🔍 BuiltWith MCP Server 🚀

Domain API v25

Domain lookups now use API v25. Technology records include numeric confidence scores from 0 to 1. Full JSON responses include Meta.company_reg, an array of company registration records with string type and number fields; registration numbers preserve leading zeros. The array is empty when unavailable or metadata is excluded. See the API reference. Full domain methods preserve both fields; live technology lookups include confidence and return technology records only.

🌟 Overview

BuiltWith MCP is a Model Context Protocol (MCP) server that allows AI assistants (Claude, Cursor, IDE agents, etc.) to query BuiltWith’s technology detection data directly and natively.

It enables natural-language questions like:

“What technologies does example.com use?” “Does this site run Shopify or Magento?” “What analytics stack is used by nytimes.com?”

BuiltWith MCP supports bring-your-own BuiltWith API key and can be used either as a hosted service or self-hosted.

Claude DEMO

Shows how to get this working in Claude as a Connector

https://github.com/user-attachments/assets/1199362a-c813-497e-8569-15b9a3ce9713

🌐 Hosted MCP (Recommended)

BuiltWith provides a hosted MCP endpoint — no local Node process required.

Endpoint

https://api.builtwith.com/mcp

Authentication

Bring your own BuiltWith API key:

Authorization: Bearer YOUR_BUILTWITH_API_KEY

Example MCP request

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/list"
}

🧩 Supported Tools

The hosted MCP exposes the following tools:

• domain-lookup – Live technology detection for a domain
• domain-api – Full domain metadata
• change-api – Technology additions and removals with business context
• lists-api – Sites using a technology, including OTHERTECHS and numeric attribute filters such as SPEND, REVENUE, and EMPLOYEES
• relationships-api – Related websites
• free-api – Category and group counts
• company-to-url – Company → domain discovery
• tags-api – IP / attribute based discovery
• recommendations-api – Technology recommendations
• redirects-api – Live and historical redirects
• keywords-api – Keyword intelligence
• trends-api – Technology trend data
• product-api – Ecommerce product search
• trust-api – Trust scoring
• vat-api – VAT, GST, and other company registration numbers for websites
• vat-types-api – Reference list of registration types returned by vat-api (no API key required)
• whoami-api – Account limits, credit costs, and endpoint inventory (no API credits)
• usage-api – Current credit balance (no API credits)
• mcp-registry-api – Search and browse the BuiltWith MCP registry (v1) of other remote MCP servers (no API credits)
• mcp-registry-v2-api – Search and browse the BuiltWith MCP registry (v2) of other remote MCP servers, with per-endpoint auth flags and first/last detected dates (no API credits)
• vector-search – Semantic similarity search across technologies and categories
• ask-api – Natural language website list lookup (e.g. "Magento websites in Spain"); supports full reports and pagination
• payment-balance – Check your API credit balance
• payment-config – Retrieve your payment configuration
• payment-purchase – Purchase API credits using your saved Stripe payment method
• agent-auth-start – Start Agent Device-Code Authorization (no API key required)
• agent-auth-token – Poll for authorization result and retrieve access token (no API key required)

⚙️ Client Configuration (Claude, Cursor, IDEs)

Add BuiltWith MCP to your MCP-compatible client configuration.

Example

{
  "mcpServers": {
    "builtwith": {
      "url": "https://api.builtwith.com/mcp",
      "headers": {
        "Authorization": "Bearer YOUR_BUILTWITH_API_KEY"
      }
    }
  }
}

Configuration locations

• Claude Desktop

  • macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
  • Windows: %APPDATA%\Claude\claude_desktop_config.json

• Cursor / Claude Dev (VS Code)

  • macOS: ~/Library/Application Support/Code/User/globalStorage/saoudrizwan.claude-dev/settings/cline_mcp_settings.json
  • Windows: %APPDATA%\Code\User\globalStorage\saoudrizwan.claude-dev\settings\cline_mcp_settings.json

🛠️ Self-Hosting (Optional)

You can also run the BuiltWith MCP server locally or inside your own infrastructure.

What changed (February 14, 2026)

The local server now supports both standard MCP transports:

• stdio (default) for local MCP clients like Claude Desktop/Cursor
• http for remote/connector style MCP usage on /mcp

Installation

git clone https://github.com/builtwith/builtwith-mcp.git
cd builtwith-mcp
npm install

Local (stdio) MCP configuration

{
  "mcpServers": {
    "builtwith": {
      "command": "node",
      "args": ["[PATH-TO]/bw-mcp-v1.js"],
      "env": {
        "BUILTWITH_API_KEY": "YOUR_BUILTWITH_API_KEY"
      }
    }
  }
}

Note: The hosted endpoint is recommended for most users. Self-hosting is useful if you need custom routing, rate-limiting, or private network access.

Local HTTP MCP endpoint

Run in HTTP mode:

MCP_TRANSPORT=http PORT=8787 node bw-mcp-v1.js

MCP endpoint:

http://127.0.0.1:8787/mcp

Optional headers/environment:

• Authorization: Bearer YOUR_BUILTWITH_API_KEY (per-request API key for HTTP mode)
• BUILTWITH_API_KEY (used by stdio mode, and as fallback when no HTTP bearer token is provided)
• MCP_ALLOWED_ORIGINS (comma-separated CORS/origin allowlist for HTTP mode)

Health check:

http://127.0.0.1:8787/health

🔐 Agent Device-Code Authorization

Agents can obtain a temporary bw- prefixed API token without the user pasting their key — the user approves access in their browser.

Flow:

1. Call agent-auth-start → receive device_code and verification_uri
2. Direct the user to open verification_uri in their browser
3. Poll agent-auth-token every 5 seconds with the device_code
4. On approval, receive an access_token (bw-...) valid for the chosen duration (1 hour / 1 day / 30 days)
5. Use the token as KEY=bw-... on any BuiltWith API endpoint

No API key is required to call agent-auth-start or agent-auth-token.

🚀 Usage Examples

Once configured, try asking your AI assistant:

• “What technologies is example.com using?”
• “What CMS does nytimes.com run on?”
• “Does amazon.com use Google Analytics?”
• “What JavaScript frameworks are used by spotify.com?”
• “What hosting provider does netflix.com use?”
• “Compare the technology stacks of facebook.com and twitter.com”

🧠 How It Works

1. 🗣️ User asks a technology question in an AI assistant
2. 🔌 The assistant calls the BuiltWith MCP server
3. 🔍 MCP translates intent into BuiltWith API calls
4. 📊 BuiltWith returns structured technology data
5. 💬 The AI assistant presents human-friendly insights

📖 BuiltWith API Documentation

• https://api.builtwith.com/
• https://api.builtwith.com/domain-api

📄 License

MIT License — see the LICENSE file for details.

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