Messages are a sub-resource of conversations.


Sending messages

There are currently two types of messages you can send to a conversation. You can either send messages to a conversation on behalf of one user or on behalf of your app. Users in the conversation must have had their data synchronized first.

The request payload of this endpoint must always be an array, even if you send only one message. This way it's possible for you to send a batch of consecutive messages in a single request. It's also possible to combine user messages and system messages in one request.

This endpoint returns an array of objects, one for each message, that contain the ids of the messages.

2 {"id": "msg_abcdefghijklm"},
3 {"id": "msg_nopqrstuvwxyz"},
4 ...

Sending on behalf of a user

You can programmatically send messages on behalf of a user in a conversation. The behavior is identical to that when sending messages via the UI; notifications are triggered based on the participating user's role. UserMessage also supports sending attachments and locations. See Sending Files.

2 {
3 text: string
4 sender: string
5 type: "UserMessage"
6 referencedMessageId?: string
7 custom?: { [key: string]: string }
8 idempotencyKey?: string
9 },
10 ...

sender has to be a participant in the conversation. type must be "UserMessage" when sender is provided or the request fails.

The referencedMessageId property is used when the message you are sending is meant to be a reply to another message.

System Messages

System Messages are messages which are not sent by a participant, but programmatically by your application. A SystemMessage is displayed differently in the UI, and doesn't trigger notifications for any user in the conversation. You are expected to handle these notifications in your application if needed. These messages support attachments but don't currently support locations.

System Messages support formatting.

Some example use cases in a marketplace for System Messages are 'order received' and 'payment failed', but these can be anything from payment confirmations to "User left the group" notifications.

2 {
3 text: string
4 type: "SystemMessage"
5 custom?: { [key: string]: string }
6 idempotencyKey?: string
7 },
8 ...

text field supports the same syntax as Subjects. sender must not be provided when sending system messages.

Ensuring exactly-once delivery of messages

TalkJS cannot guarantee exactly-once message delivery if the initial request had failed and has been retried. To avoid message duplication on retries, you can use the idempotencyKey field when sending the messages. Trying to send a message with the same idempotencyKey any amount of times will result in the message being sent exactly once.

When using idempotencyKey, please make sure you're not using the same key for different messages. The system will treat two messages with the same key as if they are the same request, so whichever one gets processed first will be the only one that is processed.

The messages are associated with the idempotencyKey by TalkJS for 24 hours, after which the key will expire and a new message with the same key can be sent.

Fetching a single message

You can check the status of a certain message from a conversation (for example, after some time to read a readBy status), by calling:

1type MessageId = string;
2type UserId = string;
4type UnixMilliseconds = number;
6type Message = {
7 attachment: { url: string; size: number, dimensions?: {width: number height: number } } | null,
8 conversationId: string,
9 createdAt: UnixMilliseconds,
10 editedAt: UnixMilliseconds | null,
11 custom: { [name: string]: string },
12 id: MessageId,
13 location: [number, number] | null,
14 origin: "web" | "rest" | "email" | "import",
15 readBy: UserId[],
16 senderId: UserId,
17 text: string,
18 type: "UserMessage" | "SystemMessage"
19 referencedMessageId: string | null

Note that the readBy field is only used for conversations with at most 300 participants. For conversations with 301 or more participants, the readBy field will be empty.

Edit a message

This endpoint lets you edit the text field and the custom data in existing message. You first need to know the id of the message you want to edit. Please use the listing messages endpoint to obtain a list of messages along with their IDs or get it via a Webhook. Afterwards, you have to call the following endpoint:

You can also pass a field called markEdited (defaulting to false). When this field is set to true, the message's editedAt field will be set to the time of this change, and depending on your theme, an indicator that the message was edited may appear in the UI.

2 custom?: { [key: string]: string },
3 text?: string,
4 markEdited?: boolean

Deleting a message

Use this endpoint to irrevocably delete a message of the given conversation. Besides deleting the message from the TalkJS database, it is also deleted in real-time from any potentially connected clients. Additionally, a message.deleted webhook event is sent. If it contains the attachment it is removed from the storage.


Listing messages from a conversation

You can list messages written in conversations by users in TalkJS. In order to do that you need to call the following endpoint:

2 "data": Array<Message>

Note that the readBy field is only used for conversations with at most 300 participants. For conversations with 301 or more participants, the readBy field will be empty.

Limits and pagination

Similarly to other list requests, pagination and limits are applicable to listing messages.



Sending files

Sending files (images, documents, etc) is a two-step process. First, you upload the file to our servers. Then, you send a message in the same way as a text message, but with a reference to the uploaded file.

1. Upload a file

You upload a file using the files endpoint:

2 "attachmentToken": "L0oQOg5DVENGFVQZABpOQVNRCxs...EFFbHxhiXVEYUBw"

This is the only resource on the TalkJS REST API that does not accept a JSON payload. Instead, send multipart/form-data formatted data with two required parameters:

  1. file - This is the file data you want to upload.
  2. filename - The name of the file.

This is the usual way files are uploaded over HTTP. Check the docs of your favorite HTTP client for information on how to upload files with it. For example: JavaScript, Python (Requests), PHP, Ruby (RestClient).

This endpoint returns a JSON object with a single property, attachmentToken.

Troubleshooting file upload issues

If you get a 400 Bad Request response, try the following:

  • Check if your code is explicitly setting a Content-type: multipart/form-data header somewhere. If so, remove it. Most HTTP libraries will autogenerate this header when uploading files, and they will usually set the header to something like Content-Type: multipart/form-data; boundary=a3eb698cd620e766f278e52886c572edcb0e4a97. Without the boundary, TalkJS can't parse the data.
  • For TalkJS to be able to detect that you're uploading a file, the file needs to have a filename directive set. Many HTTP libraries do this automatically. If not, there will be a way for you to set it explicitly. Doing so causes the library to generate a header such as Content-Disposition: form-data; file="This is a txt file."; filename="sample.txt" inside the HTTP body. You shouldn't need to set this header manually; find a facility in your HTTP library to give an uploaded file a filename.

If you get a 500 Server Error response, reach out to us through our live chat.

2. Send a message with an attachment

Now, use the usual messages resource to send a message, but replace the text field by an attachmentToken field:

2 {
3 attachmentToken: string,
4 sender: string,
5 type: 'UserMessage',
6 },

Alternatively, images can be sent using a system message by omitting the sender and using SystemMessage as the message type.

2 {
3 attachmentToken: string,
4 type: 'SystemMessage',
5 }

Deleting all messages from a conversation

Use this endpoint to irrevocably delete all messages of the given conversation. Besides deleting the messages from the TalkJS database, it is also deleted in real-time from any potentially connected clients. Note that this endpoint does not generate any webhooks.