stygian-mcp

Unified MCP (Model Context Protocol) server aggregating stygian-graph, stygian-browser, and stygian-proxy into a single JSON-RPC 2.0 process over stdin/stdout.

An LLM agent connecting to this server can scrape URLs, run pipeline DAGs, automate browsers, manage proxy pools, and combine all three capabilities — without needing to connect to three separate processes.

Installation

# Standalone binary
cargo install stygian-mcp

# Or add to your project
cargo add stygian-mcp

Usage

Run the binary directly:

stygian-mcp

This starts a JSON-RPC 2.0 server on stdin/stdout. Connect any MCP-compatible client (VS Code, Claude, IDE plugins, etc.) to begin calling scraping, browser, and proxy tools.

Features

Feature	Description	Default
Base	Proxy + browser tools	✓
`extract`	Enable browser structured extraction tools (`browser_extract`, `browser_extract_with_fallback`, `browser_extract_resilient`)	—

Enable extraction (requires stygian-browser/extract and stygian-graph/extract):

cargo install stygian-mcp --features extract

MCP Tools

All tools from the three underlying crates are available under their respective prefixes:

Prefix	Crate	Example tools
`graph_*`	`stygian-graph`	`graph_scrape`, `graph_scrape_rest`, `graph_pipeline_run`
`browser_*`	`stygian-browser`	`browser_acquire`, `browser_extract_with_fallback`, `browser_extract_resilient`
`proxy_*`	`stygian-proxy`	`proxy_add`, `proxy_acquire_with_capabilities`, `proxy_fetch_freelist`, `proxy_fetch_freeapiproxies`

The aggregator also adds two cross-crate tools:

Tool	Description
`scrape_proxied`	HTTP scrape routed through an acquired proxy
`browser_proxied`	Browser session with a proxy from the pool

Architecture

  LLM / IDE / Chat Interface
     │  JSON-RPC 2.0 (stdin/stdout)
     ▼
┌─────────────────────────────────────┐
│        McpAggregator                │
│  tools/list ── merge & dispatch     │
│  tools/call ── route by prefix ─┐  │
└──────────────────┬──────────────┼──┘
                   │              │
        ┌──────────┼──────────────┘
        ▼          ▼              ▼
   GraphHandler  BrowserHandler  ProxyHandler

Tool Execution Flow

Client calls tools/list → aggregator merges all three sub-server tool lists
Client calls tools/call with a tool name + params
Aggregator routes:

graph_* → strips prefix, forwards to graph sub-server
browser_* → forwards to browser sub-server
proxy_* → forwards to proxy sub-server
scrape_proxied, browser_proxied → handled by aggregator (cross-crate coordination)

Examples

Scrape with Proxy Rotation

{
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "name": "scrape_proxied",
    "arguments": {
      "url": "https://example.com"
    }
  }
}

Browser Screenshot Through Proxy

{
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "name": "browser_proxied",
    "arguments": {
      "url": "https://example.com"
    }
  }
}

Extract Structured Data

With extract feature enabled, use browser_extract:

{
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "name": "browser_extract",
    "arguments": {
      "session_id": "01HV4...",
      "url": "https://example.com/products",
      "root_selector": "article.product",
      "schema": {
        "name": { "selector": "h2" },
        "href": { "selector": "a", "attr": "href" }
      }
    }
  }
}

License

Licensed under either the GNU Affero General Public License v3.0 (AGPL-3.0-only) or the Commercial License at your option.

stygian-mcp 0.9.4