Web Fetch MCP Server

@pipeworx/web-fetch

Fetch the exact contents of one public URL, live from its origin server, and get back the bytes (or text decoded from them) with a SHA-256 hash of exactly what the origin sent, plus the redirect chain and the response headers.

Part of Pipeworx — an MCP gateway connecting AI agents to 1855+ live data sources. This is an independent, unofficial integration — not affiliated with, endorsed by, or published by the upstream provider.

Tools

• fetch_url(url, format?, max_bytes?, offset?) — one GET of one public http(s) URL. Returns status, url_final, redirects (present only when the URL redirected), headers (content-type, content-length, last-modified, etag, content-language, date), content_family (text | pdf | archive | binary), bytes_total, sha256 over the complete body, and a window of the body:

  • format: "auto" (default) — readable text for HTML and PDF, the raw body for everything else.
  • format: "raw" — the body itself: decoded text for text types, base64 for binary (zip, xlsx, gzip, PDF). sha256_returned hashes exactly the bytes in the window.
  • format: "text" — extracted text (text_extraction: html | pdf | none | failed). PDF extraction warnings are passed through in warnings.
  • max_bytes (default 100,000; at most 1,000,000 for text, 512,000 for base64) and offset page through a large body; follow next_offset.

  Text is decoded from the bytes, never guessed: the charset comes from a BOM, then the Content-Type header, then the page's own <meta charset> or XML declaration, then UTF-8 if the bytes are valid UTF-8, else windows-1252. charset_source says which rule decided and decode_replacements counts any characters lost in decoding (0 means none).

Checking "verbatim" yourself

sha256 is taken over the entity body after transfer compression is removed — the same bytes curl --compressed -s <url> | shasum -a 256 writes. Two caveats: a dynamic page can legitimately hash differently a second later, and some sites serve different content by location, so the answer is verbatim as served to this fetch (colo, when known, names the edge location).

Refusals — always loud, never an empty body

Limits

• One GET, no cookies, no login, no caller headers, no JavaScript execution. likely_needs_js: true flags a page that renders its content with scripts.
• 10 MB read per call; a larger body returns the first window with truncated: true, body_complete: false and sha256: null.
• 25 s per call, at most 4 redirects.
• Per site (registrable domain), across all callers: 30 requests a minute and 1,000 a day (sec.gov: 5 a minute). A 200 response is reused for 10 minutes (served_from: "cache", cache_age_s).
• Identifies itself honestly as Pipeworx/1.0 (pipeworx.io); on a 403 it retries once as Pipeworx/1.0 (+https://pipeworx.io; support@pipeworx.io) and reports which it used in user_agent_used.

Auth

Keyless.

Data sources

• Whatever public URL the caller names. Nothing is fetched except that URL and its redirects, plus a DNS-over-HTTPS lookup at https://cloudflare-dns.com/dns-query to refuse names that resolve to private addresses.

Quick Start

Add to your MCP client (Claude Desktop, Cursor, Windsurf, etc.):

{
  "mcpServers": {
    "web-fetch": {
      "url": "https://gateway.pipeworx.io/web-fetch/mcp"
    }
  }
}

What this endpoint actually serves

tools/list at https://gateway.pipeworx.io/web-fetch/mcp returns the tools in the table above plus the shared Pipeworx meta-tools — ask_pipeworx, discover_tools, search_within, remember/recall and the rest of the gateway-wide set. So the tool count you see is larger than this table: a single-pack endpoint currently lists roughly 30 shared tools alongside the pack's own. The connection's initialize response states its exact scope, and is the authoritative answer for a given day.

This is deliberate, not multiplexing by accident. The meta-tools are what let a scoped connection answer a question this pack does not cover — via ask_pipeworx, which routes across the whole catalog — without you adding a second MCP server. There is currently no way to mount a pack endpoint without them; if the extra schemas cost you more context than the routing is worth, connect to the full gateway once rather than to several pack endpoints.

Or connect to the full Pipeworx gateway to get every pack's tools listed directly, instead of just this one's:

{
  "mcpServers": {
    "pipeworx": {
      "url": "https://gateway.pipeworx.io/mcp"
    }
  }
}

Both URLs reach the same gateway and the same 1855+ data sources. The only difference is which pack's tools are listed directly; ask_pipeworx reaches all of them from either one.

No MCP client? Call it over HTTP

curl -X POST https://gateway.pipeworx.io/v1/tools/fetch_url \
  -H 'Content-Type: application/json' \
  -d '{"url":"https://data.giss.nasa.gov/gistemp/tabledata_v4/GLB.Ts+dSST.csv","max_bytes":2000}'

No account needed for the first calls. Inspect any tool: GET https://gateway.pipeworx.io/v1/tools/fetch_url. Find one: POST https://gateway.pipeworx.io/v1/tools/search_packs with {"query":"..."}.

Standalone (no gateway account)

This package also runs as a local stdio MCP server — no Pipeworx account, no gateway round-trip:

{
  "mcpServers": {
    "web-fetch": {
      "command": "npx",
      "args": ["-y", "@pipeworx/mcp-web-fetch"]
    }
  }
}

Or run it directly to confirm it starts:

npx -y @pipeworx/mcp-web-fetch

It speaks MCP over stdin/stdout and answers initialize/tools/list/tools/call for only this pack's tools — none of the shared meta-tools the gateway connection above adds. Same source, same tools, no ask_pipeworx routing.

Using with ask_pipeworx

Instead of calling tools directly, you can ask questions in plain English — this works on the pack endpoint above as well as on the full gateway:

ask_pipeworx({ question: "your question about Web Fetch data" })

The gateway picks the right tool and fills the arguments automatically.

More

• Docs and guides
• pipeworx.io

License

MIT