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Chat Thread - Send Chat Message

Service:
Communication
API Version:
2025-03-15

Sends a message to a thread.

POST {endpoint}/chat/threads/{chatThreadId}/messages?api-version=2025-03-15

URI Parameters

Name In Required Type Description
chatThreadId
 path True

string

The thread id to send the message to.
endpoint
 path True

string

The endpoint of the Azure Communication resource.
api-version
 query True

string

Version of API to invoke.

Request Header

Name Required Type Description
Authorization True

string

An ACS (Azure Communication Services) user access token.

Request Body

Name Required Type Description
content True

string

Chat message content.
metadata

object

Message metadata.
senderDisplayName

string

The display name of the chat message sender. This property is used to populate sender name for push notifications.
type

ChatMessageType

The chat message type.

Responses

Name Type Description
201 Created

SendChatMessageResult

Message sent, the Location header contains the URL for the newly sent message.
401 Unauthorized

CommunicationErrorResponse

Unauthorized.
403 Forbidden

CommunicationErrorResponse

Forbidden.
429 Too Many Requests

CommunicationErrorResponse

Too many requests.
Other Status Codes

CommunicationErrorResponse

Service unavailable.

Security

Authorization

An ACS (Azure Communication Services) user access token.

Type: apiKey
In: header

Examples

Send Message

Sample request

POST https://contoso.westus.communications.azure.com/chat/threads/34adfa4f-cedf-4dc0-ba29-b6d1a69ab345/messages?api-version=2025-03-15

{
  "content": "Let's head out for lunch in 15 minutes.",
  "senderDisplayName": "Jane",
  "metadata": {
    "someKey1": "someValue1",
    "someKey2": "someValue2"
  }
}

Sample response

Status code:
201 
Location: https://contoso.westus.communications.azure.com/chat/threads/34adfa4f-cedf-4dc0-ba29-b6d1a69ab345/messages/1593072104708
{
  "id": "1593072104708"
}
Status code:
401 
{
  "error": {
    "code": "Unauthorized",
    "message": "Request is not authorized."
  }
}
Status code:
403 
{
  "error": {
    "code": "Forbidden",
    "message": "User is not allowed to perform specified action."
  }
}
Status code:
429 
{
  "error": {
    "code": "TooManyRequests",
    "message": "Rate limit exceeded."
  }
}
Status code:
503 
{
  "error": {
    "code": "ServiceUnavailable",
    "message": "The server is currently unable to handle the request."
  }
}

Definitions

Name Description
ChatMessageType

The chat message type.
SendChatMessageRequest

Details of the message to send.
SendChatMessageResult

Result of the send message operation.

ChatMessageType

Enumeration

The chat message type.

Value Description
text
html
topicUpdated
participantAdded
participantRemoved

SendChatMessageRequest

Object

Details of the message to send.

Name Type Description
content

string

Chat message content.
metadata

object

Message metadata.
senderDisplayName

string

The display name of the chat message sender. This property is used to populate sender name for push notifications.
type

ChatMessageType

The chat message type.

SendChatMessageResult

Object

Result of the send message operation.

Name Type Description
id

string

A server-generated message id.