Why Mastro?

Over the last decade, the JavaScript ecosystem has been moving to ever more complex frameworks and build systems. What prompted me to create Mastro is that a lot of that isn’t necessary anymore.

• SPAs have peaked because browsers now have MPA view transistions and bfcache.
• Native CSS features like CSS variables and nesting replace much of SCSS.
• Node.js now supports TypeScript type stripping and file watching out of the box.
• Bundling is still necessary if you have hundreds of client-side JavaScript files. But with ES modules in all browsers, bundling shouldn’t be the default anymore.

I have been building websites for two decades. Back in the day it was PHP and Flash, then Ruby on Rails and Jekyll, and lately Next.js (with React) and Astro (with Solid). I’ve seen a lot of things that work well, and a lot of things that don’t. This has informed the following design principles of Mastro.

Design Principles

1. Mastro is for people who care about their users, and value accessible websites that load fast – even on low-end phones and slow networks.

2. Mastro is for people who care about the web and understand it as its own medium.

   • A webpage is not a printed page with fixed dimensions.
   • Mastro is designed to work with the grain of the web. Write semantic HTML, and progressively enhance it with beautiful CSS and interactive JavaScript.
   • Mastro is primarily designed for content-driven websites, and not for apps that download megabytes of client-side code and reimplement basic browser functionality.

3. Mastro is for people who care about simple technology.

   • Instead of towers of leaky abstractions, Mastro gives you direct access to the underlying platform: the browser and your JavaScript runtime.
   • Simple things should be simple, and complex things should be possible.
   • Mastro grows with you: it is a beginner-friendly static site generator, but can morph into an unopinionated full-stack framework running database-driven REST APIs and rich client-side interactivity.
   • Explicit separation of server and client-side. Code and secrets that were intended to stay on the server shouldn’t accidentally end up in the client bundle.
   • Mastro provides a uniform interface for all content types: HTML, JSON, XML, binary, whatever. Instead of being abstracted away, the full power of the HTTP protocol is at your disposal through the standard Request/Response API.

4. Mastro is for people who care about their dependencies.

   • Mastro will never take on VC-money and there will be no eventual enshittification.
   • Mastro’s implementation is low-maintenance and so small that you can read it in an hour or two. Should you ever outgrow it, you can simply fork it and adjust things to your needs.
   • Mastro is modular. If you prefer e.g. another templating engine, use that instead.
   • Mastro has a tiny API-surface, and once we hit v1.0 it will remain extremely stable, so that projects that depend on Mastro aren’t stuck on an update-treadmill.
   • Additional packages in the @mastro namespace may have higher rates of change, and we invite the community to create additional packages on top of the standard Request/Response-API.