# Website Tech Stack Detector - Signals & Alerts (`nicolas_izquierdo/tech-stack-detector`) Actor

Detect the technology stack behind any list of websites: CMS, ecommerce, analytics, chat, payments, JS frameworks, CDN and more. Diff mode flags when a target company ADOPTS or DROPS a tool - schedule it and turn tech changes into B2B buying signals. Uses only public homepage markup and headers.

- **URL**: https://apify.com/nicolas\_izquierdo/tech-stack-detector.md
- **Developed by:** [Nicolas Izquierdo](https://apify.com/nicolas_izquierdo) (community)
- **Categories:** Automation, Developer tools, Lead generation
- **Stats:** 2 total users, 1 monthly users, 100.0% runs succeeded, 0 bookmarks
- **User rating**: No ratings yet

## Pricing

from $3.00 / 1,000 results

This Actor is paid per event. You are not charged for the Apify platform usage, but only a fixed price for specific events.

Learn more: https://docs.apify.com/actors/running/actors-in-store.md#pay-per-event

## What's an Apify Actor?

Actors are web data automations that power AI and operations. They run on the Apify platform to scrape websites, process data, connect APIs, and automate workflows.
In Batch mode, an Actor accepts a well-defined JSON input, performs an action which can take anything from a few seconds to a few hours,
and optionally produces a well-defined JSON output, datasets with results, or files in key-value store.
In Standby mode, an Actor provides a web server which can be used as a website, API, or an MCP server.
Actors are written with capital "A".

## How to integrate an Actor?

If asked about integration, you help developers integrate Actors into their projects.
You adapt to their stack and deliver integrations that are safe, well-documented, and production-ready.
The best way to integrate Actors is as follows.

- **AI agents and MCP clients** — the [Apify MCP server](https://docs.apify.com/integrations/mcp.md) at `https://mcp.apify.com` (remote, streamable HTTP, OAuth on first use).
- **Agentic workflows and local Actor development** — [Agent Skills](https://apify.com/.well-known/agent-skills/index.json) with the [Apify CLI](https://docs.apify.com/cli/docs.md): `npm install -g apify-cli`, then `apify login`.
- **JavaScript/TypeScript projects** — the official [JS/TS client](https://docs.apify.com/api/client/js/docs.md): `npm install apify-client`.
- **Python projects** — the official [Python client](https://docs.apify.com/api/client/python/docs.md): `pip install apify-client`.
- **Any other language** — the [REST API](https://docs.apify.com/api/v2.md).

For usage examples, see the [API](#api) section below.

For more details, see Apify documentation as [Markdown index](https://docs.apify.com/llms.txt) and [Markdown full-text](https://docs.apify.com/llms-full.txt).

# README

## Website Tech Stack Detector — Signals & Alerts

**See exactly what any company runs its website on — and get pinged the day they switch.**

Feed this Actor a list of domains and it tells you the technology behind each one: CMS, ecommerce platform, analytics, chat widget, payment provider, JS framework, CDN, marketing automation and more — ~110 technologies across 20 categories. Turn on **diff mode**, schedule it daily, and it only reports a site when it **adopts or drops** a tool. That change *is* the B2B buying signal.

BuiltWith and Wappalyzer sell "companies that use technology X" lists for $295–995/month. This does the same detection on your own target list, on your schedule, for cents — with data you own.

### Why it's different

Most Apify tech scrapers dump raw HTML. This one gives you a **clean, categorized stack per site plus change tracking** — the difference between "here's a page" and "here's a qualified lead who just installed Intercom."

- **Official page markup only.** It reads the public homepage HTML and response headers — the same signals Wappalyzer, BuiltWith and your browser's dev tools use. No proxies, no logins, no ToS-risky scraping.
- **Diff mode = sales signals.** `newTech` / `removedTech` per site. "Target account started using Shopify Plus" or "dropped Zendesk for Intercom" → a reason to reach out today.
- **Evidence included.** Every detection ships with the exact marker that triggered it, so you can trust (and audit) the result.

### Use cases

- **B2B sales & lead gen:** filter your prospect list to "uses Stripe" / "runs on Shopify" / "just added a chat widget," then sell the matching integration or service.
- **Competitive intelligence:** watch competitors' stacks and get alerted when they change vendors.
- **Agencies:** qualify inbound by platform (WordPress vs Webflow vs custom) before the first call.
- **Investors/analysts:** tech adoption as an alt-data signal across a portfolio of companies.
- **Partnerships:** find every site already running a tool that complements yours.

### Detected categories

CMS · Ecommerce · Analytics · Tag managers · Advertising / pixels · Chat & support · Marketing automation · CRM · Payments · JS frameworks · CDN & hosting · Web servers · A/B testing · Error monitoring · Consent & privacy (CMP) · CDP · Email & forms · Video · Fonts & UI · Search

### Input

```json
{
    "domains": ["stripe.com", "notion.so", "shopify.com"],
    "newTechOnly": false,
    "trackChanges": true,
    "computeSignals": true
}
```

| Parameter | Type | Description |
|---|---|---|
| `domains` | Array (required) | Domains or URLs to analyze. `stripe.com`, `https://notion.so`, etc. One homepage fetched per entry. |
| `categories` | Array | Restrict detection to specific categories. Empty = detect everything. |
| `newTechOnly` | Boolean | Diff mode: only output sites whose stack changed since the last run. First run primes the memory. |
| `trackChanges` | Boolean | Remember each site's stack between runs and fill `newTech` / `removedTech`. Default `true`. |
| `onlyDetected` | Boolean | Skip rows for sites that couldn't be fetched (timeouts, blocks). |
| `computeSignals` | Boolean | Append one run-summary item: totals by category, top technologies, share using chat / payments / analytics. |
| `maxConcurrency` | Integer | Sites fetched in parallel (1–20, default 5). |

### Output

One record per site:

```json
{
    "type": "site",
    "domain": "stripe.com",
    "url": "https://stripe.com/",
    "statusCode": 200,
    "title": "Stripe | Financial Infrastructure...",
    "server": "nginx",
    "technologies": [
        { "name": "Stripe", "category": "Payments", "confidence": "high", "evidence": "html: js.stripe.com/v3/" },
        { "name": "Cloudflare", "category": "CDN & hosting", "confidence": "high", "evidence": "header cf-ray: 80a1..." }
    ],
    "techByCategory": { "Payments": ["Stripe"], "CDN & hosting": ["Cloudflare"] },
    "techCount": 2,
    "newTech": ["Stripe"],
    "removedTech": [],
    "isNew": false,
    "scrapedAt": "2026-07-07T12:00:00.000Z"
}
```

Plus one `run_signals` summary per run (unless disabled).

### Scheduling for alerts

Set `newTechOnly: true`, schedule the Actor daily, and connect a Slack / email / webhook integration. You'll only hear about a domain when its stack actually changes — a lightweight, always-on competitor-and-prospect radar. Runs cost cents because there are no proxies and only the homepage is fetched.

### Notes & limits

- Detection is based on the homepage only. Tools loaded exclusively on deeper pages (e.g. a checkout-only payment SDK) may not appear until v1.1 adds optional sub-page crawling.
- Presence, not version: it reports *that* a technology is used, not which version.
- Sites that hard-block bots or render everything client-side after load may expose fewer markers.

### FAQ

**Is this allowed?** It only reads public homepage markup and HTTP headers — the same data your browser receives. No authentication, no proxies, no private data.

**How accurate is it?** Signatures are the documented, stable fingerprints used across the industry. Each hit includes the evidence so you can verify it yourself. High-confidence markers are vendor-specific; medium-confidence ones are heuristic.

**Part of a suite.** Pair it with our [ATS Jobs Scraper](https://apify.com/nicolas_izquierdo/ats-jobs-scraper) (hiring signals) and [Mentions Monitor](https://apify.com/nicolas_izquierdo/mentions-monitor) (conversation signals) for a full B2B signal stack: who's hiring, what they run, and where they're talked about.

# Actor input Schema

## `domains` (type: `array`):

Domains or URLs to analyze (one homepage fetched per entry). Accepts 'stripe.com', 'https://notion.so/', etc.

## `categories` (type: `array`):

Restrict detection to specific technology categories. Leave empty to detect everything.

## `newTechOnly` (type: `boolean`):

Only output sites where the detected stack changed since the last run (tool adopted or dropped). Schedule daily + Slack/webhook = tech-change alerts. The first run primes the memory.

## `trackChanges` (type: `boolean`):

Remember each site's stack between runs and populate the `newTech` and `removedTech` fields.

## `onlyDetected` (type: `boolean`):

Do not output rows for sites that could not be fetched (timeouts, blocks, DNS errors).

## `computeSignals` (type: `boolean`):

Append one summary item per run: totals by category, top technologies, and how many sites use chat / payments / analytics.

## `maxConcurrency` (type: `integer`):

How many sites to fetch in parallel.

## Actor input object example

```json
{
  "domains": [
    "stripe.com",
    "notion.so",
    "basecamp.com"
  ],
  "categories": [],
  "newTechOnly": false,
  "trackChanges": true,
  "onlyDetected": false,
  "computeSignals": true,
  "maxConcurrency": 5
}
```

# API

You can run this Actor programmatically using our API. Below are code examples in JavaScript, Python, and CLI, as well as the OpenAPI specification and MCP server setup.

## JavaScript example

```javascript
import { ApifyClient } from 'apify-client';

// Initialize the ApifyClient with your Apify API token
// Replace the '<YOUR_API_TOKEN>' with your token
const client = new ApifyClient({
    token: '<YOUR_API_TOKEN>',
});

// Prepare Actor input
const input = {
    "domains": [
        "stripe.com",
        "notion.so",
        "basecamp.com"
    ]
};

// Run the Actor and wait for it to finish
const run = await client.actor("nicolas_izquierdo/tech-stack-detector").call(input);

// Fetch and print Actor results from the run's dataset (if any)
console.log('Results from dataset');
console.log(`💾 Check your data here: https://console.apify.com/storage/datasets/${run.defaultDatasetId}`);
const { items } = await client.dataset(run.defaultDatasetId).listItems();
items.forEach((item) => {
    console.dir(item);
});

// 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/js/docs

```

## Python example

```python
from apify_client import ApifyClient

# Initialize the ApifyClient with your Apify API token
# Replace '<YOUR_API_TOKEN>' with your token.
client = ApifyClient("<YOUR_API_TOKEN>")

# Prepare the Actor input
run_input = { "domains": [
        "stripe.com",
        "notion.so",
        "basecamp.com",
    ] }

# Run the Actor and wait for it to finish
run = client.actor("nicolas_izquierdo/tech-stack-detector").call(run_input=run_input)

# Fetch and print Actor results from the run's dataset (if there are any)
print(f"💾 Check your data here: https://console.apify.com/storage/datasets/{run.default_dataset_id}")
for item in client.dataset(run.default_dataset_id).iterate_items():
    print(item)

# 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/python/docs/quick-start

```

## CLI example

```bash
echo '{
  "domains": [
    "stripe.com",
    "notion.so",
    "basecamp.com"
  ]
}' |
apify call nicolas_izquierdo/tech-stack-detector --silent --output-dataset

```

## MCP server setup

```json
{
    "mcpServers": {
        "apify": {
            "type": "http",
            "url": "https://mcp.apify.com/?tools=fetch-actor-details,nicolas_izquierdo/tech-stack-detector"
        }
    }
}

```

The hosted server signs you in with OAuth on first connect, so no API token belongs in this config. Clients without OAuth support can send an `Authorization: Bearer <APIFY_API_TOKEN>` header instead, using a token from API & Integrations in Apify Console (https://console.apify.com/settings/integrations).

## OpenAPI specification

Download the OpenAPI definition: https://api.apify.com/v2/actors/sVYn6N8wfSiGjibaj/builds/QaUoPhO4ysMKlumRX/openapi.json