Bismuth

For macOS, Windows and Linux

A tiling browser with the agents built in.

Bismuth is a desktop browser for people who work in Claude and ChatGPT all day. Split the window into tiles, and run Claude Code or Codex next to your pages, signed in with your own accounts.

Download Other platforms

Bismuth is early software, and some things are missing. The FAQ lists them.

Bismuth on Linux, split into three tiles: Wikipedia's article on tiling window managers on the left, MDN's guide to CSS grid layout at the top right, and a terminal running a Vite dev server at the bottom right. The sidebar lists pinned sites, pinned commands and the two agents.
Three tiles in workspace 1. The terminal on the right is running a dev server.

Tiling and workspaces

Split any tile to the right or downward with the buttons in the toolbar, and keep splitting: halves become thirds, and tiles nest inside tiles. Drag the handle between two tiles to resize them.

Tabs belong to a tile. Drag a tab to another tile, or onto a tile's edge to give it a tile of its own.

Each window has five workspaces, like desktops on Linux, and each one keeps its own tiles. Switch with ⌘1–⌘5 on a Mac, or Alt+1–Alt+5 on Windows and Linux. Right-click a tab to move it to another workspace.

Bismuth showing workspace 2 of 5, split into four tiles: ArchWiki's comparison of tiling window managers, Wikipedia's Xerox Star article, Wikipedia's article on stacking window managers, and a terminal listing a project's files. A tab's right-click menu is open, offering to move the tab to workspace 1, 3, 4 or 5.
Workspace 2 in quarters. Right-clicking a tab offers to move it to another workspace.

Agents in your browser

Bismuth runs the official Claude Code and Codex command-line agents, signed in with your own accounts. Start one in a tile from the sidebar, or open it in a panel on the right with ⌘E (Ctrl+E on Windows and Linux).

They work in your tabs through tools built into Bismuth. An agent can read a page, click, type and take screenshots, and it can open pages of its own.

Claude Code and Codex aren't included. If you start one that isn't installed, Bismuth offers to type its official install command into a terminal for you.

Private by default

  • Its own workspace only An agent sees the tabs in the workspace it runs in. Your other workspaces are invisible to it.
  • Named tabs Every action names a tab by its ID, like 2-3, so an agent never acts on whatever happens to be on screen. Hover over a tab to see its ID.
  • In the background Pages an agent opens load in the background and don't take focus, so what you're doing isn't interrupted.
  • Screenshots of one tab A screenshot captures only the tab the agent names, even when that tab is in the background.
  • Asks first Bismuth tells both agents to ask you before buying, sending, posting or deleting anything.

Terminals and pins

Terminals are tabs, so they tile like any page. Each one runs your usual shell as a login shell, with the same PATH and prompt as your normal terminal. Ctrl+` opens a new one (⌃` on a Mac).

Pins in the sidebar open a website or run a command. A pinned command, like a dev server or htop, opens in a new terminal. Commands that start Claude Code or Codex are connected to Bismuth automatically.

Bismuth with three tiles: ArchWiki's page about i3 on the left, and on the right a terminal running a Vite dev server above a terminal showing a git diff and a new commit. The sidebar lists pinned sites and two pinned commands, htop and Dev server.
The Dev server pin runs its command in a terminal tile.

Zero telemetry

Bismuth has no analytics and doesn't track you. It doesn't collect or send any data about how you use it.

Two features do contact Google: search suggestions while you type in the address bar, and the small icons for your pins.

The agents are separate programs, made by Anthropic and OpenAI. What you send them goes to those companies, under your own account.

This website doesn't track you either. It has no analytics and sets no cookies.

Bismuth's new tab page: the date, the heading 'Where to?', a search field, and three pinned sites, Wikipedia, MDN Web Docs and ArchWiki. There is nothing else on the page.
The new tab page shows your pins and nothing else.

Questions

For anything else, or to report a bug, email me.

Send an email Open in Gmail
Do I need a Claude or ChatGPT subscription?

Only for the agents. Bismuth works as a browser without them. Claude Code and Codex sign in with your own accounts, through their own login.

Is it Chrome?

No. Bismuth is built on Chromium, the open-source engine Chrome is also built on, and it has Chrome's developer tools.

What's missing?

A lot, because it's early. There's no password manager, sync, bookmarks or history, and Bismuth doesn't reopen your tabs after a restart. Chrome extensions aren't supported, and video that needs DRM, like Netflix, won't play.

How do I update it?

Bismuth doesn't update itself yet. Download the new version and install it the same way: on a Mac, quit Bismuth and choose Replace; on Windows, run the new MSI; on Linux, replace the AppImage. Your settings and pins stay.

Where do I report a bug?

Email me at [email protected]. Say which system you're on and what happened, and add a screenshot if you can.