Ably Chat is a set of purpose-built APIs for a host of chat features enabling you to create 1:1, 1:Many, Many:1 and Many:Many chat rooms for any scale. It is designed to meet a wide range of chat use cases, such as livestreams, in-game communication, customer support, or social interactions in SaaS products. Built on Ably's core service, it abstracts complex details to enable efficient chat architectures.
Important
This SDK is currently under development. If you are interested in being an early adopter and providing feedback then you can sign up to the private beta and are welcome to provide us with feedback. Coming soon: chat moderation, editing and deleting messages.
Get started using the 📚 documentation.
- macOS 11 and above
- iOS 14 and above
- tvOS 14 and above
Xcode 16 or later.
The SDK is distributed as a Swift package and can hence be installed using Xcode (search for github.com/ably/ably-chat-swift
package) or by adding it as a dependency in your package’s Package.swift
:
.package(url: "https://github.com/ably/ably-chat-swift", from: "0.1.0")
This project is under development so we will be incrementally adding new features. At this stage, you'll find APIs for the following chat features:
- Chat rooms for 1:1, 1:many, many:1 and many:many participation.
- Sending and receiving chat messages.
- Online status aka presence of chat participants.
- Chat room occupancy, i.e total number of connections and presence members.
- Typing indicators
- Room-level reactions (ephemeral at this stage)
If there are other features you'd like us to prioritize, please let us know.
You will need the following prerequisites:
-
An Ably account
- You can sign up to the generous free tier.
-
An Ably API key
- Use the default or create a new API key in an app within your Ably account dashboard.
- Make sure your API key has the
following capabilities:
publish
,subscribe
,presence
,history
andchannel-metadata
.
To instantiate the Chat SDK, create an Ably client and pass it into the Chat constructor:
import Ably
import AblyChat
let realtimeOptions = ARTClientOptions()
realtimeOptions.key = "<API_KEY>"
realtimeOptions.clientId = "<clientId>"
let realtime = ARTRealtime(options: realtimeOptions)
let chatClient = DefaultChatClient(realtime: realtime, clientOptions: nil)
You can use basic authentication i.e. the API Key directly for testing purposes, however it is strongly recommended that you use token authentication in production environments.
To use Chat you must also set a clientId
so that users are
identifiable.
The Chat SDK uses a single connection to Ably, which is exposed via the ChatClient#connection
property. You can use this
property to observe the connection state and take action accordingly.
You can view the current connection status at any time:
let status = await chatClient.connection.status
let error = await chatClient.connection.error
You can subscribe to connection status changes by registering a listener, like so:
let subscription = chatClient.connection.onStatusChange()
for await statusChange in subscription {
print("Connection status changed to: \(statusChange.current)")
}
To stop listening to changes, call the unsubscribe
method on the returned subscription instance:
subscription.unsubscribe()
You can create or retrieve a chat room with name "basketball-stream"
this way:
let room = try await chatClient.rooms.get(roomID: "basketball-stream", options: RoomOptions())
The second argument to rooms.get
is a RoomOptions
argument, which tells the Chat SDK what features you would like your room to use and
how they should be configured.
You can also use RoomOptions.allFeaturesEnabled
to enable all room features with the default configuration.
For example, you can set the timeout between keystrokes for typing events as part of the room options. Sensible defaults for each of the features are provided for your convenience:
- A typing timeout (time of inactivity before typing stops) of 5 seconds.
- Entry and subscription to presence.
Here’s an example demonstrating how to specify a custom typing timeout of 3 seconds:
let room = try await chatClient.rooms.get(roomID: "basketball-stream",
options: .init(typing: TypingOptions(timeout: 3.0)))
In order to use the same room but with different options, you must first release
the room before requesting an instance with the changed
options (see below for more information on releasing rooms).
Note that:
- If a
release
call is currently in progress for the room (see below), then a call toget
will wait for that to complete before completing itself. - If a
get
call is currently in progress for the room andrelease
is called, theget
call will fail.
To start receiving events on a room, it must first be attached. This can be done using the attach
method:
try await room.attach()
To stop receiving events on a room, it must be detached, which can be achieved by using the detach
method:
room.detach()
Note: This does not remove any event listeners you have registered and they will begin to receive events again in the event that the room is re-attached.
Depending on your application, you may have multiple rooms that come and go over time (e.g. if you are running 1:1 support chat). When you
are completely finished with a room, you may release
it which allows the underlying resources to be collected:
_ = try await rooms.release(roomID: "basketball-stream")
Once release
is called, the room will become unusable and you will need to get a new instance using rooms.get
.
Note
Releasing a room may be optional for many applications. If release is not called, the server will automatically tidy up connections and other resources associated with the room after a period of time.
Monitoring the status of the room is key to a number of common chat features. For example, you might want to display a warning when the room has become detached.
To get the current status (and error), you can use the status
property like this:
switch await room.status {
case let .failed(error: error):
// use error
}
...
}
You can also subscribe to changes in the room status and be notified whenever they happen by registering a listener:
let statusSubscription = try await room.onStatusChange()
for await status in statusSubscription {
print("Room status: \(status)")
}
To stop listening to room status changes, call the unsubscribe
method on the returned subscription instance:
statusSubscription.unsubscribe()
There may be instances where the connection to Ably is lost for a period of time, for example, when the user enters a tunnel. In many circumstances, the connection will recover and operation will continue with no discontinuity of messages. However, during extended periods of disconnection, continuity cannot be guaranteed and you'll need to take steps to recover messages you might have missed.
Each feature of the Chat SDK provides an onDiscontinuity
method. Here you can register a listener that will be notified whenever a
discontinuity in that feature has been observed.
Taking messages as an example, you can listen for discontinuities like so:
let subscription = room.messages.onDiscontinuity()
for await error in subscription {
print("Recovering from the error: \(error)")
}
To stop listening to discontinuities, call unsubscribe
method on returned subscription instance.
To subscribe to incoming messages you create a subscription for the room messages
object:
let messagesSubscription = try await room.messages.subscribe()
for await message in messagesSubscription {
print("Message received: \(message)")
}
To stop listening for the new messages, call the unsubscribe
method on the returned subscription instance.
To send a message, simply call send
on the room messages
property, with the message you want to send:
let message = try await room.messages.send(params: .init(text: "hello"))
The messages object also exposes the get
method which can be used to request historical messages in the chat room according
to the given criteria. It returns a paginated response that can be used to request more messages:
let paginatedResult = try await room.messages.get(options: .init(orderBy: .newestFirst))
print(paginatedResult.items)
if paginatedResult.hasNext {
let next = try await paginatedResult.next!
print(next.items)
} else {
print("End of messages")
}
In addition to being able to unsubscribe from messages, the return value from messages.subscribe
also includes the getPreviousMessages
method. It can be used to request historical messages in the chat room that were sent up to the point that a particular listener was subscribed. It returns a
paginated response that can be used to request for more messages:
let messagesSubscription = try await room.messages.subscribe()
let paginatedResult = try await messagesSubscription.getPreviousMessages(params: .init(limit: 50)) // `orderBy` here is ignored and always `newestFirst`
print(paginatedResult.items)
if paginatedResult.hasNext {
let next = try await paginatedResult.next!
print(next.items)
} else {
print("End of messages")
}
You can get the complete list of currently online or present members, their state and data, by calling the presence.get()
method which returns
a list of the presence messages, where each message contains the most recent data for a member:
// Retrieve all users entered into presence as an array:
let presentMembers = try await room.presence.get()
// Retrieve the status of specific users by their clientId:
let presentMember = try await room.presence.get(params: .init(clientID: "clemons123"))
// To check whether the user is online or not:
let isPresent = try await room.presence.isUserPresent(clientID: "clemons123")
To appear online for other users, you can enter the presence set of a chat room. While entering presence, you can provide optional data that will be associated with the presence message (can be a nested dictionary):
try await room.presence.enter(data: ["status": "Online"])
Updates allow you to make changes to the custom data associated with a present user. Common use-cases include updating the user's status:
try await room.presence.update(data: ["status": "Busy"])
Ably automatically triggers a presence leave if a client goes offline. But you can also manually leave the presence set as a result of a UI action. While leaving presence, you can provide optional data that will be associated with the presence message:
try await room.presence.leave(data: ["status": "Bye!"])
You can provide a single listener for all presence event types:
let presenceSubscription = try await room.presence.subscribe(events: [.enter, .leave, .update])
for await event in presenceSubscription {
print("Presence event `\(event.action)` from `\(event.clientId)` with data `\(event.data)`")
}
To stop listening for the presence updates, call the unsubscribe
method on the returned subscription instance.
Note
You should be attached to the room to enable this functionality.
Typing events allow you to inform others that a client is typing and also subscribe to others' typing status.
You can get the complete set of the current typing clientId
s, by calling the typing.get
method.
// Retrieve the entire list of currently typing clients
let currentlyTypingClientIds = try await room.typing.get()
To inform other users that you are typing, you can call the start method. This will begin a timer that will automatically stop typing after a set amount of time.
try await room.typing.start()
Repeated calls to start will reset the timer, so the clients typing status will remain active.
You can immediately stop typing without waiting for the timer to expire.
try await room.typing.start()
// Some short delay - timer not yet expired
try await room.typing.stop()
// Timer cleared and stopped typing event emitted and listeners are notified
To subscribe to typing events, create a subscription with the subscribe
method:
let typingSubscription = try await room.typing.subscribe()
for await typing in typingSubscription {
typingInfo = typing.currentlyTyping.isEmpty ? "" : "Typing: \(typing.currentlyTyping.joined(separator: ", "))..."
}
To stop listening for the typing events, call the unsubscribe
method on the returned subscription instance.
Occupancy tells you how many users are connected to the chat room.
To subscribe to occupancy updates, subscribe a listener to the chat room occupancy
member:
let occupancySubscription = try await room.occupancy.subscribe()
for await event in occupancySubscription {
occupancyInfo = "Connections: \(event.presenceMembers) (\(event.connections))"
}
To stop listening for the typing events, call the unsubscribe
method on the returned subscription instance.
Occupancy updates are delivered in near-real-time, with updates in quick succession batched together for performance.
You can request the current occupancy of a chat room using the occupancy.get
method:
let occupancy = try await room.occupancy.get()
You can subscribe to and send ephemeral room-level reactions by using the room reactions
object.
To send room-level reactions, you must be attached to the room.
To send a reaction such as like
:
try await room.reactions.send(params: .init(type: "like"))
You can also add any metadata and headers to reactions:
try await room.reactions.send(params: .init(type: "🎉", metadata: ["effect": "fireworks"]))
Subscribe to receive room-level reactions:
let reactionSubscription = try await room.reactions.subscribe()
for await reaction in reactionSubscription {
print("Received a reaction of type \(reaction.type), and metadata \(reaction.metadata)")
}
To stop receiving reactions, call the unsubscribe
method on the returned subscription instance.
This repository contains an example app, written using SwiftUI, which demonstrates how to use the SDK. The code for this app is in the Example
directory.
In order to allow the app to use modern SwiftUI features, it supports the following OS versions:
- macOS 14 and above
- iOS 17 and above
- tvOS 17 and above
To run the app, open the AblyChat.xcworkspace
workspace in Xcode and run the AblyChatExample
target. If you wish to run it on an iOS or tvOS device, you’ll need to set up code signing.
It might be useful to know that each feature is backed by an underlying Pub/Sub channel. You can use this information to enable interoperability with other platforms by subscribing to the channels directly using the Ably Pub/Sub SDKs for those platforms.
The channel for each feature can be obtained via the channel
property
on that feature.
let messagesChannel = room.messages.channel
Warning: You should not attempt to change the state of a channel directly. Doing so may cause unintended side-effects in the Chat SDK.
For a given chat room, the channels used for features are as follows:
Feature | Channel |
---|---|
Messages | <roomId>::$chat::$chatMessages |
Presence | <roomId>::$chat::$chatMessages |
Occupancy | <roomId>::$chat::$chatMessages |
Reactions | <roomId>::$chat::$reactions |
Typing | <roomId>::$chat::$typingIndicators |
For guidance on how to contribute to this project, see the contributing guidelines.
Please visit http://support.ably.com/ for access to our knowledge base and to ask for any assistance. You can also view the community reported Github issues or raise one yourself.
To see what has changed in recent versions, see the changelog.
- Sign up to the private beta and get started.
- Share feedback or request a new feature.