# HALOWERK Nordic Land — Denmark Mean Surface Slope

> HALOWERK Nordic Land — Denmark Mean 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 2026-09-13).

Returns the mean first-order surface gradient (slope) across the analysis grid for a given coordinate within Denmark's boundaries.

## Facts

- Endpoint: POST https://nordland.halowerk.com/v1/dk-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-nordic-land-denmark-mean-surface-slope-1997befb
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_FbxnFK8kY4IxJvXmLHmZU

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-mean-surface-slope-1997befb -d '<json body>'
```

Example prompt: What's the mean surface slope at latitude 55.676, longitude 12.568 in Denmark? I need the terrain gradient for a site assessment.

## When to prefer this

Use this endpoint when you need a precise mean terrain slope value for a specific coordinate within Denmark. It is ideal for site suitability assessments, agricultural planning, construction feasibility studies, or any geospatial analysis requiring terrain gradient data at a Danish location. It is distinct from sibling endpoints that return soil properties, land cover, or elevation statistics.

## Known failure modes

- Coordinate outside Denmark boundary — rejected before payment with a boundary validation error
- Latitude or longitude outside the published European coverage range — schema validation error
- Malformed or missing coordinate fields — request rejected with input validation error
- Temporary service unavailability — HTTP 5xx error returned

## How this service works

Mean first-order 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

A numeric value representing the mean first-order surface gradient (slope) computed across the analysis grid for the specified coordinate. The coordinate is validated against the Natural Earth boundary for Denmark; requests outside Denmark 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-nordic-land-denmark-mean-surface-slope-1997befb/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)