# HALOWERK Article Price History Mean Drop Analyzer

> HALOWERK Article Price History Mean Drop Analyzer is a paid API for AI agents from handel.halowerk.com, paid per call via x402, $0.007/call, status unknown (last checked 2026-10-10).

Analyzes a product article's historical price series to compute the mean price drop, optionally comparing against a previous price and a custom drop-percent threshold.

## Facts

- Endpoint: POST https://handel.halowerk.com/v1/price/articles/history-mean-drop?utm_source=zero.xyz
- Price: $0.007/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-10
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/halowerk-article-price-history-mean-drop-analyzer-f454ae03
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_XCvWjqoG5Xj20FkgnTCjG

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability halowerk-article-price-history-mean-drop-analyzer-f454ae03 -d '<json body>'
```

Example prompt: Analyze the price history for this product (https://shop.example.com/product/123) using these 5 observed prices over the last month — all in EUR — and tell me the mean price drop; flag it if the drop exceeds 15%.

## When to prefer this

Choose this endpoint when you need to compute a statistically meaningful mean price drop from a set of historical price observations for a specific product URL, especially when you want to compare that drop against a known previous price or apply a custom drop-percent threshold. Ideal for e-commerce price monitoring agents, deal-detection pipelines, and competitive repricing workflows that already have a local price history array and want a server-side computation without building their own statistics layer.

## Known failure modes

- Fewer than 3 history items provided — minimum of 3 required
- Currency codes not matching standard ISO 4217 three-letter format
- Price values exceeding the maximum of 1,000,000,000
- observed_at timestamps malformed or too long (>40 chars)
- More than 60 history items supplied — maxItems limit exceeded
- drop_percent value of 0 or above 100 rejected
- Idempotency key does not match required pattern or length (32-128 chars)
- URL fields exceeding 2048 character limit
- Payment not settled via x402/USDC resulting in 402 response

## How this service works

HALOWERK handelswerk — bezahlte Endpunkte nach x402. Preise in USDC auf Base Mainnet.

## Output

A JSON object containing computed statistics about the mean price drop across the supplied historical price observations for the article, potentially including the average drop value, drop percentage, and comparison against the supplied previous price and drop_percent threshold.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "maxLength": 2048
  },
  "history": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "url",
     "observed_at",
     "value",
     "currency"
    ],
    "properties": {
     "url": {
      "type": "string",
      "maxLength": 2048
     },
     "value": {
      "type": "number",
      "maximum": 1000000000,
      "minimum": 0
     },
     "currency": {
      "type": "string",
      "pattern": "^[A-Z]{3}$"
     },
     "observed_at": {
      "type": "string",
      "maxLength": 40
     }
    },
    "additionalProperties": false
   },
   "maxItems": 60,
   "minItems": 3
  },
  "previous": {
   "type": "object",
   "required": [
    "value",
    "currency"
   ],
   "properties": {
    "value": {
     "type": "number",
     "maximum": 1000000000,
     "minimum": 0
    },
    "currency": {
     "type": "string",
     "pattern": "^[A-Z]{3}$"
    }
   },
   "additionalProperties": false
  },
  "callback_url": {
   "type": "string",
   "maxLength": 2048
  },
  "drop_percent": {
   "type": "number",
   "maximum": 100,
   "exclusiveMinimum": 0
  },
  "idempotency_key": {
   "type": "string",
   "pattern": "^[A-Za-z0-9_-]+$",
   "maxLength": 128,
   "minLength": 32
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/halowerk-article-price-history-mean-drop-analyzer-f454ae03/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from handel.halowerk.com](https://www.zero.xyz/host/handel.halowerk.com/llms.txt)