Car data and inventory integration — through a simple REST API

Who is the API for?

Authentication

Every call requires an API key, which we issue by agreement. The key is sent in the header X-Api-Key. Keys can be revoked instantly from our side, and we store only a hash of them.

curl "https://bilporten.dk/api/v1/listings?maerke=volkswagen&pris_til=200000" \
  -H "X-Api-Key: bp_live_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"

Endpoints

GET/api/v1/listings

Returns 24 listings per page, newest first. All parameters are optional and can be combined.

Response

{
  "data": [
    {
      "id": 13,
      "url": "https://bilporten.dk/bil/hyundai-kona-1-2-puretech-sport-190-hk-2015-13",
      "seller_type": "dealer",
      "dealer": { "name": "Demo Biler ApS", "url": "https://bilporten.dk/forhandler/demo-biler-aps", "city": "Tønder" },
      "make": "Hyundai", "model": "Kona", "variant": "1.2 PureTech Sport 190 hk",
      "body_type": "suv", "model_year": 2015, "mileage_km": 143000,
      "fuel": "hybrid", "transmission": "automatisk", "horsepower": 190,
      "price_dkk": 240400, "price_original_dkk": null, "price_new_dkk": 457000,
      "equipment": ["Adaptiv fartpilot", "Apple CarPlay", "Bakkamera"],
      "location": { "zip": "4700", "city": "Næstved", "region": "Sjælland" },
      "images": [{ "url": "…/uploads/listings/…/a1.webp", "thumb_url": "…/a1-thumb.webp", "width": 1600, "height": 1067 }],
      "published_at": "2026-09-09T13:41:02.000Z"
    }
  ],
  "meta": { "total": 36, "page": 1, "pages": 2, "per_page": 24 }
}

GET/api/v1/listings/{id}

Same structure as above, but with all photos and the full description. Returns 404 for sold or inactive listings.

curl "https://bilporten.dk/api/v1/listings/13" -H "X-Api-Key: bp_live_…"

Inventory sync for dealers

With a write key, your inventory system can send the whole stock as one JSON document, for example every hour. We create new cars, update price and mileage on existing ones, and mark cars that are no longer included as sold. We also support imports from the common Danish DMS formats — contact us and we will set it up with you.

POST https://bilporten.dk/api/v1/inventory/sync
X-Api-Key: bp_live_…
Content-Type: application/json

{
  "remove_missing": true,            // biler der ikke er med, markeres solgt
  "listings": [
    {
      "external_id": "DMS-48213",      // jeres eget id – bruges til at matche ved næste kald
      "make": "Volkswagen", "model": "Golf", "variant": "1.5 TSI Life",
      "year": 2021, "first_registration": "2021-03",
      "mileage_km": 48000, "fuel": "benzin", "transmission": "automatisk",
      "body_type": "hatchback", "horsepower": 150, "color": "Grå",
      "price_dkk": 219900, "price_new_dkk": 329900,
      "description": "…", "equipment": ["Apple CarPlay", "Bakkamera"],
      "plate": "AB12345",              // gemmes kun – vises aldrig offentligt
      "images": ["https://dms.example.dk/img/48213-1.jpg", "https://dms.example.dk/img/48213-2.jpg"],
      "sold": false
    }
  ]
}

→ 200 { "ok": true, "created": 1, "updated": 0, "sold": 0, "unchanged": 0, "errors": [], "imagesQueued": 2 }

• Idempotent: send the whole stock as often as you like (e.g. hourly) — only changes are written. Max 2,000 cars per call.
• fuel: benzin · diesel · el · hybrid · plugin_hybrid · gas (English synonyms such as petrol/electric/phev are accepted). transmission: automatisk · manuel.
• Images are fetched in the background and stored in our format (WebP, EXIF stripped). If you change the image URLs, they are fetched again.
• Price reductions are automatically recorded as a “price drop” on the listing.
• Errors on individual cars do not stop the rest — they come back in errors[] with external_id and a reason.

Data fields

Errors and limits

• 401 unauthorizedMissing or invalid key
• 404 not_foundThe listing does not exist / is not active
• 429 rate_limitedMore than 1,000 calls per hour per key (can be raised by agreement)
• 400 bad_requestUgyldige parametre

{ "error": { "code": "rate_limited", "message": "For mange kald. Grænsen er 1.000 kald i timen." } }

Terms and GDPR

• The API never discloses personal data: no licence plates, VINs, private sellers' names, phone numbers or addresses.
• Data may be displayed with attribution (“Source: BilPorten”) and a link to the listing. Reselling raw data requires a separate agreement.
• The servers are in the EU. All calls are logged with key id and timestamp for 30 days for security reasons.
• Prices are agreed individually (typically a fixed monthly price based on call volume). Dealers on Pro and Unlimited get inventory sync included in the subscription.