Send Message

V2 Reference

Chat Messages

POST

/api/partner/v2/chats/{chat_id}/chat_messages

const url = 'https://api.linqapp.com/api/partner/v2/chats/1/chat_messages';
const form = new FormData();
form.append('message[text]', 'Hello, how are you?');
form.append('message[idempotency_key]', 'msg-2024_01-23_abc123');

const options = {
  method: 'POST',
  headers: {'X-LINQ-INTEGRATION-TOKEN': '<X-LINQ-INTEGRATION-TOKEN>'}
};

options.body = form;

try {
  const response = await fetch(url, options);
  const data = await response.json();
  console.log(data);
} catch (error) {
  console.error(error);
}

curl --request POST \
  --url https://api.linqapp.com/api/partner/v2/chats/1/chat_messages \
  --header 'Content-Type: multipart/form-data' \
  --header 'X-LINQ-INTEGRATION-TOKEN: <X-LINQ-INTEGRATION-TOKEN>' \
  --form 'message[text]=Hello, how are you?' \
  --form 'message[idempotency_key]=msg-2024_01-23_abc123'

Sends a new message in the specified chat.

Idempotency: To prevent duplicate messages (e.g., due to network retries), include a unique message[idempotency_key] in your request. If a message with the same key was already sent, the API will return the existing message with a 200 status instead of creating a duplicate. The idempotency key must be alphanumeric and may include hyphens and underscores.

Attachments: You can attach files in two ways:

Direct upload - Use message[attachments][] fields in your multipart/form-data request to upload files directly:

-F "message[attachments][][email protected]" \
-F "message[attachments][][email protected]"

URLs - Use message[attachment_urls][] to provide URLs of files. The API will download them from the provided URLs (must be publicly accessible, 30-second timeout per download):

-F "message[attachment_urls][]=https://example.com/document.pdf" \
-F "message[attachment_urls][]=https://example.com/image.jpg"

Both methods can be used together in the same message.

Authorizations

ApiKeyAuth

Parameters

Path Parameters

chat_id

required

integer

The chat ID

Request Body^required

multipart/form-data

object

message[text]

required

The message text content

string

message[idempotency_key]

Optional unique key to prevent duplicate messages. Must be alphanumeric and may include hyphens and underscores.

string

/^[a-zA-Z0-9_-]+$/

message[attachments][]

Optional file attachments to upload. Include one field per file (e.g., message[attachments][][email protected] message[attachments][][email protected]). Omit this field if not uploading files.

Array<string>

message[attachment_urls][]

Optional URLs of files to attach. The API will download files from these URLs (must be publicly accessible). Uses a 30-second timeout per download. Omit this field if not attaching files via URLs.

Array<string>

Examples

Basic text message

{
  "message[text]": "Hello, how are you?",
  "message[idempotency_key]": "msg-2024_01-23_abc123"
}

Message with attachment URLs

{
  "message[text]": "Here are the files you requested.",
  "message[attachment_urls][]": [
    "https://example.com/document.pdf",
    "https://example.com/image.jpg"
  ]
}

Message with direct file uploads

For direct file uploads via multipart/form-data. Use cURL with -F flags: curl -X POST “https://api.linqapp.com/api/partner/v2/chats/{chat_id}/chat_messages”
-H “X-LINQ-INTEGRATION-TOKEN: your_token”
-F “message[text]=Check out these files”
-F “message[attachments][]=@/path/to/file1.jpg”
-F “message[attachments][]=@/path/to/file2.pdf”

{
  "message[text]": "Check out these files",
  "message[attachments][]": [
    "<binary file data>"
  ]
}

Responses

201

Message sent successfully

application/json

object

data

object

integer

text

string

sent_at

string format: date-time

delivered_at

string format: date-time

nullable

delivery_status

Current delivery status of the message

string

Allowed values: pending delivered service_unavailable paused

edited_at

string format: date-time

nullable

is_read

boolean

sent_from

The phone number or identifier that sent this message

string

chat_handle_id

integer

attachments

Array<object>

object

Unique identifier for the attachment

string format: uuid

url

string

filename

string

mime_type

string

file_size

integer

reactions

Array<object>

object

integer

chat_message_id

integer

reaction

The type of reaction

string

Allowed values: love like dislike laugh emphasize question

is_from_me

boolean

from_phone

string

sent_at

string format: date-time

created_at

string format: date-time

updated_at

string format: date-time

Example

{
  "data": {
    "id": 224,
    "text": "Hello, how are you?",
    "sent_at": "2025-05-21T15:30:00.123-05:00",
    "delivered_at": "2025-05-21T15:30:05.456-05:00",
    "delivery_status": "pending",
    "edited_at": "2025-05-21T15:31:00.789-05:00",
    "is_read": false,
    "sent_from": "+15551234567",
    "chat_handle_id": 123,
    "attachments": [
      {
        "id": "abc12345-1234-5678-9abc-def012345678",
        "url": "https://storage.googleapis.com/linq-files/attachments/abc123.pdf",
        "filename": "document.pdf",
        "mime_type": "application/pdf",
        "file_size": 12345
      }
    ],
    "reactions": [
      {
        "id": 456,
        "chat_message_id": 224,
        "reaction": "love",
        "is_from_me": false,
        "from_phone": "+15551234567",
        "sent_at": "2025-05-21T15:30:00.000-05:00",
        "created_at": "2025-05-21T15:30:00.000-05:00",
        "updated_at": "2025-05-21T15:30:00.000-05:00"
      }
    ]
  }
}

Send Message

Authorizations

Parameters

Path Parameters

Request Body required

Examples

Responses

201

Example

Request Body^required