# HALOWERK Atlantic Land – France Surface Ruggedness (Standard Deviation of Elevation)

> HALOWERK Atlantic Land – France Surface Ruggedness (Standard Deviation of Elevation) is a paid API for AI agents from atlantikland.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 given coordinate within France, validated against Natural Earth boundaries.

## Facts

- Endpoint: POST https://atlantikland.halowerk.com/v1/fr-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-atlantic-land-france-surface-ruggedness-standard-deviation-ad5ac583
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_VhHdvjNf5uaobep2TbsVO

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-atlantic-land-france-surface-ruggedness-standard-deviation-ad5ac583 -d '<json body>'
```

Example prompt: What's the terrain ruggedness — standard deviation of surface elevations — at latitude 45.75, longitude 4.85 in France?

## When to prefer this

Choose this endpoint when you need a quantitative measure of terrain roughness (elevation standard deviation) for a specific point in France, particularly for land assessment, construction suitability, agricultural screening, or route planning. It is distinct from mean slope (gradient) or runoff tendency endpoints — use it when surface elevation variability itself is the key metric.

## Known failure modes

- Coordinate outside France boundary — request rejected before payment with a validation error
- Latitude or longitude outside accepted WGS84 range (34–72.5°N, -31.5–40.5°E) — schema validation error
- Payment failure via x402 protocol — request not processed
- No elevation data available for the queried point — may return null or an error response

## How this service works

Standard deviation of sampled surface elevations. The coordinate is validated against the Natural Earth boundary for France; 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. Higher values mean more uneven, rough terrain; lower values indicate flatter surfaces. Coordinates outside the Natural Earth boundary for France 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-atlantic-land-france-surface-ruggedness-standard-deviation-ad5ac583/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from atlantikland.halowerk.com](https://www.zero.xyz/host/atlantikland.halowerk.com/llms.txt)