# Website Change Monitor (text & JSON diff) (`x402opklaar/website-change-monitor`) Actor

Watch pages or JSON APIs on a schedule and get precise diffs — added/removed paragraphs or changed JSON paths — plus optional webhook alerts. Pay only per check and per detected change.

- **URL**: https://apify.com/x402opklaar/website-change-monitor.md
- **Developed by:** [Opklaar](https://apify.com/x402opklaar) (community)
- **Categories:** Automation, Developer tools
- **Stats:** 2 total users, 1 monthly users, 66.7% runs succeeded, 0 bookmarks
- **User rating**: No ratings yet

## Pricing

from $5.00 / 1,000 url checkeds

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 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 Change Monitor — text & JSON diff with alerts

Watch any web page **or JSON API** on a schedule and get a precise answer to "what changed since last time?" — not a screenshot, not a hash, an actual diff:

- **HTML pages** → main content is extracted (navigation, ads, and footers stripped), then compared paragraph-by-paragraph. You get `added` and `removed` paragraphs. Template churn and reordered menus don't trigger false alarms.
- **JSON APIs** → structural diff: every `added` / `removed` / `changed` path with old and new values (`$.prices[3].usd: 42 → 45`).
- **Webhook alerts** — when something changed, the full diff is POSTed to your URL. Wire it to Slack, Zapier, or your own agent.

### How to use it

1. Add the URLs you want to watch.
2. Run once — the first run stores a baseline snapshot per URL.
3. Put the actor on an [Apify Schedule](https://docs.apify.com/platform/schedules) (e.g. hourly or daily). Every subsequent run reports exactly what changed.

Baselines persist across runs in your own key-value store, isolated per account. Changing the mode or selector starts a fresh watch for that URL (your old baseline is kept under the previous configuration).

### Output

One dataset item per URL per run:

```json
{
  "url": "https://example.com/pricing",
  "checked_at": 1755000000,
  "changed": true,
  "mode": "text",
  "added": ["Pro plan is now $29/month"],
  "removed": ["Pro plan is now $19/month"],
  "change_count": 2,
  "prev_checked_at": 1754913600
}
```

Fetch errors are reported in the item (`error` field), are never charged, and never overwrite your baseline — a flaky 500 won't make the next run misreport everything as new.

### Pricing

Pay per event, nothing else:

- **URL checked** — each successful check of one URL
- **Change detected** — only when a check actually found a change

A watch that stays quiet costs you almost nothing; you pay for the news.

### Typical uses

- Competitor pricing and changelog pages
- Terms-of-service / policy pages (compliance)
- Job boards, docs pages, status pages
- Any JSON API you depend on but don't control — catch schema or value drift before it breaks you

### Support

Issues tab of this actor, or x402@opklaar.com.

# Actor input Schema

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

Web pages or JSON API endpoints to monitor. Each run compares against the previous run and reports what changed.

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

auto = JSON endpoints get a structural path diff, HTML pages get a clean-text paragraph diff. Force with text/json.

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

Optional. Recorded with the watch so upgrading later won't reset your baselines.

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

Optional. When a change is detected, the full diff item is POSTed to this URL as JSON.

## Actor input object example

```json
{
  "urls": [
    "https://example.com"
  ],
  "mode": "auto"
}
```

# 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://example.com"
    ]
};

// Run the Actor and wait for it to finish
const run = await client.actor("x402opklaar/website-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://example.com"] }

# Run the Actor and wait for it to finish
run = client.actor("x402opklaar/website-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://example.com"
  ]
}' |
apify call x402opklaar/website-change-monitor --silent --output-dataset

```

## MCP server setup

```json
{
    "mcpServers": {
        "apify": {
            "type": "http",
            "url": "https://mcp.apify.com/?tools=fetch-actor-details,x402opklaar/website-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/tqX9MDeUK6hG45U2i/builds/yYrNB5UufIbzu3ubJ/openapi.json