PHP

Installation

Install the package

composer require keplars/email-sdk

Set your API key

KEPLARS_API_KEY=kms_your_workspace_id.live_your_secret

Send your first email

<?php

require 'vendor/autoload.php';

use Keplars\Email\Client;

$client = new Client($_ENV['KEPLARS_API_KEY']);

$response = $client->emails->sendInstant([
    'to'      => '[email protected]',
    'from'    => '[email protected]',
    'subject' => 'Hello!',
    'body'    => '<h1>It works!</h1>',
    'is_html' => true,
]);

echo $response['id'];

Priority Levels

Method	Delivery	Use case
`sendInstant`	0–5 seconds	OTP, 2FA, password reset
`sendHigh`	0–30 seconds	Transactional confirmations
`sendAsync` / `send`	0–5 minutes	Welcome emails, notifications
`sendBulk`	Background	Newsletters, campaigns

$client->emails->sendInstant([...]);
$client->emails->sendHigh([...]);
$client->emails->sendAsync([...]);
$client->emails->sendBulk([...]);

Using Templates

$response = $client->emails->sendInstant([
    'to'          => '[email protected]',
    'from'        => '[email protected]',
    'template_id' => 'your-template-id',
    'params'      => [
        'user_name'         => 'Jane',
        'verification_code' => '123456',
    ],
]);

Schedule an Email

$response = $client->emails->schedule([
    'to'            => '[email protected]',
    'from'          => '[email protected]',
    'subject'       => 'Weekly digest',
    'body'          => '<p>Here is your digest.</p>',
    'is_html'       => true,
    'scheduled_for' => '2026-02-01T09:00:00Z',
    'timezone'      => 'America/New_York',
]);

Error Handling

use Keplars\Email\Exceptions\AuthenticationException;
use Keplars\Email\Exceptions\RateLimitException;
use Keplars\Email\Exceptions\ValidationException;

try {
    $response = $client->emails->sendInstant([...]);
} catch (AuthenticationException $e) {
    echo 'Invalid API key';
} catch (RateLimitException $e) {
    echo 'Rate limit hit, retry after: ' . $e->getRetryAfter();
} catch (ValidationException $e) {
    echo 'Validation error: ' . $e->getMessage();
}

Laravel Integration

// config/services.php
'keplars' => [
    'api_key' => env('KEPLARS_API_KEY'),
],

// In your service or controller
$client = new \Keplars\Email\Client(config('services.keplars.api_key'));

Admin API

Need to manage contacts, audiences, automations, or domains? Use an admin key - same client, different key suffix:

$client = new Client('kms_xxx.adm_xxx');

$client->contacts->add(['email' => '[email protected]', 'name' => 'Jane']);
$client->audiences->create('Newsletter');
$client->automations->enroll('auto_id', '[email protected]');
$client->domains->verify('domain_id');

See the full Admin API reference.

Next Steps

Admin API - Contacts, audiences, automations, domains
Send Emails - API reference
Email Templates - Build reusable templates
Schedule Emails - Delayed delivery

PHP

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