Browser Tool
The browser tool provides headless browser automation via Playwright, enabling agents to navigate websites, interact with pages, capture screenshots, and extract accessibility snapshots.
Architecture
The browser tool uses Playwright's Chromium engine in headless mode. All actions are gated through the security supervisor for sensitive operations (screenshots, form interactions).
Agent → browser tool call
→ Launch headless Chromium
→ Navigate to URL / Perform action
→ Security gate (screenshots, form data)
→ Return result (screenshot base64, snapshot text, or action confirmation)
→ Cleanup browser context
Available Actions
| Action | Description | Parameters |
|---|---|---|
navigate | Navigate to a URL | url |
click | Click an element | target (selector or description) |
type | Type text into an input | target, text |
screenshot | Capture page screenshot | fullPage (boolean), format (png/jpeg) |
snapshot | Capture accessibility snapshot | target (optional element selector) |
evaluate | Execute JavaScript on page | code (function string) |
wait | Wait for text or time | time (seconds) or text |
Security
The browser tool triggers the security supervisor for:
- Screenshots — may capture sensitive UI content (credentials, personal data)
- Snapshots — accessibility tree may include sensitive form labels or data
- Evaluate — arbitrary JavaScript execution (RCE-equivalent, requires explicit policy approval)
Each action goes through:
- Policy validation (regex allow/deny rules)
- LLM security supervisor review (for sensitive actions)
- Human approval if needed
Configuration
The browser tool uses a 30-second default timeout for all operations. No additional configuration is required — it uses the system's Playwright installation.
Example Usage
Agent: I need to check the CortexPrism GitHub releases page.
Tool call: browser.navigate("https://github.com/CortexPrism/cortex/releases")
Result: Navigated to https://github.com/CortexPrism/cortex/releases
Tool call: browser.snapshot()
Result: [Accessibility tree showing release list with versions and dates]
Agent: The latest release is v0.53.0 from June 24, 2026...
Capabilities
The browser tool requires these capabilities from the CAP_BROWSER capability group:
network:fetch— for page navigationcomputer:screenshot— screenshot capture
See Also
- Built-in Tools — Complete tool catalog
- Security Parallax — LLM-based access control
- Computer Use — GUI automation (desktop, not browser)
- Chrome Bridge — Real-browser automation via CDP