# HALOWERK Land Compare – Topsoil Cation Exchange Capacity (Two Sites)

> HALOWERK Land Compare – Topsoil Cation Exchange Capacity (Two Sites) is a paid API for AI agents from landvergleich.halowerk.com, paid per call via x402, $0.006/call, status unknown (last checked 2026-09-15).

Measures topsoil cation exchange capacity (CEC) for exactly two European coordinates and returns the signed difference and the winner site.

## Facts

- Endpoint: POST https://landvergleich.halowerk.com/v1/compare-two-soil-cec
- Price: $0.006/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/halowerk-land-compare-topsoil-cation-exchange-capacity-two-sites-2d676177
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_VkF-i2q92NDu8SNvrorVr

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-land-compare-topsoil-cation-exchange-capacity-two-sites-2d676177 -d '<json body>'
```

Example prompt: Compare the topsoil cation exchange capacity between two European fields — one at latitude 51.5, longitude 5.2 (call it 'Noord-Brabant Farm') and another at latitude 48.8, longitude 2.3 (call it 'Île-de-France Plot') — and tell me which site has higher CEC and by how much.

## When to prefer this

Choose this endpoint when you need a direct pairwise topsoil CEC comparison for exactly two European sites using a consistent measurement method. It is ideal for land evaluation, agricultural site selection, or soil quality benchmarking within Europe. Use sibling endpoints for other soil metrics (pH, clay content) or for ranking more than two sites.

## Known failure modes

- Coordinates outside the published European coverage bounds (lat 34–72.5, lon -31.5–40.5) result in an error
- Providing fewer or more than exactly two locations causes a validation error
- Invalid or non-numeric coordinate values are rejected
- Locations in non-European regions (e.g. North America, Asia) are out of scope

## How this service works

Measures topsoil cation exchange capacity for exactly two European coordinates with one method and reports the signed difference and winner where meaningful.

## Output

Returns topsoil cation exchange capacity values for both input European coordinates, the signed numerical difference between the two sites, and an indication of which site is the 'winner' (higher CEC) where meaningful.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "locations": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "longitude",
     "latitude"
    ],
    "properties": {
     "name": {
      "type": "string",
      "maxLength": 60,
      "minLength": 1
     },
     "latitude": {
      "type": "number",
      "maximum": 72.5,
      "minimum": 34,
      "description": "WGS84 latitude inside the published European coverage."
     },
     "longitude": {
      "type": "number",
      "maximum": 40.5,
      "minimum": -31.5,
      "description": "WGS84 longitude inside the published European coverage."
     }
    },
    "additionalProperties": false
   },
   "maxItems": 2,
   "minItems": 2
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/halowerk-land-compare-topsoil-cation-exchange-capacity-two-sites-2d676177/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from landvergleich.halowerk.com](https://www.zero.xyz/host/landvergleich.halowerk.com/llms.txt)