# HALOWERK Central Land – Austria Maximum Surface Slope

> HALOWERK Central Land – Austria Maximum Surface Slope is a paid API for AI agents from mitteleuropa.halowerk.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-15).

Returns the maximum adjacent-cell surface gradient across an analysis grid for a given coordinate within Austria, derived from terrain elevation data.

## Facts

- Endpoint: POST https://mitteleuropa.halowerk.com/v1/at-max-slope
- 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-central-land-austria-maximum-surface-slope-5196fb53
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Ik0aSUo1DpC7LvhkFfUl5

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-austria-maximum-surface-slope-5196fb53 -d '<json body>'
```

Example prompt: What's the maximum surface slope at latitude 47.3, longitude 13.5 in Austria? I need the steepest adjacent-cell gradient for that terrain point.

## When to prefer this

Use this endpoint when you need the maximum (peak) surface slope value at a specific point within Austria, as opposed to mean slope or elevation. It is ideal for steepness-focused analyses such as construction suitability, erosion risk, or terrain hazard assessment. Prefer it over mean-slope sibling endpoints when the worst-case gradient matters more than the average.

## Known failure modes

- Coordinate outside Austria's Natural Earth boundary — rejected before payment with a validation error
- Latitude or longitude outside the European coverage range (lat 34–72.5, lon -31.5–40.5) — schema validation error
- Malformed or missing latitude/longitude parameters — request rejected with input error
- Service unavailable or upstream DEM data error — may return a 5xx error

## How this service works

Maximum adjacent-cell surface gradient across the analysis grid. The coordinate is validated against the Natural Earth boundary for Austria; results outside it are rejected before payment.

## Output

A numerical value representing the maximum adjacent-cell surface gradient (slope) across the analysis grid centered on the queried coordinate within Austria. Coordinates outside the Austrian Natural Earth boundary are rejected before the 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-austria-maximum-surface-slope-5196fb53/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)