In January 2020 we launched our v2 API, the documentation is available here.
Currently, the API includes calls for event information only. However, we plan on making booking data available in the future too.
You can create an API access token here on any Bookwhen account.
Version 1.0.0 (deprecated)
Our v1 API is now deprecated, the documentation is available here. If you do require a v1 API access key for your account please email firstname.lastname@example.org with your account link.