# Marketplace Deal Alerts & Price Drops (`signal_lab/marketplace-deal-alerts`) Actor

Analyze marketplace listing datasets to detect underpriced products, price drops, and resale opportunities. Score deals with peer medians, price history, freshness, and comparable counts, then export ranked alerts for monitoring and automation.

- **URL**: https://apify.com/signal\_lab/marketplace-deal-alerts.md
- **Developed by:** [Signal Lab](https://apify.com/signal_lab) (community)
- **Categories:** E-commerce, Automation, Developer tools
- **Stats:** 2 total users, 1 monthly users, 66.7% runs succeeded, 0 bookmarks
- **User rating**: No ratings yet

## Pricing

from $3.00 / 1,000 deal alerts

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 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

## Marketplace Deal Alerts

Find underpriced marketplace listings and price drops inside datasets you already collect. This Actor groups comparable products, calculates a peer median, compares the current price with a previous snapshot, and returns only the strongest deal alerts with an explainable score.

Use it for **vehicle sourcing, resale opportunities, competitor price monitoring, procurement, and inventory alerts**. The Actor is marketplace-agnostic: it analyzes listings from any source without requiring a separate API key.

### What this Actor does

- Detects listings priced below the median of comparable items.
- Detects price drops against an inline or stored previous snapshot.
- Scores deals using discount size, price drop, freshness, and comparable count.
- Preserves a named price-history snapshot between runs.
- Accepts up to 100,000 listings and returns up to 500 ranked alerts.
- Runs with limited Apify permissions and a fixed 256 MB memory ceiling.

This is an analysis Actor, not a marketplace scraper. Supply listing records inline, choose an Apify dataset, or call a compatible limited-permission upstream Actor.

### How to use Marketplace Deal Alerts

1. Choose `records`, `datasetId`, or `sourceActorId` as the current listing source.
2. Ensure records include price and currency plus a stable ID or URL.
3. For the best peer groups, provide `make`, `model`, and `year`, or an explicit `fingerprint` or `groupKey`.
4. Set `minComparableCount` and `minDiscountPercent`.
5. Start the Actor and review the ranked alerts in the default dataset.

On the first run, the Actor creates the named history store. Later runs compare new prices with the stored snapshot. You can pass `previousRecords` when you need a stateless comparison.

### Output

One dataset item represents one actionable deal alert. It includes listing identity, current and median prices, discount percentage, previous price, price-drop percentage, comparable count, freshness, signal score, reasons, and the normalized source listing.

Export results as JSON, CSV, Excel, XML, or RSS, use the Apify API, schedule daily monitoring, or trigger webhooks and integrations when new deals appear.

### Pricing

This Actor uses transparent pay-per-event pricing:

- **$0.002 per analysis run**
- **$0.003 per emitted deal alert**

Examples: 10 deal alerts cost **$0.032**; 100 alerts cost **$0.302**. Runs with no qualifying deals pay only the run event. The price covers this Actor's platform usage. Charges from an optional paid upstream Actor are separate.

Across bounded cloud benchmarks, the highest measured platform cost was approximately **$0.000619** for a run, so the launch price includes a substantial operational safety margin.

### Important limitation

A low asking price is a lead, not proof of condition, ownership, legality, or fair value. Verify the seller, documents, physical condition, taxes, delivery, and market context before purchasing.

### Other Signal Lab Actors

- [Hiring Signal Intelligence](https://apify.com/signal_lab/hiring-signal-intelligence) ranks companies showing concentrated hiring activity.
- [Review Pain Intelligence](https://apify.com/signal_lab/review-pain-intelligence) ranks recurring customer complaints with evidence.

### FAQ

#### How are comparable listings grouped?

An explicit `fingerprint` or `groupKey` takes priority. Otherwise, the Actor builds a group from common category fields such as make, model, year, or title.

#### Can I monitor the same market every day?

Yes. Use a stable `historyStoreName` and an Apify schedule. Each successful run updates the latest snapshot.

#### Why did I get no alerts?

Check prices and currencies, make sure peer listings share consistent comparison fields, reduce `minComparableCount`, or lower `minDiscountPercent`.

#### Can it read a private dataset safely?

Yes. Select the dataset in the input picker. The Actor requests read-only access to that resource while retaining limited permissions.

### Support

Open the Actor's Issues tab with a run ID and a small redacted listing sample. Never include account tokens, payment details, or private seller information.

### Free product guide

See the [Marketplace Deal Alerts workflow, use cases, and expected output](https://signal-lab-tools.vitaxastar.chatgpt.site/tools/marketplace-deal-alerts), or browse [all Signal Lab data tools](https://signal-lab-tools.vitaxastar.chatgpt.site).

# Actor input Schema

## `records` (type: `array`):

Inline listing records for testing or small analyses.

## `datasetId` (type: `string`):

Read current listings from this Apify dataset.

## `sourceActorId` (type: `string`):

Optional upstream Actor to run. It must support limited permissions; any upstream Actor charges are separate.

## `sourceActorInput` (type: `object`):

JSON input passed to the selected upstream Actor.

## `previousRecords` (type: `array`):

Optional inline history. When absent, the Actor uses its named history store.

## `historyStoreName` (type: `string`):

Named key-value store used to retain the latest price snapshot.

## `minComparableCount` (type: `integer`):

Required peer listings before a median price is trusted.

## `minDiscountPercent` (type: `number`):

Minimum below-median discount or price drop required for an alert.

## `maxResults` (type: `integer`):

Maximum number of ranked deal alerts to emit.

## `maxSourceItems` (type: `integer`):

Hard cap on listing records read from the source.

## Actor input object example

```json
{
  "records": [
    {
      "id": "deal",
      "title": "Tesla Model 3 2021",
      "make": "Tesla",
      "model": "Model 3",
      "year": 2021,
      "price": 15000,
      "currency": "USD",
      "publishedAt": "2026-08-20"
    },
    {
      "id": "a",
      "title": "Tesla Model 3 2021",
      "make": "Tesla",
      "model": "Model 3",
      "year": 2021,
      "price": 20500,
      "currency": "USD"
    },
    {
      "id": "b",
      "title": "Tesla Model 3 2021",
      "make": "Tesla",
      "model": "Model 3",
      "year": 2021,
      "price": 21000,
      "currency": "USD"
    },
    {
      "id": "c",
      "title": "Tesla Model 3 2021",
      "make": "Tesla",
      "model": "Model 3",
      "year": 2021,
      "price": 21500,
      "currency": "USD"
    }
  ],
  "sourceActorInput": {},
  "historyStoreName": "marketplace-deal-alerts-history",
  "minComparableCount": 3,
  "minDiscountPercent": 10,
  "maxResults": 20,
  "maxSourceItems": 10000
}
```

# Actor output Schema

## `alerts` (type: `string`):

No description

## `summary` (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 = {
    "records": [
        {
            "id": "deal",
            "title": "Tesla Model 3 2021",
            "make": "Tesla",
            "model": "Model 3",
            "year": 2021,
            "price": 15000,
            "currency": "USD",
            "publishedAt": "2026-08-20"
        },
        {
            "id": "a",
            "title": "Tesla Model 3 2021",
            "make": "Tesla",
            "model": "Model 3",
            "year": 2021,
            "price": 20500,
            "currency": "USD"
        },
        {
            "id": "b",
            "title": "Tesla Model 3 2021",
            "make": "Tesla",
            "model": "Model 3",
            "year": 2021,
            "price": 21000,
            "currency": "USD"
        },
        {
            "id": "c",
            "title": "Tesla Model 3 2021",
            "make": "Tesla",
            "model": "Model 3",
            "year": 2021,
            "price": 21500,
            "currency": "USD"
        }
    ],
    "minComparableCount": 3,
    "minDiscountPercent": 10,
    "maxResults": 20
};

// Run the Actor and wait for it to finish
const run = await client.actor("signal_lab/marketplace-deal-alerts").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 = {
    "records": [
        {
            "id": "deal",
            "title": "Tesla Model 3 2021",
            "make": "Tesla",
            "model": "Model 3",
            "year": 2021,
            "price": 15000,
            "currency": "USD",
            "publishedAt": "2026-08-20",
        },
        {
            "id": "a",
            "title": "Tesla Model 3 2021",
            "make": "Tesla",
            "model": "Model 3",
            "year": 2021,
            "price": 20500,
            "currency": "USD",
        },
        {
            "id": "b",
            "title": "Tesla Model 3 2021",
            "make": "Tesla",
            "model": "Model 3",
            "year": 2021,
            "price": 21000,
            "currency": "USD",
        },
        {
            "id": "c",
            "title": "Tesla Model 3 2021",
            "make": "Tesla",
            "model": "Model 3",
            "year": 2021,
            "price": 21500,
            "currency": "USD",
        },
    ],
    "minComparableCount": 3,
    "minDiscountPercent": 10,
    "maxResults": 20,
}

# Run the Actor and wait for it to finish
run = client.actor("signal_lab/marketplace-deal-alerts").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 '{
  "records": [
    {
      "id": "deal",
      "title": "Tesla Model 3 2021",
      "make": "Tesla",
      "model": "Model 3",
      "year": 2021,
      "price": 15000,
      "currency": "USD",
      "publishedAt": "2026-08-20"
    },
    {
      "id": "a",
      "title": "Tesla Model 3 2021",
      "make": "Tesla",
      "model": "Model 3",
      "year": 2021,
      "price": 20500,
      "currency": "USD"
    },
    {
      "id": "b",
      "title": "Tesla Model 3 2021",
      "make": "Tesla",
      "model": "Model 3",
      "year": 2021,
      "price": 21000,
      "currency": "USD"
    },
    {
      "id": "c",
      "title": "Tesla Model 3 2021",
      "make": "Tesla",
      "model": "Model 3",
      "year": 2021,
      "price": 21500,
      "currency": "USD"
    }
  ],
  "minComparableCount": 3,
  "minDiscountPercent": 10,
  "maxResults": 20
}' |
apify call signal_lab/marketplace-deal-alerts --silent --output-dataset

```

## MCP server setup

```json
{
    "mcpServers": {
        "apify": {
            "type": "http",
            "url": "https://mcp.apify.com/?tools=fetch-actor-details,signal_lab/marketplace-deal-alerts"
        }
    }
}

```

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/NyCNBpow7qiSoPJ3h/builds/5tjrUHODsvKg3kedl/openapi.json