---
title: "Send a multi-channel transactional message"
method: POST
path: "/messages"
tags: ["Messages"]
---

# Send a multi-channel transactional message

`POST /messages`

## Request

- Base URL: `https://sending.dev/api/v1`
- URL: `https://sending.dev/api/v1/messages`
- Auth: HTTP bearer

Unified transactional send over email, WhatsApp or Telegram (discriminated union on `channel`). Required scope: `email:send` or `messages:send`. `email:send` for the email channel, `messages:send` for WhatsApp/Telegram.

## Request body

- union
  - object
    - `channel` 'email', required
    - `to` union, required: Email recipients (To header). One or more recipients: 'a@b.com', 'Name <a@b.com>', several comma-separated addresses, or an array.
      - string
      - string[]
    - `from` string, required
    - `subject` string
    - `html` string
    - `text` string
    - `replyTo` union: Reply-To: one or more addresses ('a@b.com', 'Name <a@b.com>', comma-separated or an array, at most 10). A plain "Reply" goes to all of them.
      - string
      - string[]
    - `cc` union: One or more recipients: 'a@b.com', 'Name <a@b.com>', several comma-separated addresses, or an array.
      - string
      - string[]
    - `bcc` union: One or more recipients: 'a@b.com', 'Name <a@b.com>', several comma-separated addresses, or an array.
      - string
      - string[]
    - `templateId` string
    - `variables` object
    - `attachments` object[]: Email attachments (max 20, 10 MB each, 25 MB in total). For each item provide exactly one source: `id`, `content` (base64) or `url`.
      - `id` string, uuid: Id of an attachment already uploaded with POST /v1/attachments.
      - `filename` string: File name shown to the recipient. Required with `content` or `url`.
      - `content` string: File content in base64, without the `data:` prefix.
      - `url` string, uri: Public https URL to download the file from (private hosts are blocked).
      - `contentType` string: Content-Type override; when absent, it is inferred from the file name.
      - `contentId` string: Content-ID for inline images referenced in the HTML as `cid:<value>`: the attachment becomes `inline` instead of appearing at the end of the message.
    - `idempotencyKey` string, required
    - `disableTracking` boolean
    - `disableUtm` boolean
  - object
    - `channel` 'whatsapp', required
    - `to` string, required
    - `text` string
    - `templateId` string
    - `variables` object
    - `metaTemplate` object
      - `name` string, required
      - `params` string[]
      - `language` string
    - `idempotencyKey` string, required
  - object
    - `channel` 'telegram', required
    - `to` string, required
    - `text` string
    - `templateId` string
    - `variables` object
    - `idempotencyKey` string, required

## Response `200`

Send already processed for this idempotencyKey.

- SendResult
  - `id` string
  - `status` string, required
  - `idempotencyKey` string

## Other responses

- `202`: Message queued.
- `401`: Missing or invalid token.
- `402`: Plan quota exceeded.
- `403`: Insufficient scope.
- `409`: Recipient is suppressed for the channel (`suppressed`).
- `422`: Invalid input.
- `502`: Upstream provider error (e.g. SES).

---

[API](https://skmtc.dev/sending/apis/sending-dev-api.md) · [All operations](https://skmtc.dev/sending/apis/sending-dev-api/llms.txt) · [OpenAPI document](https://skmtc.dev/sending/apis/sending-dev-api/revisions/9fe78d2918a1?raw)