Joevix

Summary

Joevix is a Manifest V3 browser extension for Chrome, Edge, Brave, and Firefox that changes how a page looks and reads without touching the page for anyone else. Themes, custom colors, and per-site layout live in the browser, not on a server.

Problem

Most reading modes make one decision for every site, and most theming extensions ask for broad access up front. A reader who wants a warmer theme on one site, a wider column on another, and no change anywhere else has to trust a permission prompt that grants more than the job needs.

Approach

The extension declares no content scripts and no host permissions at install. A site is enabled one origin at a time, and the content script is registered at runtime. Theming is CSS custom properties applied through a constructed stylesheet, and layout editing writes CSS order, hidden state, and a reading width per site, so no DOM node is moved or rewritten. The content script never touches storage or permissions; typed, Zod-validated messages go through the service worker.

Outcome

Version 1.0.1 ships packaged Chrome and Firefox builds, built-in and custom themes, a contrast matrix, per-site layout editing with a 20-step undo history, import and export, a privacy panel, and a global off switch. The release passes type checking, lint, unit and E2E tests, axe audits, CodeQL, a manifest policy check, and a size budget.

Honest limitations

Layout presets and the spacing half of the reading-width work are not in this build. Firefox is tested by the automated suite rather than by hand, and the Firefox add-on is a temporary build because store publication is out of scope for v1.0. Theme sync between devices and the persistent diagnostic buffer are deferred.

Detail

No standing access

The manifest keeps content_scripts and web_accessible_resources empty and requests only storage, activeTab, and scripting, so a site is reachable only after the reader enables it.

No network code

ESLint bans fetch, XMLHttpRequest, WebSocket, EventSource, sendBeacon, dynamic Image, eval, and string timers. The end-to-end suite also asserts that the extension issues no request outside the page's own origin.

Layout without moving nodes

Reorder and hide are written as CSS order and display rules against adapter container sections. A reset removes one stylesheet and one attribute.

Release checks

Package and content-script size budgets, manifest policy checks, SHA-256 checksums, and a rollback document are part of the release script rather than an afterthought.