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GUI

The cockpit on GitHub Pages is a static control surface. Because Google extraction can't run in a browser (undocumented, CORS-blocked, Python-only), the page is a planner, viewer, and comparator — not the engine.

Source modes

The GUI has a source-mode selector — pick how each layer's data arrives:

Mode What it does Needs
📂 Load file Drag & drop a .geojson the CLI produced; renders it on the map. nothing (fully client-side; your file never leaves the browser)
🛠️ Command builder Draw a bbox → get the exact tracelines extract … command with a Copy button. Run it locally, then drop the result back in. the CLI, run locally
🟢 Live Mapillary Draws Mapillary sequence coverage live on the map. your own free Mapillary token (stored only in your browser)
🔵 Live Google (proxy) Live Google extraction via a proxy backend (browsers can't reach Google directly). prefilled with a shared hosted demo — or run your own free

The cockpit loop

draw bbox  →  copy CLI command  →  run tracelines locally  →  drag the GeoJSON back in
          →  overlay live Mapillary / proxy Google  →  diff sources  →  export

That loop turns an inert viewer into the actual front-end of the tool, and delivers the one thing a raw CLI can't: visual multi-source comparison — where does Google have coverage Mapillary lacks, and vice-versa.

Token & privacy

  • Your Mapillary token is stored only in your browser's localStorage; it rides in Mapillary's own tile URLs (that's how their SDK works). Tokens are free, read-only, public-scope — exposure is a quota concern, not a data breach. Use your own.
  • Uploaded GeoJSON is parsed entirely client-side — it never leaves your browser.
  • Live Google is prefilled with a shared hosted demo proxy (hardened + rate-limited; it may sleep). To run your own, deploy one free and lock its CORS to your GUI origin.

Why not "just run Google in the browser"?

Google's coverage endpoints are undocumented internal APIs with no CORS headers, and the streetlevel stack is Python (aiohttp + protobuf) — neither works under browser fetch or Pyodide. The only way to get live Google in a GUI is a proxy backend — hence the hosted demo (and the deploy-your-own options). See Architecture.