Overview

BuiltWith MCP Server exposes BuiltWith’s web-technology detection APIs through the Model Context Protocol (MCP), enabling AI assistants and agent frameworks (Claude, Cursor, IDE agents, etc.) to query site-technology data natively. Instead of wiring HTTP API calls directly inside a plugin or skill, an AI client communicates with the MCP server using the MCP transport (stdio or HTTP) and requests technology detection, metadata, trends, or semantic searches as structured tools.

This approach simplifies building assistants that can answer natural-language questions such as “What CMS does example.com use?” or “Compare analytics stacks for nytimes.com and cnn.com”, while letting developers choose between a hosted MCP endpoint or running the MCP server locally for private networks, custom routing, or rate-limiting control.

Features

Native MCP-compatible server exposing BuiltWith detection and metadata
Works with MCP-capable clients (Claude, Cursor, VS Code/IDE agents)
Hosted endpoint (recommended) and self-hosting options
Two transport modes for self-hosting: stdio (local) and HTTP (remote)
Per-request API key support and environment variable fallback
Tools covering domain lookup, trends, relationships, vector search, payments, and more

Installation / Configuration

Hosted option (recommended)

Endpoint: https://api.builtwith.com/mcp
Authentication: send your BuiltWith API key in the Authorization header

Example HTTP header:

Authorization: Bearer YOUR_BUILTWITH_API_KEY

Example MCP JSON-RPC request:

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

Self-host (local) quickstart

git clone https://github.com/builtwith/mcp.git
cd mcp
npm install
# run in HTTP mode on port 8787
MCP_TRANSPORT=http PORT=8787 node bw-mcp-v1.js
# or run default stdio mode:
node bw-mcp-v1.js

Self-host environment variables / headers

BUILTWITH_API_KEY — used by stdio mode and as fallback for HTTP mode
Authorization: Bearer — per-request header in HTTP mode
MCP_TRANSPORT — “stdio” (default) or “http”
MCP_ALLOWED_ORIGINS — comma-separated CORS allowlist (HTTP mode)
Health check: http://127.0.0.1:8787/health (HTTP mode)

Example MCP client config (Claude / Cursor / IDE)

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

StdIO client configuration example (when embedding a local node process)

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

Available Tools

Tool name	Purpose
domain-lookup	Live technology detection for a domain
domain-api	Full domain metadata
relationships-api	Related websites and associations
free-api	Category/group counts and public summaries
company-to-url	Resolve company → domain mappings
tags-api	IP / attribute based discovery
recommendations-api	Technology recommendations
redirects-api	Live and historical redirects
keywords-api	Keyword intelligence for sites
trends-api	Technology trend and time-series data
product-api	Ecommerce product search
trust-api	Trust scoring and reputation
financial-api	Financial metadata
social-api	Social profile associations
vector-search	Semantic similarity across technologies/categories
payment-balance / config / purchase	API credit balance, billing config, and purchases

Use Cases

AI assistant answering direct questions:
- “What CMS does example.com use?” → queries domain-lookup/domain-api and returns CMS name + confidence.
- “Does site X use Shopify or Magento?” → domain-lookup + recommendations-api for explicit detection.
Competitive research via AI:
- “Compare the JavaScript frameworks used by siteA and siteB” → fetch domain-api for both sites, normalize results, present a side-by-side comparison.
IDE/agent workflows:
- While editing a site-integration script, ask your IDE agent “Which analytics provider does this domain use?” and receive the provider name, script snippets, and detection metadata.
Data pipelines and enrichment:
- Use relationships-api and tags-api to discover related domains and perform batched enrichment for marketing or OSINT tasks.
Payment & quota checks:
- Agents can call payment-balance or payment-config tools to programmatically check credits before running large batched lookups.

How it integrates

AI assistant receives a user prompt requesting technology information.
The assistant uses MCP to call a specific tool exposed by the BuiltWith MCP server.
The MCP server maps the MCP request into one or more BuiltWith API calls, returning structured JSON.
The assistant formats the structured result into concise, human-readable output with sources and confidence notes.

Resources

GitHub repository: https://github.com/builtwith/mcp
BuiltWith API docs: https://api.builtwith.com/
License: MIT

Notes

The hosted MCP endpoint is simplest for most use cases; self-hosting provides control for private networks and custom behavior.
Ensure you protect your BuiltWith API key and follow your organization’s security policies when configuring agents or CI integrations.

Tags:developer-tools

BuiltWith MCP Server for Web Technology Detection