# HALOWERK Southern Land – Portugal Maximum Slope

> HALOWERK Southern Land – Portugal Maximum Slope is a paid API for AI agents from suedland.halowerk.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-13).

Returns the maximum adjacent-cell surface gradient across a local analysis grid for a given coordinate within Portugal

## Facts

- Endpoint: POST https://suedland.halowerk.com/v1/pt-max-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-southern-land-portugal-maximum-slope-99cee3bf
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_zZ7ZexYEJNs_rHLpV-2pr

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-portugal-maximum-slope-99cee3bf -d '<json body>'
```

Example prompt: What is the maximum surface slope gradient at latitude 38.72, longitude -9.14 in Portugal? I need to know how steep the terrain is at that point.

## When to prefer this

Use this endpoint when you need a precise maximum terrain slope metric for a specific coordinate in Portugal. It is ideal for land suitability assessments, construction planning, agricultural analysis, or environmental studies where steepness of terrain is a key factor. Prefer this over general DEM services when you need the adjacent-cell maximum gradient specifically and are working within Portugal's boundaries.

## Known failure modes

- Coordinate outside Portugal boundary — request rejected before payment with a validation error
- Coordinate within European bounding box but outside Portugal — rejected by Natural Earth boundary check
- Latitude or longitude out of the accepted European coverage range (lat 34–72.5, lon -31.5–40.5) — schema validation error
- Missing required latitude or longitude parameter — returns parameter error
- Network or server error — non-2xx HTTP response with no result

## How this service works

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

## Output

A numeric value representing the maximum adjacent-cell surface gradient (slope) computed across the local analysis grid at the provided coordinate. Results are only returned for coordinates validated within the Natural Earth boundary of Portugal; coordinates outside Portugal 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-portugal-maximum-slope-99cee3bf/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)