Webshift

Official

by x-hannibal · Rust

Rust MCP server for denoised web search — fetch, clean, and rerank web content for AI agents.

Fetch, clean, and rerank web content for AI agent consumption.

Topics

ai-agentsbing-searchbm25brave-searchcontext-windowdenoiserexagoogle-searchhtml-cleanerhtml-to-textllmmcpmcp-serversearxngserpapitavilytext-extractionweb-scrapingweb-searchrust

README.md16 KBView on GitHub

WebShift

What is WebShift

WebShift is a Rust library and MCP server that shifts noisy web pages into clean, right-sized text for LLM consumption.

Raw HTML is mostly junk: scripts, ads, navigation menus, cookie banners, tracking pixels. Feeding it directly to an LLM floods the context window with tens of thousands of useless tokens and leaves no room for reasoning. WebShift strips all that noise, sterilizes the text, and enforces strict size budgets so the model receives only the content that matters.

What you get

Depending on the features you enable, WebShift can be four things:

Use case	Crate	Feature flags	What it does
HTML denoiser	`webshift`	`default-features = false`	`clean()` — pure Rust HTML-to-text pipeline. Strips noise elements, sterilizes Unicode/BiDi, collapses whitespace. Zero network, zero config. Drop into any Rust project that processes web content for LLMs.
HTML text rewriter	`webshift`	`features = ["text-map"]`	`extract_text_nodes()` + `replace_text_nodes()` — extract individual text nodes from HTML, manipulate them (translate, rewrite, simplify), and rebuild the HTML with structure intact. Tags, attributes, and links are never touched.
Web content client	`webshift`	`default` or `features = ["llm"]`	`fetch()` + `query()` — streaming HTTP fetcher with size caps, 8 search backends, BM25 reranking, optional LLM query expansion and summarization. Full pipeline from search query to structured results.
MCP server	`webshift-mcp`	all features	Native binary (`mcp-webshift`) that exposes `webshift_query`, `webshift_fetch`, and `webshift_onboarding` over MCP stdio. Single static binary, zero runtime dependencies.

When to use WebShift

You're building an AI agent that needs web search and you want clean, budget-controlled text — not raw HTML.
You're processing web pages in a Rust pipeline and need a reliable HTML-to-text cleaner that strips noise without losing real content.
You need an LLM to translate, rewrite, or simplify text inside HTML without corrupting the markup — text-map gives you a safe round-trip.
You want an MCP web search server that works as a single binary — no Python, no pip, no venv, no Docker (unless you want it).
You need hard guarantees on output size: per-page caps, total budget caps, streaming download limits.

When NOT to use WebShift

You need a headless browser that renders JavaScript-heavy SPAs. WebShift parses static HTML — it doesn't execute JS.
You need to render or screenshot a page preserving its visual layout. WebShift processes HTML structure but does not render CSS or compute layout. (Note: text-map does preserve the DOM structure for text rewriting use cases.)
You're building a web scraper that needs to navigate across pages, fill forms, or handle authentication flows.

How it works

code

Question
  |
  +- (optional) LLM query expansion -> multiple search variants
  |
  +- Search via backend (SearXNG, Brave, Tavily, Exa, SerpAPI, Google, Bing, HTTP)
  |
  +- Deduplicate + filter binary URLs
  |
  +- Streaming fetch with per-page size cap
  |
  +- HTML cleaning -> plain text (noise elements, scripts, nav removed)
  |
  +- Unicode/BiDi sterilization
  |
  +- BM25 deterministic reranking
  |   +- (optional) LLM-assisted tier-2 reranking
  |
  +- Budget-aware truncation across all sources
  |
  +- (optional) LLM Markdown summary with inline citations
  |
  +- Structured JSON output

For a detailed explanation of each pipeline stage, BM25 parameters, adaptive budget allocation, and real compression metrics see Under the Hood. For the full configuration reference (TOML, env vars, CLI args) see Configuration. For ready-to-use examples see Use Cases.

Installation

Binary (MCP server)

bash

cargo install webshift-mcp

The binary is called mcp-webshift.

From source

bash

cargo install --path crates/webshift-mcp

As a library

toml

# Full pipeline (search + fetch + clean + rerank)
webshift = "0.2"

# Cleaner + fetcher only (no search backends)
webshift = { version = "0.2", default-features = false }

# Text-map only (extract/replace text nodes in HTML)
webshift = { version = "0.2", default-features = false, features = ["text-map"] }

# Everything including LLM features
webshift = { version = "0.2", features = ["llm"] }

Quick start

1. Set up a search backend

The easiest option is SearXNG — free, self-hosted, no API key:

bash

docker run -d -p 8080:8080 searxng/searxng

No Docker? Use a cloud backend — see Search backends.

2. Configure your MCP client

json

{
  "mcpServers": {
    "webshift": {
      "command": "mcp-webshift",
      "args": ["--default-backend", "searxng"]
    }
  }
}

That's it. The agent now has webshift_query, webshift_fetch, and webshift_onboarding.

For client-specific setup see docs/integrations/.

MCP tools

Tool	Description
`webshift_query`	Full search pipeline: search + fetch + clean + rerank + (optional) summarize
`webshift_fetch`	Single page fetch and clean
`webshift_onboarding`	Returns a JSON guide for the agent (budgets, backends, tips)

`webshift_query` parameters

Parameter	Type	Default	Description
`queries`	string or list	required	Search query or list of queries
`num_results_per_query`	integer	5	Results per query
`lang`	string	none	Language filter (e.g. `"en"`)
`backend`	string	config default	Override search backend

Configuration

Resolution order (highest priority first):

CLI args — --default-backend, --brave-api-key, etc.
Environment variables — WEBSHIFT_* prefix
Config file — webshift.toml (current dir, then ~/webshift.toml)
Built-in defaults

Config file

toml

[server]
max_query_budget    = 32000   # total char budget across all sources
max_result_length   = 8000    # per-page char cap
max_total_results   = 20      # hard cap on results per call
max_download_mb     = 1       # streaming cap per page (MB)
search_timeout      = 8       # seconds
results_per_query   = 5
oversampling_factor = 2
adaptive_budget     = "auto"  # "auto" | "on" | "off" — budget allocation mode

[backends]
default = "searxng"

[backends.searxng]
url = "http://localhost:8080"

[backends.brave]
api_key = "BSA-..."

[backends.tavily]
api_key = "tvly-..."

[backends.exa]
api_key = "..."

[backends.serpapi]
api_key = "..."
engine  = "google"    # google | bing | duckduckgo | yandex

[backends.google]
api_key = "..."
cx      = "..."       # Custom Search Engine ID

[backends.bing]
api_key = "..."
market  = "en-US"

[backends.http]
url           = "https://my-search.example.com/api/search"
query_param   = "q"
count_param   = "limit"
results_path  = "data.items"     # dot-path to results array in JSON response
title_field   = "title"
url_field     = "link"
snippet_field = "description"

[backends.http.headers]
"Authorization" = "Bearer my-token"

[llm]
enabled               = false
base_url              = "http://localhost:11434/v1"   # OpenAI-compatible
api_key               = ""
model                 = "gemma3:27b"
timeout               = 60
expansion_enabled     = true
summarization_enabled = true
llm_rerank_enabled    = false

For every setting with all three config methods (TOML, env vars, CLI args) and plain-language descriptions, see the full Configuration Reference. Ready-to-use config examples are in Use Cases and examples/.

Key environment variables

bash

WEBSHIFT_DEFAULT_BACKEND=searxng
WEBSHIFT_SEARXNG_URL=http://localhost:8080
WEBSHIFT_BRAVE_API_KEY=BSA-xxx
WEBSHIFT_GOOGLE_API_KEY=xxx
WEBSHIFT_GOOGLE_CX=xxx
WEBSHIFT_BING_API_KEY=xxx
WEBSHIFT_LLM_ENABLED=true
WEBSHIFT_LLM_BASE_URL=http://localhost:11434/v1
WEBSHIFT_LLM_MODEL=gemma3:27b

Search backends

Backend	Auth	Notes
SearXNG	none	Self-hosted, free. Default: `http://localhost:8080`
Brave	API key	Free tier. brave.com/search/api
Tavily	API key	AI-oriented. tavily.com
Exa	API key	Neural search. exa.ai
SerpAPI	API key	Multi-engine proxy (Google, Bing, DDG...). serpapi.com
Google	API key + CX	Custom Search. Free: 100 req/day. programmablesearchengine.google.com
Bing	API key	Web Search API. Free: 1,000 req/month. Microsoft Azure
HTTP	configurable	Generic REST backend — no code required, TOML-only config

LLM features (optional)

All opt-in — disabled by default, no data leaves your machine unless enabled.

Feature	What it does
Query expansion	Single query -> N complementary search variants
Summarization	Markdown report with inline `[1]` `[2]` citations
LLM reranking	Tier-2 reranking on top of deterministic BM25

Cross-language normalization (bonus): when BM25 reranking surfaces pages in foreign languages (e.g. Chinese, Japanese, Arabic), the LLM summarizer still produces the final report in the prompt language. The agent receives clean, readable output regardless of the language mix in the source pages.

Works with any OpenAI-compatible API (OpenAI, Ollama, vLLM, LM Studio, etc.):

toml

[llm]
enabled  = true
base_url = "http://localhost:11434/v1"
model    = "gemma3:27b"

Anti-flooding protections

Always active — the core value proposition:

Protection	Description
`max_download_mb`	Streaming cap — never buffers full response
`max_result_length`	Hard cap on characters per cleaned page
`max_query_budget`	Total character budget across all sources
`max_total_results`	Hard cap on results per call
Binary filter	`.pdf`, `.zip`, `.exe`, etc. filtered before any network request
Unicode sterilization	BiDi control chars, zero-width chars removed

Library usage

rust

use webshift::{Config, clean, fetch, query};

// Clean raw HTML — cap output at 8000 chars
let result = clean("<html><body><p>Hello world</p></body></html>", 8000);
println!("{}", result.text);

// Pass 0 to disable the per-page cap entirely (no truncation)
let full = clean("<html><body><p>Hello world</p></body></html>", 0);
assert!(!full.truncated);

// Fetch and clean a single page
let config = Config::default();
let page = fetch("https://example.com", &config).await?;

// Full search pipeline
let results = query(&["rust async programming"], &config).await?;
for source in &results.sources {
    println!("[{}] {} — {} chars", source.id, source.title, source.content.len());
}

// Backend partial failures (CAPTCHA, rate-limits, engine outages) are surfaced
// in `warnings` rather than as Err. Empty sources + non-empty warnings means
// "all backends blocked" — distinct from a legitimate "no matches found".
if results.sources.is_empty() && !results.warnings.is_empty() {
    eprintln!("all backends failed: {:?}", results.warnings);
}

Text-map: rewrite HTML content without breaking markup

Extract text nodes, manipulate them (translate, rewrite, simplify), and rebuild the HTML with structure, attributes, and links intact.

rust

use webshift::{extract_text_nodes, replace_text_nodes, TextReplacement};

let html = r#"<p>Hello <a href="https://example.com">world</a></p>"#;
let map = extract_text_nodes(html);
// map.nodes = [(0, "Hello"), (1, "world")]

let replacements = vec![
    TextReplacement { id: 0, text: "Ciao".into() },
    TextReplacement { id: 1, text: "mondo".into() },
];
let result = replace_text_nodes(html, &replacements).unwrap();
// → <p>Ciao <a href="https://example.com">mondo</a></p>
// href untouched, tags intact, only text changed.

Requires features = ["text-map"]. See Use Cases #11 for a full translation example.

Feature flags

Feature	Default	Enables
`backends`	on	All search backends + query pipeline
`llm`	off	LLM client, expander, summarizer, LLM reranking
`text-map`	off	`extract_text_nodes()` + `replace_text_nodes()` — DOM round-trip for content rewriting

Integrations

Platform	Guide
Claude Desktop, Claude Code, Cursor, Windsurf, VS Code	IDE Integration
Zed — native extension with auto-download and Configure Server modal	Zed Extension
Gemini CLI, Claude CLI, custom agents	Agent Integration

Beta Status

WebShift is in beta. Core functionality is stable and the server is used daily, but the API surface may still change before 1.0.

Feedback is very welcome. If something doesn't work as expected, behaves oddly, or you have a use case that isn't covered:

Open an issue on GitHub

Bug reports, configuration questions, and feature requests all help shape the roadmap.

Contributing

Contributions are welcome! Please see CONTRIBUTING.md for detailed guidelines on:

Development setup and workflow
Code style and conventions
Testing requirements
Documentation standards
Pull request process

License

MIT License — see LICENSE for details.

Topics

WebShift

What is WebShift

What you get

When to use WebShift

When NOT to use WebShift

How it works

Installation

Binary (MCP server)

From source

As a library

Quick start

1. Set up a search backend

2. Configure your MCP client

MCP tools

webshift_query parameters

Configuration

Config file

Key environment variables

Search backends

LLM features (optional)

Anti-flooding protections

Library usage

Text-map: rewrite HTML content without breaking markup

Feature flags

Integrations

Beta Status

Contributing

License

Links

Install

`webshift_query` parameters