# Web Contract Regression Monitor (`bread-kim/web-contract-regression-monitor`) Actor

Detect web contract regressions by URL. Track structural and response changes and get evidence-ready results for QA, monitoring, and automated checks.

- **URL**: https://apify.com/bread-kim/web-contract-regression-monitor.md
- **Developed by:** [bread kim](https://apify.com/bread-kim) (community)
- **Stats:** 1 total users, 0 monthly users, 0.0% runs succeeded, 0 bookmarks
- **User rating**: No ratings yet

## Pricing

from $2.00 / 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/actors/running/actors-in-store.md#pay-per-event

## What's an Apify Actor?

An Actor is a serverless cloud program that runs on the Apify platform. It has two run modes.
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.

Apify vocabulary and the platform model are defined once, in the agent quickstart at https://apify.com/agents.md.

## 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.

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 examples already wired to this Actor's own input schema, see the [API](#api) section below.

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`).

# README

## Web Contract Regression Monitor

Monitor public web endpoints for contract regressions before they become production incidents.

This Actor checks URLs against explicit expectations such as HTTP status, final URL, DOM content, metadata, and JSON-LD assertions.

### What it checks

- HTTP status codes
- Final URLs and redirects
- DOM selectors and text
- Page metadata
- JSON-LD structured data
- Multiple URLs in a single run

### Use cases

- Detect website regressions
- Monitor critical public pages
- Verify SEO and metadata contracts
- Check structured data
- Add lightweight web contract monitoring to CI or scheduled workflows

### Input

Provide one or more public HTTP/HTTPS URLs and the assertions that should be checked.

### Output

Each completed URL check produces a structured result containing the observed values and assertion results.

### Pricing

Pay per event:

- Actor start: $0.0005
- URL checked: $0.002 per completed URL check

Platform usage is included.

### Security

The Actor validates target addresses and blocks private, reserved, and unsafe network destinations.

### Limits

Only publicly accessible HTTP/HTTPS endpoints are supported.

# Actor input Schema

## `targets` (type: `array`):

Public HTTP(S) pages and their assertions.

## `timeoutSeconds` (type: `number`):

Per-request timeout from 1 to 15 seconds.

## `concurrency` (type: `integer`):

Maximum simultaneous checks from 1 to 5.

## Actor input object example

```json
{
  "targets": [
    {
      "url": "https://example.com",
      "assertions": [
        {
          "type": "statusEquals",
          "value": 200
        }
      ]
    }
  ],
  "timeoutSeconds": 10,
  "concurrency": 3
}
```

# Actor output Schema

## `dataset` (type: `string`):

No description

# 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 = {
    "targets": [
        {
            "url": "https://example.com",
            "assertions": [
                {
                    "type": "statusEquals",
                    "value": 200
                }
            ]
        }
    ]
};

// Run the Actor and wait for it to finish
const run = await client.actor("bread-kim/web-contract-regression-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 = { "targets": [{
            "url": "https://example.com",
            "assertions": [{
                    "type": "statusEquals",
                    "value": 200,
                }],
        }] }

# Run the Actor and wait for it to finish
run = client.actor("bread-kim/web-contract-regression-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 '{
  "targets": [
    {
      "url": "https://example.com",
      "assertions": [
        {
          "type": "statusEquals",
          "value": 200
        }
      ]
    }
  ]
}' |
apify call bread-kim/web-contract-regression-monitor --silent --output-dataset

```

## MCP server setup

```json
{
    "mcpServers": {
        "apify": {
            "type": "http",
            "url": "https://mcp.apify.com/?tools=fetch-actor-details,bread-kim/web-contract-regression-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/wWsxnDOYhBPd0UsLl/builds/LJCIGXBMHbHNF1zQn/openapi.json