# HALOWERK Nordic Land – Denmark Terrain Ruggedness (Elevation Std Dev)

> HALOWERK Nordic Land – Denmark Terrain Ruggedness (Elevation Std Dev) is a paid API for AI agents from nordland.halowerk.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-13).

Returns the standard deviation of sampled surface elevations (terrain ruggedness index) for a WGS84 coordinate validated within Denmark's boundary.

## Facts

- Endpoint: POST https://nordland.halowerk.com/v1/dk-ruggedness
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/halowerk-nordic-land-denmark-terrain-ruggedness-elevation-std-dev-9adca2c4
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_KVx8kTt6QDX4e55gOxJaq

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-denmark-terrain-ruggedness-elevation-std-dev-9adca2c4 -d '<json body>'
```

Example prompt: What's the terrain ruggedness at latitude 56.1629, longitude 10.2039 in Denmark — give me the elevation standard deviation for that point.

## When to prefer this

Choose this endpoint when you need a precise, point-level terrain ruggedness metric (elevation standard deviation) for a specific coordinate within Denmark, particularly when boundary validation and pay-per-use pricing ($0.003/call) are acceptable. Prefer it over raster tile downloads or bulk DEM processing when you only need a single-point scalar metric for Danish locations.

## Known failure modes

- Coordinate outside Denmark's Natural Earth boundary — request rejected, no charge applied
- Latitude or longitude outside the published European coverage range (lat 34–72.5, lon -31.5–40.5) — validation error
- Missing or malformed latitude/longitude fields — schema validation error
- Payment failure via x402 protocol — request not processed

## How this service works

Standard deviation of sampled surface elevations. The coordinate is validated against the Natural Earth boundary for Denmark; results outside it are rejected before payment.

## Output

A numeric value representing the standard deviation of sampled surface elevations at the queried coordinate, indicating terrain ruggedness. Coordinates outside Denmark's Natural Earth boundary are rejected before any charge is applied.

## 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-denmark-terrain-ruggedness-elevation-std-dev-9adca2c4/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)