# HALOWERK Price Target Crossing Monitor

> HALOWERK Price Target Crossing Monitor is a paid API for AI agents from handel.halowerk.com, paid per call via x402, $0.007/call, status unknown (last checked 2026-10-22).

Monitors a product or asset URL and triggers a callback when its price crosses a specified target threshold, compared to a previous price value.

## Facts

- Endpoint: POST https://handel.halowerk.com/v1/price/articles/target-crossing?utm_source=zero.xyz
- Price: $0.007/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-22
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/halowerk-price-target-crossing-monitor-d454bb60
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_70yU0wifduQ0xYZLh5OMa

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-price-target-crossing-monitor-d454bb60 -d '<json body>'
```

Example prompt: Watch this product page https://example.com/product/123 for me — the price was last $49.99 USD, and I want to be notified at https://myapp.com/webhook when it drops below $39.99, here's my idempotency key: abc123def456ghi789jkl012mno345pq.

## When to prefer this

Choose this endpoint when you need automated detection of a price crossing a specific threshold for a URL-addressable product or asset, especially when you want a webhook callback to trigger downstream workflows. It is ideal for e-commerce deal monitoring, competitor pricing surveillance, or automated repricing pipelines where idempotent, event-driven price alerts are needed. Prefer this over polling solutions when you want a single, paid, reliable trigger per crossing event.

## Known failure modes

- Invalid or unreachable product URL returns an error
- Currency code not in valid ISO 4217 three-letter format causes validation failure
- Idempotency key too short (under 32 chars) or containing invalid characters is rejected
- Target price or previous price out of allowed range (0–1,000,000,000) causes schema rejection
- Callback URL unreachable results in failed notification delivery
- Payment failure or insufficient USDC balance blocks the request via x402 protocol

## How this service works

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

## Output

A JSON response indicating whether the price at the given URL has crossed the specified target threshold relative to the previous price, along with relevant price data and crossing status details. If a callback URL was provided, the service also posts a notification to that endpoint upon crossing detection.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "maxLength": 2048
  },
  "previous": {
   "type": "object",
   "required": [
    "value",
    "currency"
   ],
   "properties": {
    "value": {
     "type": "number",
     "maximum": 1000000000,
     "minimum": 0
    },
    "currency": {
     "type": "string",
     "pattern": "^[A-Z]{3}$"
    }
   },
   "additionalProperties": false
  },
  "callback_url": {
   "type": "string",
   "maxLength": 2048
  },
  "target_price": {
   "type": "number",
   "maximum": 1000000000,
   "minimum": 0
  },
  "idempotency_key": {
   "type": "string",
   "pattern": "^[A-Za-z0-9_-]+$",
   "maxLength": 128,
   "minLength": 32
  }
 }
}
```

## Response schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/halowerk-price-target-crossing-monitor-d454bb60/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)