Single Verification API

The single verification endpoint lets you verify one email address per request. It's ideal for real-time verification in sign-up forms, CRMs, or any workflow where you need instant results.

Endpoint

POST /api/v1/verify

Request

Headers:

Header	Required	Description
Authorization	Yes	`Bearer ek_your_api_key`
Content-Type	Yes	`application/json`
Idempotency-Key	No	UUID for retry safety (cached 24 hours)

Body:

{
  "email": "user@example.com"
}

Response

Success (200):

{
  "email": "user@example.com",
  "status": "deliverable",
  "reason": "valid_mailbox",
  "isDeliverable": true,
  "isDisposable": false,
  "isRoleBased": false,
  "isCatchAll": false
}

Response fields:

Field	Type	Description
email	string	The email address that was verified
status	string	`deliverable`, `undeliverable`, `risky`, or `unknown`
reason	string	Detailed reason for the status
isDeliverable	boolean	Whether the email can receive messages
isDisposable	boolean	Whether the email is from a disposable email service
isRoleBased	boolean	Whether the email is a role-based address (info@, admin@, etc.)
isCatchAll	boolean	Whether the domain accepts all email addresses

Error Responses

400 Bad Request — Invalid email format:

{
  "error": "Invalid email address"
}

401 Unauthorized — Invalid or missing API key:

{
  "error": "Invalid API key"
}

402 Insufficient Credits:

{
  "error": "Insufficient credits"
}

429 Rate Limit Exceeded:

{
  "error": "Rate limit exceeded",
  "retryAfter": 1
}

Code Examples

Node.js

const response = await fetch('https://api.emailkit.dev/api/v1/verify', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer ek_your_api_key',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({ email: 'user@example.com' }),
});

const result = await response.json();
console.log(result.status); // "deliverable"

Python

import requests

response = requests.post(
    'https://api.emailkit.dev/api/v1/verify',
    headers={
        'Authorization': 'Bearer ek_your_api_key',
        'Content-Type': 'application/json',
    },
    json={'email': 'user@example.com'}
)

result = response.json()
print(result['status'])  # "deliverable"

PHP

$ch = curl_init('https://api.emailkit.dev/api/v1/verify');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, [
    'Authorization: Bearer ek_your_api_key',
    'Content-Type: application/json',
]);
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode(['email' => 'user@example.com']));

$response = curl_exec($ch);
$result = json_decode($response, true);
echo $result['status']; // "deliverable"

Best Practices

Use idempotency keys when retrying failed requests to avoid duplicate charges
Handle rate limits with exponential backoff (start at 1 second, double each retry)
Cache results on your side — an email's deliverability rarely changes within a few hours
Validate email format before sending to the API to avoid wasting credits on obviously invalid addresses

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