# Tech Stack Change Monitor — CMS, CDN & Analytics Delta Feed (`stubbie/tech-stack-change-monitor`) Actor

Detects the CMS, ecommerce platform, JS framework, CDN, analytics and marketing tags a website runs, and remembers the last result per domain so a scheduled run only returns and charges for domains whose tech stack actually changed since the last check.

- **URL**: https://apify.com/stubbie/tech-stack-change-monitor.md
- **Developed by:** [Marco Jakobsen](https://apify.com/stubbie) (community)
- **Stats:** 2 total users, 1 monthly users, 100.0% runs succeeded, 0 bookmarks
- **User rating**: No ratings yet

## Pricing

from $10.00 / 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?

An Actor is a serverless cloud program that runs on the Apify platform. It has two run modes.
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.

Apify vocabulary and the platform model are defined once, in the agent quickstart at https://apify.com/agents.md.

## 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.

Do not guess an integration path. Every one of them is in the agent quickstart at https://apify.com/agents.md: the Apify MCP server, Agent Skills with the Apify CLI, the JavaScript and Python clients, the REST API, and the account-free path for an agent with no human to sign in. It also carries the rule on stating cost before the first paid run.

For examples already wired to this Actor's own input schema, see the [API](#api) section below.

Each client library has reference documentation the quickstart does not restate: [JavaScript/TypeScript](https://docs.apify.com/api/client/js/docs.md) (`npm install apify-client`) and [Python](https://docs.apify.com/api/client/python/docs.md) (`pip install apify-client`).

# README

## Website Tech Stack Change Monitor

### What it does

Point this Actor at a list of websites and it fingerprints each one — CMS, ecommerce
platform, JS framework, CDN/hosting, analytics tags, marketing/chat widgets, payment
scripts, consent banners and backend server — from the page's HTML and response headers.
No headless browser, no login, just one fast HTTP request per domain.

The part that matters for scheduling: this Actor remembers what it found last time. Run it
daily or hourly on the same watch-list and by default it only returns (and only charges you
for) a domain when its tech stack actually changed since the last check — a competitor
switching from WooCommerce to Shopify, dropping Google Analytics for a self-hosted tool,
moving behind Cloudflare, adding a new chat widget. A quiet day costs nothing. That is the
point: build a feed you can leave running, not a one-off report you have to remember to
re-run. Typical uses: sales and SEO teams tracking a prospect or competitor list, agencies
auditing client sites for platform migrations, investors watching a portfolio company's
stack for signs of a rebuild.

### Input

| Field | Type | Default | Notes |
|---|---|---|---|
| `domains` | array of strings | — (required) | Plain domains (`example.com`) or full URLs, one per item. |
| `onlyChanges` | boolean | `true` | When true, a domain identical to its last check is skipped — no row, no charge. The very first check of any domain always returns a baseline row. Set to `false` to always get a full row for every domain on every run. |
| `stateStoreName` | string | `TECH-STACK-MONITOR-STATE` | Name of the memory that stores each domain's last-seen stack. Use a different name per independent watch-list if you run more than one. |
| `requestTimeoutSecs` | integer | `20` | Per-site fetch timeout, 5–60 seconds. |

See `test-input.json` in this Actor for a working example.

### Output

One dataset row per domain that is returned (see `onlyChanges` above). Example row:

```json
{
  "domain": "example.com",
  "url": "https://example.com/",
  "checkedAt": "2026-09-22T08:12:00.000Z",
  "httpStatus": 200,
  "technologies": [
    { "name": "WordPress", "category": "CMS" },
    { "name": "Cloudflare", "category": "CDN" },
    { "name": "Google Analytics", "category": "Analytics" }
  ],
  "added": ["Cloudflare"],
  "removed": [],
  "changed": true,
  "isFirstCheck": false
}
```

A row where a fetch failed instead carries an `error` field and the last known
`technologies` list, so a failing site does not silently vanish from your feed.

### Pricing

Pay-per-event. You are charged **$0.03 per result row returned** (roughly $30 per 1,000
rows) — not per domain checked. A run over 50 domains where nothing changed on any of them
produces zero rows and costs you nothing beyond the Actor start event. Scheduling this
hourly on a watch-list you care about is the intended way to use it; unlike a flat per-run
price, your bill tracks how much actually changed, not how often you looked.

# Actor input Schema

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

Websites to check, one per line/item. Plain domains (example.com) or full URLs both work.

## `onlyChanges` (type: `boolean`):

When true (recommended for scheduled runs), a domain whose tech stack is identical to the last run is skipped entirely: no dataset item, no charge. The first check of any domain always returns a baseline row. Turn this off to always get a full row for every domain.

## `stateStoreName` (type: `string`):

Name of the named key-value store used to remember each domain's last-seen tech stack between runs. Leave the default unless you are running several independent watch-lists and want them to keep separate memory.

## `requestTimeoutSecs` (type: `integer`):

How long to wait for each site to respond before giving up on it.

## Actor input object example

```json
{
  "domains": [
    "wordpress.org",
    "nextjs.org",
    "vercel.com",
    "tailwindcss.com"
  ],
  "onlyChanges": true,
  "stateStoreName": "TECH-STACK-MONITOR-STATE",
  "requestTimeoutSecs": 20
}
```

# Actor output Schema

## `results` (type: `string`):

Every domain checked on this run, with the technologies detected and what changed since last time.

## `changesOnly` (type: `string`):

Just the domains whose stack actually moved, which is the reason to run this on a schedule.

## `csv` (type: `string`):

The same rows as a spreadsheet, for handing to someone who does not want JSON.

## `console` (type: `string`):

Browse the results in the table view with the Changes and Full stack tabs.

# 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": [
        "wordpress.org",
        "nextjs.org",
        "vercel.com",
        "tailwindcss.com"
    ]
};

// Run the Actor and wait for it to finish
const run = await client.actor("stubbie/tech-stack-change-monitor").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": [
        "wordpress.org",
        "nextjs.org",
        "vercel.com",
        "tailwindcss.com",
    ] }

# Run the Actor and wait for it to finish
run = client.actor("stubbie/tech-stack-change-monitor").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": [
    "wordpress.org",
    "nextjs.org",
    "vercel.com",
    "tailwindcss.com"
  ]
}' |
apify call stubbie/tech-stack-change-monitor --silent --output-dataset

```

## MCP server setup

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

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/8kwtDJsE7GJciMhbU/builds/kNOyIVxfvXyZyi7Yl/openapi.json