plasmo
Plasmo
Overview
Plasmo is a build framework for browser extensions. File names are the configuration: popup.tsx becomes the popup, files in contents/ become content scripts, background.ts becomes the service worker, options.tsx the options page. The manifest.json is generated, with overrides in package.json. plasmo dev rebuilds with live reload into build/chrome-mv3-dev; plasmo build writes build/chrome-mv3-prod. Companion packages: @plasmohq/storage and @plasmohq/messaging.
Maintenance note: the latest npm releases are plasmo 0.90.5 (May 2025), @plasmohq/storage 1.15.0 and @plasmohq/messaging 0.7.2. If a user is starting a new project and open to alternatives, WXT is another actively used extension framework; do not migrate an existing Plasmo project unprompted.