# 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/platform/actors/running/actors-in-store#pay-per-event

## What's an Apify Actor?

Actors are a software tools running on the Apify platform, for all kinds of web data extraction and automation use cases.
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.

In JavaScript/TypeScript projects, use official [JavaScript/TypeScript client](https://docs.apify.com/api/client/js.md):

```bash
npm install apify-client
```

In Python projects, use official [Python client library](https://docs.apify.com/api/client/python.md):

```bash
pip install apify-client
```

In shell scripts, use [Apify CLI](https://docs.apify.com/cli/docs.md):

````bash
# MacOS / Linux
curl -fsSL https://apify.com/install-cli.sh | bash
# Windows
irm https://apify.com/install-cli.ps1 | iex
```bash

In AI frameworks, you might use the [Apify MCP server](https://docs.apify.com/platform/integrations/mcp.md).

If your project is in a different language, use 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("💾 Check your data here: https://console.apify.com/storage/datasets/" + run["defaultDatasetId"])
for item in client.dataset(run["defaultDatasetId"]).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": {
            "command": "npx",
            "args": [
                "mcp-remote",
                "https://mcp.apify.com/?tools=nicolas_izquierdo/tech-stack-detector",
                "--header",
                "Authorization: Bearer <YOUR_API_TOKEN>"
            ]
        }
    }
}

```

## OpenAPI specification

```json
{
    "openapi": "3.0.1",
    "info": {
        "title": "Website Tech Stack Detector - Signals & Alerts",
        "description": "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.",
        "version": "1.0",
        "x-build-id": "QaUoPhO4ysMKlumRX"
    },
    "servers": [
        {
            "url": "https://api.apify.com/v2"
        }
    ],
    "paths": {
        "/acts/nicolas_izquierdo~tech-stack-detector/run-sync-get-dataset-items": {
            "post": {
                "operationId": "run-sync-get-dataset-items-nicolas_izquierdo-tech-stack-detector",
                "x-openai-isConsequential": false,
                "summary": "Executes an Actor, waits for its completion, and returns Actor's dataset items in response.",
                "tags": [
                    "Run Actor"
                ],
                "requestBody": {
                    "required": true,
                    "content": {
                        "application/json": {
                            "schema": {
                                "$ref": "#/components/schemas/inputSchema"
                            }
                        }
                    }
                },
                "parameters": [
                    {
                        "name": "token",
                        "in": "query",
                        "required": true,
                        "schema": {
                            "type": "string"
                        },
                        "description": "Enter your Apify token here"
                    }
                ],
                "responses": {
                    "200": {
                        "description": "OK"
                    }
                }
            }
        },
        "/acts/nicolas_izquierdo~tech-stack-detector/runs": {
            "post": {
                "operationId": "runs-sync-nicolas_izquierdo-tech-stack-detector",
                "x-openai-isConsequential": false,
                "summary": "Executes an Actor and returns information about the initiated run in response.",
                "tags": [
                    "Run Actor"
                ],
                "requestBody": {
                    "required": true,
                    "content": {
                        "application/json": {
                            "schema": {
                                "$ref": "#/components/schemas/inputSchema"
                            }
                        }
                    }
                },
                "parameters": [
                    {
                        "name": "token",
                        "in": "query",
                        "required": true,
                        "schema": {
                            "type": "string"
                        },
                        "description": "Enter your Apify token here"
                    }
                ],
                "responses": {
                    "200": {
                        "description": "OK",
                        "content": {
                            "application/json": {
                                "schema": {
                                    "$ref": "#/components/schemas/runsResponseSchema"
                                }
                            }
                        }
                    }
                }
            }
        },
        "/acts/nicolas_izquierdo~tech-stack-detector/run-sync": {
            "post": {
                "operationId": "run-sync-nicolas_izquierdo-tech-stack-detector",
                "x-openai-isConsequential": false,
                "summary": "Executes an Actor, waits for completion, and returns the OUTPUT from Key-value store in response.",
                "tags": [
                    "Run Actor"
                ],
                "requestBody": {
                    "required": true,
                    "content": {
                        "application/json": {
                            "schema": {
                                "$ref": "#/components/schemas/inputSchema"
                            }
                        }
                    }
                },
                "parameters": [
                    {
                        "name": "token",
                        "in": "query",
                        "required": true,
                        "schema": {
                            "type": "string"
                        },
                        "description": "Enter your Apify token here"
                    }
                ],
                "responses": {
                    "200": {
                        "description": "OK"
                    }
                }
            }
        }
    },
    "components": {
        "schemas": {
            "inputSchema": {
                "type": "object",
                "required": [
                    "domains"
                ],
                "properties": {
                    "domains": {
                        "title": "Websites",
                        "type": "array",
                        "description": "Domains or URLs to analyze (one homepage fetched per entry). Accepts 'stripe.com', 'https://notion.so', etc.",
                        "items": {
                            "type": "string"
                        }
                    },
                    "categories": {
                        "title": "Only these categories (optional)",
                        "type": "array",
                        "description": "Restrict detection to specific technology categories. Leave empty to detect everything.",
                        "items": {
                            "type": "string",
                            "enum": [
                                "CMS",
                                "Ecommerce",
                                "Analytics",
                                "Tag manager",
                                "Advertising",
                                "Chat & support",
                                "Marketing automation",
                                "CRM",
                                "Payments",
                                "JS framework",
                                "CDN & hosting",
                                "Web server",
                                "A/B testing",
                                "Error monitoring",
                                "Consent & privacy",
                                "CDP",
                                "Email & forms",
                                "Video",
                                "Fonts & UI",
                                "Search"
                            ],
                            "enumTitles": [
                                "CMS",
                                "Ecommerce",
                                "Analytics",
                                "Tag manager",
                                "Advertising / pixels",
                                "Chat & support",
                                "Marketing automation",
                                "CRM",
                                "Payments",
                                "JS framework",
                                "CDN & hosting",
                                "Web server",
                                "A/B testing",
                                "Error monitoring",
                                "Consent & privacy",
                                "CDP",
                                "Email & forms",
                                "Video",
                                "Fonts & UI",
                                "Search"
                            ]
                        },
                        "default": []
                    },
                    "newTechOnly": {
                        "title": "New / changed sites only (diff mode)",
                        "type": "boolean",
                        "description": "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.",
                        "default": false
                    },
                    "trackChanges": {
                        "title": "Track stack changes across runs",
                        "type": "boolean",
                        "description": "Remember each site's stack between runs and populate the `newTech` and `removedTech` fields.",
                        "default": true
                    },
                    "onlyDetected": {
                        "title": "Skip failed fetches",
                        "type": "boolean",
                        "description": "Do not output rows for sites that could not be fetched (timeouts, blocks, DNS errors).",
                        "default": false
                    },
                    "computeSignals": {
                        "title": "Add a run summary signal",
                        "type": "boolean",
                        "description": "Append one summary item per run: totals by category, top technologies, and how many sites use chat / payments / analytics.",
                        "default": true
                    },
                    "maxConcurrency": {
                        "title": "Max concurrent sites",
                        "minimum": 1,
                        "maximum": 20,
                        "type": "integer",
                        "description": "How many sites to fetch in parallel.",
                        "default": 5
                    }
                }
            },
            "runsResponseSchema": {
                "type": "object",
                "properties": {
                    "data": {
                        "type": "object",
                        "properties": {
                            "id": {
                                "type": "string"
                            },
                            "actId": {
                                "type": "string"
                            },
                            "userId": {
                                "type": "string"
                            },
                            "startedAt": {
                                "type": "string",
                                "format": "date-time",
                                "example": "2025-01-08T00:00:00.000Z"
                            },
                            "finishedAt": {
                                "type": "string",
                                "format": "date-time",
                                "example": "2025-01-08T00:00:00.000Z"
                            },
                            "status": {
                                "type": "string",
                                "example": "READY"
                            },
                            "meta": {
                                "type": "object",
                                "properties": {
                                    "origin": {
                                        "type": "string",
                                        "example": "API"
                                    },
                                    "userAgent": {
                                        "type": "string"
                                    }
                                }
                            },
                            "stats": {
                                "type": "object",
                                "properties": {
                                    "inputBodyLen": {
                                        "type": "integer",
                                        "example": 2000
                                    },
                                    "rebootCount": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "restartCount": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "resurrectCount": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "computeUnits": {
                                        "type": "integer",
                                        "example": 0
                                    }
                                }
                            },
                            "options": {
                                "type": "object",
                                "properties": {
                                    "build": {
                                        "type": "string",
                                        "example": "latest"
                                    },
                                    "timeoutSecs": {
                                        "type": "integer",
                                        "example": 300
                                    },
                                    "memoryMbytes": {
                                        "type": "integer",
                                        "example": 1024
                                    },
                                    "diskMbytes": {
                                        "type": "integer",
                                        "example": 2048
                                    }
                                }
                            },
                            "buildId": {
                                "type": "string"
                            },
                            "defaultKeyValueStoreId": {
                                "type": "string"
                            },
                            "defaultDatasetId": {
                                "type": "string"
                            },
                            "defaultRequestQueueId": {
                                "type": "string"
                            },
                            "buildNumber": {
                                "type": "string",
                                "example": "1.0.0"
                            },
                            "containerUrl": {
                                "type": "string"
                            },
                            "usage": {
                                "type": "object",
                                "properties": {
                                    "ACTOR_COMPUTE_UNITS": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "DATASET_READS": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "DATASET_WRITES": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "KEY_VALUE_STORE_READS": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "KEY_VALUE_STORE_WRITES": {
                                        "type": "integer",
                                        "example": 1
                                    },
                                    "KEY_VALUE_STORE_LISTS": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "REQUEST_QUEUE_READS": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "REQUEST_QUEUE_WRITES": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "DATA_TRANSFER_INTERNAL_GBYTES": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "DATA_TRANSFER_EXTERNAL_GBYTES": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "PROXY_RESIDENTIAL_TRANSFER_GBYTES": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "PROXY_SERPS": {
                                        "type": "integer",
                                        "example": 0
                                    }
                                }
                            },
                            "usageTotalUsd": {
                                "type": "number",
                                "example": 0.00005
                            },
                            "usageUsd": {
                                "type": "object",
                                "properties": {
                                    "ACTOR_COMPUTE_UNITS": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "DATASET_READS": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "DATASET_WRITES": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "KEY_VALUE_STORE_READS": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "KEY_VALUE_STORE_WRITES": {
                                        "type": "number",
                                        "example": 0.00005
                                    },
                                    "KEY_VALUE_STORE_LISTS": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "REQUEST_QUEUE_READS": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "REQUEST_QUEUE_WRITES": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "DATA_TRANSFER_INTERNAL_GBYTES": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "DATA_TRANSFER_EXTERNAL_GBYTES": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "PROXY_RESIDENTIAL_TRANSFER_GBYTES": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "PROXY_SERPS": {
                                        "type": "integer",
                                        "example": 0
                                    }
                                }
                            }
                        }
                    }
                }
            }
        }
    }
}
```
