# HALOWERK Nordic Land – Finland Terrain Ruggedness Index

> HALOWERK Nordic Land – Finland Terrain Ruggedness Index 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) for a given coordinate within Finland.

## Facts

- Endpoint: POST https://nordland.halowerk.com/v1/fi-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-finland-terrain-ruggedness-index-4a7d834a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_g7y0kQIxWje2TL_HDd73c

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-finland-terrain-ruggedness-index-4a7d834a -d '<json body>'
```

Example prompt: What's the terrain ruggedness at latitude 65.3 and longitude 25.7 in Finland — I need the standard deviation of surface elevations for that spot.

## When to prefer this

Use this endpoint when you need terrain ruggedness specifically for Finnish coordinates, as it enforces Finland boundary validation before charging and provides a focused, cost-efficient single-call computation. Prefer this over generic elevation APIs when you need standard deviation of sampled elevations (not just point elevation) and are working within Finland.

## Known failure modes

- Coordinate outside Finland's Natural Earth boundary — request rejected before payment
- Latitude or longitude outside the published European coverage range (lat 34–72.5, lon -31.5–40.5) — validation error
- Missing required latitude or longitude parameters — schema validation failure
- 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 Finland; results outside it are rejected before payment.

## Output

A numeric value representing the standard deviation of sampled surface elevations at the queried coordinate — quantifying terrain ruggedness. Higher values indicate more variable, hilly, or rough terrain; lower values indicate flatter land. Coordinates outside Finland's Natural Earth boundary are rejected before any payment is charged.

## 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-finland-terrain-ruggedness-index-4a7d834a/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)