API access, and Subfinder on the way
ActiveDNS now has API access. Instead of copying results from the website, tools can ask ActiveDNS directly with a free API token.
Tokens are self-service: enter your e-mail address on a token page, open the link we send you, and press the button. The token is created and shown once, in your browser. During this beta, tokens are valid for 90 days and come with an hourly and a daily budget, so the service stays free and responsive for everyone. We do not keep your e-mail address, only a keyed hash of it, so we can limit how many tokens one address gets.
The first integration is Subfinder by ProjectDiscovery, the passive subdomain discovery tool. I have written an ActiveDNS source for it and am submitting it to the project. Until it is merged and part of a Subfinder release, Subfinder does not know about ActiveDNS yet, but a token already works with the API directly. You can get one on the Subfinder token page, and the API documentation shows what you can ask.
Feedback on the API, and requests for other tools you would like to see supported, are very welcome through the contact page.