Island

Status: pre-1.0. Every build is unsigned: each vX.Y.Z is the latest GitHub release, and nightly is a prerelease. Only macOS Apple Silicon (arm64) has been built, run and packaged by hand. See Status and platforms.

Why Island

It is a native browser, not a web page in a wrapper. Island is C++20 on the Chromium Embedded Framework and its native cef_views toolkit. The sidebar, tabs, palettes and overlays are native views, not an Electron app and not a web-based shell, so it opens fast and sits in the system like any other Mac app.

The agent works with your pages. Run Claude Code, Codex, OpenCode, Gemini CLI, Qwen Code, Goose or your own Agent Client Protocol command in a panel next to your tabs. It can read the page you are on, open and switch tabs, navigate, click and type through Island's browser tools. Island does not bundle a model: it starts the agent program you already use.

Research you can steer. Ask a question in Research mode and the agent first proposes a plan. You see it as a graph in a pinned Plan tab. You edit it, skip branches, add your own, and nothing runs until you press Run plan. The plan lists its limits up front: the agent is asked to sign in to a site only after asking you, and not to purchase, post or delete. Island does not yet enforce those limits in code. The agent cannot approve its own plan.

Privacy is built in. Ads and trackers are blocked natively, before subresources load, on Brave's open-source adblock engine with EasyList and EasyPrivacy. History search runs on your computer and your history never leaves it. Bookmark import is local too.

A calm, Mac-native look. The default Native look is a macOS-style source list, the system font and one blue accent. Prefer something else? Arc and Graphite looks are one setting away, in light or dark.

Take the tour

Spaces and a sidebar that stays out of the way

Group tabs into spaces (work, travel, research), pin what you need, and reorder from the sidebar or the menu. ⌘B collapses the sidebar into a narrow rail of favicons. ⇧⌘A shows every space's tabs as searchable cards. The sidebar can sit on the left or the right.

⌘K: one palette for everything

Find open tabs, spaces, bookmarks, on-device history, research reports and commands from one field, or type a URL. ⇧⌘K sends a query to Google, ChatGPT, Perplexity, Claude or Gemini.

Split view

⇧⌘S pairs the active tab with the next one, side by side. On macOS the divider moves with ⌥⌘[ and ⌥⌘] (and the menu), not by dragging.

A start page with three modes

Every new tab opens on Search, Ask Agent or Research. Under the field, six speed-dial tiles come from the sites you visit most. They come from your on-device history, and clearing history clears them.

The agent panel

⌘J opens the agent. It shares the current tab as context (you can turn that off), renders Markdown replies and offers prompts to start from. Pick the agent in the panel header; the menu shows which ones are installed.

Research and the Plan tab

In Research mode the plan is a graph you can read before anything happens: a question, steps, branches (up to three levels), joins and a result. Click a step to give it an instruction, branch from it, skip it or ask the agent to expand it. When it runs, the pages the agent opens become grouped child tabs in the sidebar, and the answer lands in a Report tab you can save, copy or continue in the agent panel.

(The screenshot shows Island's built-in sample plan, with its grouped child tabs.)

Privacy

• Ad and tracker blocking with separate controls for ads and trackers, a shield with a count in the address field, and a per-site allowlist.
• On-device history search through the command palette. History can be turned off or cleared.

Reading and pages

• Reader view (⌥⌘R) and find in page (⌘F).
• Tab sleep releases the browser of tabs you have not used (30 minutes by default; set 15, 30, 60 or Never in Settings > Tabs). Sleeping tabs keep their title and place.
• Peek opens a link in a floating card: ⌘-click, middle-click or the context menu.

Looks and settings

Settings (⌘,) has General, Appearance, Privacy & blocking, Tabs, Reader, Agent & tools, Shortcuts and About, with search. Appearance holds the look preset and theme, sidebar density and position, corner radius, font and more. Every shortcut can be rebound.

For contrast, here is the Arc look: a space-tinted canvas with a rounded page card.

Try it in 2 minutes

1. Download. Open GitHub Releases and take island_browser-<version>-macosarm64.dmg (or the .zip) for an Apple Silicon Mac. Other targets: island_browser-<version>-macosx64.*, -windows64-setup.exe / -windows64.zip, -windowsarm64-*, -linux64.deb / -linux64.tar.gz, -linuxarm64-*. Each release has a SHA256SUMS.txt. nightly is a rolling prerelease of main; vX.Y.Z is one per version, marked latest.
2. Open it. Builds are not signed or notarized, so Gatekeeper refuses at first. Drag Island to Applications, then either allow it in System Settings > Privacy & Security or run xattr -dr com.apple.quarantine /Applications/Island.app.
3. First launch. A Welcome card asks for a theme and offers to import bookmarks from Chrome-family browsers, Safari, Firefox and Arc. Skip it with Start browsing.

Then try five things:

Try this	Keys
Jump anywhere: tabs, history, commands, or type a URL	⌘K
Open two pages side by side	⇧⌘S
Ask the agent about the page you are on	⌘J
Run a Research from the start page and review its plan	⌘T, then Research
Read without distractions, then find a word	⌥⌘R, ⌘F

(On Windows and Linux, use Ctrl for ⌘ and Alt for ⌥.)

Examples

Ask about a page. Open an article, press ⌘J, and pick Summarize this page in five bullet points or type your own request. The current tab is shared as context.

Run a research.

1. Open a new tab and choose Research.
2. Type a question, for example Which laptop fits my budget and work?.
3. Island opens the Plan tab. Read the graph, skip a branch, add one, or select a step and write an instruction for it.
4. Press Run plan (or Run A only to run one branch). Watch child tabs open, grouped by branch.
5. Read the answer in the Report tab; save or copy it, or continue in the agent panel.

Use Island from Claude Code or another MCP client. Island serves its browser tools at http://127.0.0.1:<port>/mcp on your machine, protected by a bearer token that changes on every launch. Settings > Agent & tools > MCP endpoint shows the live config with a Copy button. It looks like this:

{
  "mcpServers": {
    "island": {
      "type": "http",
      "url": "http://127.0.0.1:<port>/mcp",
      "headers": {
        "Authorization": "Bearer <token>"
      }
    }
  }
}

Island also writes a discovery file, agent-endpoint.json, with the url, token, transport (streamable-http) and pid. It lives next to your preferences:

OS	Path
macOS	~/Library/Application Support/Island/agent-endpoint.json
Linux	$XDG_DATA_HOME/Island/ or ~/.local/share/Island/agent-endpoint.json
Windows	%APPDATA%\Island\agent-endpoint.json (no pid field)

For clients that only launch stdio MCP servers, use the bridge that ships next to the browser binary (island_mcp_bridge, in Island.app/Contents/MacOS/ on macOS). It finds the endpoint from ISLAND_MCP_URL and ISLAND_MCP_TOKEN, then from --endpoint-file <path>, then from the discovery file. Island must be running. Island's own agent panel and an external agent use the same tools, and neither can approve or edit the Plan tab.

Keyboard shortcuts

Shortcuts are for macOS; on Windows and Linux use Ctrl for ⌘ and Alt for ⌥. Every shortcut can be changed in Settings > Shortcuts, and ⌘/ shows a cheatsheet.

Action	Keys
Command palette	⌘K
Search palette (Google, ChatGPT, Perplexity, Claude, Gemini)	⇧⌘K
Show or hide the agent	⌘J
New tab / Close tab / Reopen closed tab	⌘T / ⌘W / ⇧⌘T
Next / previous tab	⇧⌘] / ⇧⌘[
Select tab 1 to 8 / the last tab	⌘1–⌘8 / ⌘9
Focus the address field	⌘L
Back / Forward / Reload	⌘[ / ⌘] / ⌘R
Toggle sidebar	⌘B
All tabs	⇧⌘A
Pin or unpin tab	⌘D
New space / Rename space	⌥⌘N / F2
Next / previous space	⌥⌘↓ / ⌥⌘↑
Split view with the next tab	⇧⌘S
Move split divider left / right	⌥⌘[ / ⌥⌘]
Find in page / next / previous	⌘F / ⌘G / ⇧⌘G
Reader mode	⌥⌘R
Zoom in / out / reset	⌘= / ⌘- / ⌘0
Copy tab URL	⇧⌘C
Settings	⌘,
Shortcut cheatsheet	⌘/

The full list, with Windows and Linux keys, is in docs/user-guide/reference/keyboard-shortcuts.md.

Status and platforms

• Unsigned builds only. Versioned releases (vX.Y.Z, marked latest) and the nightly prerelease are not signed. Stable public release is blocked until signing and notarization verification exist.
• Platforms. The intended targets are macosarm64, macosx64, windows64, windowsarm64, linux64 and linuxarm64. Only macOS arm64 is built, tested and run by hand. The other five need native GitHub Actions evidence before they count as supported; see docs/supported-platforms.md.
• Not in scope: browser extensions (they need CEF's Chrome runtime; Island uses Alloy), sync, profiles and accounts, and more than one top-level window.
• Updates. The built-in updater checks GitHub releases, verifies the SHA-256 checksum and swaps the app in on "Restart to update".
• Visual acceptance (Phase 3 U10) still needs a human with display access.

Build from source

Requirements: CMake, a C++20 compiler, Python 3, network access for the first configure (GoogleTest), and a stable Rust toolchain for the ad blocker (without cargo, a no-op blocker is built).

bash -n scripts/setup_deps.sh
./scripts/setup_deps.sh --dry-run
./scripts/setup_deps.sh
python3 scripts/deps.py verify
cmake -B build -S .
cmake --build build
ctest --test-dir build --output-on-failure
open build/src/main/island_browser.app

scripts/setup_deps.sh vendors the pinned CEF distribution into third_party/cef/ and the Geist fonts into assets/fonts/; both stay out of git. Smoke run on macOS:

open build/src/main/island_browser.app --args --island-smoke-test
pgrep -fl island_browser || true   # after quitting: no helper processes should remain

The AI-agent kernel and the search kernel also build standalone, without CEF:

cmake -B build-agent -S src/agent && cmake --build build-agent
ctest --test-dir build-agent --output-on-failure
python3 -m pytest tests/deps tests/package tests/design tests/version

Build-time detail: AGENTS.md, docs/release-process.md.

Project layout

Path	Contents
src/main/	The browser: CEF app and window, native chrome, tabs, spaces, local pages (pages/)
src/agent/	CEF-free agent kernel: MCP tools endpoint and ACP client
src/search/	CEF-free search kernel behind on-device history search
src/content_blocker_ffi/	Rust crate wrapping Brave's adblock engine
tests/, bench/	GoogleTest and pytest suites; benchmark support
scripts/, deps/, cmake/	Dependency vendoring, packaging, versioning, platform CMake
docs/	Process docs, specs and plans, and the user guide
DESIGN.md	The product and visual design narrative

Documentation

• User guide: task-first help, written to be published on GitBook.
• CHANGELOG.md: every release and the unreleased notes.
• DESIGN.md: why Island looks and behaves the way it does.
• docs/supported-platforms.md and docs/release-process.md.

Contributing

• Read AGENTS.md first. Only units of an accepted spec and plan are implemented.
• Work on a branch and open a pull request. Build and test locally before committing; GitHub Actions triggers are mostly paused.
• Add your change to ## [Unreleased] in CHANGELOG.md. Do not edit VERSION by hand: the project owner bumps it with python3 scripts/version.py bump <part> and merges the PR. Run python3 scripts/version.py check before committing version changes.
• Style: Google-based, 4-space indent, 100 columns, explicit std::, target-scoped CMake.

Licensed under the terms in LICENSE.