Eleventy + Nunjucks

Operational defaults for Eleventy v3 and Nunjucks static sites — directory layout, configuration surface, filter inventory, autoescape rules, stability and security checks. Load this skill when authoring templates, editing build config, or reviewing static output before merge or deploy.

Version boundary (rechecked September 13, 2026): Eleventy 3.1.6 is the stable production baseline. Build Awesome 4.0.0-alpha.10 is a prerelease available through @11ty/eleventy@canary or @awesome.me/buildawesome@alpha. Existing Eleventy commands remain compatible, but v4 changes runtime and template behavior. Keep stable guidance as the default and load references/build-awesome-v4.md before any v4 install or migration.

When this skill applies

Use explicit Eleventy/Build Awesome or Nunjucks context. Generic static-site/security topics and .data.*/.server.* filenames alone do not select this skill over another framework. Standalone Nunjucks work is in scope; apply Eleventy-specific steps only when that project uses Eleventy. Relevant cues include:

• Paths mentioning .eleventy.js, eleventy.config.{js,mjs,cjs}, .njk, .11tydata.js, .data.js, .11ty.js, .server.js, src/_includes/, or src/_data/
• package.json lists @11ty/eleventy or @awesome.me/buildawesome
• Topics: 11ty, Eleventy, Nunjucks, SSG, JAMstack, static site, layout chain, permalink, collection, shortcode, filter, dev server, CSP, JSON-LD in templates

Operating procedure