--- area: "Learn" parent: "Learn" url: "https://unpoly.com/learn/extensions" --- # Extensions Unpoly works without extensions. This chapter collects the optional tooling around the core, for when it saves you work. ## Agent skill {#agent-skill} Unpoly's documentation is available as an agent skill for AI coding tools. ## Protocol implementations {#protocol-implementations} Your server can inspect and manipulate Unpoly's rendering through simple [HTTP headers](https://unpoly.com/api/up.protocol.md). Libraries implementing this protocol exist for many languages and frameworks, like Rails, Django, Laravel or Phoenix. ## Supporting legacy browsers {#supporting-legacy-browsers} Unpoly supports all modern browsers out of the box. On older browsers your app degrades gracefully, and a transpiled build covers old build tools. ## Bootstrap integration {#bootstrap-integration} Optional files configure Unpoly to use Bootstrap's CSS classes for navigation feedback, form validation and overlays. Builds exist for Bootstrap 3, 4 and 5.