# HALOWERK Nordic Land – Surface Aspect (Dominant Gradient Direction)

> HALOWERK Nordic Land – Surface Aspect (Dominant Gradient Direction) 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 circular direction (in degrees, clockwise from north) of the dominant surface gradient for a given coordinate within Norway.

## Facts

- Endpoint: POST https://nordland.halowerk.com/v1/no-aspect
- 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-surface-aspect-dominant-gradient-direction-c9050ff9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_eKufjHCmWD8Wf2Lafu8wJ

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-surface-aspect-dominant-gradient-direction-c9050ff9 -d '<json body>'
```

Example prompt: What direction does the dominant surface slope face at latitude 60.3 and longitude 5.2 in Norway? I need the aspect in degrees clockwise from north.

## When to prefer this

Choose this endpoint when you need terrain aspect (slope-facing direction) specifically for coordinates within Norway and want pre-payment boundary validation to avoid wasted charges. It is part of a suite of Norwegian land-surface endpoints (soil, slope, texture) from the same provider, making it ideal when you are already using sibling endpoints from HALOWERK Nordic Land for multi-layer terrain analysis.

## Known failure modes

- Coordinate outside Norway's Natural Earth boundary — request rejected before payment, error returned indicating out-of-coverage area
- Latitude or longitude outside the published European coverage range (lat 34–72.5, lon -31.5–40.5) — schema validation error
- Flat terrain with no discernible gradient — may return null or a sentinel value
- Network timeout or service unavailability — generic 5xx error
- Malformed JSON body — 400 validation error

## How this service works

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

## Output

A numeric value representing the dominant surface gradient direction in degrees, measured clockwise from north (0°=North, 90°=East, 180°=South, 270°=West), for the queried coordinate within Norway. Coordinates outside Norway's Natural Earth boundary 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-surface-aspect-dominant-gradient-direction-c9050ff9/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)