fetch-mcp

An MCP server that fetches a URL, fully renders it in a headless Chromium browser (so JavaScript-heavy single-page apps built with Angular, React, Vue, etc. actually populate their DOM), and returns clean, scrapeable content. Plain-HTTP "fetch" MCP servers return pre-render HTML — often just an empty <div id="root"> shell for a SPA. This server renders first, then scrapes.

Install and build

npm install
npm run build

Related MCP server: web-to-markdown-mcp

Run a standalone sanity check

npm run build
npx @modelcontextprotocol/inspector node dist/index.js

This opens the MCP Inspector, where you can call fetch_page interactively against a real URL.

Claude Desktop configuration

Add to claude_desktop_config.json:

{
  "mcpServers": {
    "fetch-mcp": {
      "command": "node",
      "args": ["/absolute/path/to/fetch-mcp/dist/index.js"]
    }
  }
}

Claude Code configuration

Add to .mcp.json:

{
  "mcpServers": {
    "fetch-mcp": {
      "command": "node",
      "args": ["/absolute/path/to/fetch-mcp/dist/index.js"]
    }
  }
}

fetch_page tool reference

Input:

Output:

Example call:

{
  "url": "https://example.com/dashboard",
  "waitForSelector": "#app-loaded",
  "timeoutMs": 20000
}

Security model

Every request URL — the initial navigation, and every subresource, redirect, or XHR/fetch the page's own JavaScript issues — is checked against a DNS-based SSRF guard before it's allowed through. A hostname is resolved via dns.lookup for all its addresses, and the request is blocked unless every resolved address falls in the unicast (i.e. public, globally-routable) range — this rejects loopback, RFC1918 private ranges, link-local addresses (including the 169.254.169.254 cloud metadata address), carrier-grade NAT, and other non-routable ranges.

Known limitation: this guard has a DNS-rebinding TOCTOU gap — the DNS check and the actual TCP connection are not atomically pinned to the same resolved IP, so a hostname could theoretically re-resolve to an unsafe address between the check and the connection. Closing this fully would require pinning the connection to the checked IP, which breaks TLS/SNI for HTTPS targets, so it isn't done for v1.

Known limitations

• If Readability can't find article-like content (common for dashboard-style SPA shells), the full page body is converted to Markdown instead — this fallback is best-effort and may include navigation chrome or other non-content markup.

• content is truncated at maxContentLength characters; a [content truncated] marker and truncated: true are included when this happens.

• At most 3 pages render concurrently; additional concurrent fetch_page calls queue rather than fail.

Development

npm run dev         # run directly with tsx, no build step
npm run typecheck   # tsc --noEmit
npm test            # vitest
npm run build        # tsc, then chmod +x dist/index.js