# HALOWERK Nordic Land – Denmark Maximum Surface Slope

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

Returns the maximum adjacent-cell surface gradient (steepest slope) across an analysis grid for a given coordinate within Denmark.

## Facts

- Endpoint: POST https://nordland.halowerk.com/v1/dk-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-nordic-land-denmark-maximum-surface-slope-c4f125fd
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_F1Hm6rzKrE2oZ6Zo3jvl-

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-nordic-land-denmark-maximum-surface-slope-c4f125fd -d '<json body>'
```

Example prompt: What's the maximum surface slope gradient at latitude 55.68, longitude 12.57 in Denmark? I need the steepest adjacent-cell terrain value for that location.

## When to prefer this

Use this endpoint when you need the maximum steepness (steepest adjacent-cell slope gradient) specifically for a coordinate within Denmark, rather than mean elevation or standard deviation of elevations. Prefer it over generic elevation APIs when you need terrain ruggedness or slope extremity for use cases like construction feasibility, drainage modeling, or renewable energy site assessment within the Danish boundary.

## Known failure modes

- Coordinate outside Denmark boundary — rejected before payment with a boundary validation error
- Latitude or longitude out of the published European coverage range (lat 34–72.5, lon -31.5–40.5) — schema validation error
- Malformed or missing coordinate parameters — request rejected with input validation error
- Network or service timeout — transient error, retry recommended

## How this service works

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

## Output

Returns the maximum adjacent-cell surface slope gradient value across the analysis grid for the queried coordinate. The coordinate is first validated against the Natural Earth boundary for Denmark; requests outside Denmark are rejected before any 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-nordic-land-denmark-maximum-surface-slope-c4f125fd/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from nordland.halowerk.com](https://www.zero.xyz/host/nordland.halowerk.com/llms.txt)