Content
# Browser-Integration MCP
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An MCP server for Claude Desktop that gives Claude a controllable browser agent — a **shared** browser running in a **separate, isolated profile** (Google Chrome, Microsoft Edge, or Vivaldi), driven over the Chrome DevTools Protocol from behind a **token-guarded local broker** (Chrome on a private pipe — no debugging TCP port). Windows-only. ~29 tools, Russian/English tool titles, Chrome DevTools telemetry disabled.
**Why this, and not just built-in web access?** A plain web fetch returns a page's static text and stops at anything behind a login or rendered by JavaScript. Browser-Integration drives a **real browser** through the Chrome DevTools Protocol, so Claude can sign in and work on **login-gated pages** (the agent keeps its own persistent browser session), act on live, JavaScript-rendered pages — click, type, fill forms, handle dialogs — and read the page at the **structural level** (accessibility tree, DOM, console, network) or run JavaScript in it, instead of guessing from a screenshot.
**➡️ [Download the latest installer](../../releases/latest)** · Windows · MIT License
> **⚠️ Unsigned installer.** The installer is not code-signed, so Windows SmartScreen (or your antivirus) may warn on first run. If you downloaded it from this repository's **Releases** page, you can proceed via **More info → Run anyway**. The full source of the installer is in this repository — nothing is hidden.
## Build from source
```
cd payload && npm ci && cd ..
cd payload\broker && npm install && cd ..\..
ISCC.exe setup.iss # Inno Setup 6 -> build\BrowserIntegrationMCP-Setup-v5.0.1.exe
```
`node_modules/` is not committed. `npm ci` in `payload/` restores `chrome-devtools-mcp` (pinned in `package-lock.json`); `npm install` in `payload/broker/` restores the broker's `ws` dependency. The shipped installer bundles a **rebrowser-patched** `chrome-devtools-mcp` for anti-detection — a plain `npm ci` restores the stock package, so for the patched build use the installer from **Releases**.
<details>
<summary><b>📖 English — full README</b></summary>
<br>
# Browser-Integration MCP
## Legal
### Trademarks
Not affiliated with, endorsed by, or sponsored by Vivaldi Technologies AS, Google LLC, Microsoft Corporation, or Anthropic PBC. Vivaldi, Google Chrome, Microsoft Edge, and Claude are trademarks of their respective owners.
### Third-party (bundled)
Bundles chrome-devtools-mcp (Copyright Google LLC, licensed under Apache-2.0). Its LICENSE and THIRD_PARTY_NOTICES ship inside `node_modules/chrome-devtools-mcp`.
### Usage / Intended use
Intended for lawful, personal use. The tool automates a copy of a supported browser (Google Chrome, Microsoft Edge, or Vivaldi) that you installed yourself, via Chromium's built-in DevTools Protocol (CDP) using public command-line switches; it does not modify, reverse-engineer, redistribute, or bundle any browser or Claude, and runs as an MCP extension inside your own Claude Desktop. You are responsible for complying with applicable law and with the terms of the software it works with (your browser's terms of use or EULA and Anthropic's Usage Policy / Consumer Terms), and for any actions performed through the browser agent.
### Disclaimer of Warranty and Limitation of Liability
This software (the "MCP") is provided "AS IS" and "AS AVAILABLE", without
warranty of any kind, whether express, implied, or statutory, including but not
limited to the implied warranties of merchantability, fitness for a particular
purpose, title, and non-infringement.
Installation and use of the MCP are carried out solely at the user's own free
will and risk. To the maximum extent permitted by applicable law, in no event
shall the author be liable for any claim, damages, or other liability -
including, without limitation, any theft, leakage, disclosure, alteration,
corruption, deletion, or loss of data, or any direct, indirect, incidental,
special, exemplary, punitive, or consequential damages - arising from, out of,
or in connection with the MCP, its use or inability to use it, or any actions
performed through it, even if the author has been advised of the possibility of
such damages.
The user bears full responsibility for operating the MCP and for any
consequences thereof.
By installing or using the MCP, the user acknowledges,
agrees to, and accepts these terms.
## What it is
Browser-Integration is an MCP server for Claude Desktop that gives Claude a
controllable browser agent. Under the hood it uses `chrome-devtools-mcp`
(Chrome DevTools Protocol) driving a separate instance of a supported browser (Google Chrome, Microsoft Edge, or Vivaldi) running a
clean, isolated profile. Claude gets ~29 tools: navigation, clicks, typing,
page snapshots, network, scripting, and so on. Tool titles are shown in
Russian and English, and Chrome DevTools telemetry is disabled.
**Why this, and not just built-in web access?** A plain web fetch returns a page's static text and stops at anything behind a login or rendered by JavaScript. Browser-Integration drives a **real browser** through the Chrome DevTools Protocol, so Claude can sign in and work on **login-gated pages** (the agent keeps its own persistent browser session), act on live, JavaScript-rendered pages — click, type, fill forms, handle dialogs — and read the page at the **structural level** (accessibility tree, DOM, console, network) or run JavaScript in it, instead of guessing from a screenshot.
Key idea: the agent works not in your everyday browser but in a **separate,
shared browser** owned by a small local **broker**. Chrome itself runs on a
private pipe (no debugging TCP port); the broker exposes a loopback WebSocket
guarded by a random token and a connecting-process check. Multiple chats/apps
attach to the one browser and take turns. This keeps your main profile's data
out of reach and keeps the agent profile clean (it holds none of your everyday
data).
## Requirements
- **Node.js** - any version (located via PATH and standard install paths).
- **A supported browser** - Google Chrome, Microsoft Edge, or Vivaldi (any version; located via the registry and standard paths).
- **Windows** + **Claude Desktop** with unpacked-extension support.
Administrator rights are not required: everything is installed into the user
profile. The installer creates no registry entries (it only cleans up entries
left by older versions, under `HKCU`).
## How the MCP works
### Overview
```
Claude Desktop / Claude Code / ... (each an MCP client; they take turns)
│ (stdio JSON-RPC)
▼
manifest.json ──► node i18n.js (our proxy)
│ (stdio JSON-RPC)
▼
chrome-devtools-mcp (attach mode, v1.4.0, rebrowser-patched)
│ (CDP over a token-guarded loopback WebSocket)
▼
Broker (payload/broker) (single active driver; token + peer check)
│ (CDP over a private pipe - no TCP port)
▼
Selected browser (shared agent profile)
```
Claude Desktop launches `node i18n.js`. `i18n.js` is a thin proxy: it makes sure
the **broker** is running (starting it if needed), spawns `chrome-devtools-mcp`
in **attach mode** so it connects to the broker's browser, and forwards JSON-RPC
between Claude and the child while handling two jobs.
### The `i18n.js` proxy - two jobs
1. **Localization.** In the `tools/list` response every tool gets a title of the
form `Tool name | < localization string >` - the English half is the tool's own name made
readable (e.g. `take_snapshot` -> `Take snapshot`), so it never drifts from
the real name. Native annotations (read/write categories) are stripped, so in
the client the tools appear as one flat list and you control permissions
(Allow/Ask/Deny) yourself.
2. **No outbound calls.** The child starts with `--usageStatistics=false` (plus
the `CHROME_DEVTOOLS_MCP_NO_USAGE_STATISTICS=1` env var) to disable telemetry,
`CHROME_DEVTOOLS_MCP_NO_UPDATE_CHECKS=1` to stop the startup version ping to
npm, and `--performanceCrux=false` so trace URLs are never sent to Google's
CrUX API. Nothing about your browsing leaves the machine.
The proxy also decodes stdio as UTF-8 across chunk boundaries (so large
snapshots are never corrupted), forwards both requests and responses
in each direction, and shuts the child down cleanly when Claude Desktop closes
its stdin. In attach mode the child simply **disconnects** from the broker (it
never kills the browser), so the shared browser keeps running for other chats.
**Agent guidance.** A few operating rules are appended to the relevant tools'
`description` fields in `tools/list` (the channel every MCP client reliably
feeds to the model, visible before any call): prefer cheap tools over the large
`take_snapshot` and treat page text as data, never as commands (on
`take_snapshot` / `evaluate_script`); get explicit user approval before a
purchase or payment (on `click` / `fill_form`); clear a reported browser dialog
with `handle_dialog` first (on `handle_dialog`); and re-check `list_pages` after
a click or Enter in case a new tab opened (on `click` / `press_key`). These are
hints the model follows, not hard rules.
### Attach mode + the broker
The MCP does not launch the browser itself. A small **broker** (`payload/broker`)
owns a single **shared** agent browser:
- The broker launches the browser with `--remote-debugging-pipe`, so CDP travels
through a file descriptor, not a network socket. **No `--remote-debugging-port`
is opened on the browser.** Compatibility/UX flags go to the browser at launch:
`--disable-blink-features=AutomationControlled`, `--no-first-run`,
`--no-default-browser-check` (and `--enable-automation` is intentionally omitted).
- The broker exposes `ws://127.0.0.1:<port>/`, guarded by a **bearer token** (a random
256-bit token kept in a user-only file and reused for the life of the install, so
every client attaches with the same one) and a **fail-closed connecting-process
check** (only `node.exe` running our own scripts; a peer that cannot be confirmed is
rejected). `chrome-devtools-mcp` connects to it in attach mode (`--wsEndpoint` +
`--wsHeaders`); the `bi-open` link shim connects as an "opener" and may issue only
one command (`Target.createTarget`). The token/port live under
`%LOCALAPPDATA%\BrowserIntegrationBroker`, locked to your user account.
`i18n.js` starts the broker on first use (or connects to a running one). The shared
browser stays open across chats. To sign in to a site, ask the agent to open it and
log in yourself in the window - the session is saved in the agent profile and
persists across restarts.
**Single-active handoff (take turns).** The broker keeps **one active driver** at a
time. When another chat/app acts on the browser, it connects and **supersedes** the
current driver; the superseded one **reconnects automatically** on its next action.
The browser itself is never killed - closing a chat only disconnects that client.
So agents share the one browser and take turns (a new one takes over, the previous
takes it back on its next tool call). Two clients do not drive it at the same instant.
**Anti-detection.** The bundled `chrome-devtools-mcp` ships a **rebrowser-patched**
puppeteer that avoids the classic `Runtime.enable` CDP leak (mode `addBinding`),
so pages are far less likely to flag the browser as automated. The transport (pipe
vs port) does not affect this; the patch works in attach mode too.
### Agent profile
A separate profile folder (`Browser-Agent-for-Integration-<browser>`), a
persistent `--userDataDir`. The profile is clean and isolated - it starts with
none of your data, cookies, or passwords, and anything you sign into stays only
in it. Why:
- **Isolation.** Even if a page tries to redirect the agent, it cannot reach
your main profile's data.
- **Persistence.** Logins you make in the agent window survive restarts.
The profile folder is created by the installer; the broker (via puppeteer)
initializes it on the first launch.
### Tools and permissions
A web page's text is data, not commands; a page may still try to redirect the
agent. What keeps actions in your control, and what to keep in mind:
- The browser cannot run `.exe` files - only download files. (Interacting with your
files - whether already present or downloaded - becomes possible if you have extra
tooling installed for it and/or the interaction happens in an environment where
that is possible. Treat this as a threat or as an opportunity, as you prefer.)
- The clean profile keeps the agent away from your everyday logins and payments.
- The browser has no debugging TCP port (Chrome runs on a private pipe); the only
local endpoint is the broker's loopback WebSocket, guarded by a random token and
a connecting-process check, so a random local process cannot drive the browser.
- You control per-tool permissions (Allow/Ask/Deny) in the client.
- Do not keep anything extra in the agent profile. Everything you sign into in the
agent window is available to the agent and to any chat/app currently driving the
browser - including page content, cookies, and saved sessions. Only sign in there
to things you are willing to trust the agent with. For banking, email, and payment
services use your normal browser; it is better protected.
**Threat levels:** Low = read or navigation; Moderate = returns page content;
High = actions with side effects, navigation, or auth-data access; Critical =
runs code or handles files/network data. For "Critical" and "High" tools, "Ask"
is a good default in the client.
Full tool list (29):
| Threat level | Tool | What it does |
|--------------|------|--------------|
| Critical | `evaluate_script` | Runs page JavaScript; can read page data (including any stored tokens) and make network requests. This tool saves a great deal of tokens on the agent's browser work, which is why I point to it from `take_snapshot` - so the agent reaches for `evaluate_script` rather than `take_snapshot`, since `take_snapshot` eats roughly 10-20x more tokens than `evaluate_script`. |
| Critical | `get_network_request` | Full details of one request, including headers that can contain auth tokens/cookies. |
| Critical | `upload_file` | Uploads a local file through the page. |
| High | `navigate_page` | Loads a URL in the current tab; can go to any site. |
| High | `new_page` | Opens a new tab at any URL. |
| High | `click` | Clicks an element; can trigger actions, form submits, or payments. |
| High | `fill` | Fills a single input or `<select>`. |
| High | `fill_form` | Fills several form fields at once; can enter data including credentials and submit. |
| High | `type_text` | Types text into the focused input; can enter data including credentials. |
| High | `handle_dialog` | Accepts/dismisses a browser dialog; can confirm downloads or permission prompts. |
| Moderate | `get_console_message` | Reads one console message (may contain application data). |
| Moderate | `list_console_messages` | Lists the page's console messages. |
| Moderate | `list_network_requests` | Lists network requests (URLs/metadata) made by the page. |
| Moderate | `take_snapshot` | Captures the page's accessibility (text) tree; returns page content. |
| Moderate | `take_screenshot` | Screenshots the page or an element; may capture visible private data. |
| Moderate | `take_heapsnapshot` | Captures a JS heap snapshot; may contain in-memory application data. |
| Moderate | `drag` | Drags one element onto another. |
| Moderate | `press_key` | Presses a key or combination; can trigger shortcuts or submit. |
| Low | `list_pages` | Lists open tabs. |
| Low | `select_page` | Switches the active tab. |
| Low | `wait_for` | Waits until the specified text appears on the page. |
| Low | `hover` | Hovers over an element. |
| Low | `close_page` | Closes a tab. |
| Low | `resize_page` | Resizes the browser window. |
| Low | `emulate` | Emulates device/feature conditions. |
| Low | `performance_start_trace` | Starts a performance trace recording. |
| Low | `performance_stop_trace` | Stops the active performance trace. |
| Low | `performance_analyze_insight` | Returns details for a specific performance insight. |
| Low | `lighthouse_audit` | Runs a Lighthouse audit (a11y / SEO / best practices). |
## How the installer works
### Philosophy
The installer **prepares everything** and leaves only one final manual step to
the user. No administrator rights (only the user folder, nothing in
`Program Files`/`ProgramData`; the registry is touched only to clean up entries
from older versions). No downloads from the internet. A clean profile -
nobody's data is copied.
### Steps (in order)
1. **Precheck.** Finds Node.js and a supported browser (Chrome, Edge, or Vivaldi), and lets you choose one. No Node -> abort (code 1); no browser
-> abort (code 2). Paths are resolved via PATH, the registry (App Paths /
StartMenuInternet), and standard install locations.
2. **Deploy.** Copies the MCP folder to `Documents\Browser-Integration-mcp\
Core-Browser-Integration-mcp` and creates the profile folder.
3. **Bake.** Substitutes real values into `i18n.js` in place of the
placeholders: `__NODE__` (node path), `__BROWSER__` (selected browser exe
path), `__PROFILE__` (profile path). Each value is written as a JSON string
literal, so paths with spaces, Cyrillic, apostrophes, or `$` are escaped
safely.
4. **Legacy cleanup.** Removes artifacts from any previous attach-mode install:
the `HKCU` browser registration and the three desktop shortcuts (which used
to launch the browser with a debugging TCP port).
5. **Self-check + report + instructions.** Writes a machine-readable result
(UTF-8, paths, success flags), shows a "what was done" screen and a screen
with the manual step.
At runtime the agent browser is launched by the **broker** (bundled under
`payload/broker`, shipped with the MCP) on a private pipe; the compatibility/UX
flags are passed at launch:
```
--disable-blink-features=AutomationControlled
--no-first-run
--no-default-browser-check
```
### Folder layout (under Documents)
```
Browser-Integration-mcp\
├── Core-Browser-Integration-mcp\ ← the MCP itself (point Claude here)
└── Browser-Agent-for-Integration-<browser> ← the clean agent browser profile
```
### Manual steps after installation
1. **Load the MCP into Claude Desktop:** Settings -> Extensions (Advanced
Settings) -> "Install Unpacked Extension" -> select the
`Core-Browser-Integration-mcp` folder -> enable the extension.
That is the only required step. On first use the MCP starts the broker and the
shared agent browser opens; it stays open across chats (closing a chat does not
close it), and chats/apps take turns driving it. To sign in to sites, ask the
agent to open the page and log in yourself in the window. The profile is separate
and clean, and your sessions persist in it.
2. **(Optional) Open clicked links in the agent browser:** run
`Core-Browser-Integration-mcp\broker\install\register.ps1`, then choose
"Agent Browser" in Windows Settings -> Default apps. `unregister.ps1` reverses
it. (Windows requires the final default-browser pick to be manual.)
### Uninstallation
The uninstaller removes leftover registry entries and desktop shortcuts from
older versions. If you registered the agent browser as a default-browser
candidate, run `broker\install\unregister.ps1` first to remove that HKCU
registration and the "Agent Browser" shortcut. The MCP folder and the agent
profile can be removed manually.
## Project files (for development)
```
installer-src\
├── setup.iss ← Inno Setup script (English UI, ASCII)
├── installer-logic.ps1 ← all install logic (precheck/install)
├── payload\ ← what is delivered to the user (goes into the build)
│ ├── manifest.json ← MCP manifest
│ ├── i18n.js ← proxy (placeholders + localization + broker bootstrap + attach)
│ ├── broker\ ← the shared-browser auth broker (src, tools/bi-open, install)
│ └── node_modules\chrome-devtools-mcp ← bundled, rebrowser-patched
├── build\ ← the compiled installer
├── README.md ← project README (GitHub)
├── LICENSE ← MIT license (deployed with the MCP)
├── README.txt ← this file, EN (deployed with the MCP)
└── README.ru.txt ← Russian version (deployed with the MCP)
```
### Third-party components (included)
Included is chrome-devtools-mcp (Copyright Google LLC, Apache-2.0 license). Its LICENSE and THIRD_PARTY_NOTICES files are located within `node_modules/chrome-devtools-mcp`.
### Usage / purpose
This tool is intended for legitimate personal use. It automates a supported browser (Google Chrome, Microsoft Edge, or Vivaldi) that you have installed, using the Chromium debugging protocol (CDP) with public command-line keys. It does not modify, reverse-engineer, distribute, or embed any browser or Claude, and operates as an MCP extension within your Claude Desktop. You are responsible for complying with applicable law and the terms of the software it works with (your browser's terms of use / EULA and Usage Policy / Consumer Terms of Anthropic), as well as any actions taken by the browser agent.
### Disclaimer of warranties and limitation of liability
This software (the "MCP") is provided "AS IS" and "AS AVAILABLE", without any warranties - express, implied, or statutory - including, but not limited to, implied warranties of merchantability, fitness for a particular purpose, title, and non-infringement.
You install and use MCP at your own free will and risk. To the maximum extent permitted by applicable law, the author under no circumstances assumes liability for any claims, damages, or other liabilities - including, without limitation, any theft, leakage, disclosure, alteration, damage, deletion, or loss of data, as well as any direct, indirect, incidental, special, punitive, or consequential damages - arising from MCP, in connection with it, from its use or inability to use, or from any actions taken with its help, even if the author was notified of the possibility of such losses.
The user is fully responsible for the operation of MCP and its consequences.
By installing or using MCP, you confirm that you have read, agree to, and accept these terms.
## What is this
Browser-Integration is an MCP server for Claude Desktop that provides Claude with a managed browser agent. Under the hood, it uses `chrome-devtools-mcp` (Chrome DevTools Protocol) to control a separate instance of a supported browser (Google Chrome, Microsoft Edge, or Vivaldi) with a clean, isolated profile. Claude gets ~29 tools: navigation, clicks, input, page screenshots, network and script work, etc. Tool names are in Russian and English; Chrome DevTools telemetry is disabled.
**Why is this needed if there is built-in web access?** Ordinary page retrieval returns its static text and stops at everything that requires login or is rendered via JavaScript. Browser-Integration controls a **real browser** via Chrome DevTools Protocol, so Claude can log into accounts and work with **pages behind authorization** (the agent maintains its own permanent browser session), act on live JS pages - click, enter text, fill out forms, process dialogs - and read the page at the **structural level** (accessibility tree, DOM, console, network) or execute JavaScript in it, rather than guessing from the screenshot.
The key idea is that the agent works not in your usual browser, but in a **separate, shared browser**, owned by a small local **broker**. Chrome itself works through a private channel (pipe) - the debugging port over TCP is not opened; the broker provides a local WebSocket protected by a random token and process verification. Several chats/applications connect to one browser and work in turn. This way, your main profile data is inaccessible, and the agent profile remains clean (it does not contain your everyday data).
## Requirements
- **Node.js** - any version (searched in PATH and standard installation paths).
- **Supported browser** - Google Chrome, Microsoft Edge, or Vivaldi (any version; searched in the registry and standard paths).
- **Windows** + **Claude Desktop** with support for unpacked extensions.
Administrator rights are not required: everything is installed in the user's profile. The installer does not make registry entries (it only removes entries left from previous versions in `HKCU`).
## How MCP works
### General scheme
```
Claude Desktop / Claude Code / ... (MCP clients; work in turn)
│ (stdio JSON-RPC)
▼
manifest.json ──► node i18n.js (our proxy)
│ (stdio JSON-RPC)
▼
chrome-devtools-mcp (attach mode, v1.4.0, rebrowser patch)
│ (CDP via local WebSocket with token)
▼
Broker (payload/broker) (one active "driver"; token + process verification)
│ (CDP via private pipe - without TCP port)
▼
Selected browser (shared agent profile)
```
Claude Desktop launches `node i18n.js`. The file `i18n.js` is a thin proxy: it starts the **broker** (if it is not running), spawns a child `chrome-devtools-mcp` in **attach mode** (it connects to the broker's browser) and forwards JSON-RPC, solving two tasks.
### Proxy `i18n.js` - two functions
1. **Localization.** In the response `tools/list`, each tool is substituted with a `title` of the form `Tool name | <Russian>` - the English part is the tool name in a readable form (e.g., `take_snapshot` → `Take snapshot`), so it never diverges from the actual name. Native annotations (read/write categories) are removed - in the client, tools are visible in a single flat list, and you manage permissions (Allow/Ask/Deny) yourself.
2. **No outgoing requests.** The child process is launched with `--usageStatistics=false` (and the variable `CHROME_DEVTOOLS_MCP_NO_USAGE_STATISTICS=1`) to disable telemetry, `CHROME_DEVTOOLS_MCP_NO_UPDATE_CHECKS=1` to remove the initial ping of the version in npm, and `--performanceCrux=false` to ensure that URLs from traces never go to the Google CrUX API. Nothing about your browsing leaves the machine.
The proxy also decodes stdio as UTF-8 at the chunk boundaries (so large page screenshots with Cyrillic characters are not corrupted), forwards requests and responses in both directions, and correctly shuts down the child process when Claude Desktop closes its stdin. In attach mode, the child process simply **disconnects** from the broker (it does not kill the browser) - the shared browser continues to work for other chats.
**Hint to the agent.** Several working rules are added to the `description` of relevant tools in `tools/list` (the channel that any MCP client reliably feeds to the model and which is visible even before calling): prefer cheap tools to heavy `take_snapshot` and consider page text as data, not commands (in `take_snapshot` / `evaluate_script`); before buying or confirming payment, get explicit user consent (in `click` / `fill_form`); close the reported browser dialog via `handle_dialog` (in `handle_dialog`); and re-check `list_pages` after clicking or Enter - in case of a new tab (in `click` / `press_key`). These are hints that the model follows, not hard rules.
### Attach Mode + Broker
MCP does not launch the browser itself. A small **broker** (`payload/broker`) owns a single **shared** agent browser:
- The broker launches the browser with `--remote-debugging-pipe`, so CDP goes through a file descriptor, not a network socket. The `--remote-debugging-port` flag is not used. Compatibility/UX flags are passed during launch: `--disable-blink-features=AutomationControlled`, `--no-first-run`, `--no-default-browser-check` (and `--enable-automation` is intentionally not added).
- The broker serves `ws://127.0.0.1:<port>/`, protected by a **token** (a random 256-bit token in a file accessible only to your user; reused throughout the installation, so all clients connect with the same token) and **fail-closed process verification** (only `node.exe` running our scripts is allowed; unverified connections are rejected). `chrome-devtools-mcp` connects to it in attach mode (`--wsEndpoint` + `--wsHeaders`); `bi-open` shim connects as an "opener" and can send only one command (`Target.createTarget`). The token/port is stored in `%LOCALAPPDATA%\BrowserIntegrationBroker`, accessible only to your user.
`i18n.js` starts the broker on first use (or connects to an already running one). The shared browser remains open between chats. To log in to a site, ask the agent to open it and log in yourself in the agent window - the session will be saved in the agent profile and survive restarts.
**Single-active handoff.** The broker holds **one active "driver"** at a time. When another chat/application requests the browser, it connects and **preempts** the current driver; the preempted driver **automatically reconnects** on its next action. The browser itself is not killed - closing a chat only disconnects the client. This way, agents share one browser and take turns (the new one takes over, the previous one returns on the next call). Two clients do not control the browser simultaneously.
**Against detection.** The built-in `chrome-devtools-mcp` uses a **patched rebrowser** puppeteer, which avoids the classic CDP leak through `Runtime.enable` (the `addBinding` mode), so pages are much less likely to mark the browser as automated. The transport (pipe or port) does not affect this - the patch works in attach mode.
### Agent Profile
A separate profile folder (`Browser-Agent-for-Integration-<browser>`), a permanent `--userDataDir`. The profile is clean and isolated - initially, it contains none of your data, cookies, or passwords, and everything you log in to remains only in that profile. Reasons:
- **Isolation.** Even if a page tries to hijack the agent, it will not access your main profile data.
- **Persistence.** Logins made in the agent window survive restarts.
The profile folder is created by the installer; the broker (via puppeteer) initializes it on the first run.
### Tools and Permissions
The page text is data, not commands; however, the page can still try to hijack the agent. What keeps actions under your control and what you should remember:
- The browser cannot run `.exe` files - only download files. (Interaction with your files, whether existing or downloaded, will be possible if you have additional tools for interaction and/or the interaction occurs in an environment where this is possible. You can perceive this as a threat or an opportunity.)
- A clean profile keeps the agent away from your everyday logins and payments.
- The browser has no debug TCP port (Chrome is on a private pipe); the only local entry point is the broker's WebSocket, protected by a random token and process verification, so a random local process cannot control the browser.
- You manage permissions for each tool (Allow/Ask/Deny) in the client.
- Do not keep unnecessary items in the agent profile. Everything you log in to in the agent window is accessible to the agent and any chat/application currently controlling the browser - including page content, cookies, and saved sessions. Only log in to what you are willing to trust the agent with. For banks, email, and payment services, use your regular browser, which is more secure.
**Threat levels:** Low = read or navigation; Moderate = returns page content; High = actions with consequences, navigation, or access to authentication data; Critical = executes code or works with files/network data. For Critical and High levels, it's convenient to set "Ask" in the client.
Full list of tools (29):
| Threat Level | Tool | What it does |
|----------------|------------|------------|
| Critical | `evaluate_script` | Executes page JavaScript; can read page data (including any saved tokens) and make network requests. This tool significantly saves tokens on agent-browser interaction, so I linked it in `take_snapshot` to encourage the agent to use `evaluate_script` more often than `take_snapshot`. As `take_snapshot` consumes about 10-20 times more tokens than `evaluate_script`. |
| Critical | `get_network_request` | Full details of a single request, including headers that may contain authorization tokens/cookies. |
| Critical | `upload_file` | Uploads a local file through the page. |
| High | `navigate_page` | Loads a URL in the current tab; can open any site. |
| High | `new_page` | Opens a new tab with any URL. |
| High | `click` | Clicks an element; can trigger actions, form submissions, or payments. |
| High | `fill` | Fills a single field or `<select>`. |
| High | `fill_form` | Fills multiple form fields; can enter data, including credentials, and submit. |
| High | `type_text` | Types text into an active field; can enter data, including credentials. |
| High | `handle_dialog` | Accepts/closes a browser dialog; can confirm a load or permission request. |
| Moderate | `get_console_message` | Reads a console message (may contain application data). |
| Moderate | `list_console_messages` | Lists page console messages. |
| Moderate | `list_network_requests` | Lists page network requests (URL/metadata). |
| Moderate | `take_snapshot` | A snapshot of the page's accessibility tree (text); returns content. |
| Moderate | `take_screenshot` | A screenshot of the page or element; may capture visible private data. |
| Moderate | `take_heapsnapshot` | A JavaScript heap snapshot; may contain application data from memory. |
| Moderate | `drag` | Drags one element to another. |
| Moderate | `press_key` | Presses a key or combination; may trigger hotkeys or submissions. |
| Low | `list_pages` | Lists open tabs. |
| Low | `select_page` | Switches the active tab. |
| Low | `wait_for` | Waits for the specified text to appear on the page. |
| Low | `hover` | Hovers over an element. |
| Low | `close_page` | Closes a tab. |
| Low | `resize_page` | Resizes the browser window. |
| Low | `emulate` | Emulates a device/conditions. |
| Low | `performance_start_trace` | Starts recording a performance trace. |
| Low | `performance_stop_trace` | Stops an active trace. |
| Low | `performance_analyze_insight` | Returns details of a specific performance slice. |
| Low | `lighthouse_audit` | Runs a Lighthouse audit (accessibility/SEO/practices). |
## How the Installer Works
### Philosophy
The installer **prepares everything** and leaves the user with one final manual step. No administrator rights required (only the user folder, nothing in `Program Files`/`ProgramData`; registry is only touched for cleaning up old version records). No internet downloads. A clean profile - no one else's data is copied.
### Steps (in order)
1. **Precheck.** Searches for Node.js and a supported browser (Chrome, Edge, Vivaldi) and allows the user to select one. If Node.js is not found → exit (code 1); if no browser is found → exit (code 2). Paths are determined through PATH, registry (App Paths / StartMenuInternet), and standard installation locations.
2. **Deployment.** Copies the MCP folder to `Documents\Browser-Integration-mcp\Core-Browser-Integration-mcp` and creates a profile folder.
3. **Bake.** Substitutes real values into `i18n.js` instead of placeholders: `__NODE__` (path to node), `__BROWSER__` (path to the selected browser's exe), `__PROFILE__` (path to the profile). Each value is written as a JSON string literal, so paths with spaces, Cyrillic characters, apostrophes, or `$` are safely escaped.
4. **Legacy cleanup.** Removes artifacts from previous installations in attach mode: browser registration in `HKCU` and three desktop shortcuts (which launched the browser with a TCP debugging port).
5. **Self-check + report + instructions.** Writes a machine-readable result (UTF-8, paths, success flags), displays a "what's done" screen, and a screen with manual steps.
At runtime, the agent browser launches the **broker** (located in `payload/broker`, supplied with MCP) on a private pipe; compatibility/UX flags are passed during launch:
```
--disable-blink-features=AutomationControlled
--no-first-run
--no-default-browser-check
```
### Folder structure (in "Documents")
```
Browser-Integration-mcp\
├── Core-Browser-Integration-mcp\ ← MCP itself (which you specify to Claude)
└── Browser-Agent-for-Integration-<browser> ← clean agent browser profile
```
### Manual steps after installation
1. **Load MCP in Claude Desktop:** Settings → Extensions (Advanced Settings) → "Install Unpacked Extension" → select the `Core-Browser-Integration-mcp` folder → enable the extension.
This is the only required step. When using MCP for the first time, it launches the broker, and the general agent browser opens; it remains open between chats (closing a chat does not close it), and chats/applications go one by one. To log in to sites, ask the agent to open a page and log in yourself in the window. The profile is separate and clean, and your sessions are saved in it.
2. **(Optional) Open clicked links in the agent browser:** run `Core-Browser-Integration-mcp\broker\install\register.ps1`, then select "Agent Browser" in "Windows Settings → Default Apps". To revert, run `unregister.ps1`. (The final selection of the default browser in Windows requires manual action.)
### Uninstallation
The uninstaller removes remaining registry entries and shortcuts from old versions. If you registered the agent browser as a default candidate, first run `broker\install\unregister.ps1` to remove HKCU registration and the "Agent Browser" shortcut. The MCP folder and profile can be deleted manually.
## Project files (for development)
```
installer-src\
├── setup.iss ← Inno Setup script (UI in English, ASCII)
├── installer-logic.ps1 ← entire installation logic (precheck/install)
├── payload\ ← what is delivered to the user (goes into the build)
│ ├── manifest.json ← MCP manifest
│ ├── i18n.js ← proxy (placeholders + localization + broker launch + attach)
│ ├── broker\ ← general browser broker (src, tools/bi-open, install)
│ └── node_modules\chrome-devtools-mcp ← included, patched rebrowser
├── build\ ← compiled installer
├── README.md ← project README (GitHub)
├── LICENSE ← MIT license (installed with MCP)
├── README.txt ← English version (installed with MCP)
└── README.ru.txt ← this file, RU (installed with MCP)
```
