Melian

Browser

Overview

Melian can operate a web browser autonomously, opening pages, clicking elements, filling forms, extracting content, and taking screenshots. This enables web-based research, form submission, and visual verification of page state. The agent-browser binary is spawned as a subprocess per tool call via Bun.spawn(). Each tool call has a 30-second default timeout.

Tools

Tool Parameters Description
browser_open url: string Navigate to a URL and return an accessibility tree snapshot
browser_snapshot - Return an accessibility tree snapshot of the current page state
browser_click ref: string Click an element by its @ref identifier from the accessibility tree
browser_fill ref: string, text: string Type text into a form field identified by its @ref identifier
browser_extract_text selector?: string Extract visible text from the page or a specific element
browser_screenshot - Capture a PNG screenshot of the current viewport
browser_close - Close the browser session and release the binary

Tool Parameter Details

browser_click

Parameter Type Required Notes
ref string yes A @ref identifier from the accessibility tree snapshot

browser_fill

Parameter Type Required Notes
ref string yes A @ref identifier for the input field from the accessibility tree
text string yes Text to type into the field

browser_extract_text

Parameter Type Required Notes
selector string no Omit to extract full page text; provide to scope to a subtree

Architecture

The agent-browser binary is spawned as a subprocess per tool call via Bun.spawn(). The 30-second timeout applies per tool call; long-running navigations that exceed this will return an error.

Browser automation is used by the self-healing pipeline for visual verification of deployed changes, and is available as a general-purpose tool in conversations for any web-based task.