> ## Documentation Index > Fetch the complete documentation index at: https://docs.profy.cn/llms.txt > Use this file to discover all available pages before exploring further. # Browser Automation > browser(action=...) — DOM-aware browser automation tool # Browser Automation `browser(action=...)` provides DOM-aware browser control via Chrome DevTools Protocol (CDP). ## Overview The Browser tool is the middle-layer interaction tool — it understands web page DOM structure and can precisely operate elements via CSS selectors or Accessibility Tree refs. Suitable for all web interaction scenarios. ## Available Actions | Action | Description | Key Params | | ------------ | --------------------------- | ------------------------------------- | | `navigate` | Go to URL | `url`, `new_tab` | | `screenshot` | Page screenshot | `url`/`html`/`file_path`, `full_page` | | `snapshot` | Get Accessibility Tree | `selector` | | `click` | Click element | `ref`, `button` | | `type` | Type keystroke-by-keystroke | `ref`, `text`, `clear`, `submit` | | `fill` | Set value instantly | `ref`, `text` | | `scroll` | Scroll | `direction`, `amount`, `ref` | | `press_key` | Press key | `key` | | `tabs` | Tab management | `tab_action`, `tab_index` | | `set_html` | Inject HTML via CDP | `html` | | `go_back` | Navigate back | — | ## Screenshot: Three Modes ### 1. URL Mode (running page) ```python theme={null} browser(action="screenshot", url="http://localhost:5173") ``` ### 2. HTML Injection Mode (zero-server) ```python theme={null} browser(action="screenshot", html="

Hello

") ``` Injects HTML via CDP `Page.setDocumentContent`. No server needed. ### 3. File Path Mode (local file) ```python theme={null} browser(action="screenshot", file_path="/home/user/workspace/demo.html") ``` Auto-starts `bun serve` and captures the file. ## Accessibility Tree Workflow ```python theme={null} # 1. Get page structure browser(action="snapshot") # → [0] button "Submit" [1] input "Email" [2] link "Home" ... # 2. Operate by ref browser(action="fill", ref="input[1]", text="user@example.com") browser(action="click", ref="button[0]") ``` ## Execution Backends | Environment | Backend | Notes | | ------------- | ----------------------- | ------------------ | | Cloud Sandbox | CDP on sandbox Chromium | Direct CDP control | | Desktop | Electron in-app browser | WebSocket MCP | ## Difference from `chrome` | Aspect | browser | chrome | | -------------- | -------------------------- | ------------------------- | | Environment | Sandbox/controlled browser | User's real Chrome | | Auth state | Clean (no logins) | User's logged-in sessions | | Confirmation | Not required | 4-level policy | | Tab management | AI creates freely | Discover → Claim | | Risk | None (isolated) | Real-world actions |