How do I install Argus?

Copy the stdio config for Cursor, Claude Desktop, Claude Code, or VS Code on this page. It uses the publisher's install, not a PlugMCP proxy.

Does Argus need an API key?

No required environment variable is listed on this record.

When was Argus last checked?

Last checked 2026-10-28. Eyes & Hands for AI in the Browser — Chrome extension + MCP server giving AI agents full browser visibility and control

Argus MCP server

The Problem

You know this loop:

You: "Fix the login page" Agent: changes 3 files You: refreshes browser — white screen, console full of errors You: copies error, pastes it back — "It's showing TypeError on line 42" Agent: tries again You: refreshes — button renders but doesn't work You: opens DevTools, copies the network error, screenshots the layout, describes what's wrong in words...

Repeat 5–10 times. Your agent is powerful — but blind. It can't see the browser, so you become the middleman between the AI and your running app.

This loop kills productivity.

The Solution

Argus gives AI agents eyes and hands in the browser.

Your agent can now:

See console errors, network failures, screenshots, component state
Act by clicking buttons, filling forms, navigating pages, running JavaScript
Test with visual regression, responsive audits, accessibility checks
Debug by inspecting React/Vue/Svelte/Angular components, mapping errors to source code

All through MCP — no custom APIs, no complex setup. Just install the extension, connect, and start talking to your agent.

Features

31 MCP tools — observe, act, inspect, test, measure
Natural language E2E testing — write tests in plain English, no code
Works with any MCP client — Cursor, Claude Code, Windsurf, Cline, etc.
Secure by default — all data stays local, auth tokens, site filtering
Zero config — auto-connects, IDE starts server automatically
Visual regression — pixel-perfect UI testing
Accessibility audits — catch a11y issues automatically
Framework-aware — inspects React/Vue/Svelte/Angular components

Natural Language E2E Testing

Write tests in plain English in a markdown file — no framework, no selectors, no test code:

## Test: Login flow
1. Go to http://localhost:3000/login
2. Type "[email protected]" in the email field
3. Click Sign In
4. Verify the heading says "Welcome back, Admin"
5. Make sure there are no console errors

Then tell your agent: "Read tests/e2e.md and run all the tests."

The agent executes each step using Argus tools — clicking, typing, navigating, screenshotting, checking errors — and reports results. No Playwright, no Selenium, no brittle selectors. Anyone on your team can write tests.

See argus-demo for a full 18-test example covering search, cart, checkout, visual regression, responsive layout, and accessibility.

MCP Compatibility

Works with any MCP-compatible IDE or client:

Cursor — Add to .cursor/mcp.json
Claude Code — claude mcp add argus
Claude Desktop — Add to claude_desktop_config.json
Windsurf — Configure in settings
Cline — Add to config
Any MCP client — Standard stdio or SSE transport

Your IDE automatically starts the Argus server — no terminal commands needed.

MCP Tools

31 tools across 5 categories:

Category	What the agent can do
Observe	Console errors · network failures · screenshots · page info · element details · error source mapping
Act	Click · type · scroll · navigate · fill forms · run JS · highlight elements
Inspect	React / Vue / Svelte / Angular component props, state, hooks, context
Test	Visual regression (pixel-diff) · responsive audit (mobile / tablet / desktop) · accessibility
Runtime	Web Vitals · localStorage · sessionStorage · cookies

Tool	Description
`get_console_errors`	JS errors with stack traces
`get_console_logs`	Console output (log, warn, info, debug)
`get_network_failures`	Failed HTTP requests (4xx, 5xx)
`get_network_log`	All recent network requests
`get_screenshot`	Browser screenshot as native image
`list_screenshots`	Timeline of captured screenshots with metadata
`get_selected_element`	Right-click captured element — selector, styles, HTML
`get_page_info`	Current page URL, title, viewport
`get_error_source_context`	Parse stack trace to file:line:column
`clear_context`	Clear stored context

Tool	Description
`click_element`	Click any element by CSS selector
`type_text`	Type into inputs (React/Vue compatible)
`scroll_to`	Scroll to element, position, or direction
`navigate_to`	Navigate to any URL
`get_text`	Read text content of any element
`run_javascript`	Execute JS in page context
`highlight_element`	Highlight element with colored outline
`wait_for_element`	Wait for element to appear in DOM

Tool	Description
`detect_framework`	Detect React, Vue, Svelte, Angular, Next.js, Nuxt, jQuery
`inspect_component`	Read component props, state, hooks, context

Tool	Description
`snapshot_baseline`	Save current screenshot as named baseline
`compare_with_baseline`	Pixel-diff current vs baseline
`list_baselines`	List all saved baselines
`delete_baseline`	Delete a saved baseline

Tool	Description
`fill_form`	Fill multiple form fields in one call
`capture_at_viewport`	Resize browser + screenshot
`responsive_audit`	Capture at mobile, tablet, desktop breakpoints
`get_performance_metrics`	Web Vitals, memory, resource counts
`get_storage`	Read localStorage / sessionStorage
`get_cookies`	List cookies for current domain
`get_accessibility_issues`	Audit for missing alt text, labels, contrast

Comparison

Feature	Argus	Playwright/Selenium	Browser DevTools	Puppeteer
AI agent integration	✅ Native MCP	❌ Manual scripting	❌ Manual inspection	❌ Manual scripting
Natural language tests	✅ Yes	❌ Code required	❌ N/A	❌ Code required
Component inspection	✅ React/Vue/Svelte	❌ No	⚠️ DevTools only	❌ No
Visual regression	✅ Built-in	⚠️ Requires setup	❌ No	⚠️ Requires setup
Zero config	✅ Auto-connects	❌ Complex setup	✅ Built-in	⚠️ Requires setup
Framework-aware	✅ Yes	❌ No	⚠️ DevTools only	❌ No

Argus is designed for AI agents first — while Playwright and Selenium are powerful, they require writing code. Argus lets you describe what you want in plain English, and your agent figures out how to do it.

Quick Start

Prerequisites: Python 3.11+, Node.js 18+, Chrome, and an MCP-compatible IDE (Cursor, Claude Code, etc.)

1. Clone & Install

git clone https://github.com/itachi-hue/argus.git
cd argus

# Server
cd server
pip install -e .

# Extension
cd ../extension
npm install
npm run build

2. Add to Your IDE

Your IDE starts the Argus server automatically — no need to run anything in the terminal.

Add to .cursor/mcp.json (project) or ~/.cursor/mcp.json (global):

{
  "mcpServers": {
    "argus": {
      "command": "python",
      "args": ["-m", "argus"],
      "cwd": "/absolute/path/to/argus/server"
    }
  }
}

Important: Replace /absolute/path/to/argus/server with the actual path to the server/ folder on your machine (e.g. C:/Users/you/argus/server on Windows or /home/you/argus/server on Linux/Mac).

Restart Cursor. Look for argus with a green dot under Settings → MCP.

cd /absolute/path/to/argus/server
claude mcp add argus -- python -m argus

Replace /absolute/path/to/argus/server with the actual path.

Add to claude_desktop_config.json (Settings → Developer → Edit Config):

{
  "mcpServers": {
    "argus": {
      "command": "python",
      "args": ["-m", "argus"],
      "cwd": "/absolute/path/to/argus/server"
    }
  }
}

Replace /absolute/path/to/argus/server with the actual path.

stdio (local, default):

command: python -m argus
working directory: /absolute/path/to/argus/server

SSE (remote):

ARGUS_TRANSPORT=sse python -m argus
# Connect your client to http://127.0.0.1:42777/mcp/sse

3. Load the Chrome Extension

Open chrome://extensions in Chrome
Enable Developer mode (toggle in top-right)
Click Load unpacked → select the extension/ folder

4. Connect

Open any page in Chrome (e.g. your app at localhost:3000)
Click the Argus extension icon → Connect

That's it. The extension auto-detects the running server and connects instantly.

If auto-connect isn't available (e.g. another extension already claimed it), expand Manual setup in the popup to paste a token from http://127.0.0.1:42777/api/pair.

5. Use It

Open your web app in Chrome and talk to your agent:

"Check the browser for errors and fix them"
"Take a screenshot and fix the layout"
"Click the login button and see what happens"
"Run an accessibility audit on the page"

Security

All data stays on your machine — server binds to 127.0.0.1 only
Auth token required on every request (constant-time comparison)
Auto-connect is first-come-first-served — locks after the first extension connects
WebSocket authenticated via token on handshake
Authorization, Cookie, Set-Cookie headers automatically redacted
Request/response bodies truncated · in-memory only · rate limited
Site filtering — configurable allowlist / denylist in extension settings to control which sites Argus can observe

Variable	Default	Description
`ARGUS_TRANSPORT`	`stdio`	`stdio`, `sse`, or `all`
`ARGUS_PORT`	`42777`	HTTP server port
`ARGUS_AUTH_TOKEN`	auto-generated	Auth token
`ARGUS_MAX_ERRORS`	`100`	Max errors in buffer
`ARGUS_MAX_SCREENSHOTS`	`15`	Max screenshots stored
`ARGUS_RATE_LIMIT`	`120`	Max requests/minute

Roadmap

Near-term

Chrome Web Store — One-click install for instant usage
Firefox extension — Cross-browser support
Safari extension — Full browser coverage
Record & replay — Capture user flows and replay them automatically
CI/CD integration — Run natural language tests in GitHub Actions
Team features — Share baselines, test results, and dashboards
More frameworks — Better support for Svelte, Solid, Qwik

Future directions

Desktop apps — Electron and native desktop support
Mobile observability — iOS and Android monitoring
Terminal / CLI monitoring — Observe command-line tools and scripts
Self-healing workflows — Automatically detect and fix issues across platforms

Have ideas? Open an issue!

Development

# Server
cd server
pip install -e ".[dev]"
pytest tests/ -v              # run tests
ruff check src/ tests/        # lint
ruff format src/ tests/       # format

# Extension
cd extension
npm install
npm run build                 # production build
npm run watch                 # dev mode with auto-rebuild

Contributing

Contributions welcome! See CONTRIBUTING.md for guidelines.

Fork the repo
Create a feature branch
Make your changes
Run tests and linting
Open a PR

License

## Test: Login flow 1. Go to http://localhost:3000/login 2. Type "[email protected]" in the email field 3. Click Sign In 4. Verify the heading says "Welcome back, Admin" 5. Make sure there are no console errors

Add this server

Host a copy with our keys and logs.

Server facts

Tools

Questions

How do I install Argus?

Does Argus need an API key?

What transport does Argus use?

When was Argus last checked?

Documentation

The Problem

The Solution

Features

Natural Language E2E Testing

MCP Compatibility

MCP Tools

Comparison

Quick Start

1. Clone & Install

2. Add to Your IDE

3. Load the Chrome Extension

4. Connect

5. Use It

Security

Roadmap

Near-term

Future directions

Development

Contributing

License

Add this server

Host a copy with our keys and logs.

Server facts

Tools

Questions

How do I install Argus?

Does Argus need an API key?

What transport does Argus use?

When was Argus last checked?

Documentation

The Problem

The Solution

Features

Natural Language E2E Testing

MCP Compatibility

MCP Tools

Comparison

Quick Start

1. Clone & Install

2. Add to Your IDE

3. Load the Chrome Extension

4. Connect

5. Use It

Security

Roadmap

Near-term

Future directions

Development

Contributing

License