

for reactionCount in message.reactions {
    print("Reaction: \(reactionCount.reaction)")
    print("Reacted by me: \(reactionCount.reactedByMe)")
}

Update Message With Reaction Info

When you receive a real-time reaction event, use this method to update the message with the latest reaction information. This keeps your local message state in sync with the server.

Method Signature

Swift

CometChat.updateMessageWithReactionInfo(
    baseMessage: BaseMessage,
    messageReaction: MessageReaction,
    action: ReactionAction
) -> BaseMessage

Parameters

Parameter	Type	Description
baseMessage	`BaseMessage`	The message to update
messageReaction	`MessageReaction`	Reaction info from event
action	`ReactionAction`	`.REACTION_ADDED` or `.REACTION_REMOVED`

ReactionAction Enum Values

Value	Description
`.REACTION_ADDED`	A reaction was added to the message
`.REACTION_REMOVED`	A reaction was removed from the message

Usage Example - Reaction Added

Swift

extension YourViewController: CometChatMessageDelegate {
    
    func onMessageReactionAdded(reactionEvent: ReactionEvent) {
        // Get the message from your local list
        var message: BaseMessage = getMessageFromList(reactionEvent.reaction.messageId)
        
        // Get the reaction from the event
        let messageReaction: MessageReaction = reactionEvent.reaction
        
        // Update the message with new reaction info
        let modifiedMessage = CometChat.updateMessageWithReactionInfo(
            baseMessage: message,
            messageReaction: messageReaction,
            action: .REACTION_ADDED
        )
        
        // Update your UI with the modified message
        updateMessageInList(modifiedMessage)
    }
}

Usage Example - Reaction Removed

Swift

extension YourViewController: CometChatMessageDelegate {
    
    func onMessageReactionRemoved(reactionEvent: ReactionEvent) {
        // Get the message from your local list
        var message: BaseMessage = getMessageFromList(reactionEvent.reaction.messageId)
        
        // Get the reaction from the event
        let messageReaction: MessageReaction = reactionEvent.reaction
        
        // Update the message with removed reaction info
        let modifiedMessage = CometChat.updateMessageWithReactionInfo(
            baseMessage: message,
            messageReaction: messageReaction,
            action: .REACTION_REMOVED
        )
        
        // Update your UI with the modified message
        updateMessageInList(modifiedMessage)
    }
}

Complete Real-Time Handling Example

Swift

class ChatViewController: UIViewController, CometChatMessageDelegate {
    
    var messages: [BaseMessage] = []
    
    override func viewDidLoad() {
        super.viewDidLoad()
        CometChat.addMessageListener("reaction-listener", self)
    }
    
    func onMessageReactionAdded(reactionEvent: ReactionEvent) {
        handleReactionEvent(reactionEvent, action: .REACTION_ADDED)
    }
    
    func onMessageReactionRemoved(reactionEvent: ReactionEvent) {
        handleReactionEvent(reactionEvent, action: .REACTION_REMOVED)
    }
    
    private func handleReactionEvent(_ event: ReactionEvent, action: ReactionAction) {
        let messageId = event.reaction.messageId
        
        // Find the message in local list
        guard let index = messages.firstIndex(where: { $0.id == messageId }) else {
            return
        }
        
        // Update message with reaction info
        let updatedMessage = CometChat.updateMessageWithReactionInfo(
            baseMessage: messages[index],
            messageReaction: event.reaction,
            action: action
        )
        
        // Replace in list and refresh UI
        messages[index] = updatedMessage
        tableView.reloadRows(at: [IndexPath(row: index, section: 0)], with: .none)
    }
    
    deinit {
        CometChat.removeMessageListener("reaction-listener")
    }
}

Sample Payloads - Update Message With Reaction Info

Return Value

The method returns a BaseMessage with updated reactions array:

Property	Type	Description
reactions	`[ReactionCount]`	Updated list of reaction counts

Each ReactionCount contains:

Property	Type	Description
reaction	`String`	The emoji reaction
count	`Int`	Total count of this reaction
reactedByMe	`Bool`	If logged-in user reacted

Notes:

This is a synchronous method - no callbacks needed
Always use this method to keep local message state in sync
The returned message has updated reactions array
Works with both user and group messages
Handle both REACTION_ADDED and REACTION_REMOVED events

ReactionCount Object Properties

Property	Type	Description
`reaction`	`String`	The reaction emoji
`count`	`Int`	Number of users who reacted
`reactedByMe`	`Bool`	Whether logged-in user reacted

MessageReaction Object Properties

Property	Type	Description
`reaction`	`String`	The reaction emoji
`reactedBy`	`User?`	User who added the reaction
`reactedAt`	`Double`	Unix timestamp when reacted
`messageId`	`Int`	ID of the message

ReactionEvent Object Properties

Property	Type	Description
`reaction`	`Reaction`	The reaction details
`receiverId`	`String`	ID of the receiver
`receiverType`	`ReceiverType`	`.user` or `.group`
`conversationId`	`String`	ID of the conversation
`parentMessageId`	`Int`	Parent message ID (for threads)

Common Error Codes

Error Code	Description	Resolution
`ERR_MESSAGE_NOT_FOUND`	Message doesn’t exist	Verify message ID
`ERR_INVALID_REACTION`	Invalid reaction emoji	Use valid emoji
`ERR_ALREADY_REACTED`	Already reacted with emoji	Remove first
`ERR_REACTION_NOT_FOUND`	Reaction not on message	User hasn’t reacted

​Add a Reaction

​Remove a Reaction

​Fetch Reactions for a Message

​Fetch Next Reactions

​Fetch Reactions for Specific Emoji

​Fetch Previous Reactions

​Real-time Reaction Events

​Get Reactions List

​Check if Logged-in User Has Reacted

​Update Message With Reaction Info

​Method Signature

​Parameters

​ReactionAction Enum Values

​Usage Example - Reaction Added

​Usage Example - Reaction Removed

​Complete Real-Time Handling Example

​ReactionCount Object Properties

​MessageReaction Object Properties

​ReactionEvent Object Properties

​Common Error Codes

Add a Reaction

Remove a Reaction

Fetch Reactions for a Message

Fetch Next Reactions

Fetch Reactions for Specific Emoji

Fetch Previous Reactions

Real-time Reaction Events

Get Reactions List

Check if Logged-in User Has Reacted

Update Message With Reaction Info

Method Signature

Parameters

ReactionAction Enum Values

Usage Example - Reaction Added

Usage Example - Reaction Removed

Complete Real-Time Handling Example

ReactionCount Object Properties

MessageReaction Object Properties

ReactionEvent Object Properties

Common Error Codes