September was two things: a page that shows what people ship with Extension.js, and a run of releases that took the CLI from 4.1.18 to 4.1.30.
Creator and Lead Developer, Extension.js
The showcase
extension.js.org/showcase is live. Five extensions, all shipped and all in the stores: Better Lyrics, Star Citizen Box, Simple Virtual Keyboard, Better Trello, and Send to PocketBook.The bar is deliberate. A card needs a real store listing and at least a hundred users, and no card shows a user count, so nothing on the page rots. A weekly job proposes candidates and a person adds them.Two more runtimes
4.1.20 added Deno.deno run -A npm:extension@latest runs dev and build, and both are covered by CI.4.1.21 added Bun. bunx --bun extension@latest dev works on Bun 1.2 or newer, and an older Bun gets one line pointing at the Node.js path.More browsers by name
4.1.26 added--browser=zen and --browser=floorp. They find a stock install on macOS, Windows, and Linux, the same way Waterfox and LibreWolf already did.4.1.29 fixed a bug there too. --browser=brave, opera, vivaldi, and yandex could open the managed Chrome while the terminal named the fork. Each one runs its own app now, and a check launches every browser and reads which app is really running.One manifest, sharper
Since 4.1.19,chrome: and edge: mean that one browser, not the whole Chromium family. chromium: is the family. That made a new failure possible, a manifest that scopes every manifest_version to a vendor, so 4.1.21 refuses that build and names the fix.Production Edge builds now drop a top-level key, because Edge Add-ons rejects any manifest that contains one. That came from the maintainer of Better Lyrics, who was stripping it by hand after every build.Reloads
In dev on Chrome and Edge, saving a content script used to leave the old copy running next to the new one. 4.1.25 registers dev content scripts at runtime, so an edit runs exactly one copy, in the open tabs and in every new page. Editing an HTML page now refreshes that page alone.One bug worth naming
A fresh install of 4.1.18 through 4.1.23 could pull a newer rspack than the one we test against, and every page with a linked stylesheet threw on load. 4.1.24 pins the bundler and adds a build spec that guards the shape. If you are on any of those versions, upgrade.Also
extension create --template transformers-js scaffolds a side panel that classifies text on device, modeled on Hugging Face’s own extension sample. extension build --browser=opera ships code without minification, which Opera Add-ons asks for in review. Extension.js is now listed on the Preact integrations page, awesome-vue, and awesome-shadcn-ui.October is already at 4.1.33. One sidebar key builds for every browser, Safari dev runs leave your own Safari alone, and the sidebar starters read the open tab. More on that next time.Cezar AugustoCreator and Lead Developer, Extension.js