Pages and cells
A page is Clay source. Each let definition is a cell; a line before it decides how it is shown:
@phaistos({title: "Balance", format: {decimals: 2, prefix: "$"}})
let balance = principal * Float.pow(1.0 + rate, years)
Annotation fields
title: the cell's heading.x,y: a position on the canvas. Without them cells flow in a grid.renderer,chart: show a value as a table or a chart.input: make a value a control you can change.format: decimals, prefix and suffix for numbers.
The full authoring guide is docs/phaistos-authoring.md in the repository; it will move here.