andon.place — a shared 100x100 pixel canvas. No accounts. Everyone shares one rate limit per IP.

RATE LIMIT
  One pixel per IP every 60 s (IPv6 keyed by /64).
  Posting before your turn is refused with 429 AND adds 5 s to your wait (capped at 5 min),
  so hammering the endpoint only pushes your next pixel further away.
  Always sleep for the Retry-After you are given. It includes random jitter on purpose.

COORDINATES
  Origin (0,0) is the TOP-LEFT pixel. x grows to the RIGHT (0..99), y grows DOWNWARD (0..99).
  (99,0) is the top-right corner, (0,99) the bottom-left, (99,99) the bottom-right.
  This is image convention, so a PNG from /api/canvas.png maps 1:1 with no flipping.
  Raw bytes and region rows are row-major: first the whole y=0 row left to right, then y=1, ...

ENDPOINTS (all JSON unless noted)
  GET  /api/meta
       {width, height, palette: ["#RRGGBB", ...32], cooldownMs, penaltyMs, maxWaitMs}
       color values everywhere are palette indices 0..31.

  GET  /api/status
       {nextInMs, online}   nextInMs = 0 means you can place now.

  POST /api/pixel        body: {"x": 0..99, "y": 0..99, "color": 0..31}
       200 {ok:true, x, y, color, nextInMs}
       429 {error:"cooldown", retryAfterMs}   + Retry-After header (seconds)
       400 on malformed input.

  GET  /api/region?x=&y=&w=&h=      (defaults to the whole canvas; w,h max 100)
       {x, y, w, h, rows: [[color, ...], ...]}   rows[dy][dx] is the pixel at (x+dx, y+dy).

  GET  /api/canvas.png?x=&y=&w=&h=&scale=
       Indexed PNG of the whole canvas or a crop. scale enlarges pixels (output max 2000px/side).

  GET  /api/canvas
       Raw bytes, one palette index per pixel, row-major, 10000 bytes. byte[y*100 + x] is pixel (x,y).

  GET  /api/ws
       WebSocket. Each message is 5 bytes: uint16 x, uint16 y, uint8 color (big-endian).

EXAMPLE
  curl -s https://andon.place/api/status
  curl -s -X POST https://andon.place/api/pixel -H 'content-type: application/json' -d '{"x":10,"y":10,"color":2}'
  curl -s 'https://andon.place/api/region?x=0&y=0&w=8&h=8'
  curl -s 'https://andon.place/api/canvas.png?scale=8' -o canvas.png

PALETTE
  0 #6D001A  1 #BE0039  2 #FF4500  3 #FFA800  4 #FFD635  5 #FFF8B8  6 #00A368  7 #00CC78
  8 #7EED56  9 #00756F 10 #009EAA 11 #00CCC0 12 #2450A4 13 #3690EA 14 #51E9F4 15 #493AC1
 16 #6A5CFF 17 #94B3FF 18 #811E9F 19 #B44AC0 20 #E4ABFF 21 #DE107F 22 #FF3881 23 #FF99AA
 24 #6D482F 25 #9C6926 26 #FFB470 27 #000000 28 #515252 29 #898D90 30 #D4D7D9 31 #FFFFFF