Cleanse addresses in n8n with the HTTP Request node

n8n does not need a dedicated Danadresse node. The HTTP Request node calls the API, and the JSON response comes out as fields you can use in the next nodes. The short recipe is at /en/integrationer/n8n. This guide adds field mapping, batching against the per-minute limit, error handling and a workflow you can import.

1. Store the key as a credential#

Go to Credentials → Add credential → Header Auth. Set Name to X-Api-Key and Value to your key, and call the credential Danadresse. The key is then stored encrypted in n8n rather than in plain text in the workflow.

2. Set up the HTTP Request node#

Batching makes n8n send one call per second instead of all at once. Without it, a long list can hit the per-minute limit within seconds. On the free plan the limit is 360 calls per minute, so set the interval to match your plan.

With Include Response Headers and Status the response sits under body, and you also get statusCode and headers.

/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 adresse then also has etage, dør and adgangsadresseid. Separate query parameters (vejnavn, husnr, etage, dør, postnr) work too.

3. Map the fields#

n8n expressions are JavaScript, and lists count from 0. ?. makes the expression return empty instead of failing when there is no candidate.

Use an IF or Switch node on the category. A is an exact match. B is one safe match with small spelling differences: continue, and store the official text from adresse. C (several candidates or larger differences) goes to manual review and is never accepted automatically.

The cleanse answer has no municipality or coordinates. If you need them, add a second HTTP Request node with the URL https://api.danadresse.dk/adgangsadresser/{{ $json.body.resultater[0].adresse.id }} and the same credential. Read kommune.kode, kommune.navn and adgangspunkt.koordinater[0] / [1] (longitude, latitude) from its response. That is one extra call per row.

4. Errors and 429#

Open the node's Settings:

• Retry On Fail: on, Max Tries 3, Wait Between Tries 5000 ms (the most n8n allows). At the per-minute limit (rate_limit_per_minute) the API sends Retry-After with the seconds until the minute window resets (1-60), so a retry after 5 seconds can come too early. With batching as above that is rare.
• On Error: Continue (using error output). The node then gets an extra output for rows that still fail after the retries. Connect it to a node that logs the address and the error.

Retries do not help when the code is quota_exceeded. That means the free plan's monthly quota and its 20 % grace are used up. The response has no Retry-After, and the quota resets on the 1st of next month. Error responses on the DAWA paths have a code field, so you can tell them apart in the error branch. For quota_exceeded, title explains it in plain language and details has resets_at and upgrade_url. Refused calls are not counted.

If you would rather control it all yourself, turn on Never Error under Options → Response. Every response then leaves through the normal output, and you can send statusCode 429 with body.code = rate_limit_per_minute to a Wait node that waits {{ $json.headers['retry-after'] }} seconds, and back.

5. Import a ready-made workflow#

Copy the JSON and paste it onto an empty canvas in n8n with Ctrl+V or Cmd+V. Then pick your Danadresse credential in the HTTP Request node and run the workflow.

{
  "name": "Danadresse datavask",
  "nodes": [
    {
      "parameters": {},
      "name": "Start",
      "type": "n8n-nodes-base.manualTrigger",
      "typeVersion": 1,
      "position": [0, 0]
    },
    {
      "parameters": {
        "jsCode": "return [\n  { json: { adresse: 'Strandvejen 100, 2900 Hellerup' } },\n  { json: { adresse: 'Rådhuspladsen 1, 1550 København V' } }\n];"
      },
      "name": "Testadresser",
      "type": "n8n-nodes-base.code",
      "typeVersion": 2,
      "position": [220, 0]
    },
    {
      "parameters": {
        "url": "https://api.danadresse.dk/datavask/adgangsadresser",
        "authentication": "genericCredentialType",
        "genericAuthType": "httpHeaderAuth",
        "sendQuery": true,
        "queryParameters": {
          "parameters": [{ "name": "betegnelse", "value": "={{ $json.adresse }}" }]
        },
        "options": {
          "batching": { "batch": { "batchSize": 1, "batchInterval": 1000 } },
          "response": { "response": { "fullResponse": true } }
        }
      },
      "name": "Datavask",
      "type": "n8n-nodes-base.httpRequest",
      "typeVersion": 4.2,
      "position": [440, 0],
      "retryOnFail": true,
      "maxTries": 3,
      "waitBetweenTries": 5000,
      "onError": "continueErrorOutput"
    }
  ],
  "connections": {
    "Start": { "main": [[{ "node": "Testadresser", "type": "main", "index": 0 }]] },
    "Testadresser": { "main": [[{ "node": "Datavask", "type": "main", "index": 0 }]] }
  }
}

Test the call#

The same call the node makes, from a terminal:

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