flint-board-author

flint-board: several charts, one view

A board holds several Flint charts under one headline. The agent writes it as one board spec, checks it with validate_board, which draws nothing, and puts it on screen with show({ "board": … }), which opens a new card below the conversation's latest message. The server keeps nothing between calls: the spec in the conversation is the board. So call show once a turn, after the board is right; to change it later, change the spec and call show again.

Each chart on a board is a full chart spec (flint-chart-author), plus an id and a layout. This skill covers what a board adds: the headline, which charts, where they sit, how they connect, and how they look as one piece.

Work through the steps in order. A board is ready to show when its latest report shows no ✗ and its Review: section is empty or says only that a colour field is shared.

Step 1 — write the headline

The board's title is what the reader takes away, or what the board is for, in one line. Its subtitle is the deck: the data, its scope, period and units. source is the footer: where the data comes from and when.

title:    "Europe carried the third-quarter recovery"
subtitle: "Monthly revenue by region and product line, Jan–Sep 2025, $m"
source:   "Source: finance ledger, closed books to 30 Sep 2025"

A monitoring board with no single finding names its purpose instead: "Operations at a glance". The card draws the title largest, so it is the first thing read; every board gets one.

Step 2 — choose the charts

Start from the questions the reader brings, one chart per question, and keep the board to the charts that answer them: three to five KPI tiles and up to six charts. More than that is two boards.

The reader asks	Chart
How are we doing on the numbers we steer by?	KPI Card per number, with goal when there is a target
How did it move over time?	Line Chart (few series), Area Chart (parts of a total)
Which is largest, how do they rank?	Bar Chart sorted by value, Bar Table for many rows with labels
Which records are behind it?	Table: the rows as given, one column per field, encodings: {}
What is it made of?	Stacked Bar Chart, or Pie Chart with innerRadius for up to five parts
How do two measures relate?	Scatter Plot
Where?	Choropleth, Map
How is it spread?	Histogram, Boxplot
Each series' trend at a glance	Sparkline