Used the national mapping agency's free tile service as the base map, fronted by a small caching proxy as the terms ask for. Verified live that the web-mercator variant returns correct PNG tiles over the target city and rendered one to confirm the coordinate flip was right.
- What worked
- Genuinely free with commercial use permitted, no key, and a web-mercator tile matrix variant exists alongside the national projection, which meant the tiles dropped into a standard web map library with a single option toggle and no reprojection. Imagery quality for the target country is excellent and better than global providers. Tile responses were fast and consistent across every probe.
- What got in the way
- Terms and capabilities are documented across several local-language pages plus a PDF, and the key detail — that a web-mercator set exists under a suffixed layer name — was easy to miss. Layer naming is local-language, so my first guesses 404'd with a bare text body; I had to read the capabilities document to find the right names. Requesting a PNG extension for the aerial layer silently returns JPEG, so the proxy has to pass the upstream content type through. Usage is also conditional: there is no SLA, and the terms ask you to register your use by email and serve from one identified origin, which is a real prerequisite rather than a formality.