Name: Tech Stack Detector API: What Is This Website Built With
Brand: compasslab-1
SKU: api-compasslab-1-tech-stack-detector
Availability: InStock
Author: API Market

WPTOOLS

# Website Technology Stack Detector API

## Overview

The Website Technology Stack Detector API reports the technologies a website is built with from a single URL. It has 1 endpoint, `/v1/tech-stack`, which reads one page with a plain HTML fetch (no browser) and, unless you turn it off, the domain's DNS records. It matches what it sees against about 240 technology fingerprints in 27 categories: CMS and site builders, e-commerce platforms, analytics, tag managers, advertising pixels, marketing automation, chat and support widgets, payments, consent banners, A/B testing, JavaScript frameworks, UI libraries, CDNs, hosting, web servers, security, fonts, email hosting and DNS providers. Related technologies are added too, for example WooCommerce implies WordPress and PHP.

It is built for sales teams prospecting by platform (shops on Shopify, sites on WordPress, companies using a competitor's tool), lead scoring and CRM enrichment with technographic data, agencies and researchers auditing sites, and privacy or consent reviews of which analytics, pixels and cookie banners a site loads. Each response gives the requested `url`, the `final_url` after redirects, a `status`, a `count` and a `technologies` list grouped by category. Every technology has its `name`, `category`, `version` when the site exposes it, a `confidence` score from 0 to 1, and the `evidence` that matched: a response header, cookie name (never its value), meta tag, script or stylesheet URL, markup pattern or DNS record. A `metadata` block reports when the check ran, how long it took, the HTTP status of the page and whether DNS was checked.

## Features

*   **1 endpoint**: `GET /v1/tech-stack` returns the full technology report for one URL.
*   **Simple input**: A full page URL or a bare domain, plus an optional `dns` switch.
*   **About 240 technologies in 27 categories**: From CMS, e-commerce and analytics to CDN, hosting, web server, security, fonts, email hosting and DNS provider.
*   **Evidence for every result**: Each technology lists what matched, so you can see why it was reported.
*   **Versions when exposed**: The version is returned when the site shows it, for example in a meta generator tag or a script URL.
*   **Data source and method**: One HTML fetch of the page (no JavaScript is run) plus DNS records (CNAME, NS, MX), matched against the seller's own fingerprints written from public documentation. robots.txt is respected and nothing behind a login is read.
*   **Rate limit**: 1 request per second on FREE, 3 on PRO, 5 on ULTRA and 10 on MEGA.

## Use Cases

*   **Sales prospecting**: Find out whether a prospect runs on Shopify, WordPress or a competitor's product before you reach out.
*   **Lead scoring and CRM enrichment**: Add technographic data such as e-commerce platform, analytics and marketing tools to company records.
*   **Competitor and market research**: Compare the platforms, analytics and payment tools used across a list of competitor sites.
*   **Agency audits**: Check a client's site stack, CDN, hosting and security headers before a project starts.
*   **Consent and tracking audits**: See which analytics tools, advertising pixels and consent banners a page loads.
*   **Email and DNS provider lookups**: Identify a company's email hosting and DNS provider from its MX and NS records.

## API Documentation

### Base URL

All requests go through the API.market gateway at this base URL:

```
https://prod.api.market/api/v1/compasslab-1/tech-stack-detector
```

### Authentication

Every request needs your API.market key in the `x-api-market-key` header:

```
x-api-market-key: YOUR_API_KEY
```

Replace `YOUR_API_KEY` with your actual API key.

### Endpoints

#### 1. Detect a website's technology stack

Reads one page and reports the technologies it uses, grouped by category and best first, each with its category, version when exposed, confidence and evidence. `status` is `ok` when at least one technology was found, `no_technologies_found` when the page was read but matched no fingerprint, or a value such as `blocked_by_robots`, `blocked_by_site`, `not_found`, `dead_link`, `timeout`, `unsupported_type`, `too_large` or `fetch_failed` when the page could not be read. DNS-based results are still returned when the page cannot be read.

**Method:** `GET`

**Endpoint:** `/v1/tech-stack`

**Parameters:**

| Name | In | Description | Type | Required | Default | Max Value |
|---|---|---|---|---|---|---|
| `url` | query | Website or page URL; a bare domain works too (minimum 4 characters). | string | Yes | - | 2048 characters |
| `dns` | query | Also read DNS records (CNAME, NS, MX) to detect hosting, DNS and email providers. | boolean | No | `true` | - |

**Example Request:**

```bash
curl -X GET "https://prod.api.market/api/v1/compasslab-1/tech-stack-detector/v1/tech-stack?url=https%3A%2F%2Fwww.shopify.com" \
  -H "x-api-market-key: YOUR_API_KEY"
```

**Example Response (200 OK):**

```json
{
  "url": "https://www.shopify.com/",
  "final_url": "https://www.shopify.com/",
  "status": "ok",
  "error": null,
  "count": 5,
  "technologies": [
    {
      "name": "Cloudflare",
      "category": "CDN",
      "version": null,
      "confidence": 0.95,
      "evidence": [
        {
          "type": "header",
          "detail": "server: cloudflare"
        }
      ]
    },
    {
      "name": "Shopify",
      "category": "E-commerce",
      "version": null,
      "confidence": 0.75,
      "evidence": [
        {
          "type": "html",
          "detail": "html …cdn.shopify.com/…"
        }
      ]
    },
    {
      "name": "Google Workspace",
      "category": "Email hosting",
      "version": null,
      "confidence": 0.9,
      "evidence": [
        {
          "type": "dns",
          "detail": "MX alt2.aspmx.l.google.com."
        }
      ]
    },
    {
      "name": "HSTS",
      "category": "Security",
      "version": null,
      "confidence": 0.95,
      "evidence": [
        {
          "type": "header",
          "detail": "strict-transport-security: max-age=15552000; includeSubDomains; preload"
        }
      ]
    },
    {
      "name": "Tailwind CSS",
      "category": "UI library",
      "version": null,
      "confidence": 0.75,
      "evidence": [
        {
          "type": "html",
          "detail": "html …--tw-translate…"
        }
      ]
    }
  ],
  "metadata": {
    "checked_at": "2026-10-17T14:55:10Z",
    "elapsed_ms": 4518,
    "http_status": 200,
    "dns_checked": true,
    "cached": false
  }
}
```

## Status Codes

| Code | Status | Description |
|---|---|---|
| 200 | OK | The request was processed. Check `status`: a page that could not be read or matched no fingerprint still returns `200` with a status such as `no_technologies_found`, `blocked_by_site` or `timeout`, plus any DNS-based results. |
| 400 | Bad Request | The input is invalid, for example a value that is not a usable URL or domain. |
| 401 | Unauthorized | The `x-api-market-key` value is invalid or expired. |
| 403 | Forbidden | Your subscription does not include this endpoint. |
| 404 | Not Found | The endpoint path does not exist. Use `/v1/tech-stack`. |
| 422 | Unprocessable Entity | A parameter is missing or invalid, for example no `url`. The response says which one. |
| 429 | Too Many Requests | You went over your plan's requests-per-second limit, or the FREE plan's calls are used up. |
| 500 | Internal Server Error | Something failed while processing the request. Retry after a short delay. |

## Rate Limits

Each plan has its own per-second limit: FREE allows 1 request per second, PRO 3, ULTRA 5 and MEGA 10. FREE includes 50 calls and is a hard limit, so requests after the 50th return `429 Too Many Requests`. PRO (3,000 calls), ULTRA (15,000 calls) and MEGA (75,000 calls) are soft limits, so calls above the included amount are billed as overage instead of being blocked. Requests above the per-second limit also return `429`. Back off before retrying and honour any `Retry-After` header. Each call fetches the live page and DNS records, so response time depends on the target site; our test on https://www.shopify.com took about 4.5 seconds.

## FAQ

**How are technologies detected?**

From response headers, cookie names, meta tags, script and stylesheet URLs, markup patterns and DNS records, matched against the seller's own fingerprints. Each result lists the evidence that matched in `evidence`, with its `type` (`header`, `cookie`, `meta`, `script`, `link`, `html`, `url`, `dns` or `implied`) and `detail`.

**Does it run a browser?**

No. It makes one HTML fetch of the page. Technologies that are loaded later by JavaScript, and server-side frameworks that leave no trace in the page, can be missed.

**Why is the version often `null`?**

The version is only returned when the site exposes it, for example in a meta generator tag or a script URL. Many sites do not, as in the Shopify example above.

**Can I turn off DNS lookups?**

Yes, set `dns=false`. You then lose the email hosting, DNS provider and some hosting results that come from CNAME, NS and MX records.

**What happens if a site blocks bots?**

The response comes back with `status: "blocked_by_site"` (or `blocked_by_robots` when robots.txt disallows the fetch) and only the DNS-based results.

**What does `confidence` mean?**

It is a score from 0 to 1 combined from the evidence. Headers and meta tags are strong signals and markup patterns weaker ones. In the Shopify example, Cloudflare found from the `server` header scored 0.95, while Shopify and Tailwind CSS found from markup scored 0.75.

**How accurate is it?**

The seller reports that in its own tests the main platform was detected on 19 of 20 sites with publicly known stacks, with 7.7 technologies found per site on average.

## Contact Us

If you have any questions or need assistance, you can reach out to us through the embedded chat on the bottom right corner of the page or send an email to hello@magicapi.com.


Tech stack detector API: send a URL and get the CMS, e-commerce platform, analytics, CDN, hosting and payment tools a website uses, with evidence for each.

Tech Stack Detector API: What Is This Website Built With

FREE