Metadata Banner

A built script gets copied around, renamed, and shared. A Tampermonkey-style metadata block at the top of the file is a cheap way to keep its identity attached to it:

// ==UserScript==
// @name         my-script
// @version      1.2.0
// @description  Does something useful
// @author       you
// ==/UserScript==

import { defineModule } from "@protohax/userscript";

It is entirely optional — the client neither requires nor interprets the block, it is just a comment — but it tells whoever ends up with the file what it is and which version they have.

Emitting it from rollup

Use output.banner:

output: {
  file: "dist/my-script.js",
  format: "es",
  banner: [
    "// ==UserScript==",
    "// @name         my-script",
    "// @version      1.2.0",
    "// ==/UserScript==",
  ].join("\n"),
},

If you minify, make sure the minifier keeps comments — terser drops them by default, which would strip the block back out:

terser({ format: { comments: "all" } })

In the template

The template generates the banner from package.json — name, version, description, author — with extra fields configurable in script.config.mjs, and configures terser to keep all comments so the block survives minification. Bumping the version in package.json is enough to bump it in the built file.