Transactional e-mails

A transactional e-mail goes to one person because of what they have just done. It needs no list and no marketing consent, and it is logged and followed like a campaign. See Overview.

With a template

The cleanest way: the content lives in Lekalao, the application sends only the data. Create a template named order-confirmation (Transactional templates), then:

curl -X POST https://lekalao.example.com/api/v1/transactional-mails/send \
  -H "Authorization: Bearer $LEKALAO_TOKEN" \
  -H "Content-Type: application/json" \
  -H "Accept: application/json" \
  -H "Idempotency-Key: order-2026-00481-confirmation" \
  -d '{
    "template": "order-confirmation",
    "to": ["ada@example.com"],
    "locale": "en",
    "variables": {
      "customer": { "name": "Ada" },
      "order": {
        "number": "2026-00481",
        "total": "12,500 FCFA",
        "items": ["Wholemeal bread", "Croissant x4"]
      }
    }
  }'

In the template:

<p>Hello {{ customer.name }},</p>
<p>Your order <strong>{{ order.number }}</strong> is confirmed.</p>
<ul>
    {% for item in order.items %}
    <li>{{ item }}</li>
    {% endfor %}
</ul>
<p>Total: {{ order.total }}</p>

Variables are escaped; loops run over lists of plain values. The whole syntax is in Personalisation.

Without a template

Send the HTML as it is:

curl -X POST https://lekalao.example.com/api/v1/transactional-mails/send \
  -H "Authorization: Bearer $LEKALAO_TOKEN" \
  -H "Content-Type: application/json" \
  -H "Accept: application/json" \
  -d '{
    "to": ["ada@example.com"],
    "subject": "Your September invoice",
    "html": "<p>Hello Ada, your invoice is attached.</p>",
    "from_email": "invoices@mybakery.example",
    "from_name": "The Bakery",
    "attachments": [
      { "name": "invoice-2026-09.pdf", "content": "JVBERi0xLjcKJcfsj6IK…", "mime": "application/pdf" }
    ]
  }'

The fields

Field
`template`	The name of a transactional template.
`html`	The body, when there is no template. One of the two is required.
`subject`	The subject. With a template, it replaces the template’s own.
`to`, `cc`, `bcc`	Arrays of addresses. Without `to`, the template’s default recipients.
`variables`	A free object, which fills the template.
`locale`	Which language version of the template to send. See below.
`from_email`, `from_name`, `reply_to`	The sender; otherwise the template’s, otherwise the team’s.
`mailer`	The name of a configured sending provider, to force the route.
`attachments`	10 at most: `name`, `content` in base64, `mime` optional.

In several languages

A template can have one version per language (Languages). locale picks it:

`locale` sent	Version used
absent	The base version.
`pt-BR`, and the template has `pt-BR`	`pt-BR`.
`pt-BR`, the template only has `pt`	`pt`.
`pt`, the template only has `pt-BR`	The base version: a language never takes a regional version.
a language with no version	The base version.

Pass your customer’s language as your application knows it: Lekalao falls back on its own.

The answer

201 once the provider has taken the e-mail:

{
    "data": {
        "id": "e3b0c442-98fc-4c14-9a1e-2f6b7d8a9c10",
        "template": "order-confirmation",
        "subject": "Order 2026-00481 confirmed",
        "from": "hello@mybakery.example",
        "to": ["ada@example.com"],
        "cc": [],
        "bcc": [],
        "status": "sent",
        "failure_reason": null,
        "opens": 0,
        "clicks": 0,
        "sent_at": "2026-09-17T10:14:03+00:00",
        "created_at": "2026-09-17T10:14:02+00:00"
    }
}

502 when the provider refused it: the e-mail is logged with status: failed and the reason in failure_reason. It is failed too when the plan’s monthly allowance is used up. 422 when the sender is not allowed, when neither template nor html is given, or when there is no recipient at all.

Sending is synchronous: the answer comes back once the provider has replied. Call the API from a background job of your application, not during your customer’s own request.

Follow and send again

Call
`GET /transactional-mails?template=order-confirmation&status=failed&to=ada@example.com`	The log, filtered.
`GET /transactional-mails/{id}`	One e-mail, with opens and clicks.
`POST /transactional-mails/{id}/resend`	Sends it again unchanged; a new e-mail is created. `409` when the template did not keep the content.

Bounces and complaints arrive through the mail.bounced and mail.complaint webhooks.

Other roads

A Laravel application can keep Mail::to()->send(): see Laravel transport.
Software that only speaks SMTP: see SMTP relay.

The API

Recipes

Integrations

Transactional e-mails

With a template

Without a template

The fields

In several languages

The answer

Follow and send again

Other roads

​With a template

​Without a template

​The fields

​In several languages

​The answer

​Follow and send again

​Other roads

With a template

Without a template

The fields

In several languages

The answer

Follow and send again

Other roads