# Atr Browser

> Control browser, automate browser interactions, navigate to URLs, click on webpages, fill forms, take screenshots, inspect webpages, web scraping with browser, test websites manually, or interact with web pages programmatically using ATR browser server mode. Use when this capability is needed.

- Skill: `tomevault-io/atr-browser` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add tomevault-io/atr-browser`
- Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/atr-browser/raw
- Safety review: pending (external: skill-scanner PASS, skillspector CAUTION)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: tomevault-io (https://skillmd.com/u/tomevault-io)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/tomevault-io/atr-browser

---


# ATR Browser Automation Skill

This skill provides browser automation capabilities through ATR's browser server mode. The browser server runs as a daemon process and accepts CLI commands for browser control.

## Architecture

```
Claude Code --> atr CLI (client) --> ATR Server + Browser
```

The browser runs in visible (non-headless) mode by default for debugging and verification.

## Getting Started

### Step 1: Check Browser Status and Start if Needed

Before any browser operations, verify the browser server is running:

```bash
atr browser status
```

If the server is not running, start it:

```bash
atr browser start
```

The server stores state at `~/.atr/browser.state` which allows subsequent commands to discover the endpoint automatically.

### Step 2: Navigate and Interact

Once running, use navigation and interaction commands to control the browser.

## Command Categories

### Lifecycle Commands

| Command | Description |
|---------|-------------|
| `atr browser start [--port PORT]` | Start browser daemon (default port: 9333) |
| `atr browser stop` | Stop browser daemon |
| `atr browser status` | Check if browser is running |

### Navigation Commands

| Command | Description |
|---------|-------------|
| `atr browser navigate <url>` | Navigate to URL |
| `atr browser back` | Go back in history |
| `atr browser forward` | Go forward in history |
| `atr browser reload` | Reload current page |

### Page Management Commands

| Command | Description |
|---------|-------------|
| `atr browser new-page [url]` | Open new tab |
| `atr browser list-pages` | List all tabs |
| `atr browser select-page <index>` | Switch to tab (0-based) |
| `atr browser close-page <index>` | Close tab |

### Interaction Commands

| Command | Description |
|---------|-------------|
| `atr browser click <target> [--double]` | Click element (use --double for double-click) |
| `atr browser fill <target> <value>` | Type into input field |
| `atr browser hover <target>` | Hover over element |
| `atr browser press-key <key>` | Press keyboard key (e.g., Enter, Tab, Control+A) |
| `atr browser drag <from> <to>` | Drag element |
| `atr browser wait <selector> [--timeout] [--visible]` | Wait for element to appear |
| `atr browser scroll --selector "<sel>" [--y N] [--to-bottom]` | Scroll inside an element |
| `atr browser download-images "<sel>" [--output-dir] [--fallback-screenshot]` | Download/screenshot images within elements |
| `atr browser viewport [W H] [--preset mobile\|tablet\|desktop\|wide]` | Get or set viewport size |
| `atr browser batch [--file F] [--on-error stop\|continue\|retry:N]` | Execute multiple commands from stdin/file |

### Inspection Commands

| Command | Description |
|---------|-------------|
| `atr browser snapshot [--verbose]` | Get page elements with UIDs |
| `atr browser screenshot --file [--full] [-s SELECTOR]` | Capture screenshot (saves to /tmp/) |
| `atr browser screenshot --file --selector-all "<sel>"` | Screenshot all matching elements |
| `atr browser computed-styles "<selector>" [--properties]` | Get computed CSS styles for single element |
| `atr browser computed-styles --selector-all "<sel>"` | Get computed CSS styles for all matching elements |
| `atr browser computed-styles-diff "<sel>" --against N` | Compare styles between pages |
| `atr browser text "<selector>" [--flat\|--links\|--headings]` | Extract text content |
| `atr browser font-check "<font-family>"` | Check if font is loaded and rendering |
| `atr browser clean-snapshot "<selector>" [--depth N] [--max-length N]` | Get cleaned DOM subtree (no noise/tracking attrs) |
| `atr browser computed-styles --selector "h1" --selector "p"` | Batch computed styles for multiple selectors |
| `atr browser computed-styles-diff --selector "h1" --selector "p" --against 0` | Batch style diff with overall score |
| `atr browser html` | Get page HTML |
| `atr browser url` | Get current URL |
| `atr browser title` | Get page title |
| `atr browser eval <script>` | Execute JavaScript |
| `atr browser ask "<question>"` | Ask a question about the current page |

**Screenshot Note:** Use `--file` to save screenshots to `/tmp/` with a timestamped filename (e.g., `/tmp/atr-screenshot-20240105-103045.png`). Add `--full` for full-page screenshots. Use `--selector` / `-s` to screenshot a specific element by CSS selector (e.g., `-s "header"`, `-s "#nav"`, `-s "main > section:nth-child(2)"`). Combine `--selector` with `--full` to capture an element's full scrollable height. Use `--selector-all` to screenshot every matching element as numbered PNGs — elements that fail or timeout are skipped (use `--timeout <ms>` to control per-element timeout, default 30s). Without `--file`, returns base64-encoded image data.

### Debugging Commands

| Command | Description |
|---------|-------------|
| `atr browser console [--limit N]` | Get console messages (default: 50) |
| `atr browser network [--limit N]` | Get network requests (default: 50) |
| `atr browser errors` | Get failed requests |

## Workflow Pattern

Follow this workflow for browser automation tasks:

1. **Ensure Server Running**
   ```bash
   atr browser status || atr browser start
   ```

2. **Navigate to Target**
   ```bash
   atr browser navigate https://example.com
   ```

3. **Inspect Page Elements**
   ```bash
   atr browser snapshot
   ```
   This returns elements with unique IDs (UIDs) like `e0`, `e1`, etc.

4. **Interact with Elements**
   Target elements by:
   - Text content: `"Sign In"`
   - UID from snapshot: `e5`
   - CSS selector: `.submit-button`

5. **Verify Results**
   ```bash
   atr browser url
   atr browser title
   atr browser screenshot --file
   ```

6. **Cleanup When Done**
   ```bash
   atr browser stop
   ```

## Asking Questions About a Page

Use `atr browser ask` when you need specific information from a page without flooding your context with raw HTML or snapshot data. A lightweight sub-agent inspects the page using multiple tools and returns a concise text answer.

```bash
atr browser ask "What is the main heading on this page?"
atr browser ask "How many items are in the navigation menu?"
atr browser ask "Is there a login form on this page?"
```

Prefer `ask` over `html` or `snapshot` when:
- You need a specific fact, not the full page structure
- You want to keep your context clean for subsequent reasoning
- The answer can be expressed as a short text response

## Using JSON Output

Add `--json` flag for structured output when parsing is needed:

```bash
atr browser snapshot --json
atr browser list-pages --json
atr browser network --json
```

## Element Targeting

The `<target>` parameter in click, fill, hover, and drag commands accepts:

1. **Element UID**: `e0`, `e5` (from snapshot output)
2. **Visible text**: `"Sign In"`, `"Submit Form"`
3. **aria-label**: Elements with matching aria-label attribute
4. **data-testid**: Elements with matching data-testid attribute
5. **CSS selector**: `#login-button`, `.nav-link`, `header`, `footer`, `nav`, `main > section`, `div.hero`, `li:nth-child(2)`

Best practice: Use `atr browser snapshot` first to see available elements and their UIDs.

## Keyboard Keys

For `press-key` command:
- Named keys: `Enter`, `Tab`, `Escape`, `Backspace`
- Modifiers: `Control+a`, `Shift+Tab`, `Alt+Enter`
- Arrow keys: `ArrowUp`, `ArrowDown`, `ArrowLeft`, `ArrowRight`

## Troubleshooting

**Browser won't start:**
```bash
atr browser status
rm ~/.atr/browser.state  # If stale state
atr browser start
```

**Port already in use:**
```bash
atr browser start --port 9334
```

**Element not found:**
```bash
atr browser snapshot --verbose --json
```

## Additional Resources

For complete command reference with all flags, see `references/commands-reference.md`.

---
> Converted and distributed by [TomeVault](https://tomevault.io/claim/imyousuf) — claim your Tome and manage your conversions.
<!-- tomevault:4.0:skill_md:2026-04-11 -->