One chord a day, drawn by the whole Warrior Network from a single shared seed: a hash of the calendar date over a curated pool, so every sister site is looking at exactly the chord you are. What changes from site to site is the answer, and on a cavaquinho the answer is a top voice riding over an open-string ledger.
A cavaquinho does not just hold a chord and strum it — the batida chops it, and whichever note lands highest becomes the top voice the chop keeps flagging on its accents. So the useful question about today's chord is not "what is the grip" but "which of these four strings is singing loudest, and which of the open ones already belong to this chord".
The page answers both by reading the voicing rather than guessing: it finds the highest sounded pitch and names its degree, then checks every string left open (fret 0) against today's chord tones — some belong, some do not, and the ledger says which.
The shape is computed in your browser, from your own calendar date, and never on the server: rendered pages here are cached at the edge for hours at a time, so a date baked into the HTML would cheerfully hand you yesterday's chord a minute after midnight. Once the page knows what day it is where you are, today's chord, its top voice, and its open-string ledger appear below.
While you wait — or if scripting is off — the batida pages have all three cells recomputed slot by slot, and the chord reference has the whole library.