Email send Slack bot notification
I'm developing a Slack bot that posts a notification to our company's Slack channel 15 mins before a scheduled email send to give everyone a heads up about what is about to be sent and the size.
I'm testing a beta version using a screen scraping application that logs into the Marketo calendar on the front end and extracts the program name, send timestamp and send size. It then calls a Slack webhook the post the data.

I would like to develop a more reliable method using the Marketo API.
I've looked at Marketo's API endpoints but I haven't found one that exposes scheduled email sends. I've tried:
/rest/asset/v1/programs.json
/rest/asset/v1/emails.json
Are scheduled email sends only exposed from the front end UI?