Friday, 13th November 2026
OpenStreetMap have a very reasonable policy that hits to their hosted tile server should send a referrer header. Datasette table pages used the Referrer-Policy: no-referrer HTTP header, causing plugins that loaded tiles from OpenStreetMap to violate that policy.
datasette-leaflet is the plugin that loads a bundled Leaflet so other Datasette plugins can depend on it. It now sets the referrer policy on the tile requests themselves to strict-origin-when-cross-origin, passing the host but not the full path to the page.
One of the oldest Datasette plugins, and still one of my favorites. It now works with Datasette 1.0a42, and depends on the new datasette-leaflet to ensure OpenStreetMap tiles are requested with a referrer header.
Here's a map of power plants owned by California's PG&E, also demonstrating Datasette's recently redesigned facets:
