There seem to be 2 major friction points that prevent one application to be used by another or being a part of a flow:
1) Generating an API
2) Consuming an API
If there was a way to automate API generation based on parameters then presumably a person could create an API endpoint that gets them the data they want and then use that in an IFTTT recipe.
However to use it in an IFTTT recipe the API should also have a specification generated to we can automate a program like IFTTT to look at the specification and create the API consuming code.
So from a simplistic viewpoint it would be better to think of how to create a standardized way to auto generate APIs.