Opens a brand new conversation with a contact on WhatsApp and sends an approved template as its first
message. This is the only way to reach a contact that never wrote to you, or that has been silent for
more than 24 hours: outside that window Meta only accepts template messages.

The list of templates you can send, and the variables each one expects, is returned by
GET /v2/whatsapp/templates. Only text-only templates are supported.

Choosing the contact

polymorphic_contact_id accepts the usual contact identifiers: a numeric ID ("12345"), a custom user
ID ("cuid:user_123"), a custom lead ID ("clid:lead_456"), an email ("uem:[email protected]" or
"lem:[email protected]"), or a WhatsApp number ("wa:+1234567890").

The contact must already exist and must have a WhatsApp number on its profile. Create it first with
POST /v2/contacts when it does not.

Choosing the sender and the assignee

account_id is the account the template is sent as. It is recorded as the author of the message in the
Customerly inbox and drives the send attribution; the contact only ever sees the WhatsApp business number,
never the account. It defaults to the account owning the access token.

assignee_type and assignee_id decide who the new conversation is assigned to, and must be provided
together. assignee_type is "account" or "team". When omitted, the conversation is assigned to the
sender account.

Choosing the sender number

whatsapp_business_number selects which of your connected WhatsApp Business numbers sends the message.
It can be omitted when your project has a single connected number. The template must belong to the same
WhatsApp Business Account (WABA) as the number, otherwise the request is rejected with
whatsapp_template_waba_mismatch.

Example request

{
  "polymorphic_contact_id": "wa:+1234567890",
  "whatsapp_template_id": 42,
  "whatsapp_business_number": "+1555000111",
  "account_id": 123,
  "assignee_type": "team",
  "assignee_id": 7,
  "parameters": {
    "name": "John",
    "order_id": "A-19822"
  }
}

The message is handed over to WhatsApp asynchronously: a 201 means the conversation was created and the
template accepted, not that it has already been delivered to the phone. Delivery is reported on the
message itself (GET /v2/conversations/{conversation_id}/messages).