# Website Change Monitor & Alerter (`second_coming/website-change-monitor`) Actor Monitor web pages for content changes. Track page diffs, get webhook alerts when monitored pages change. Supports CSS selectors for targeting specific sections. - **URL**: https://apify.com/second\_coming/website-change-monitor.md - **Developed by:** [Richard P](https://apify.com/second_coming) (community) - **Categories:** Developer tools, AI - **Stats:** 2 total users, 1 monthly users, 0.0% runs succeeded, 0 bookmarks - **User rating**: No ratings yet ## Pricing $0.01 / website check run 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 a software tools running on the Apify platform, for all kinds of web data extraction and automation use cases. 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. In JavaScript/TypeScript projects, use official [JavaScript/TypeScript client](https://docs.apify.com/api/client/js.md): ```bash npm install apify-client ``` In Python projects, use official [Python client library](https://docs.apify.com/api/client/python.md): ```bash pip install apify-client ``` In shell scripts, use [Apify CLI](https://docs.apify.com/cli/docs.md): ````bash # MacOS / Linux curl -fsSL https://apify.com/install-cli.sh | bash # Windows irm https://apify.com/install-cli.ps1 | iex ```bash In AI frameworks, you might use the [Apify MCP server](https://docs.apify.com/platform/integrations/mcp.md). If your project is in a different language, use 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 & Alerter Monitor web pages for content changes and get alerted when something changes. ### How it works 1. Provide a list of URLs to watch 2. The Actor fetches each page and computes a content fingerprint (SHA-256 hash) 3. On each run, it compares against the previously stored fingerprint 4. If content changed: it generates a diff, records the change event, and optionally sends a webhook alert 5. If unchanged: quietly records the check (in "all_runs" mode) or skips (in "changes_only" mode) ### Features - **CSS Selector Support** — monitor only a specific part of a page (e.g., `#pricing-table`, `.announcement-bar`) - **Smart Diffing** — generates unified diffs showing exactly what changed - **Webhook Alerts** — POST change notifications to any HTTP endpoint - **Persistent State** — fingerprints are stored in Apify's key-value store between runs - **Schedule-Friendly** — designed for cron/scheduled runs; only alerts on actual changes ### Input | Field | Type | Description | |-------|------|-------------| | `urls` | array | List of URL objects to monitor | | `urls[].url` | string | **Required.** The page URL | | `urls[].name` | string | Optional label for the page | | `urls[].selector` | string | Optional CSS selector to watch a specific section | | `webhookUrl` | string | URL to POST change notifications to | | `notificationType` | enum | `"changes_only"` (default) or `"all_runs"` | ### Webhook Payload When a change is detected, a POST request with JSON body is sent to your webhook URL: ```json { "event": "page_changed", "name": "My Page", "url": "https://example.com", "changed_at": "2024-01-01T00:00:00+00:00", "diff_preview": "--- previous\n+++ current\n@@ -1 +1 @@\n-old content\n+new content", "previous_hash": "abc...", "current_hash": "def..." } ```` ### Use Cases - Monitor competitor website changes (pricing, features, copy) - Track documentation, terms of service, or policy updates - Watch job postings for new openings - Monitor regulatory or compliance page changes - Detect when a product goes in/out of stock # Actor input Schema ## `urls` (type: `array`): List of web pages to monitor for changes. Each entry can optionally include a CSS selector to watch only a specific part of the page. ## `webhookUrl` (type: `string`): Optional URL to POST change notifications to. The webhook will receive a JSON payload with change details when a page changes. ## `notificationType` (type: `string`): When to send webhook notifications: 'changes\_only' (default) sends alerts only when a change is detected. 'all\_runs' sends a summary after every run. ## Actor input object example ```json { "urls": [ { "url": "https://example.com", "name": "Example Homepage", "selector": "" } ], "notificationType": "changes_only" } ``` # Actor output Schema ## `results` (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 '' with your token const client = new ApifyClient({ token: '', }); // Prepare Actor input const input = { "urls": [ { "url": "https://example.com", "name": "Example Homepage", "selector": "" } ], "webhookUrl": "" }; // Run the Actor and wait for it to finish const run = await client.actor("second_coming/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 '' with your token. client = ApifyClient("") # Prepare the Actor input run_input = { "urls": [{ "url": "https://example.com", "name": "Example Homepage", "selector": "", }], "webhookUrl": "", } # Run the Actor and wait for it to finish run = client.actor("second_coming/website-change-monitor").call(run_input=run_input) # Fetch and print Actor results from the run's dataset (if there are any) print("💾 Check your data here: https://console.apify.com/storage/datasets/" + run["defaultDatasetId"]) for item in client.dataset(run["defaultDatasetId"]).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": [ { "url": "https://example.com", "name": "Example Homepage", "selector": "" } ], "webhookUrl": "" }' | apify call second_coming/website-change-monitor --silent --output-dataset ``` ## MCP server setup ```json { "mcpServers": { "apify": { "command": "npx", "args": [ "mcp-remote", "https://mcp.apify.com/?tools=second_coming/website-change-monitor", "--header", "Authorization: Bearer " ] } } } ``` ## OpenAPI specification ```json { "openapi": "3.0.1", "info": { "title": "Website Change Monitor & Alerter", "description": "Monitor web pages for content changes. Track page diffs, get webhook alerts when monitored pages change. Supports CSS selectors for targeting specific sections.", "version": "0.0", "x-build-id": "yq2eXwi9GqwDFuYMX" }, "servers": [ { "url": "https://api.apify.com/v2" } ], "paths": { "/acts/second_coming~website-change-monitor/run-sync-get-dataset-items": { "post": { "operationId": "run-sync-get-dataset-items-second_coming-website-change-monitor", "x-openai-isConsequential": false, "summary": "Executes an Actor, waits for its completion, and returns Actor's dataset items in response.", "tags": [ "Run Actor" ], "requestBody": { "required": true, "content": { "application/json": { "schema": { "$ref": "#/components/schemas/inputSchema" } } } }, "parameters": [ { "name": "token", "in": "query", "required": true, "schema": { "type": "string" }, "description": "Enter your Apify token here" } ], "responses": { "200": { "description": "OK" } } } }, "/acts/second_coming~website-change-monitor/runs": { "post": { "operationId": "runs-sync-second_coming-website-change-monitor", "x-openai-isConsequential": false, "summary": "Executes an Actor and returns information about the initiated run in response.", "tags": [ "Run Actor" ], "requestBody": { "required": true, "content": { "application/json": { "schema": { "$ref": "#/components/schemas/inputSchema" } } } }, "parameters": [ { "name": "token", "in": "query", "required": true, "schema": { "type": "string" }, "description": "Enter your Apify token here" } ], "responses": { "200": { "description": "OK", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/runsResponseSchema" } } } } } } }, "/acts/second_coming~website-change-monitor/run-sync": { "post": { "operationId": "run-sync-second_coming-website-change-monitor", "x-openai-isConsequential": false, "summary": "Executes an Actor, waits for completion, and returns the OUTPUT from Key-value store in response.", "tags": [ "Run Actor" ], "requestBody": { "required": true, "content": { "application/json": { "schema": { "$ref": "#/components/schemas/inputSchema" } } } }, "parameters": [ { "name": "token", "in": "query", "required": true, "schema": { "type": "string" }, "description": "Enter your Apify token here" } ], "responses": { "200": { "description": "OK" } } } } }, "components": { "schemas": { "inputSchema": { "type": "object", "required": [ "urls" ], "properties": { "urls": { "title": "URLs to Monitor", "type": "array", "description": "List of web pages to monitor for changes. Each entry can optionally include a CSS selector to watch only a specific part of the page." }, "webhookUrl": { "title": "Webhook URL", "type": "string", "description": "Optional URL to POST change notifications to. The webhook will receive a JSON payload with change details when a page changes." }, "notificationType": { "title": "Notification Type", "enum": [ "changes_only", "all_runs" ], "type": "string", "description": "When to send webhook notifications: 'changes_only' (default) sends alerts only when a change is detected. 'all_runs' sends a summary after every run.", "default": "changes_only" } } }, "runsResponseSchema": { "type": "object", "properties": { "data": { "type": "object", "properties": { "id": { "type": "string" }, "actId": { "type": "string" }, "userId": { "type": "string" }, "startedAt": { "type": "string", "format": "date-time", "example": "2025-01-08T00:00:00.000Z" }, "finishedAt": { "type": "string", "format": "date-time", "example": "2025-01-08T00:00:00.000Z" }, "status": { "type": "string", "example": "READY" }, "meta": { "type": "object", "properties": { "origin": { "type": "string", "example": "API" }, "userAgent": { "type": "string" } } }, "stats": { "type": "object", "properties": { "inputBodyLen": { "type": "integer", "example": 2000 }, "rebootCount": { "type": "integer", "example": 0 }, "restartCount": { "type": "integer", "example": 0 }, "resurrectCount": { "type": "integer", "example": 0 }, "computeUnits": { "type": "integer", "example": 0 } } }, "options": { "type": "object", "properties": { "build": { "type": "string", "example": "latest" }, "timeoutSecs": { "type": "integer", "example": 300 }, "memoryMbytes": { "type": "integer", "example": 1024 }, "diskMbytes": { "type": "integer", "example": 2048 } } }, "buildId": { "type": "string" }, "defaultKeyValueStoreId": { "type": "string" }, "defaultDatasetId": { "type": "string" }, "defaultRequestQueueId": { "type": "string" }, "buildNumber": { "type": "string", "example": "1.0.0" }, "containerUrl": { "type": "string" }, "usage": { "type": "object", "properties": { "ACTOR_COMPUTE_UNITS": { "type": "integer", "example": 0 }, "DATASET_READS": { "type": "integer", "example": 0 }, "DATASET_WRITES": { "type": "integer", "example": 0 }, "KEY_VALUE_STORE_READS": { "type": "integer", "example": 0 }, "KEY_VALUE_STORE_WRITES": { "type": "integer", "example": 1 }, "KEY_VALUE_STORE_LISTS": { "type": "integer", "example": 0 }, "REQUEST_QUEUE_READS": { "type": "integer", "example": 0 }, "REQUEST_QUEUE_WRITES": { "type": "integer", "example": 0 }, "DATA_TRANSFER_INTERNAL_GBYTES": { "type": "integer", "example": 0 }, "DATA_TRANSFER_EXTERNAL_GBYTES": { "type": "integer", "example": 0 }, "PROXY_RESIDENTIAL_TRANSFER_GBYTES": { "type": "integer", "example": 0 }, "PROXY_SERPS": { "type": "integer", "example": 0 } } }, "usageTotalUsd": { "type": "number", "example": 0.00005 }, "usageUsd": { "type": "object", "properties": { "ACTOR_COMPUTE_UNITS": { "type": "integer", "example": 0 }, "DATASET_READS": { "type": "integer", "example": 0 }, "DATASET_WRITES": { "type": "integer", "example": 0 }, "KEY_VALUE_STORE_READS": { "type": "integer", "example": 0 }, "KEY_VALUE_STORE_WRITES": { "type": "number", "example": 0.00005 }, "KEY_VALUE_STORE_LISTS": { "type": "integer", "example": 0 }, "REQUEST_QUEUE_READS": { "type": "integer", "example": 0 }, "REQUEST_QUEUE_WRITES": { "type": "integer", "example": 0 }, "DATA_TRANSFER_INTERNAL_GBYTES": { "type": "integer", "example": 0 }, "DATA_TRANSFER_EXTERNAL_GBYTES": { "type": "integer", "example": 0 }, "PROXY_RESIDENTIAL_TRANSFER_GBYTES": { "type": "integer", "example": 0 }, "PROXY_SERPS": { "type": "integer", "example": 0 } } } } } } } } } } ```