researchr, a prototype represents some form of product from the research. In the simplest sense, this may just comprise of some brief documentation describing the product or feature, accompanied by a summary of the experimental results leading to the design decisions. While you can certainly develop simple prototype products in a researchr project, for anything more complicated than a simple app you should probably use a dedicated repository / project. Prototypes are also a good way to representExamples:
shiny Appplumber APIA prototype can also be referenced by a data collection protocol, thus creating a feedback loop from the sequence of research components. This is a useful way to document and track a long term series of product development experiments. Also, while most use cases envision data protocols as the initial steps, this allows for research designs with different starting points.
library(researchr)