AlterLab MCP Server

Give Claude, Cursor, and Windsurf the ability to scrape any website, extract structured data, and take screenshots — with automatic anti-bot bypass.

Get Started Free →   $1 free balance on signup — up to 5,000 scrapes.

One-Line Install

Claude Code

claude mcp add alterlab -- npx -y alterlab-mcp-server@latest

Then set your API key: export ALTERLAB_API_KEY=sk_live_... or add it to .claude.json (see full setup below).

Cursor

# Add to .cursor/mcp.json — see full config below

Smithery

npx -y @smithery/cli install alterlab-mcp-server --client claude

Why AlterLab Instead of WebFetch or Browser MCP?

Claude's built-in WebFetch tool and open-source browser MCP servers fail on most real-world websites. They cannot bypass Cloudflare, render JavaScript SPAs, or extract structured data.

AlterLab replaces broken fetch tools with one MCP server that actually works:

How Does AlterLab Web Scraping Work?

AlterLab uses a multi-tier scraping architecture. It automatically selects the cheapest method capable of fetching each URL:

1. Curl ($0.0002/req) — Direct HTTP for static pages, RSS feeds, public APIs
2. HTTP ($0.0003/req) — TLS fingerprint rotation for moderately protected sites
3. Stealth ($0.0005/req) — Browser impersonation for Cloudflare/DataDome-protected sites
4. Light JS ($0.0007/req) — Lightweight JS extraction from server-rendered HTML
5. Browser ($0.001/req) — Full headless Chromium for JavaScript-heavy SPAs

Auto mode starts at Tier 1 and escalates only when blocked. Most websites resolve at Tiers 1-2, so $1 gets you 1,000 to 5,000 scrapes depending on the sites you target.

Installation

Install in Claude Desktop / Claude Code

Add to your Claude config file (~/.claude.json for Claude Code, or Settings for Claude Desktop):

{
  "mcpServers": {
    "alterlab": {
      "command": "npx",
      "args": ["-y", "alterlab-mcp-server@latest"],
      "env": {
        "ALTERLAB_API_KEY": "sk_live_your_key_here"
      }
    }
  }
}

Install in Cursor

Add to .cursor/mcp.json in your project root:

{
  "mcpServers": {
    "alterlab": {
      "command": "npx",
      "args": ["-y", "alterlab-mcp-server@latest"],
      "env": {
        "ALTERLAB_API_KEY": "sk_live_your_key_here"
      }
    }
  }
}

Install in Windsurf

Add to Windsurf MCP settings (~/.codeium/windsurf/mcp_config.json):

{
  "mcpServers": {
    "alterlab": {
      "command": "npx",
      "args": ["-y", "alterlab-mcp-server@latest"],
      "env": {
        "ALTERLAB_API_KEY": "sk_live_your_key_here"
      }
    }
  }
}

Install via Smithery

npx -y @smithery/cli install alterlab-mcp-server --client claude

Get Your API Key

1. Sign up free — $1 free balance on signup
2. Go to Dashboard → API Keys and copy your key
3. Paste it into the ALTERLAB_API_KEY field in your MCP config

Tools

alterlab_scrape — Scrape Any Webpage

Scrape a URL and return its content as markdown, text, HTML, or JSON. Automatically handles anti-bot protection with tier escalation. Returns markdown by default — optimized for LLM context windows.

"Scrape https://www.amazon.com/dp/B0BSHF7WHW and summarize the product"

alterlab_extract — Extract Structured Data

Extract structured fields from any webpage using pre-built profiles or custom JSON Schema. Returns clean JSON — ready for databases, spreadsheets, or downstream processing.

"Extract the product name, price, and rating from this Amazon page"

Extraction profiles:

• Product — name, price, currency, rating, reviews, availability, images, description
• Article — title, author, published date, body text, featured image
• Job Posting — title, company, location, salary, description, requirements
• FAQ — question-answer pairs
• Recipe — ingredients, instructions, prep time, servings
• Event — name, date, location, description, organizer

alterlab_screenshot — Screenshot Any Page

Take a full-page screenshot of any URL. Returns a PNG image directly in the conversation — no URLs to copy, no files to download.

"Take a screenshot of our landing page at https://alterlab.io"

alterlab_estimate_cost — Estimate Before You Scrape

Check how much a scrape will cost before running it. Returns the predicted tier, cost per request, and confidence level.

"How much would it cost to scrape linkedin.com?"

alterlab_check_balance — Check Your Credits

Check your account balance, total deposited, and total spent. No parameters needed.

"Check my AlterLab balance"

alterlab_list_sessions — List Stored Sessions

List all stored sessions for authenticated scraping. Sessions contain cookies for specific domains, allowing you to scrape content behind login walls.

"List my stored sessions"

alterlab_create_session — Create a Session

Create a new stored session with cookies from a logged-in browser. The session is stored securely and can be reused across multiple scrape requests.

"Create an Amazon session with these cookies: session-id=abc123, session-token=xyz789"

alterlab_validate_session — Validate a Session

Check whether a stored session is still active and its cookies are valid.

"Is my Amazon session still valid?"