^Features Site globals

siteData adds global site data via eleventyComputed. All scalar fields from pkg.site (package.json) and data.site (_data/site.*) are spread onto site; page-level wins over pkg. The asset keys below are merged (pkg → site) rather than overridden.

Variable	Value / Description
`{{ site.year }}`	Current year (e.g. `2026`)
`{{ site.prod }}`	`true` for `eleventy build`, `false` for `eleventy serve`
`{{ site.styles }}`	Merged array of stylesheet URLs
`{{ site.scripts }}`	Merged array of script URLs
`{{ site.head_extras }}`	Merged array of custom head HTML/strings
`{{ site.body_extras }}`	Merged array of custom body HTML/strings

The named export siteData(data) is also usable directly (e.g. as RSS feed metadata).

How it works

/anyblades/eleventy-blades/refs/heads/main/features/siteData.js :

const MERGED_KEYS = ["styles", "scripts", "head_extras", "body_extras"];

// Lodash style
export const castArray = (val) => (val == null ? [] : Array.isArray(val) ? val : [val]);

export const concatUnique = (a, b) => [...new Set([...castArray(a), ...castArray(b)])];

export const siteData = (data) => {
  const pkgSite = data.pkg?.site ?? {};
  const dataSite = data.site ?? {};
  return {
    ...pkgSite,
    ...dataSite,
    ...Object.fromEntries(MERGED_KEYS.map((key) => [key, concatUnique(pkgSite[key], dataSite[key])])),
  };
};

export default function (eleventyConfig) {
  eleventyConfig.addGlobalData("eleventyComputed", {
    site: (data) => ({
      ...siteData(data),
      prod: process.env.ELEVENTY_RUN_MODE === "build",
      year: new Date().getFullYear(),
    }),
  });
}