# HALOWERK Southern Land – Mean Slope (Spain)

> HALOWERK Southern Land – Mean Slope (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 mean first-order surface gradient (slope) across an analysis grid cell for a given coordinate within Spain's boundaries.

## Facts

- Endpoint: POST https://suedland.halowerk.com/v1/es-mean-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-mean-slope-spain-e5251f1a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_iSqBhxgizfQWkS6-xZTRb

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-mean-slope-spain-e5251f1a -d '<json body>'
```

Example prompt: What's the mean surface slope at latitude 40.4 and longitude -3.7 in Spain? I need the terrain gradient for that location.

## When to prefer this

Use this endpoint when you need the mean surface slope at a specific point within Spain and want a validated, per-call computation that rejects out-of-boundary coordinates automatically. Prefer this over generic elevation APIs when the focus is specifically on Spain and terrain gradient (not raw elevation), and when pay-per-call pricing at $0.003 per query fits your usage pattern.

## Known failure modes

- Coordinate outside Spain's Natural Earth boundary — request rejected with validation error before payment
- Latitude or longitude outside published European coverage range (lat 34–72.5, lon -31.5–40.5) — schema validation failure
- Network timeout or service unavailability — no result returned
- Invalid coordinate format — input parsing error

## How this service works

Mean first-order 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 mean first-order surface gradient (average slope) across the analysis grid cell centered on the given coordinate. Coordinates outside the Natural Earth boundary for Spain are rejected before any charge is made.

## 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-mean-slope-spain-e5251f1a/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)