Buttondown Documentation
We've expanded the Newsletter API to include the following new fields that allow for further programmatic customization of your newsletter:
css - Custom CSS styling for your newsletter emailsweb_css - Custom CSS styling for your newsletter's web presenceicon - URL to your newsletter's icon imagedescription - A brief description of your newsletterimage - URL to your newsletter's header or branding imageThese additions make it possible to programmatically customize the visual appearance of your newsletter both in email and on the web, giving you more control when integrating Buttondown as a headless email or newsletter provider.
With these fields, you can now update your newsletter's branding and styling via the API, matching the capabilities previously only available through the web interface.