# HALOWERK Eastern Land – Croatia Solar Orientation Index

> HALOWERK Eastern Land – Croatia Solar Orientation Index is a paid API for AI agents from ostland.halowerk.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-15).

Returns a south-facing slope orientation index (solar aspect score) for a given coordinate within Croatia, derived from terrain aspect and slope data.

## Facts

- Endpoint: POST https://ostland.halowerk.com/v1/hr-solar-orientation
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/halowerk-eastern-land-croatia-solar-orientation-index-50f84b9c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_aYNv2Ta_lOnN5ihHgY830

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-croatia-solar-orientation-index-50f84b9c -d '<json body>'
```

Example prompt: What's the south-facing solar orientation index for the location at latitude 45.81, longitude 16.01 in Croatia? I want to know how favorable the slope aspect is for solar exposure.

## When to prefer this

Choose this endpoint when you need a quantitative solar orientation metric specifically for locations within Croatia, particularly for renewable energy siting, agricultural land assessment, or land development due diligence. Prefer it over generic elevation or aspect APIs when you need a pre-validated, Croatia-specific south-facing slope index with built-in boundary enforcement.

## Known failure modes

- Coordinate outside Croatia boundary: request rejected before payment with a validation error
- Latitude or longitude outside the accepted European coverage range (lat 34–72.5, lon -31.5–40.5): schema validation error
- Malformed or missing coordinate fields: input schema validation failure
- Edge cases near Croatian border may be ambiguously accepted or rejected depending on boundary resolution

## How this service works

South-facing slope orientation index derived from aspect and slope. The coordinate is validated against the Natural Earth boundary for Croatia; results outside it are rejected before payment.

## Output

A numeric south-facing slope orientation index value derived from terrain aspect and slope for the queried coordinate. Coordinates outside the Natural Earth boundary of Croatia are rejected before any computation or 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-eastern-land-croatia-solar-orientation-index-50f84b9c/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)