---
title: "Send a free-form WhatsApp session message"
method: POST
path: "/api/public/whatsapp/message/session"
tags: ["WhatsApp Message"]
---

# Send a free-form WhatsApp session message

`POST /api/public/whatsapp/message/session`

Sends a free-form text message inside an active WhatsApp conversation (the 24h customer-care window), without using a template. Target the recipient with "contact_id" or "phone". Only official WhatsApp API numbers are supported; WhatsApp rejects messages sent outside the 24h window.

## Headers

- `x-api-key` string, required

## Request body

- SendSessionMessageDto
  - `message` string, required — Free-form text body to send inside the active 24h session
  - `contact_id` string, uuid — Vambe contact id to send the message to
  - `phone` string — Recipient phone number, used when contact_id is not provided. Keep an explicit "+" for numbers in a different country than the sender
  - `reply_message_id` string — Provider message id to quote when replying
  - `from_phone_number` string — Business WhatsApp number to send from. Required when targeting by "phone" and the account has more than one WhatsApp number
  - `type` 'text' — Message type. Only "text" is supported for now
  - `pause_assistant` boolean — Pause the AI assistant for this contact (human handoff)

## Response `201`

Message accepted for delivery.

## Other responses

- `400` — Bad request.
- `401` — Unauthorized.
- `404` — No contact found for the given phone or contact_id.

---

[API](https://skmtc.net/vambe/apis/vambe-ai-api.md) · [All operations](https://skmtc.net/vambe/apis/vambe-ai-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/vambe/vambe-ai-api/revisions/e206709d4be5/schema)