NetLens

NetLens

An MCP server for unobstructed web reading. It fetches any URL directly with browser-like headers — past robots.txt and naive bot blocks — and returns the full page as clean, ad-stripped Markdown, not a summary. Plus web search that returns real links. Zero dependencies: pure Python standard library.

Built for AI Agents

AI agents constantly hit pages their built-in tools can't read. NetLens fixes the three usual reasons a fetch comes back empty or useless:

Native web tools	NetLens
Honor robots.txt, so crawler-disallowed pages return nothing	Reads like the browser you'd open yourself — doesn't consult robots.txt
Blocked by header/User-Agent bot filters (403/202 to non-browser clients)	Sends real browser headers via the system curl; commonly turns 403 → 200
Return a summary of the page	Returns the full page content as Markdown
Leave ads, cookie banners, nav, and related-links chrome in the output	Strips boilerplate locally so only the content reaches your context

It does not try to defeat JavaScript/Cloudflare challenge pages or CAPTCHAs — that's out of scope by design. When a page is a hard block, the HTTP status is surfaced honestly rather than faked.

Installation

npm (via npx):

{
  "mcpServers": {
    "netlens": {
      "command": "npx",
      "args": ["-y", "netlens-mcp"]
    }
  }
}

PyPI (via uvx):

{
  "mcpServers": {
    "netlens": {
      "command": "uvx",
      "args": ["netlens-mcp"]
    }
  }
}

Add either to your MCP client config (e.g. .mcp.json for Claude Code), then restart the session so the tools load.

Tools

web_search

Search the web and return real result links (title, URL, snippet), parsed locally — links, not summaries. Follow up with web_fetch to read a result.

Argument	Type	Description
query	string (required)	The search query
limit	integer	Optional cap; default returns the full first page (~10)
engine	string	auto (default), duckduckgo, bing, mojeek, searxng
page	integer	Result page, 1-based. SearXNG only
time_range	string	day, week, month, year. SearXNG only
categories	string	e.g. it, science, news. SearXNG only

The result reports which engine answered and what happened to any that were skipped, so falling through to a different backend is visible rather than silent:

{
  "query": "…",
  "engine": "mojeek",
  "results": [ … ],
  "engines_skipped": [ { "engine": "duckduckgo", "outcome": "HTTP 202" } ]
}

Outcomes are observations, not conclusions — HTTP 202 is what the server sent; whether that is throttling, changed markup or genuinely no matches cannot be determined from the response. With SearXNG configured, direct answers, infoboxes and suggestions appear alongside the results.

A search fetches a single result page (~10 results), returned in full by default so nothing at position 9/10 is dropped. There's no deep pagination — if the answer isn't in the first page, refine the query.

web_fetch

Fetch any page and return its full content as clean Markdown.

Argument	Type	Description
url	string (required)	URL to fetch (scheme optional; https assumed)
mode	string	article (main content only, default), full (whole body), raw (unconverted HTML), outline (heading structure)
section	string	Return only this heading's content, plus anything nested under it
links	string	inline (default) keeps link targets; none keeps link text but drops URLs
max_chars	integer	Optional cap on returned characters (truncates with a note)

Reading part of a long page

A large article can be tens of thousands of characters when you want one part of it. mode="outline" returns its shape, and section returns just that piece — on a large encyclopedia article that is 153,000 characters full, 1,000 as an outline, and 7,400 for the section actually wanted.

web_fetch(url=…, mode="outline")      → headings with each section's size
web_fetch(url=…, section="Gameplay")  → that section and its subsections

On link-heavy pages the URLs themselves are a large share of the output — around 40% of a big encyclopedia article — so links="none" roughly halves it when you only need the prose. Links pointing back into the same page are always rendered as plain text.

If a page turns out to be a client-rendered shell, web_fetch says so rather than returning an empty result as a success:

(note: Only 10 characters of readable text were found in 6,856 characters of HTML. This page appears to be rendered client-side by JavaScript…)

Workflow: web_search to find pages, then web_fetch to read them.

Search engines

Search is a pluggable, selectable registry. In auto mode NetLens tries engines in order and returns the first with results, so a rate-limit/challenge page on one falls through to the next.

Engine	Notes
duckduckgo	Default; html.duckduckgo.com endpoint
bing	Automatic fallback
mojeek	Independent index; automatic fallback
searxng	Self-hosted/public SearXNG JSON API — set NETLENS_SEARXNG_URL

Pick per call with the engine argument, or set a default with NETLENS_SEARCH_ENGINE.

Configuration

Environment Variable	Default	Description
NETLENS_SEARCH_ENGINE	auto	Default search backend
NETLENS_SEARXNG_URL	—	SearXNG base URL, e.g. http://192.168.1.10:8888
NETLENS_SEARXNG_TIMEOUT	8	Seconds before an unreachable SearXNG is skipped
NETLENS_USER_AGENT	Chrome UA	Override the request User-Agent
NETLENS_MAX_BYTES	10485760	Cap on a single response; larger ones are truncated
NETLENS_CACHE_TTL	300	Seconds to reuse a fetched page; 0 disables caching
NETLENS_HOST_DELAY	0.5	Minimum seconds between requests to the same host
NETLENS_REQUEST_TIMEOUT	120	Ceiling on a single tool call

Self-hosted SearXNG

Point NETLENS_SEARXNG_URL at an instance with the JSON API enabled (search.formats must include json in its settings.yml). It is then tried first in auto mode, which removes the HTML scraping — and the rate limiting that comes with it — from the common path.

Because it is tried first, it must fail fast when the box is off: the connect timeout is bounded separately so an unreachable instance is skipped in a few seconds rather than stalling every search, and the skip is reported in the result.

How it works

• Direct fetch. Requests go straight to the target site via the system curl (better TLS/HTTP-2/compression, so it looks like a real browser), falling back to urllib. No third-party proxy or reader is involved.
• Local conversion. HTML → Markdown happens in-process with a hand-rolled html.parser converter — headings, lists, links (relative URLs resolved), code blocks, and GFM tables with colspan/rowspan.
• Content selection, not deletion. NetLens picks the page's main content region — the HTML5 landmark (<main> / <article> / [role=main]) when one exists, otherwise the subtree holding the most prose relative to its link density — and converts only that. Because it selects a winner rather than deleting anything that matches a name pattern, extraction cannot silently return an empty page. Nothing inspects CSS class or id names to decide what is content.
• Pruning by measurement. Within that region, blocks that are overwhelmingly link anchors (navboxes, tag clouds, "more from this site" grids) are dropped based on their link density. Non-rendering elements (<script>, <style>, …), explicitly hidden elements, and third-party ad-network slots (identified by vendor names like adsbygoogle, which cannot collide with real prose) are removed outright.
• Response charset is honored (from Content-Type or <meta>), so non-UTF-8 pages don't come back garbled.

Usage from the CLI

The server is also a plain script — handy for testing before a client loads it:

python -m netlens_mcp.server search "http caching best practices"
python -m netlens_mcp.server fetch  https://example.com/article
python -m netlens_mcp.server full   https://example.com   # whole body
python -m netlens_mcp.server raw    https://example.com   # unconverted HTML

python -m netlens_mcp runs the stdio MCP server; python -m netlens_mcp.server <cmd> runs the CLI.

Development

pip install -e ".[dev]"
python -m pytest        # run the test suite
ruff check .            # lint

Requirements

• Python 3.10+ (and the system curl, which ships with modern Windows/macOS/Linux; falls back to urllib if absent)

License

Apache License 2.0 — see LICENSE and NOTICE.