# Website Change Monitor: Page Diff Tracker, Pay Per Check (`mrlarryjohnson/website-change-monitor`) Actor Watch any list of public pages on a schedule and get the ACTUAL changed lines, not just a ping. Detects edits, removals, and pages going 404. Failed fetches are never billed. No JavaScript rendering — honest about that. - **URL**: https://apify.com/mrlarryjohnson/website-change-monitor.md - **Developed by:** [Larry Johnson](https://apify.com/mrlarryjohnson) (community) - **Categories:** Automation, Developer tools, SEO tools - **Stats:** 2 total users, 1 monthly users, 100.0% runs succeeded, NaN bookmarks - **User rating**: No ratings yet ## Pricing from $2.00 / 1,000 url checks 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 — see the actual diff, not just a ping Put it on a schedule with your list of URLs. Every run, each page is fetched, fingerprinted, and compared with the previous run — and when something changes you get **the changed lines themselves** (`diffAdded` / `diffRemoved`), not a useless "something changed" flag. ### What it catches - **Edits** — price changes, doc updates, policy rewrites, changelog entries - **Removals** — content quietly deleted from a page - **Pages going dark** — a previously-live page returning 404/410 (`status: "gone"`) ### Typical uses Competitor pricing pages, terms-of-service watching, job boards, product docs, government/regulatory pages, "is my own site still up and unchanged" sanity checks. ### Statuses | status | meaning | billed? | |---|---|---| | `baseline` | first time this URL is seen — fingerprint stored | yes | | `unchanged` | same content as last run | yes | | `changed` | content differs — see `diffAdded`/`diffRemoved` | yes | | `gone` | a previously-observed page now returns 404/410 | yes | | `restored` | page back online after `gone` | yes | | `not-found` | 404/410 on a URL we never successfully saw (typo?) | **no** | | `fetch-error` | timeout / 5xx / blocks / non-text content | **no — never** | You pay per **verdict**, not per attempt. If we can't reach a page, that row is free and the old baseline is kept so the next run diffs correctly. ### Honest limits - **Monitoring scope is the first 2,000 text lines (300 chars each)** of a page — the same capped content is fingerprinted, stored, and diffed, so verdicts and diffs always agree. Virtually every real page fits. - **Bot-protected sites may block cloud IPs.** Blocks show up as free `fetch-error` rows; switch on the RESIDENTIAL proxy input for those targets. - **Up to 500 URLs per run** (duplicates removed); split bigger sets across schedules with different `stateKey`s. - **No JavaScript rendering.** Server-rendered HTML only. Heavy SPAs that draw everything client-side will show little text (check `textLength`); this tool is the wrong fit for those — and we'd rather say so than bill you for noise. - `sectionHint` is a plain-text region anchor (id/class/heading), deliberately simpler than CSS selectors — it cuts header/footer noise on most real pages. - Fingerprints normalize whitespace, so cosmetic reformatting won't false-alarm, but a rotating timestamp printed in page text will. Use `sectionHint` to scope. ### Suggested setup 1. Create a Schedule (hourly/daily) with your URL list as input 2. Add an Apify webhook on run-succeeded → Slack/Discord/email/Zapier 3. Filter rows where `status = "changed"` or `"gone"` Built by the maker of the [whale-tracking and MCP suite](https://apify.com/mrlarryjohnson) — same rules everywhere: fail-loud integrity, errors never billed, state committed only after your data is safely delivered. # Actor input Schema ## `urls` (type: `array`): The public page URLs to monitor (one per line, up to 500, duplicates removed). Each run compares every page against its previous fingerprint. ## `sectionHint` (type: `string`): Only watch the part of the page AFTER this text first appears (an element id, class name, or unique heading text). Cuts noise from headers/footers. ## `stateKey` (type: `string`): Separate monitoring sets (e.g. per client or per schedule) keep separate baselines. Letters, numbers, dashes. ## `proxyConfiguration` (type: `object`): Use Apify Proxy for sites that block datacenter IPs (pick RESIDENTIAL for bot-protected targets). Off by default. ## Actor input object example ```json { "urls": [ "https://example.com", "https://www.iana.org/help/example-domains" ], "stateKey": "default" } ```` # Actor output Schema ## `results` (type: `string`): All records produced by this run as JSON items. # 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": [ "https://example.com", "https://www.iana.org/help/example-domains" ] }; // Run the Actor and wait for it to finish const run = await client.actor("mrlarryjohnson/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": [ "https://example.com", "https://www.iana.org/help/example-domains", ] } # Run the Actor and wait for it to finish run = client.actor("mrlarryjohnson/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": [ "https://example.com", "https://www.iana.org/help/example-domains" ] }' | apify call mrlarryjohnson/website-change-monitor --silent --output-dataset ``` ## MCP server setup ```json { "mcpServers": { "apify": { "command": "npx", "args": [ "mcp-remote", "https://mcp.apify.com/?tools=mrlarryjohnson/website-change-monitor", "--header", "Authorization: Bearer " ] } } } ``` ## OpenAPI specification ```json { "openapi": "3.0.1", "info": { "title": "Website Change Monitor: Page Diff Tracker, Pay Per Check", "description": "Watch any list of public pages on a schedule and get the ACTUAL changed lines, not just a ping. Detects edits, removals, and pages going 404. Failed fetches are never billed. No JavaScript rendering — honest about that.", "version": "0.1", "x-build-id": "GKClrueANZaRHmKbJ" }, "servers": [ { "url": "https://api.apify.com/v2" } ], "paths": { "/acts/mrlarryjohnson~website-change-monitor/run-sync-get-dataset-items": { "post": { "operationId": "run-sync-get-dataset-items-mrlarryjohnson-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": { "$ref": "#/components/schemas/inputSchema" } } } }, "parameters": [ { "name": "token", "in": "query", "required": true, "schema": { "type": "string" }, "description": "Enter your Apify token here" } ], "responses": { "200": { "description": "OK" } } } }, "/acts/mrlarryjohnson~website-change-monitor/runs": { "post": { "operationId": "runs-sync-mrlarryjohnson-website-change-monitor", "x-openai-isConsequential": false, "summary": "Executes an Actor and returns information about the initiated run in response.", "tags": [ "Run Actor" ], "requestBody": { "required": true, "content": { "application/json": { "schema": { "$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": { "$ref": "#/components/schemas/runsResponseSchema" } } } } } } }, "/acts/mrlarryjohnson~website-change-monitor/run-sync": { "post": { "operationId": "run-sync-mrlarryjohnson-website-change-monitor", "x-openai-isConsequential": false, "summary": "Executes an Actor, waits for completion, and returns the OUTPUT from Key-value store in response.", "tags": [ "Run Actor" ], "requestBody": { "required": true, "content": { "application/json": { "schema": { "$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": "Pages to watch", "type": "array", "description": "The public page URLs to monitor (one per line, up to 500, duplicates removed). Each run compares every page against its previous fingerprint.", "items": { "type": "string" } }, "sectionHint": { "title": "Section hint (optional)", "type": "string", "description": "Only watch the part of the page AFTER this text first appears (an element id, class name, or unique heading text). Cuts noise from headers/footers." }, "stateKey": { "title": "State key", "type": "string", "description": "Separate monitoring sets (e.g. per client or per schedule) keep separate baselines. Letters, numbers, dashes.", "default": "default" }, "proxyConfiguration": { "title": "Proxy (optional)", "type": "object", "description": "Use Apify Proxy for sites that block datacenter IPs (pick RESIDENTIAL for bot-protected targets). Off by default." } } }, "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 } } } } } } } } } } ```