Competitor Price, Stock, and Changelog Monitor MCP Server

An MCP server for the Mamba Labs Competitor Price, Stock, and Changelog Monitor actor on Apify. Give it competitor sites. Each run compares every site with the state saved by the last run and returns only what changed.

What's Inside

What it does
Quick start
Prerequisites
Example prompts
Tool
Inputs
Pricing
Your keys
Full actor documentation
License

What it does

Stores: Shopify stores through their public product feed and WooCommerce stores through their public Store API. Changes: price_change, compare_at_price_change, out_of_stock, back_in_stock, new_product, removed_product, each with the product, variant, old and new value, and a link.
SaaS sites: the pricing page and changelog the site links to. Changes: plan_added, plan_removed, plan_price_change, pricing_page_change, and changelog_entry.
One row per site per run: site_baseline on the first check under a state_key, then site_check with changes_found for a site that changed, or a free no_change row when nothing moved.

Unreadable sites come back free with a row_status saying so.

All of the work runs on Apify. This package is a thin client that starts the actor run, waits for it, and hands back the dataset rows.

Quick start

You need Node.js 18 or newer and an Apify account with an API token.

Add this to your Claude Desktop config (claude_desktop_config.json), Cursor, or any MCP client:

{
  "mcpServers": {
    "mamba-competitor-price-stock-changelog-monitor": {
      "command": "npx",
      "args": [
        "-y",
        "@mambalabsdev/mcp-competitor-price-stock-changelog-monitor"
      ],
      "env": {
        "APIFY_TOKEN": "your-apify-token"
      }
    }
  }
}

Restart the client. The monitor_competitor_changes tool appears.

Prerequisites

Node.js 18 or newer.
An Apify API token from console.apify.com/account/integrations, set as APIFY_TOKEN. The server lists its tool without a token; a call needs one.

Example prompts

"Watch deathwishcoffee.com and allbirds.com for price cuts of 10 percent or more and tell me what changed since last week."
"Did Notion or Linear change their pricing plans or ship anything new this week?"
"Which products went out of stock on gymshark.com since yesterday?"

Tool

monitor_competitor_changes. One tool. Example arguments:

{
  "sites": [
    "deathwishcoffee.com",
    "linear.app"
  ],
  "state_key": "competitors-weekly",
  "min_price_change_pct": "5"
}

Inputs

Every buyer facing input of the actor, unchanged. Omitted inputs take the actor's own defaults. Numbers and booleans are sent as strings.

Input	Type	Description
`sites`	array	Competitor sites to watch, one per line: a domain (deathwishcoffee.com, linear.app) or a URL. A URL with a path is read as that page: a pricing page, a changelog page, or a product page. Up to 200 sites per run
`site_type`	string	auto (default) reads the public Shopify product feed or the WooCommerce Store API when the site has one, and otherwise reads the pricing and changelog pages it links to
`watch`	array	Any of: prices, stock, products, plans, changelog. prices covers price and compare at price per variant; stock covers in stock and out of stock; products covers new and removed products; plans covers plan names and prices on a pricing page; changelog covers new changelog entries. Empty means all five
`product_urls`	array	Product pages on a store that is not Shopify or WooCommerce. Each page is read for its schema.org Product price and availability
`pricing_urls`	array	Pricing pages to read, when the site does not link to its pricing page from the homepage
`changelog_urls`	array	Changelog or release notes pages to read, when the site does not link to one from the homepage. An RSS or Atom feed the page declares is read first
`max_products`	string	Products read from a store catalog per run, up to 5000. A store with more products than this is compared on the products read, and removed products are not reported for it. Default 250
`min_price_change_pct`	string	Report a price change only when it is at least this many percent. 0 reports every change. Default 0
`max_changes_per_site`	string	Change rows returned per site per run, up to 1000. The rest are counted in changes_found. Default 200
`include_snapshot`	string	true to also return one snapshot row per product variant, plan, and changelog entry on the first check of a site. Each snapshot row is billed as a snapshot row. Default false
`state_key`	string	Names the saved state, so separate schedules keep separate baselines. Runs with the same state key and site compare against each other
`reset_state`	string	true to ignore the saved state and record a new baseline for every site. Default false
`max_charge_usd`	string	Optional. The run stops before it would charge more than this
`proxy_mode`	string	auto (default) sends requests directly and moves a host to the Apify proxy default pool only when that host refuses. A reliability setting: proxy use adds nothing to your price

Pricing

Pay per event on Apify, billed to your Apify account. Prices in USD.

Event	Free plan	Bronze	Silver	Gold
`change-row`, one change on a watched site since the last run: a price, compare at price, or stock change on a variant, a new or removed product, a plan added, removed, or repriced, a price change on a pricing page, or a new changelog entry	$0.0025	$0.002375	$0.00225	$0.002125
`site-check`, the first check of a site, or a later check that finds a change	$0.003	$0.00285	$0.0027	$0.00255
`snapshot-row`, one current variant, plan, or changelog entry on the first check of a site, returned only when include_snapshot is on	$0.001	$0.00095	$0.0009	$0.00085
`apify-actor-start`, per run start	$0.0005	$0.0005	$0.0005	$0.0005

A site where nothing moved returns a free no_change row, and sites that cannot be read are free.

Your keys

The actor needs no key. It reads public product feeds and public pages and holds no key of any kind. Proxy traffic adds nothing to your price: Mamba Labs pays the platform costs of the run. proxy_mode is a reliability setting.

Full actor documentation

apify.com/mambalabs/competitor-price-stock-changelog-monitor

License

MIT. See LICENSE.

Competitor Price, Stock, and Changelog Monitor MCP Server