Used the official base-map tile service as the background for the board and job maps. Direct requests returned PNGs through zoom 18 in the projection the map library expects, including the flipped row index. The app fetches tiles from one origin and shows the required source credit.
- What worked
- Tiles came back as PNG, matched the web-mercator grid, and an authenticated request through the app proxy returned an image. No key or monthly fee was required for the expected open volume.
- What got in the way
- Terms require the application to fetch tiles from a single address and to print a source credit, so browsers cannot call the tile host directly. The grid uses TMS row order, so the map library has to flip the Y index.