Integrate the Kennzeichen-Check: activate it yourself, no waiting

To the Kennzeichen-Check · See coverage · Data security at Zevra

How is the Kennzeichen-Check activated?

How do I add the widget?

One line before the closing body element is enough. The widget shows the input field, the result and free alternatives and does not take over any styles of your page.

<script src="https://zevra24.de/kc.js"
  data-site-key="IHR_SITE_SCHLUESSEL"
  data-prefix="RE"
  async></script>

The site key is bound to your domain. The secret API key does not belong in a web page.

Example: widget in a dealer page, combination taken with 3 free alternatives

How do I call the API?

Every call needs the header X-WKZ-Key with your key. The key belongs in the header, never in the URL and never in the browser.

curl "https://app.zevra24.de/api/kc/v1/search?prefix=RE&letters=AB&numbers=123" \
  -H "X-WKZ-Key: IHR_SCHLUESSEL"

{
 "plate": "RE-AB 123",
 "available": true,
 "reason": "checked",
 "latency_ms": 3771
}

Machine-readable description of the API (OpenAPI 3.1)

Which calls are there?

curl -X POST https://app.zevra24.de/api/kc/v1/search/batch \
  -H "X-WKZ-Key: IHR_SCHLUESSEL" \
  -H "Content-Type: application/json" \
  -d '{"items":[{"prefix":"RE","letters":"AB","numbers":"123"},{"prefix":"RE","letters":"AB","numbers":"124"}]}'

What does the answer mean?

Which answers are counted?

How do I test in the sandbox at no cost?

In the customer area you create a sandbox key. It starts with wkz_sbx_, reaches no authority and is not charged. The letters of the combination determine the result.

How do I reserve through the API?

You send the combination and the holder's data with the header Idempotency-Key. The same key with the same content returns the same job, never a second reservation. The answer names the job; the status follows by query or webhook.

Real reservation is in preparation. In the sandbox the flow can be tested at launch.

curl -X POST https://app.zevra24.de/api/kc/v1/reservations \
  -H "X-WKZ-Key: wkz_sbx_IHR_SANDBOX_SCHLUESSEL" \
  -H "Idempotency-Key: auftrag-2026-0001" \
  -H "Content-Type: application/json" \
  -d '{"prefix":"RE","letters":"OK","numbers":"123","customerReference":"Auftrag 0001",
       "halter":{"name":"Mustermann","vorname":"Max","plz":"45657","ort":"Recklinghausen"}}'

{
 "id": "RES-7F3K2M9Q",
 "status": "queued",
 "environment": "sandbox",
 "plate": "RE-OK 123",
 "customerReference": "Auftrag 0001",
 "reservationCode": null,
 "authorityFeeAdvancedCents": 0
}

How do I learn the status of a reservation?

In the customer area you store an https address. Zevra sends the event reservation.updated on every status change. Every message is signed with HMAC-SHA256.

• X-Zevra-Timestamp names the time of the message in seconds.
• X-Zevra-Signature is HMAC-SHA256 over timestamp, dot and body, with your secret.
• If your system does not answer with 2xx, Zevra repeats the delivery after 1, 5, 30, 120 and 720 minutes.

import hmac, hashlib

def echt(secret, timestamp, body, signature):
    soll = hmac.new(secret.encode(), f"{timestamp}.{body}".encode(), hashlib.sha256).hexdigest()
    return hmac.compare_digest(soll, signature)

Which errors does the API report?

Which response times and limits apply?

• Response time of a check, measured over 7 days and 7.020 checks: half under 4,2 seconds, 75 % under 7,3 seconds, 95 % under 14,6 seconds.
• An answer arrives after 58 seconds at the latest. Please set your timeout to 65 seconds.
• Each key allows 120 requests per minute. A batch search counts per combination.
• A free plate is not an allocation. The plate is allocated only at registration.