# Get only new and changed products between two runs

**Use case:** 

See how the monitor works on a small product list: the first run saves a baseline, and every later run returns only the products that are new, changed (with the old and new price) or removed. Point it at your own scraper's dataset or run it from a scraper's integration to get only what changed, with optional Telegram, Slack or email alerts.

## Input

```json
{
  "items": [
    {
      "url": "https://shop.example.com/p/1",
      "name": "Blue mug",
      "price": 12.5
    },
    {
      "url": "https://shop.example.com/p/2",
      "name": "Red mug",
      "price": 9.9
    },
    {
      "url": "https://shop.example.com/p/3",
      "name": "Green mug",
      "price": 11
    }
  ],
  "monitorName": "demo-products",
  "idFields": [
    "url"
  ],
  "ignoreFields": [
    "scrapedAt",
    "crawledAt",
    "timestamp"
  ],
  "reportNew": true,
  "reportChanged": true,
  "trackRemoved": true,
  "reportAllOnFirstRun": true,
  "detailedDiff": true,
  "maxChangesPerItem": 20,
  "maxItems": 0,
  "notifyMaxItems": 10,
  "notifyOnNoChanges": false,
  "webhookMaxItems": 100,
  "resetState": false,
  "allowEmptySource": false,
  "stateStoreName": "change-monitor-state"
}
```

## Output

```json
{
  "changeType": {
    "label": "Change",
    "format": "text"
  },
  "key": {
    "label": "Key",
    "format": "text"
  },
  "changedFields": {
    "label": "Changed fields",
    "format": "array"
  },
  "changes": {
    "label": "Before → after",
    "format": "array"
  },
  "item": {
    "label": "Item",
    "format": "object"
  }
}
```

## About this Actor

This example demonstrates how to use [Dataset Change Monitor](https://apify.com/egra_van/dataset-change-monitor.md) with a specific input configuration. Visit the [Actor detail page](https://apify.com/egra_van/dataset-change-monitor.md) to learn more, explore other use cases, and run it yourself.


## How to integrate an Actor?

This Task's input is already configured above. Use it as-is rather than inventing a new one.

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 full API examples (JavaScript, Python, CLI, MCP, OpenAPI), see this Task's Actor page: https://apify.com/egra_van/dataset-change-monitor.md

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`).