# HALOWERK Nordic Land – Iceland Surface Clay Fraction (0-5 cm)

> HALOWERK Nordic Land – Iceland Surface Clay Fraction (0-5 cm) is a paid API for AI agents from nordland.halowerk.com, paid per call via x402, $0.004/call, status unknown (last checked 2026-09-15).

Returns the mean SoilGrids clay fraction (%) for the 0-5 cm depth layer at a given WGS84 coordinate within Iceland, validated against Natural Earth boundaries.

## Facts

- Endpoint: POST https://nordland.halowerk.com/v1/is-soil-clay
- Price: $0.004/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/halowerk-nordic-land-iceland-surface-clay-fraction-0-5-cm-7b451ce9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Lv-VYQcNsEPXe4NwA7xsj

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-nordic-land-iceland-surface-clay-fraction-0-5-cm-7b451ce9 -d '<json body>'
```

Example prompt: What is the mean clay fraction in the top 5 cm of soil at latitude 64.13, longitude -21.93 in Iceland? I need the SoilGrids value for that surface layer.

## When to prefer this

Use this endpoint when you need topsoil clay fraction data specifically for Iceland and want a pay-per-call, boundary-validated lookup without managing a full SoilGrids API integration. Prefer it over raw SoilGrids when Iceland-specific coordinate gating and per-query micropayment billing are desired. For other soil properties (sand, pH, organic carbon) or other Nordic countries, use the sibling endpoints on the same provider.

## Known failure modes

- Coordinate outside Iceland Natural Earth boundary — request rejected with a boundary validation error, no charge
- Latitude or longitude outside the declared European coverage range (lat 34–72.5, lon -31.5–40.5) — schema validation error
- Invalid or missing coordinate fields — 400-level error
- SoilGrids data unavailable for the exact cell — possible null or no-data response

## How this service works

Mean SoilGrids clay fraction for the 0-5 cm layer. The coordinate is validated against the Natural Earth boundary for Iceland; results outside it are rejected before payment.

## Output

A numeric value representing the mean clay fraction (as a percentage or volumetric fraction) in the 0-5 cm topsoil layer at the requested coordinate, sourced from SoilGrids. Requests with coordinates outside Iceland's Natural Earth boundary are rejected before billing.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "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."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/halowerk-nordic-land-iceland-surface-clay-fraction-0-5-cm-7b451ce9/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from nordland.halowerk.com](https://www.zero.xyz/host/nordland.halowerk.com/llms.txt)