🔍 BuiltWith MCP Server 🚀

🌟 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

• Cursor / Claude Dev (VS Code)

🛠️ 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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