Glance
AI-powered browser automation for Claude Code
by DebugBase
Navigate, click, screenshot, test — all from your terminal.
What is Glance?
Glance is an MCP server that gives Claude Code a real browser. Instead of guessing what your web app looks like, Claude can actually see it, interact with it, and test it.
You: "Test the login flow on localhost:3000"
Claude: *opens browser* *navigates* *fills form* *clicks submit*
*takes screenshot* *verifies redirect* *checks for errors*
"Login flow works. Found 1 console warning about..."
Features
- 30 MCP tools for complete browser control
- Inline screenshots — Claude sees what the browser sees
- Accessibility snapshots — full page structure as text
- Test scenario runner — define multi-step tests in JSON
- 12 assertion types — exists, textContains, urlEquals, and more
- Session recording — record and replay browser sessions
- Visual regression — pixel-level screenshot comparison
- Network & console monitoring — catch errors and failed requests
- Security controls — URL allowlist/denylist, rate limiting, JS execution policies
- Headed mode — watch the browser in real-time
Quick Start
1. Install
npm install -g glance-mcp
Or add directly to Claude Code:
claude mcp add glance -- npx glance-mcp
2. Configure
Add to your .mcp.json:
{
"mcpServers": {
"glance": {
"command": "npx",
"args": ["glance-mcp"],
"env": {
"BROWSER_HEADLESS": "false"
}
}
}
}
3. Use
Just ask Claude to interact with your web app:
"Open localhost:3000 and take a screenshot"
"Test the signup flow with invalid email"
"Check if the pricing page has all three tiers"
"Run a visual regression test on the dashboard"
Tools Reference
Browser Control (19 tools)
| Tool | Description |
|---|---|
browser_navigate | Navigate to a URL |
browser_click | Click an element (CSS selector or text) |
browser_type | Type into an input field |
browser_hover | Hover over an element |
browser_drag | Drag and drop between elements |
browser_select_option | Select from a dropdown |
browser_press_key | Press a keyboard key |
browser_scroll | Scroll the page or to an element |
browser_screenshot | Capture a screenshot (returned inline to Claude) |
browser_snapshot | Get the accessibility tree as text |
browser_evaluate | Execute JavaScript in the page |
browser_console_messages | Read console logs and errors |
browser_network_requests | Monitor network activity |
browser_go_back | Navigate back |
browser_go_forward | Navigate forward |
browser_tab_new | Open a new tab |
browser_tab_list | List all open tabs |
browser_tab_select | Switch to a tab |
browser_close | Close the browser |
Test Automation (7 tools)
| Tool | Description |
|---|---|
test_scenario_run | Run a multi-step test scenario |
test_scenario_status | Check running scenario status |
test_assert | Run a single assertion |
test_fill_form | Auto-fill a form |
test_auth_flow | Test a login/signup flow |
test_watch_events | Watch for DOM/network events |
test_stop_watch | Stop watching events |
Session & Visual (4 tools)
| Tool | Description |
|---|---|
session_start | Start recording a session |
session_end | End and save a session |
session_list | List recorded sessions |
visual_baseline | Save a visual baseline |
visual_compare | Compare against baseline |
Test Scenarios
Define multi-step test scenarios in JSON:
{
"name": "Login Flow",
"steps": [
{ "name": "Go to login", "action": "navigate", "url": "http://localhost:3000/login" },
{ "name": "Enter email", "action": "type", "selector": "input[type='email']", "value": "user@test.com" },
{ "name": "Enter password", "action": "type", "selector": "input[type='password']", "value": "password123" },
{ "name": "Click submit", "action": "click", "selector": "button[type='submit']" },
{ "name": "Wait for redirect", "action": "sleep", "ms": 2000 },
{ "name": "Verify dashboard", "action": "assert", "type": "urlContains", "expected": "/dashboard" },
{ "name": "Screenshot result", "action": "screenshot", "screenshotName": "post-login" }
]
}
Assertion Types
| Type | Description |
|---|---|
exists | Element exists in DOM |
notExists | Element does not exist |
textContains | Element text contains value |
textEquals | Element text equals value |
hasAttribute | Element has attribute with value |
hasClass | Element has CSS class |
isVisible | Element is visible |
isEnabled | Element is enabled |
urlContains | Current URL contains value |
urlEquals | Current URL equals value |
countEquals | Number of matching elements |
consoleNoErrors | No console errors |
Configuration
All configuration is via environment variables:
| Variable | Default | Description |
|---|---|---|
BROWSER_HEADLESS | true | Run browser in headed mode |
BROWSER_SESSIONS_DIR | .browser-sessions | Directory for screenshots and sessions |
BROWSER_SECURITY_PROFILE | local-dev | Security profile (local-dev, restricted, open) |
BROWSER_VIEWPORT_WIDTH | 1280 | Browser viewport width |
BROWSER_VIEWPORT_HEIGHT | 720 | Browser viewport height |
BROWSER_TIMEOUT | 30000 | Default timeout in ms |
BROWSER_CHANNEL | — | Browser channel (e.g., chrome, msedge) |
Security Profiles
| Profile | URL Access | JS Execution | Rate Limit |
|---|---|---|---|
local-dev | All HTTP/HTTPS | Always | 60/min |
restricted | localhost only | Disabled | 30/min |
open | Everything | Always | 120/min |
How It Works
graph LR
A["Claude Code<br/>(Agent)"] -- "MCP stdio<br/>tools & results" --> B["Glance<br/>(MCP Server)"]
B -- "Playwright<br/>automation API" --> C["Browser<br/>(Chromium)"]
C -- "screenshots<br/>DOM snapshots" --> B
B -- "inline images<br/>a11y trees" --> A
- Claude Code connects to Glance via MCP (stdio transport)
- Claude calls tools like
browser_navigate,browser_screenshot - Glance translates these into Playwright commands
- Screenshots are returned as base64 images — Claude literally sees the page
- Accessibility snapshots give Claude the full DOM structure as text
Real-World Usage
Glance has been battle-tested on production apps:
- DebugBase (debugbase.io) — 12 scenarios, 104 test steps, 97% pass rate
- GitScribe AI — 16 scenarios, 196 test steps, 96% pass rate
Requirements
- Node.js 18+
- Playwright-compatible browser (auto-installed)
Development
git clone https://github.com/DebugBase/glance.git
cd glance
npm install
npx playwright install chromium
npm run build
npm start
Claude Code Integration
Agent: e2e-tester
Glance ships with a Claude Code agent definition for comprehensive browser testing. The agent knows all 30 tools and follows a structured test workflow: navigate, screenshot, assert, report.
You: "Test the entire login flow on localhost:3000"
Agent: Opens browser → navigates → fills forms → clicks → screenshots → asserts → reports
Skill: /glance-test
Quick E2E test runner. Just provide a URL:
/glance-test https://myapp.com
The skill will:
- Navigate to the URL
- Screenshot and snapshot the page
- Discover all navigation links
- Test each page with assertions
- Check console for JS errors
- Generate a pass/fail report
Contributing
We welcome contributions! Please see CONTRIBUTING.md for guidelines.