Install

Install the three local pieces ABG needs: the browser extension, the Gateway app, and the abg CLI.

Requirements

macOS 14 or newer on Apple Silicon for the current Gateway app. The Homebrew cask and DMG are arm64 only.
Google Chrome 120 or newer for the Chrome extension.
A terminal that can run abg.
For source builds: Xcode 16 or newer, mise, Node.js, and pnpm.

macOS with Homebrew

Homebrew installs Agent Browser Gateway.app into /Applications and abg into Homebrew’s bin.

Tap the repository, trust the cask, and install it:

brew tap arcmanagement/agent-browser-gateway https://github.com/arcmanagement/agent-browser-gateway
brew trust --cask arcmanagement/agent-browser-gateway/agent-browser-gateway
brew install --cask agent-browser-gateway

Start the app once so the menu bar icon appears:
Terminal window
```
open -a "Agent Browser Gateway"
```
Confirm that the CLI can reach the Gateway:
Terminal window
```
abg status
```
The JSON output shows running as true.

To update later, run brew upgrade --cask agent-browser-gateway.

Homebrew troubleshooting

Not upgrading agent-browser-gateway, the latest version is already installed: the cask is already installed. Check it with brew info --cask agent-browser-gateway or abg --help. Run brew reinstall --cask agent-browser-gateway only to force a fresh install.
Trust warnings for other taps: Homebrew may print them for unrelated taps. Check the final install line and brew info --cask agent-browser-gateway for the ABG cask state.
You tapped an older ABG repository: if you previously tapped the temporary public Homebrew repository or the private source repository, run brew untap arcmanagement/agent-browser-gateway once. Then tap again with the explicit GitHub URL above.

macOS with the DMG

Download the current DMG and its matching .sha256.txt file from the download page or GitHub Releases.
Verify the checksum in the folder where both files are saved:
Terminal window
```
shasum -a 256 -c agent-browser-gateway-X.Y.Z-macos-arm64.dmg.sha256.txt
```
Replace X.Y.Z with the version you downloaded. The output ends with OK. If it does not, do not install the file.
Open the DMG and double-click Install Agent Browser Gateway.app. The installer copies the app to /Applications, installs abg to /usr/local/bin, and starts the menu bar app.
Confirm the connection:
Terminal window
```
abg status
```

To update, download the newer DMG and run the installer again. If abg is not on your PATH, install the CLI from the release artifact or use the Homebrew cask.

Browser extension

For normal use, install Agent Browser Gateway from the Chrome Web Store. The public listing currently serves extension v0.4.8 while review of v0.5.2 completes.

To use ABG in incognito windows, open the extension details page and turn on Allow in incognito. Chrome disables extension access to incognito windows by default. Normal windows do not need this setting.

The popup, approval windows, and annotation overlay are available in English and Japanese. Set Display language under Advanced in the popup. Auto follows the browser language. Output from abg, error codes, and audit entries stay in English.

For extension development, load an unpacked build instead. See Source builds.

Agent skills and MCP

After the Gateway and CLI work, install or refresh the Claude Code and Codex skills with the skills CLI:

npx skills add arcmanagement/agent-browser-gateway -g

Add -a claude-code or -a codex to install for one agent only. Run npx skills update -g to refresh installed skills later.

For MCP clients, abg mcp-server runs a stdio MCP server that exposes one abg_cli tool. It calls the same local CLI, so sharing, approvals, and audit logging still apply.

Claude Code:

claude mcp add abg -- abg mcp-server

Codex (~/.codex/config.toml):

[mcp_servers.abg]
command = "abg"
args = ["mcp-server"]

Windows

Windows 0.5.3 includes The Gate dashboard and setup design, matching the Mac app and Chrome extension. Open the dashboard from the tray for shared tabs, copy/revoke actions, audit search, and appearance/language settings.

WinGet is the planned install path:

winget install --id ArcManagement.AgentBrowserGateway --source winget

Download the Windows v0.5.3 setup ZIP and its .sha256.txt file from the same release. Verify the checksum, extract the ZIP, and run AgentBrowserGatewaySetup.exe.

For a source build, clone the repository on Windows and run this from the repository root:

.\windows-build-install.cmd

Source builds

Gateway and CLI

mise trust
mise install
./build-app.sh
open "Agent Browser Gateway.app"

./build-app.sh produces Agent Browser Gateway.app and .build/release/abg.

Unpacked extension

cd extension
pnpm install
pnpm run build

In Chrome, open chrome://extensions, turn on Developer mode, choose Load unpacked, and select extension/dist/.

Development app

The development variant is a separate menu bar app on port 8766 with its own local state:

CONFIG=debug APP_VARIANT=dev ./build-app.sh
open "Agent Browser Gateway Dev.app"
ABG_PORT=8766 .build/debug/abg status

Production user plugins live under ~/.abg/plugins/. Development runs with ABG_PORT=8766 use ~/.abg-dev/plugins/, so local experiments do not change production plugin state.

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Distribution: release status and artifact verification.