Call the API without a key (IP authentication)

What is it?

Normally you send your API key in a header. With IP authentication we recognise you by the IP address your server calls from instead. The request carries neither key nor token:

curl "https://api.danskadresseapi.dk/dawa/adgangsadresser/autocomplete?q=Rentemestervej"

When does it make sense?

When your system cannot set its own HTTP headers on outbound calls. This is typically older integration and ERP platforms where the HTTP layer is built in and cannot be extended.

If you can set a header, use a regular API key. It is stronger: it can be rotated, restricted to specific endpoints and given an expiry date.

Good to know

• The addresses belong to the account — not to a single key. Deleting a key does not affect your IP addresses.
• It works on both /v1 and /dawa.
• Calls count towards your normal quota and appear in the call log like any other call.
• You can restrict what an address may call, so it only reaches the endpoints you actually use.

Requirements

• Basis, Pro or Enterprise.
• A fixed, public IP address. Private addresses (10.x, 172.16–31.x, 192.168.x) cannot be used — they never reach us.
• The address cannot be changed after it is created. It is the credential itself, and if it could be rewritten, a foreign address would inherit your proof of ownership. To correct it, delete the binding and create it again.
• One address can only belong to one account. If two customers share the same outbound address, only one of them can use IP authentication.

Is it secure enough?

An IP address is a weaker credential than a key, so we require you to prove the address is yours before it works. A new address therefore shows as Pending until you have made one call from the same server using your normal API key.

Be aware that everyone calling from that address calls as you. Only use IP authentication on a server you control — not on a shared office network you do not manage.