Module mcp 

MCP (Model Context Protocol) server for browser automation.

Exposes stygian-browser capabilities as an MCP server over stdin/stdout using the JSON-RPC 2.0 protocol. External tools (LLM agents, IDE plugins) can acquire browsers, navigate pages, evaluate JavaScript, and capture screenshots via the standardised MCP interface.

Enabling

[dependencies]
stygian-browser = { version = "0.1", features = ["mcp"] }

Running the server

STYGIAN_MCP_ENABLED=true cargo run --example mcp_server -p stygian-browser

Protocol

The server implements MCP 2024-11-05 over JSON-RPC 2.0 on stdin/stdout. Supported methods:

MCP Method	Description
initialize	Handshake, return server capabilities
tools/list	List available browser tools
tools/call	Execute a browser tool
resources/list	List active browser sessions as MCP resources
resources/read	Read session state

Tools

Tool	Parameters	Returns
browser_acquire	–	session_id: String
browser_open_page	session_id	page_url: String
browser_navigate	session_id, url, timeout_secs?	title, url
browser_eval	session_id, script	result: Value
browser_screenshot	session_id	data: base64 PNG
browser_content	session_id	html: String
browser_release	session_id	success
pool_stats	–	active, max, available

Structs

JsonRpcError

A JSON-RPC 2.0 error object.

JsonRpcRequest

A JSON-RPC 2.0 request.

JsonRpcResponse

A JSON-RPC 2.0 response.

McpBrowserServer

MCP server that exposes BrowserPool over stdin/stdout JSON-RPC.

Functions

is_mcp_enabled

Returns true if the MCP server is enabled via the STYGIAN_MCP_ENABLED environment variable.