# HALOWERK Central Land – Surface Aspect (Slovenia)

> HALOWERK Central Land – Surface Aspect (Slovenia) is a paid API for AI agents from mitteleuropa.halowerk.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-13).

Returns the dominant terrain aspect (circular direction of the steepest surface gradient, clockwise from north) for a given WGS84 coordinate within Slovenia.

## Facts

- Endpoint: POST https://mitteleuropa.halowerk.com/v1/si-aspect
- 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-central-land-surface-aspect-slovenia-3ec728dd
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_FZUS8sZkfHqdkmH5DJFVi

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-central-land-surface-aspect-slovenia-3ec728dd -d '<json body>'
```

Example prompt: What direction does the slope face at latitude 46.12, longitude 14.38 in Slovenia — give me the dominant surface aspect in degrees clockwise from north.

## When to prefer this

Choose this endpoint when you need terrain aspect data specifically for a point location within Slovenia and want a pay-per-call model with pre-payment validation (no charge for out-of-bounds coordinates). It is ideal for precision land analysis workflows — viticulture, solar siting, ecological surveys, or trail planning — where slope orientation is a key variable. Prefer it over general DEM APIs when you need Slovenia-bounded validation and Copernicus GLO-30 derived data.

## Known failure modes

- Coordinates outside Slovenia's Natural Earth boundary → rejected before charge, coordinate validation error returned
- Coordinates within European bounding box but outside Slovenia polygon → rejection with boundary error
- Flat terrain with no dominant gradient → may return null or special value indicating undefined aspect
- Malformed latitude/longitude values outside European coverage range → validation error
- Network or service timeout → no result returned

## How this service works

Circular direction of the dominant surface gradient, clockwise from north. The coordinate is validated against the Natural Earth boundary for Slovenia; results outside it are rejected before payment.

## Output

A numeric value representing the dominant surface aspect angle in degrees, measured clockwise from north (0°/360° = north, 90° = east, 180° = south, 270° = west). Coordinates outside the Slovenia boundary polygon are rejected before payment is processed.

## 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-central-land-surface-aspect-slovenia-3ec728dd/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from mitteleuropa.halowerk.com](https://www.zero.xyz/host/mitteleuropa.halowerk.com/llms.txt)