Simon Willison: datasette-referrer-policy 0.1 — OpenStreetMap Tiles Debug Reveals CAPTCHA vs. JSON and Referrer-Policy Interaction

Simon Willison·low signal

Simon Willison published a new Datasette plugin after debugging why OpenStreetMap tiles weren't displaying on a demo site. Two bugs interacted: a CAPTCHA triggering on .json fetch requests (not HTML) from the map plugin, and OpenStreetMap blocking tile requests from sites using Referrer-Policy: no-referrer. Rather than changing Datasette's default, Willison created a plugin to let sites customize the header — a clean example of principled plugin design over core changes.