How to use a data object from a package as an input for a function in OpenCPU?

Question

When using OpenCPU's api,

For example, I can retrieve the cats dataset from MASS using this api:

curl https://cloud.opencpu.org/ocpu/library/MASS/R/cats/json

and suppose there is a function, say:

play(x)

then how can I use the cats set retrieved from first api as the input for play() function?