I recently wanted to copy-paste all of the Chunk Base coordinates for every single POI on the map for a ±5000 block square around (0, 0). There is no (current) official way to download a Chunk Base map as a CSV file.

Here's how you can do it anyway:

  1. Navigate to https://www.chunkbase.com/apps/seed-map
  2. Enter your seed, version, etc.
  3. Make sure the map shows everything you want to export
  4. Open DevTools using F12 or Ctrl+Shift+I
  5. Type allow pasting if pasting is disabled
  6. Copy & paste the script into your DevTools panel
  7. Right-click & Copy string contents to get the CSV export and use it however you want to! ����
const CSV = await import("https://esm.run/csv-string@4.1.1");
const table = [["Type", "X", "Y", "Z", "Details"]];
const oldOnPoiDrawn = CB3TooltipManager.onPoiDrawn;
CB3TooltipManager.onPoiDrawn = function (type, repr, coords, details) {
  const [x, y, z] = coords;
  table.push([type, x, y, z, JSON.stringify(details)]);
};
CB3FinderApp.trigger("redrawmap");
CB3TooltipManager.onPoiDrawn = oldOnPoiDrawn;
CSV.stringify(table);

screenshot of me doing that

How it works

The real trick is intercepting the onPoiDrawn event and using the provided structured data to construct our own CSV table instead of drawing images to the map canvas. We really lucked out that CB3FinderApp and friends are all global variables!

So we:

  1. Create our table. It has Type, X, Y, Z, and Details columns.
  2. Stash the old onPoiDrawn function that probably does some important things.
  3. Overwrite the onPoiDrawn function with our own that .push()-es a new row for each POI that needs to be drawn. You can console.log(arguments) to see the complete arguments list. This was the most complicated part; you need to inspect the arguments in the console and then pluck the right attributes off the right objects to get the data you want.
  4. Trigger a redraw. This was another case of trial and error. You can console.log(CB3FinderApp) in the console and look for any event-related properties to find more events. redrawmap seemed like a good thing to try and it worked! There may be other events that do different things. Who knows!
  5. Reset the onPoiDrawn callback back to the original.
  6. Return the table stringified as CSV. Since this is the last evaluated expression it will be shown to the user in the DevTools console. Chrome (no idea about other browsers) has a handy Copy string contents option in the right-click menu which can be used to easily copy the CSV string to your clipboard.

You can very easily edit the code and export the POI data in JSON or some other format if you like.