Cleanse addresses in Zapier with Webhooks or Code by Zapier

Zapier can cleanse an address every time a form is submitted, a lead is created or a row arrives in a spreadsheet. The short recipe is at /en/integrationer/zapier. Here you get the exact field mapping, a pitfall with lists, and a version with error handling.

1. Webhooks by Zapier: GET#

Add a step: Webhooks by Zapier → GET. Fill in:

Put the key under Headers rather than api_key in the query string. The URL with its query string is shown in the Zap history.

/datavask/adgangsadresser matches the entrance (street, house number, postcode). To hit a specific flat, use /datavask/adresser: it reads floor and door straight from betegnelse (Strandvejen 100, 2. tv, 2900 Hellerup), and the result then also has etage, dør and adgangsadresseid. Separate parameters (vejnavn, husnr, etage, dør, postnr) work too.

2. The pitfall: lists get joined#

The response has a list, resultater, which can hold several candidates. Zapier shows fields from a list as one value with all items joined by commas. The field Resultater Adresse Postnr can therefore be 2900,2900 if two candidates came back.

Use only the first item. Add Formatter by Zapier → Utilities → Pick from List, choose the field (e.g. Resultater Adresse Id) and Choose: First. Repeat for the fields you need, or use Code by Zapier from step 4, which gives you one object.

The cleanse answer has no municipality or coordinates. The Code by Zapier version in step 4 fetches them with one extra call.

3. Filter on category#

Add Filter by Zapier: continue only if Kategori is A or B. A is an exact match. B is one safe match with small spelling differences, so write back the official text from the result. C addresses (several candidates or larger differences) need a human to look at them. On a plan with Paths you can send them down their own branch, for example to a Slack message.

4. With error handling: Code by Zapier#

The Webhooks step does not give you the status code as a field, and an error response stops the step. To tell error types apart, use Code by Zapier → Run JavaScript instead. Under Input Data, set adresse to the address field and apiKey to the key.

const BASE = "https://api.danadresse.dk";
const headers = { "X-Api-Key": inputData.apiKey };
const url = new URL(BASE + "/datavask/adgangsadresser");
url.searchParams.set("betegnelse", inputData.adresse || "");

const res = await fetch(url, { headers });
const body = await res.json().catch(() => ({}));

// Per-minute limit: throw, so Zapier can run the step again later.
if (res.status === 429 && res.headers.get("retry-after")) {
  throw new Error("Danadresse: too many calls per minute, try again");
}
// Other errors, e.g. quota_exceeded or a blocked key: pass the code and the explanation on.
if (!res.ok) {
  return {
    status: res.status,
    fejlkode: body.code || "unknown",
    besked: body.title || "",
    upgrade_url: (body.details && body.details.upgrade_url) || "",
    kategori: "",
  };
}

const top = (body.resultater && body.resultater[0] && body.resultater[0].adresse) || {};
let adg = {};
if (top.id) {
  // The cleanse answer has no municipality or coordinates: one more call for them.
  const r2 = await fetch(BASE + "/adgangsadresser/" + top.id, { headers });
  if (r2.ok) adg = await r2.json();
}
return {
  status: res.status,
  fejlkode: "",
  kategori: body.kategori,
  id: top.id || "",
  vejnavn: top.vejnavn || "",
  husnr: top.husnr || "",
  postnr: top.postnr || "",
  by: top.postnrnavn || "",
  kommune: (adg.kommune && adg.kommune.navn) || "",
  x: adg.adgangspunkt?.koordinater?.[0] ?? "", // longitude
  y: adg.adgangspunkt?.koordinater?.[1] ?? "", // latitude
};

Zapier runs the code inside an async function, so top-level await and return are valid there. After the step you have flat fields such as kategori, postnr and fejlkode that you can filter on directly. On an error, besked holds the API's plain-language explanation.

fejlkode can be, for example:

If your Zapier plan has Autoreplay turned on, Zapier reruns failed steps later. That suits the per-minute limit. It does not help with a used-up monthly quota.

5. Usage#

Each Zap run is one call with Webhooks, two with the Code by Zapier version. Refused calls (429) are not counted. If your Zap runs on an import with many rows, you can hit the per-minute limit of 360 calls per minute on the free plan. Check your usage under Usage.

Test the call#

curl -s "https://api.danadresse.dk/datavask/adgangsadresser?betegnelse=Strandvejen%20100%2C%202900%20Hellerup" \
  -H "X-Api-Key: $DANADRESSE_API_KEY"

Next steps#

• Make and n8n
• Limits, quotas and 429
• Short recipe: /en/integrationer/zapier