# HALOWERK Central Land – Slovenia Mean Slope

> HALOWERK Central Land – Slovenia Mean Slope 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 mean first-order surface gradient (slope) across an analysis grid for a given coordinate within Slovenia.

## Facts

- Endpoint: POST https://mitteleuropa.halowerk.com/v1/si-mean-slope
- 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-slovenia-mean-slope-9a0a4961
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_dv4soyyTIJKHQj1mOWcuG

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-slovenia-mean-slope-9a0a4961 -d '<json body>'
```

Example prompt: What's the mean surface slope at latitude 46.12, longitude 14.51 in Slovenia? I need the first-order terrain gradient for that coordinate.

## When to prefer this

Use this endpoint when you need the mean surface slope (first-order gradient) specifically for a point within Slovenia, validated against official boundary data. Prefer it over generic elevation services when you need slope rather than raw elevation, and when your use case is scoped to Slovenia (the boundary validation ensures data quality and relevance).

## Known failure modes

- Coordinate outside Slovenia boundary: rejected before computation, returns error indicating out-of-bounds
- Coordinate outside European coverage bounds (lat 34–72.5, lon -31.5–40.5): validation error
- Invalid or missing latitude/longitude fields: schema validation error
- Payment failure: x402 payment not completed, request not processed
- Service unavailable: upstream terrain data source unreachable

## How this service works

Mean first-order surface gradient across the analysis grid. The coordinate is validated against the Natural Earth boundary for Slovenia; results outside it are rejected before payment.

## Output

A numeric value representing the mean first-order surface gradient (slope) across the analysis grid centered on the requested coordinate within Slovenia. Coordinates outside the Slovenian Natural Earth boundary are rejected before processing.

## 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-slovenia-mean-slope-9a0a4961/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)