# Diff Dataset Fields (`lukaskrivka/diff-dataset-fields`) Actor

Compare changes in text fields between two datasets. Monitor new and updated content on websites.

- **URL**: https://apify.com/lukaskrivka/diff-dataset-fields.md
- **Developed by:** [Lukáš Křivka](https://apify.com/lukaskrivka) (community)
- **Categories:** AI, Automation, Open source
- **Stats:** 37 total users, 4 monthly users, 100.0% runs succeeded, 1 bookmarks
- **User rating**: No ratings yet

## Pricing

Pay per usage

This Actor is paid per platform usage. The Actor is free to use, and you only pay for the Apify platform usage, which gets cheaper the higher subscription plan you have.

Learn more: https://docs.apify.com/actors/running/actors-in-store.md#pay-per-usage

## 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

Compare items of two datasets to see changes in their fields. You match the items by a key field and then compare the any number of textual fields.

### Diff

You can choose one or more fields to diff between two items that are matched by a key field. The diff is computed using the [fast-diff](https://www.npmjs.com/package/fast-diff) package where the output is a list of text parts that are marked with a number depending if they are inserted (1), deleted (-1) or unchanged (0).

### Output

The output is a JSON object with the following properties:

- `type`: Representing how the items were compared. Can be `new`, `removed`, `unchanged` or `updated`.
- `oldItem`: The item from the old dataset
- `newItem`: The item from the new dataset
- `diff`: The diff between the two items. Only present if the type is `updated`.

#### Example input

```json
{
    "oldDatasetId": "0Azg4BxggC3RmcPpY",
    "newDatasetId": "i4mfnrQEP8QmQAbHu",
    "fieldToMapBy": "url",
    "fieldsToDiff": ["text", "markdown"],
    "outputTypes": ["new", "removed", "updated", "unchanged"],
}
```

#### Example output

This is one item that was matched in both datasets, the real output will have all items from both datasets.

```json
{
    "type": "updated",
    "oldItem": {
        "url": "https://www.peacocktv.com/start",
        "text": "PeacockAdobe AudienceManagerBack ButtonSearch IconFilter Icon\nEnter your email to get started",
		"markdown": "# PeacockAdobe AudienceManagerBack ButtonSearch IconFilter Icon\n\n## \n\nEnter your email to get started",
    },
    "newItem": {
        "url": "https://www.peacocktv.com/start",
        "text": "PeacockBack ButtonSearch IconFilter Icon\nEnter your email to get started",
		"markdown": "# PeacockBack ButtonSearch IconFilter Icon\n\n## \n\nEnter your email to get started",
    }
    ,
    "diff":{
        "text": [
            [
                0,
                "Peacock"
            ],
            [
                -1,
                "Adobe AudienceManager"
            ],
            [
                0,
                "Back ButtonSearch IconFilter Icon\nEnter your email to get started"
            ]
        ],
        "markdown": [
            [
                0,
                "# Peacock"
            ],
            [
                -1,
                "Adobe AudienceManager"
            ],
            [
                0,
                "Back ButtonSearch IconFilter Icon\n\n## \n\nEnter your email to get started"
            ]
        ]
    }
}
```

# Actor input Schema

## `oldDatasetId` (type: `string`):

ID of the old dataset to compare.

## `newDatasetId` (type: `string`):

ID of the new dataset to compare.

## `fieldToMapBy` (type: `string`):

Field used to find which items should be matched for comparison. Usually some identifier like `url` or `id`.

## `fieldsToDiff` (type: `array`):

Fields that will be compared between matched items. Usually fields like `text`, `description`, `markdown`.

## `outputTypes` (type: `array`):

Which items should be pushed to the default dataset

## `outputDatasetId` (type: `string`):

Enables storing the diff items into a separate dataset. Useful for tracking historical changes or integration workflows.

## `onlyLoadStoreDiffedFields` (type: `boolean`):

If enabled, only the fields specified in `fieldsToDiff` and `fieldToMapBy` will be loaded and stored in the output diff dataset. This helps to reduce storage costs and make the run faster.

## Actor input object example

```json
{
  "fieldToMapBy": "url",
  "outputTypes": [
    "new",
    "removed",
    "updated",
    "unchanged"
  ],
  "onlyLoadStoreDiffedFields": false
}
```

# 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 = {};

// Run the Actor and wait for it to finish
const run = await client.actor("lukaskrivka/diff-dataset-fields").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 = {}

# Run the Actor and wait for it to finish
run = client.actor("lukaskrivka/diff-dataset-fields").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 '{}' |
apify call lukaskrivka/diff-dataset-fields --silent --output-dataset

```

## MCP server setup

```json
{
    "mcpServers": {
        "apify": {
            "type": "http",
            "url": "https://mcp.apify.com/?tools=fetch-actor-details,lukaskrivka/diff-dataset-fields"
        }
    }
}

```

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/QLFf1OMzWZuVMu6d8/builds/lGf6ItOMHGZI3favK/openapi.json