Blueprint is still experimental. Future versions may have breaking changes, and most GTK tutorials use XML syntax.

Blueprint is a markup language and compiler for GTK 4 user interfaces.

using Gtk 4.0;

template MyAppWindow : ApplicationWindow {
  default-width: 600;
  default-height: 300;
  title: _("Hello, Blueprint!");

  HeaderBar {}

  Label {
    label: bind MyAppWindow.main_text;

Blueprint helps you build user interfaces in GTK quickly and declaratively. It has modern IDE features like code completion and hover documentation, and the compiler points out mistakes early on so you can focus on making your app look amazing.


  • Easy setup. A porting tool is available to help port your projects from XML. The compiler’s only dependency is Python, and it can be included as a meson subproject. See the Setup page for more information.

  • Concise syntax. No more clumsy XML! Blueprint is designed from the ground up to match GTK’s widget model, including templates, child types, signal handlers, and menus.

  • Easy to learn. The syntax should be very familiar to most people. Take a look at the reference to get started.

  • Modern tooling. Blueprint ships a Language Server for IDE integration.


  1. Simplify our UI declarative language, a strawman proposal

  2. A Markup Language for GTK

  3. Introducing Blueprint: A New Way to Craft User Interfaces

  4. Next Steps for Blueprint

Built with Blueprint#