This is an old revision of the document!
Update
https://www.duckdns.org/
https://www.duckdns.org/spec.jsp
HTTP API Specification The update URL can be requested on HTTPS or HTTP. It is recommended that you always use HTTPS We provide HTTP services for unfortunate users that have HTTPS blocked You can update your domain(s) with a single HTTPS get to DuckDNS https://www.duckdns.org/update?domains={YOURVALUE}&token={YOURVALUE}[&ip={YOURVALUE}][&ipv6={YOURVALUE}][&verbose=true][&clear=true] The domain can be a single domain - or a comma separated list of domains. The domain does not need to include the .duckdns.org part of your domain, just the subname. If you do not specify the IP address, then it will be detected - this only works for IPv4 addresses You can put either an IPv4 or an IPv6 address in the ip parameter If you want to update BOTH of your IPv4 and IPv6 records at once, then you can use the optional parameter ipv6 to clear both your records use the optional parameter clear=true A normal good response is OK A normal bad response is KO if you add the &verbose=true parameter to your request, then OK responses have more information OK 127.0.0.2 [The current IP address for your update - can be blank] 2002:DB7::21f:5bff:febf:ce22:8a2e [The current IPV6 address for your update - can be blank] UPDATED [UPDATED or NOCHANGE] HTTP Parameters domains - REQUIRED - comma separated list of the subnames you want to update token - REQUIRED - your account token ip - OPTIONAL - if left blank we detect IPv4 addresses, if you want you can supply a valid IPv4 or IPv6 address ipv6 - OPTIONAL - a valid IPv6 address, if you specify this then the autodetection for ip is not used verbose - OPTIONAL - if set to true, you get information back about how the request went clear - OPTIONAL - if set to true, the update will ignore all ip's and clear both your records Special no-parameter request format Some very basic routers can only make requests without parameters For these requirements the following request is possible https://duckdns.org/update/{YOURDOMAIN}/{YOURTOKEN}[/{YOURIPADDRESS}] Restrictions YOURDOMAIN - REQUIRED - only a single subdomain YOURTOKEN - REQUIRED - your account token YOURIPADDRESS - OPTIONAL - if left blank we detect IPv4 addresses, if you want to over-ride this, with a valid IPv4 or IPv6 address TXT Record API The TXT update URL can be requested on HTTPS or HTTP. It is recommended that you always use HTTPS We provide HTTP services for unfortunate users that have HTTPS blocked You can update your domain(s) TXT record with a single HTTPS get to DuckDNS your TXT record will apply to all sub-subdomains under your domain e.g. xxx.yyy.duckdns.org shares the same TXT record as yyy.duckdns.org https://www.duckdns.org/update?domains={YOURVALUE}&token={YOURVALUE}&txt={YOURVALUE}[&verbose=true][&clear=true] The domain can be a single domain - or a comma separated list of domains. The domain does not need to include the .duckdns.org part of your domain, just the subname. to clear the TXT value of your records use the optional parameter clear=true A normal good response is OK A normal bad response is KO if you add the &verbose=true parameter to your request, then OK responses have more information OK sometxt=thistext [The current TXT record for your update - can be blank] UPDATED [UPDATED or NOCHANGE] HTTP Parameters domains - REQUIRED - comma separated list of the subnames you want to update token - REQUIRED - your account token txt - REQUIRED - the txt you require verbose - OPTIONAL - if set to true, you get information back about how the request went clear - OPTIONAL - if set to true, the update will ignore the txt parameter and clear the txt record Note that the TXT record does not show up in the WEB interface You can use online web based Dig tools to query your record https://www.digwebinterface.com/?hostnames=test.duckdns.org&type=TXT&ns=resolver&useresolver=8.8.4.4 To see your TXT record on linux or osx you can query DNS directly dig test.duckdns.org TXT As stated before, this record will be also presented for any sub-subdomain queries dig test.test.duckdns.org TXT This can be used for example to prove your ownership with letsencrypt.org