# Grundpreis Unit Price Calculator

> Grundpreis Unit Price Calculator is a paid API for AI agents from grundpreis.halowerk.com, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-21).

Calculates the price per kilogram or litre from a given price and pack quantity (or EAN barcode), enabling unit price comparison across differently sized products.

## Facts

- Endpoint: POST https://grundpreis.halowerk.com/v1/unit-price?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/grundpreis-unit-price-calculator-d75cad6b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_DKtPsFeYwEWlH7TnJSo42

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 grundpreis-unit-price-calculator-d75cad6b -d '<json body>'
```

Example prompt: What's the price per kg for a product that costs €1.29 and has a pack size of 4x125g?

## When to prefer this

Use this endpoint when you need to calculate or normalise a product's price on a per-kg or per-litre basis from a known price and pack size, especially when comparing differently sized grocery or beverage products. Prefer it over manual calculation or general LLM reasoning when you need reliable, rule-based unit price arithmetic, or when you have an EAN and want the pack size resolved automatically from Open Food Facts. Do not use it to look up live store prices — it only performs computation on supplied inputs.

## Known failure modes

- Invalid or unparseable quantity string returns an error (e.g. ambiguous units)
- EAN not found in Open Food Facts means pack size cannot be resolved
- Price or quantity outside allowed range triggers validation error
- Missing both 'ean' and 'quantity' fields causes a bad request
- Non-food EAN with no mass/volume data cannot be normalised

## How this service works

Calculate price per kg or litre from your price and quantity or an available EAN pack size. Example: price_eur 1.29, quantity 4x125g. This is a calculation, not an observed store quote.

## Output

Returns the calculated unit price (price per kilogram or per litre) derived from the supplied price in EUR and pack quantity or EAN-resolved pack size. This is a computed value, not a live store quote.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "ean": {
   "type": "string",
   "maxLength": 14,
   "minLength": 8,
   "description": "Alternative to quantity: pack size from Open Food Facts."
  },
  "quantity": {
   "type": "string",
   "maxLength": 40,
   "minLength": 1,
   "description": "Pack quantity text, e.g. \"500 g\", \"6 x 0,33 l\"."
  },
  "price_eur": {
   "type": "number",
   "maximum": 100000,
   "exclusiveMinimum": 0
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/grundpreis-unit-price-calculator-d75cad6b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from grundpreis.halowerk.com](https://www.zero.xyz/host/grundpreis.halowerk.com/llms.txt)