# HALOWERK Atlantic Land – Netherlands Terrain Aspect (Dominant Gradient Direction)

> HALOWERK Atlantic Land – Netherlands Terrain Aspect (Dominant Gradient Direction) is a paid API for AI agents from atlantikland.halowerk.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-13).

Returns the circular direction of the dominant surface gradient (aspect) in degrees clockwise from north for a given coordinate within the Netherlands.

## Facts

- Endpoint: POST https://atlantikland.halowerk.com/v1/nl-aspect
- 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-atlantic-land-netherlands-terrain-aspect-dominant-gradient-490b08db
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_pYy0aHdY9vaRlz5vzRrV2

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-atlantic-land-netherlands-terrain-aspect-dominant-gradient-490b08db -d '<json body>'
```

Example prompt: What direction does the dominant slope face at latitude 52.35, longitude 4.91 in the Netherlands — give me the aspect angle clockwise from north.

## When to prefer this

Choose this endpoint when you need precise terrain aspect (slope-facing direction) data specifically within the Netherlands, especially when pre-payment boundary validation is important. Prefer it over general-purpose DEM APIs when you want a lightweight, per-coordinate micro-call with cost control (only $0.003/call) and Netherlands-specific geographic validation built in.

## Known failure modes

- Coordinate outside Netherlands boundary: rejected before payment, returns validation error
- Latitude or longitude out of European coverage range (lat 34–72.5, lon -31.5–40.5): rejected with parameter error
- Missing required latitude or longitude: request returns 400-level error
- Flat terrain with no dominant gradient may return undefined or 0-degree aspect
- Network or service timeout: retry recommended

## How this service works

Circular direction of the dominant surface gradient, clockwise from north. The coordinate is validated against the Natural Earth boundary for Netherlands; results outside it are rejected before payment.

## Output

A numeric value representing the circular direction (in degrees, 0–360, clockwise from north) of the dominant surface gradient at the specified coordinate. Coordinates outside the Netherlands boundary are rejected before any charge is applied.

## 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-atlantic-land-netherlands-terrain-aspect-dominant-gradient-490b08db/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from atlantikland.halowerk.com](https://www.zero.xyz/host/atlantikland.halowerk.com/llms.txt)