Agent Browser Gateway: hand your AI agent one tab

01Consent

The agent starts with zero tabs. You share one from the extension popup or with a shortcut, and only that tab crosses the gate. Try it: toggle the tabs below and watch what the agent can list.

Default: No tabs. The extension declares no default host permissions.
Scope: Reads, screenshots, and operations reach only the tabs you shared.
Auto-revoke: When the tab closes, navigates to another origin, or you revoke it.
Writes: Click, fill, navigate, upload, and similar actions ask for local approval by default.

Keyboard shortcuts act on the current tab only

Share the tab, or revoke it if it is already shared.
Copy the tab ID. It never grants access.
Start or stop annotating. Shares the tab first if needed.
Switch between Area and Text while annotating.

Option on macOS, Alt elsewhere. Rebind or assign Clear all and toolbar visibility at chrome://extensions/shortcuts. The toolbar displays your current keys and remembers where you move it.

The controls you actually click

Screens from the extension's popup and approval window.

Not shared Agents can't see or operate the tab until you share it.
Shared with agents One click revokes access. Annotations live here too.
Writes ask first The approval window names the exact action and tab before anything runs.

02Local only

A small local bridge.An optional Cloud connection.

Local mode uses a Chrome extension, a menu bar Gateway, and the abg CLI. The desktop Gateway binds only to 127.0.0.1 and accepts WebSocket connections only from browser-extension origins. Cloud mode instead connects the extension to your selected service and authorized AI clients.

Your Mac

Chrome extension Shares the tabs you choose
WebSocket127.0.0.1:8765
Gateway app Permissions · audit log
Local IPCowner-only socket
abg CLI Read, screenshot, operate
ShellJSON on stdout
Your agent Claude Code, Codex, Cursor, Cline, scripts

ABG-operated servers in local mode None

No analytics
No crash reporter
No auto-update phone-home
No account in local mode

Local mode does not send browser data to an ABG server. Optional Cloud mode uses an account and relays shared data through your selected service. If your agent sends prompts to a model provider, that transfer is made by the agent under its own terms.

Check the listeners yourself

$lsof -nP -iTCP -sTCP:LISTEN

03Token-efficient reads

Clean Markdown,not a wall of HTML.

Raw page HTML drags scripts, styles, and framework wrappers into the prompt. abg read returns the page as Markdown with headings, links, and lists intact, and per-domain plugins trim app chrome further.

abg read t1 --selector article --format markdown

# Reset your password
Open Settings, then choose Security.

## Steps
1. Choose **Reset password**
2. Check your inbox for the link
- [Contact support](https://example.com/support)

Tokens to read one article page

Playwright page.content() ~50,000 124,476 chars · structure kept, heavy overhead
Playwright article innerHTML() ~17,000 42,070 chars · structure kept, with overhead
abg read --format markdown ~5,900 11,780 chars · structure kept, clean
Playwright article innerText() ~3,800 6,543 chars · headings, links, and lists lost

~88% fewer input tokens than full HTML, with structure preserved

README benchmark on a Japanese WordPress post. Token counts are approximate (~2 chars/token).

04Annotations

Point at the page,like you would in chat.

Annotation mode lets you drag a box or select text, add a comment, and hand the agent structured context: selectors, text anchors, and coordinates. Reload the page and the annotations wait in session storage until you restore them.

staging.example.com/checkout

Order summary

PlanTeam plan

Seats3

Total$96.00 / month

Place order 1Total should include tax 2Wrong plan name

$abg annotate t1
{ "ok": true, "count": 2,
  "annotations": [
    { "kind": "dom", "comment": "Total should include tax",
      "selector": ".summary .total" },
    { "kind": "text", "comment": "Wrong plan name",
      "text": "Team plan" } ] }

$abg annotate t1
{ "ok": true, "count": 0,
  "saved": { "count": 2, "urlMatches": true },
  "nextCommand": "abg annotate t1 --restore" }

$abg annotate t1 --restore
{ "ok": true, "count": 2,
  "restore": { "status": "restored",
    "restored": [ … 2 ], "unrestored": [],
    "alreadyPresent": 0 } }

Area and Text annotations, auto-classified as dom, screenshot, or text
Stored per tab in Chrome session storage, which page scripts cannot read
Restored only when the target can still be identified

05Audit log

Every actionleaves a line.

The Gateway appends a JSON line for each read, operation, permit, and revoke to a local, owner-only log. Review it in the Gateway window, with abg audit, or open the file.

abg audit --lines 50
abg activity --period day

Pasted values and clipboard payloads are recorded as byte lengths, not content.

~/Library/Logs/AgentBrowserGateway/audit.jsonl 0600 · owner-only

Audit log
time	action	tab	agent	detail
09:41:02	permit	418	—	accessMode: manual
09:41:06	read_dom	418	cli	staging.example.com/checkout
09:41:09	screenshot	418	cli	staging.example.com/checkout
09:41:15	click	418	cli	staging.example.com/checkout
09:41:21	paste	418	cli	selector · textBytes: 42
09:41:30	revoke	418	—	reason: user_revoked

{"ts":"2026-10-03T09:41:06Z","extensionId":"…","tabId":418,"url":"https://staging.example.com/checkout","action":"read_dom","agent":"cli"}

06Where it fits

Not a test runner.Not a hosted assistant.

ABG is for handing a human-owned, already-open tab to an agent workflow. Playwright remains the better fit when automation should own the whole browser lifecycle.

Option	Best fit	Tradeoff	Where ABG differs
Agent Browser Gateway	AI-assisted work in a tab you are already using	Requires explicit local setup and tab sharing	Per-tab consent, local transport, CLI-first workflow, local audit log
Playwright	Deterministic E2E tests, CI, screenshots, clean browser profiles	Automation owns the browser session	ABG uses your everyday Chrome tab with your current login and context
Claude in Chrome	Provider-integrated browser assistance	Tied to that provider's product surface and data path	ABG is agent-agnostic and designed around local-first browser access
Browser MCP tools	MCP-native browser control and structured snapshots	Often targets a dedicated or broader browser context	ABG keeps the human's selected tab as the permission boundary

Works with the agent you already use

Claude Code
Codex
Cursor
Cline
Your own scripts

Anything that can run a shell command can run abg. MCP clients can use abg mcp-server, a stdio wrapper over the same CLI.

07Download

Install in a minute.Verify before you trust it.

Chrome extension v1.3.6 supports Cloud login without a desktop app. For local mode, install macOS v0.5.2 with Homebrew or the signed DMG, then add the extension.

1Install the Gateway and CLI
2Add the Chrome extension
3Share a tab and run abg tabs

Homebrew

Tap the repository, trust the cask when Homebrew asks for tap trust, then install.

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

Already installed? brew info --cask agent-browser-gateway or abg --help confirms it. Use brew reinstall --cask agent-browser-gateway only to force a fresh install.

macOS DMG

v0.5.2 · macOS 14+ · Apple Silicon

macOS DMG · v0.5.2

SHA-256

4469b7d9e69b4bfe48329facd269381bf011660d3db1b9d638a2799f4cd35732

Verify the checksum before opening the DMG.

Chrome Web Store

v1.0.0

Chrome Web Store

Chrome Web Store review and publication are separate from the v1.3.6 GitHub ZIP release. Check the Store listing's version before installing.

Cloud extension ZIP · v1.3.6

Cloud mode needs no desktop app. Extract the ZIP, load it in Chrome, then sign in on the Web and authorize the browser. Store review and publication are separate.

Windows

v0.5.3 · Windows 10/11 x64 · The Gate UI

Windows ZIP · v0.5.3 SHA-256

Extract the ZIP and run AgentBrowserGatewaySetup.exe. This ZIP is unsigned and may show a Windows security warning. WinGet remains pending.

Windows install guide

CLI and agent skills

The installer puts abg on your PATH. Claude Code and Codex skills come from the skills CLI:

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

Uninstall. Remove the app from /Applications, delete abg from your PATH if you linked it manually, and remove the Chrome extension.

Published by ArcManagement, Inc. Release artifacts are served from GitHub Releases.

Free for personal use, non-profits, and small companies under the ArcManagement Source License. License details

Hand your agent one tab. Nothing else.

Nothing is visibleuntil you share it.