The initiative comes from Tesco Labs, the supermarket's innovation arm, and sees the supermarket dabbling with an Internet of Things-powered future.
IFTTT stands for 'If This Then That', and allows users to connect different online accounts to trigger clever actions.
For example, a user could use IFTTT to connect their smartphone to their Dropbox account. Through a simple 'recipe' on IFTTT, they could ensure any photo they take on mobile is automatically saved to Dropbox.
Tesco Labs will use the same principle to allow Tesco.com shoppers to automatically add items to their basket or set price alerts.
In a blog post, Tesco Labs' head of technology research, Paul Wilkinson, said customers could use the service to automatically order milk from Tesco.com on a particular day of the week, automatically add items (such as salmon) when the price drops, or even add food to their shopping basket according to the weather.
There is a full list of examples on Tesco's IFTTT channel, and Wilkinson is encouraging consumers to think up their own use cases.
Customers will need to have an account both with IFTTT and Tesco.com.
The experiment suggests Tesco is looking at services like Amazon Dash, a physical button which reorders groceries when pressed. Amazon more generally is a threat to Tesco as it branches further into grocery shopping in the UK through a tie-up with Morrisons.
"Competition will make us stronger," he said. "Bring it on."