I recently watched Todoist Office Hours: Automating Your Productivity with Jono Loeser (Zapier). This led me to take a look at Zapier. This is a very slick tool for putting together personal automations in an easy to use interface. The number of applications it works with is astounding.
The free tier allows for 100 “tasks” per month. (A task is essentially a single invocation of one of the automations you define.) This is more than enough to play around with and see how it works. I could see this tool being a must have for certain people.
In terms of integration with Todoist, I suspect many people would burn through the free tier. At that point, you go to the paid tier which may be a bit pricey for some people ($19.99 USD per month with an annual commitment.)