Group chats

Manage group chats created or received through your LoopMessage account.

Create a group

POST https://a.loopmessage.com/api/v1/group/new/

Creates a group and sends the first message to its participants.

Headers

Name	Type	Description
Authorization*	String	API Key. Required*.
Content-Type*	String	application/json

Request Body

Name	Type	Description
contacts*	Array	Phone numbers or iMessage email addresses of the group participants.
text*	String	The first message sent to the group.
name	String	Group name. Required for WhatsApp groups.
sender*	String	Sender name ID.
channel*	String	Delivery channel. Possible values: imessage, sms , rcs, or whatsapp.

{
    "contacts": ["+13231112233", "+13232223344"],
    "text": "Hello everyone",
    "sender": "sender-name-id",
    "channel": "imessage"
}

Create a WhatsApp group

Set channel to whatsapp and provide the group name in name:

{
    "contacts": ["+13231112233", "+13232223344"],
    "name": "Project team",
    "text": "Hello everyone",
    "sender": "sender-name-id",
    "channel": "whatsapp"
}

The request is asynchronous. LoopMessage creates the WhatsApp group, sends the first message, and then reports the resulting group ID through the webhook. The initial HTTP response contains the message/request ID, not the WhatsApp group ID.

WhatsApp privacy settings can prevent some contacts from being added directly to a group. In that case, you can still create the group and send the first message. The webhook’s group participants list will include only the participants whose WhatsApp privacy policy has been accepted.

Response {.tabset .tabset-fade}

tab 200: Request accepted

{
    "contacts": ["+13231112233", "+13232223344"],
    "id": "2BC4FD6A-CE49-439F-81DF-E895C09CA49C",
    "sender": "sender-id"
}

Get group information

GET https://a.loopmessage.com/api/v1/group/{group_id}/

Returns the group name, participants, channel, and activity dates.

Response {.tabset .tabset-fade}

tab 200: Request accepted

{
    "id": "2BC4FD6A-CE49-439F-81DF-E895C09CA49C",
    "name": "Project team",
    "participants": ["+13231112233", "+13232223344"],
    "create_date": "2026-08-30T12:00:00+00:00",
    "channel": "imessage",
    "sender": "sender-name"
}

Add a participant

PUT https://a.loopmessage.com/api/v1/group/{group_id}/

Request Body

Name	Type	Description
contact*	String	Phone number or iMessage email.

{
    "contact": "+13233334444"
}

Remove a participant

DELETE https://a.loopmessage.com/api/v1/group/{group_id}/

Request Body

Use the same body as for adding a participant:

{
    "contact": "+13233334444"
}

Update a group

PATCH https://a.loopmessage.com/api/v1/group/{group_id}/

Updates the group name or photo. Send one update at a time.

Request Body

Name	Type	Description
name	String	Optional group name. Maximum length: 32 characters.
photo_url	String	Optional publicly accessible HTTPS image URL.

Change the name:

{
    "name": "New group name"
}

Change the photo:

{
    "photo_url": "https://example.com/group-photo.jpg"
}

To remove the group photo, send an empty value:

{
    "photo_url": ""
}

Response {.tabset .tabset-fade}

tab 200: Request accepted

{
    "group": "2BC4FD6A-CE49-439F-81DF-E895C09CA49C",
    "id": "2BC4FD6A-CE49-439F-81DF-E895C09CA49C",
    "sender": "sender-uuid"
}