# Page Change Monitor — price, stock & content alerts (`edwin_beale/page-change-monitor`) Actor

Watch any public URL on a schedule. Get a dataset row and an optional webhook only when the price, stock status, or content actually changes.

- **URL**: https://apify.com/edwin\_beale/page-change-monitor.md
- **Developed by:** [Edwin Beale](https://apify.com/edwin_beale) (community)
- **Categories:** Automation, E-commerce, Developer tools
- **Stats:** 2 total users, 1 monthly users, 0.0% runs succeeded, 0 bookmarks
- **User rating**: No ratings yet

## Pricing

from $10.00 / 1,000 change detecteds

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

## Page Change Monitor

Watch any public web page and get a row — and an optional webhook — **only when something actually changes**: a price, a stock status, or the content itself.

### What it does

1. You give it URLs (and optionally a CSS selector for the exact element to watch).
2. Run it on a [schedule](https://docs.apify.com/platform/schedules) — every 10 minutes, hourly, daily.
3. First run records a baseline. Every later run compares against the last seen value.
4. On change you get a dataset row `{url, before, after, diffSummary, checkedAt}` and, if configured, a JSON POST to your webhook (Slack, n8n, Zapier, Make, your API).

### Modes

- **text** — visible text of the page or selector changed
- **price** — first money amount (`$ € £ ₹ ¥`) inside the selector changed
- **stock** — a keyword (e.g. `in stock`, `sold out`) appeared or disappeared
- **html** — raw HTML changed

### Pricing

Pay per event: a tiny fee per URL check, a small fee per detected change. No subscription, no minimum. Baselines and failed checks are never charged as changes.

### Examples

**Price watch:** urls `[product page]`, selector `.price`, mode `price`, schedule hourly.
**Back-in-stock:** selector `#availability`, mode `stock`, stockKeyword `in stock`, webhook to Slack.
**Competitor page watch:** no selector, mode `text`, schedule daily.

### Limits & fair use

Only public, login-free pages. You are responsible for the URLs you watch. JavaScript-heavy pages that render nothing without a browser may need the raw HTML mode; a headless-browser option is on the roadmap.

### Output example

```json
{
  "url": "https://example.com/product",
  "changeType": "price",
  "before": "$49.99",
  "after": "$39.99",
  "diffSummary": "$49.99 → $39.99",
  "checkedAt": "2026-08-24T09:00:00.000Z",
  "status": "ok"
}
```

# Actor input Schema

## `urls` (type: `array`):

Public pages to check. One row per URL.

## `selector` (type: `string`):

Watch only this part of the page, e.g. `.price` or `#availability`. Leave empty to watch the whole page text.

## `mode` (type: `string`):

`text` = visible text changed · `price` = first money amount changed · `stock` = a keyword appeared/disappeared · `html` = raw HTML changed

## `stockKeyword` (type: `string`):

Only for `stock` mode. Keyword whose presence is tracked, e.g. `In stock` or `Sold out`.

## `webhookUrl` (type: `string`):

POSTed a JSON body for every detected change — plug in Slack, n8n, Zapier, Make.

## `notifyOnFirstRun` (type: `boolean`):

If on, the first run outputs one `baseline` row per URL so you can see what is being watched. No change events are charged for baselines.

## `proxyConfiguration` (type: `object`):

Keep default unless a site blocks datacenter IPs.

## Actor input object example

```json
{
  "urls": [
    "https://www.apple.com/in/shop/buy-iphone/iphone-17"
  ],
  "mode": "text",
  "stockKeyword": "in stock",
  "notifyOnFirstRun": true,
  "proxyConfiguration": {
    "useApifyProxy": true
  }
}
```

# Actor output Schema

## `changes` (type: `string`):

One row per baseline, detected change or failed check, across every watched URL.

## `summary` (type: `string`):

URLs checked, changes detected and failures for this run.

# 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 = {
    "urls": [
        "https://www.apple.com/in/shop/buy-iphone/iphone-17"
    ]
};

// Run the Actor and wait for it to finish
const run = await client.actor("edwin_beale/page-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 = { "urls": ["https://www.apple.com/in/shop/buy-iphone/iphone-17"] }

# Run the Actor and wait for it to finish
run = client.actor("edwin_beale/page-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 '{
  "urls": [
    "https://www.apple.com/in/shop/buy-iphone/iphone-17"
  ]
}' |
apify call edwin_beale/page-change-monitor --silent --output-dataset

```

## MCP server setup

```json
{
    "mcpServers": {
        "apify": {
            "type": "http",
            "url": "https://mcp.apify.com/?tools=fetch-actor-details,edwin_beale/page-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/a6wOKlBXoxObMvdwj/builds/wgkwxmEjgYQt2FdKN/openapi.json