---
title: "Message sent event"
method: POST
path: "message.sent"
tags: ["Webhook Events"]
---

# Message sent event

`POST message.sent` (webhook)

Fired when a message is sent via the API, or from the WhatsApp Business app on Coexistence numbers.

## Payload

- WebhookPayloadMessageSent — Webhook payload for message sent events (fired when a message is sent via the API, or from the WhatsApp Business app on Coexistence numbers)
  - `id` string, required — Stable webhook event ID
  - `event` 'message.sent', required
  - `message` object, required
    - `id` string, required — Internal message ID
    - `conversationId` string, required — Internal conversation ID
    - `platform` 'instagram' | 'facebook' | 'telegram' | 'whatsapp', required
    - `platformMessageId` string, required — Platform's message ID
    - `direction` 'incoming' | 'outgoing', required
    - `text` string, nullable, required — Message text content
    - `attachments` object[], required
      - `type` string, required — Attachment type (image, video, file, sticker, audio)
      - `url` string, required — Where to fetch the attachment. For outgoing messages this is the media URL as sent, so for WhatsApp it is the URL you supplied when publishing (WhatsApp sends media by link), not a Zernio endpoint, and it needs no Zernio credentials. Contrast the inbound direction: `message.received` attachment URLs on WhatsApp point at the authenticated `GET /v1/whatsapp/media/{mediaId}`.
      - `payload` object — Additional attachment metadata
    - `sender` object, required
      - `id` string, required
      - `contactId` string — Zernio CRM Contact id for this sender, when one exists.
      - `name` string
      - `username` string
      - `picture` string
    - `sentAt` string, date-time, required
    - `isRead` boolean, required
    - `source` 'whatsapp_business_app' | 'cloud_api' — WhatsApp send origin. whatsapp_business_app when sent from the WhatsApp Business phone app on a Coexistence number; cloud_api when sent through Zernio (dashboard, API, or broadcasts). Absent on non-WhatsApp platforms. This is not the inbox metadata.source lineage field.
  - `conversation` InboxWebhookConversation, required — The conversation context included in inbox webhook payloads.
    - `id` string, required
    - `platformConversationId` string, required
    - `participantId` string
    - `participantName` string
    - `participantUsername` string
    - `participantPicture` string
    - `status` 'active' | 'archived', required
    - `contactId` string — Zernio CRM Contact ID for the participant, when one exists. Resolved by joining `participantId` to the ContactChannel collection. Best-effort: omitted when no channel matches or `participantId` is absent. Lets integrators join any inbox webhook back to the CRM Contact without needing to look at the sender — which matters for outgoing and delivery-status events whose sender is the business.
  - `account` InboxWebhookAccount, required — The account context included in inbox webhook payloads.
    - `id` string, required — Social account ID
    - `accountId` string — Social account ID (same value as id). Canonical field so consumers can filter every webhook event on one field (e.g. route staging vs production by account). id is kept for backward compatibility.
    - `profileId` string — Zernio profile (workspace) ID this account belongs to. Use it to route or filter inbox webhooks by workspace. This is the profile ID only, not its name (resolve the name via the API with this ID). Optional; omitted on the shared WhatsApp sandbox account and when the account has no resolvable profile.
    - `platform` string, required
    - `username` string, required
    - `displayName` string
  - `timestamp` string, date-time, required

## Acknowledgement `200`

Webhook received successfully

---

[API](https://skmtc.net/zernio/apis/zernio-api.md) · [All operations](https://skmtc.net/zernio/apis/zernio-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/zernio/zernio-api/versions/51932b099b2f/schema)