# HALOWERK Southern Land – Maximum Adjacent-Cell Surface Gradient (Spain)

> HALOWERK Southern Land – Maximum Adjacent-Cell Surface Gradient (Spain) is a paid API for AI agents from suedland.halowerk.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-15).

Returns the maximum adjacent-cell surface slope gradient across the analysis grid for a given coordinate within Spain.

## Facts

- Endpoint: POST https://suedland.halowerk.com/v1/es-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-southern-land-maximum-adjacent-cell-surface-gradient-spain-993ce63f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ESrj2Bum-lbbcL4kFQQoj

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-southern-land-maximum-adjacent-cell-surface-gradient-spain-993ce63f -d '<json body>'
```

Example prompt: What's the maximum surface slope gradient at latitude 40.42, longitude -3.70 in Spain? I need the steepest adjacent-cell gradient across the analysis grid for that point.

## When to prefer this

Use this endpoint when you specifically need the maximum adjacent-cell surface gradient (peak steepness) for a coordinate in Spain, as opposed to mean elevation, elevation standard deviation, or slope direction. It is ideal for terrain suitability analysis, slope risk assessment, and land use planning where the worst-case steepness is the key metric.

## Known failure modes

- Coordinate outside Spain's Natural Earth boundary — request rejected before payment
- Latitude or longitude out of published European coverage range (lat 34–72.5, lon -31.5–40.5) — validation error
- Malformed or missing coordinate fields — input schema validation error
- Payment failure via x402 protocol — request not processed

## How this service works

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

## Output

A numerical value representing the maximum adjacent-cell surface slope gradient across the analysis grid at the specified coordinate in Spain. Coordinates outside the validated Natural Earth boundary for Spain 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-southern-land-maximum-adjacent-cell-surface-gradient-spain-993ce63f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from suedland.halowerk.com](https://www.zero.xyz/host/suedland.halowerk.com/llms.txt)