Pluto is fundamentally built upon reactivity, and hence knowledge of how notebook cells interact is known. Therefore cells can update in response to other cells changing, which happens in a Pluto notebook every time you run a cell. But what if these intelligent updates could also happen on-demand programmatically?

Introducing the new, experimental “What you see is what you REST” feature! (WYSIWYR for short.) Every global variable becomes an HTTP endpoint, and you can provide other global variables as parameters. Instead of experimenting with a model inside Pluto and then moving your code to an API script, your notebook is an API, using reactivity to automatically create an execution model for each endpoint.

With this feature, interacting with Pluto notebooks from both outside and inside of other Pluto notebooks is revolutionarily simple. Everything from sharing models to writing custom web APIs with Julia is now possible, entirely from within Pluto, without having to transition from notebook code to “production code”.

This talk will demonstrate how to get started with WYSIWYR and use it in your own projects. By also explaining how the feature works, we hope to get experienced users interested in the feature. Along the way, we will discover how its expansion to existing notebook interactivity features opens the door to more seamless inter-notebook communication, and even to building web applications and APIs all from inside Pluto notebooks.