Currently, it's possible to export your personal listens through Settings → Export Data → Download Listens on the website.
However, to automate regular listening history backups, an API endpoint would be really useful. Of course, this would need to be designed in a way so that it's not abused, and the server load is reduced to a minimum.

Instead of synchronously providing a list of listens, I suggest an asynchronous design:

1. You can schedule an export through an authenticated API request, which returns an export ID
2. You can check the status (in process, finished) of an export through another endpoint
3. You can list all current or recent exports with their IDs from another endpoint
4. If the export is done, you can download the exported file that's stored on the server from another endpoint

Exports would be persisted on the server for a fixed number of days, 7 or 30 or something like that.