Send Custom Transactional Email

Send a custom transactional email with full control over HTML content, text, attachments, and email properties. This endpoint allows you to send emails with custom HTML or text content without using pre-built templates.

POST /v1/transactional/custom

Try it

cURL

basic

curl --request POST \
  --url https://api.flywheel.cx/v1/transactional/custom \
  --header 'Auth-Type: <api-key>' \
  --header 'Authorization: <api-key>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "params": {
    "from": "[e-mail]",
    "to": "[e-mail]",
    "subject": "Welcome to our platform!",
    "html": "<h1>Welcome!</h1><p>Thank you for signing up for our platform.</p>"
  }
}
'

200

{
  "success": true,
  "email_id": "123e4567-e89b-12d3-a456-426614174000"
}

Authorizations

Authorization · string · header · required

Enter your API key obtained from the Flywheel dashboard (without 'Bearer ' prefix)

Auth-Type · string · header · default: api · required

Authentication type header. Must be set to 'api' for all API requests.

Body

application/json

params · object · required

Show child attributes

params. from · string · required

Sender email address. To include a friendly name, use "Your Name [e-mail]" format

Example:

"[e-mail]"

params. to · required

Recipient email address(es). For multiple addresses, send as an array. Maximum 50 recipients

Example:

"[e-mail]"

params. subject · string · required

Email subject line

Example:

"Welcome to our platform!"

params. bcc

Bcc recipient email address(es). For multiple addresses, send as an array

params. cc

Cc recipient email address(es). For multiple addresses, send as an array

params. scheduled_at · string

Schedule email to be sent later. Natural language (e.g.: "in 1 min") or ISO 8601 format

Example:

"2024-03-15T10:00:00Z"

params. reply_to

Reply-to email address(es). For multiple addresses, send as an array

params. html · string

The HTML version of the message

Example:

"<h1>Welcome!</h1><p>Thank you for signing up.</p>"

params. text · string

The plain text version of the message

Example:

"Welcome! Thank you for signing up."

params. react · object

A React Email component for creating beautiful emails using React and TypeScript. This parameter accepts React Email components from https://react.email/ - a collection of high-quality, unstyled components for email design. Only available in Node.js environments.

params. headers · object

Custom headers to add to the email

Show child attributes

params.headers. {key} · string

params. attachments · object[]

Filename and content of attachments (max 40MB per email, after Base64 encoding)

Show child attributes

params.attachments. content · string

Content of an attached file, passed as Base64 string

params.attachments. filename · string

Name of attached file

Example:

"invoice.pdf"

params.attachments. path · string

Path where the attachment file is hosted

params.attachments. content_type · string

Content type for the attachment, if not set will be derived from the filename property

Example:

"application/pdf"

params.attachments. content_id · string

Content ID for embedding images using cid: in HTML

params. tags · object[]

Custom data passed in key/value pairs for tracking and analytics

Show child attributes

params.tags. name · string · required

The name of the email tag (ASCII letters, numbers, underscores, dashes only, max 256 chars)

Example:

"category"

params.tags. value · string · required

The value of the email tag (ASCII letters, numbers, underscores, dashes only, max 256 chars)

Example:

"welcome"

Response

200

application/json

Email sent successfully

success · boolean

Whether the email was sent successfully

Example:

true

email_id · string<uuid>

Unique UUID identifier for the sent email, can be used for tracking delivery status

Example:

"123e4567-e89b-12d3-a456-426614174000"