{
  lib,
  buildGo127Module,
  fetchurl,
}:
let
  # The API reference page is Redoc (MIT), served from the web UI's own address.
  redoc = fetchurl {
    url = "https://cdn.jsdelivr.net/npm/redoc@2.5.2/bundles/redoc.standalone.js";
    hash = "sha256-a+ta6iO3HQkSLuNd6PMm44rsBQ53Tzv7ofNOXDZgiYY=";
  };
in
buildGo127Module {
  pname = "router-webui";
  version = "0.1.0";
  src = lib.fileset.toSource {
    root = ./.;
    fileset = lib.fileset.unions [
      ./go.mod
      (lib.fileset.fileFilter (f: f.hasExt "go") ./.)
      ./providers.json
      ./templates
      ./static
    ];
  };
  # static/redoc.standalone.js is not in the source tree (git ignores it); it
  # is embedded in the binary with the other static files.
  preBuild = ''
    cp ${redoc} static/redoc.standalone.js
  '';
  # Standard library only.
  vendorHash = null;
  meta = {
    description = "Web UI for a nixos-router configured by settings.json";
    mainProgram = "router-webui";
  };
}