# HALOWERK Eastern Land – Bulgaria Terrain Ruggedness Index

> HALOWERK Eastern Land – Bulgaria Terrain Ruggedness Index is a paid API for AI agents from ostland.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 WGS84 coordinate within Bulgaria.

## Facts

- Endpoint: POST https://ostland.halowerk.com/v1/bg-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-eastern-land-bulgaria-terrain-ruggedness-index-f1ef6602
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Bjha2Rt3cY__IToRX0Lqu

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-eastern-land-bulgaria-terrain-ruggedness-index-f1ef6602 -d '<json body>'
```

Example prompt: What's the terrain ruggedness at latitude 42.15, longitude 24.75 in Bulgaria — I need the elevation standard deviation for that point.

## When to prefer this

Use this endpoint when you need a point-level terrain ruggedness (elevation standard deviation) metric specifically for locations within Bulgaria. It is preferable over generic elevation APIs when you need ruggedness rather than raw elevation, and over broader European terrain services when Bulgaria-scoped validation and per-point pricing are acceptable. Well-suited for land suitability, agriculture, renewable energy siting, and infrastructure planning workflows.

## Known failure modes

- Coordinate outside Bulgaria's Natural Earth boundary — request rejected, no charge
- 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 in request body
- 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 Bulgaria; results outside it are rejected before payment.

## Output

A numeric terrain ruggedness index value representing the standard deviation of sampled surface elevations at the queried Bulgarian coordinate. Coordinates outside Bulgaria'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-eastern-land-bulgaria-terrain-ruggedness-index-f1ef6602/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from ostland.halowerk.com](https://www.zero.xyz/host/ostland.halowerk.com/llms.txt)