Quasar

A browser and work environment for you and your agents.

Source · Documentation · Issues

Quasar is an open-source desktop browser forked from Zephium, created by crynta. It combines everyday browsing with an AI assistant and a persistent workspace for agent-assisted work.

Browse, Ask, Work

• Browse: vertical tabs, spaces, profiles, split views, native ad and tracker blocking, Chrome-extension compatibility, notes, tasks and focus tools.
• Ask Quasar: ask about open pages, follow citations, open links, take bounded actions on a page, and propose CSS changes to a site.
• Work: describe an outcome, let helpers work on its parts, and keep results on a canvas as documents, tables, charts, plans and other structured objects. Work includes 25 built-in skills and connections to configured MCP servers.

AI connects through Sign in with ChatGPT. Eligible ChatGPT Plus and Pro accounts can authorize plan usage without API keys. Quasar calls OpenAI's public API directly; the upstream Zephium account, billing service, provider keys and local model endpoints have been retired. See ChatGPT setup and implementation notes. Linux currently remains a browsing-only preview.

General shell execution and coding-agent hand-offs are currently gated in the source pending a confined native runner. Some platform-specific capabilities have additional qualification requirements. The code and tests determine availability; upstream documentation may describe a broader target.

Platforms and architecture

• macOS: Apple Silicon, using WebKit. Requires an updated macOS and Safari that meet the application's runtime security policy.
• Windows: x64, Windows 10 or 11, using WebView2.
• Linux preview: x86_64, Ubuntu 26.04 or newer (glibc 2.43+), distributed as an AppImage with WebKitGTK included. Browsing is available; AI and Work are disabled while their Linux backend is unfinished.

Download test builds from Releases. See preview installation and release workflow for platform requirements, installation and development details.

Rust owns browser state, native integrations, storage and agent execution. Tauri and Wry host the native WebViews. The interface uses Svelte 5, TypeScript, Vite and Tailwind CSS. Untrusted websites use WebViews separated from the privileged application interface.

See architecture, frontend conventions and the security model. Internal zephium-* crate names and IPC contracts retain their upstream names for compatibility.

Develop

Install the toolchain pinned in rust-toolchain.toml, the Node.js version in .node-version, pnpm through Corepack, and the native Tauri prerequisites for your platform.

git clone https://github.com/fordft/Quasar.git
cd Quasar
pnpm install --frozen-lockfile
pnpm dev

Quasar uses app.quasar for installed builds and app.quasar.dev for development, separate from Zephium's application profiles. Existing Zephium data is not moved or adopted automatically.

Automatic updates are disabled until Quasar has its own signing key and update endpoint. Builds do not install releases from the upstream Zephium project.

Branding and checks

The source icon and wordmark live in assets/brand. Regenerate the native and frontend assets with:

pnpm brand:assets

Installer artwork is regenerated with pnpm -C frame installer-art after changing the wordmark or sky. Frontend verification uses:

pnpm -C frame check
pnpm -C frame test:component
pnpm -C frame build
cargo xtask check-frame-styles

See CONTRIBUTING.md for the inherited development workflow. Documents describing the upstream project retain their historical references and do not establish a separate Quasar service or support channel.

Credits and license

Quasar builds on Zephium and preserves the upstream authors' copyright and license notices. The source is licensed under MPL-2.0. Bundled EasyList and EasyPrivacy data retain their CC BY-SA 3.0 license and notices. The wordmark's DejaVu-derived outlines retain their font license.