# HALOWERK marktwerk Cross-Exchange Price Comparator

> HALOWERK marktwerk Cross-Exchange Price Comparator is a paid API for AI agents from markt.netzhandwerker.de, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-15).

Compares live order book prices for a trading pair across up to 5 crypto exchanges, optionally computing executable average prices for a given order size.

## Facts

- Endpoint: POST https://markt.netzhandwerker.de/cross-exchange
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/halowerk-marktwerk-cross-exchange-price-comparator-01fc4c3b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_omnzpZ1Zunx2CaKmNYs27

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-marktwerk-cross-exchange-price-comparator-01fc4c3b -d '<json body>'
```

Example prompt: Compare the current ETH/USDC price across Binance, Coinbase, and Kraken — I want to buy 2 ETH, so show me the executable average price per exchange.

## When to prefer this

Use this endpoint when you need real-time, cross-exchange price comparison for a specific crypto trading pair, especially when evaluating execution quality for a given order size. Prefer this over single-exchange APIs when the goal is best execution routing, arbitrage detection, or market surveillance across Binance, Coinbase, Kraken, OKX, and Bybit simultaneously.

## Known failure modes

- Invalid symbol format (must match BASE/QUOTE pattern like ETH/USDC) — returns validation error
- Requested exchange venue not supported or not connected — partial or empty results for that venue
- Symbol not listed on one or more requested exchanges — missing data for those venues
- Network timeout fetching live order book data from an exchange
- Payment failure via x402 — 402 response if USDC payment not included or insufficient

## How this service works

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

## Output

Returns current order book price data for the requested trading pair across the specified exchanges. If an order size is provided, includes the computed executable average price (volume-weighted fill price) per exchange based on the visible book depth. Enables direct comparison of which venue offers the best price.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "size": {
   "type": "number",
   "description": "Optional order size in BASE. With it the executable average price per exchange is computed from the visible book.",
   "exclusiveMinimum": 0
  },
  "symbol": {
   "type": "string",
   "pattern": "^[A-Za-z0-9]{2,15}/[A-Za-z0-9]{2,15}$",
   "description": "Trading pair as BASE/QUOTE, for example ETH/USDC."
  },
  "venues": {
   "type": "array",
   "items": {
    "enum": [
     "binance",
     "coinbase",
     "kraken",
     "okx",
     "bybit"
    ],
    "type": "string"
   },
   "maxItems": 5,
   "minItems": 1,
   "description": "Exchanges to compare. Without it all connected exchanges are used.",
   "uniqueItems": true
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/halowerk-marktwerk-cross-exchange-price-comparator-01fc4c3b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from markt.netzhandwerker.de](https://www.zero.xyz/host/markt.netzhandwerker.de/llms.txt)