Start message session

Sends a chat, SMS, or MMS message without a session ID, and answers with the stored message. Every scope reaches its own user. Office Manager reaches every user in its domain, Reseller the domains in its territory, and Super User every domain. You send as the user in the path.

The session is found from who takes part: the same sender and recipients always land in the same session, so calling this again continues the conversation. Read messagesession-id in the answer and use it with POST /domains/{domain}/users/{user}/messagesessions/{messagesession}/messages for later messages.

type is one of these values:

chat: a text message to users in the same domain. The default.

chat-media: a chat message with a file attached.

sms: a text message to phone numbers, sent from one of your SMS numbers.

mms: an SMS with a file attached.

chat-video-invite, chat-video-decline: video call invitations sent in a chat.

The API itself writes chat-name-change, chat-participant-add, chat-participant-remove, chat-participant-remove-notification, and chat-participant-leave messages when a session changes. Do not send them.

Chat

Send message and destination, the extension of a user in the same domain. type can be left out.

Group chat

Send destination as a list of extensions, or as one comma-separated string.

Media chat

Set type to chat-media and attach the file as base64 in data, with mime-type and size. Or send upload_id for a file you already uploaded. message is still required.

SMS

Set type to sms, destination to the phone number, and from-number to your SMS number. from-number must be assigned in this domain to the sending user, or to a call queue.

Group SMS

Send destination as a list of numbers. The message goes out as a group MMS.

MMS

Set type to mms, add from-number, and attach the file as for a media chat.

A number that texted STOP to from-number does not get the message. When every recipient has opted out, the request answers 409. For the opt-out list, see GET /domains/{domain}/smsblocks.

Bearer Token

Provide your bearer token in the

Authorization

header when making requests to protected resources.

Example:

Authorization: Bearer ********************

Responses

🟢200OK

application/json

The message as stored, in an array, with the session it went to in messagesession-id.

Bodyapplication/json

🟠400Bad Request

🟠401Unauthorized

🟠403Forbidden

🟠404Not Found

🟠409Conflict

🟠415Unsupported Media Type

🔴500Internal Server Error

🟠420Rate Limit Exceeded

curl --location 'https://awqacore01.crexendocloud.com/ns-api/v2/domains//users//messages' \ --header 'Authorization: Bearer <token>' \ --header 'Content-Type: application/json' \ --data '{ "type": "chat", "message": "Can you cover the front desk at 3?", "destination": "1002" }'

[ { "id": "m-66f1c2a4b3d5e", "timestamp": "2026-09-01 14:30:00", "type": "chat", "domain": "example.com", "direction": "term", "from-number": "", "from-user-id": "1001@example.com", "from-video-attendee-id": null, "from-user-agent": "Mozilla/5.0", "dialed": "", "text": "Can you cover the front desk at 3?", "terminating-user-id": "1002@example.com", "terminating-number": "", "status": "sending", "meeting-instance-id": null, "media-type": "", "media-size": 0, "deleted-datetime": null, "messagesession-receiver-hostname": "core1.example.com", "messagesession-id": "b1946ac92492d2347c6235b4d2611184", "messagesession-participants": "" } ]

Chat#

Group chat#

Media chat#

SMS#

Group SMS#

MMS#

Request

Responses

Chat

Group chat

Media chat

SMS

Group SMS

MMS