# HALOWERK Central Land – CZ Maximum Surface Slope

> HALOWERK Central Land – CZ Maximum Surface Slope is a paid API for AI agents from mitteleuropa.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 the analysis grid for a given coordinate within Czechia.

## Facts

- Endpoint: POST https://mitteleuropa.halowerk.com/v1/cz-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-central-land-cz-maximum-surface-slope-207eb85a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_OqpY4jmPws74tPznf0I-A

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-central-land-cz-maximum-surface-slope-207eb85a -d '<json body>'
```

Example prompt: What's the maximum surface slope gradient at coordinates 50.08 latitude, 14.42 longitude in Czechia — I need the steepest adjacent-cell gradient from the terrain grid there.

## When to prefer this

Use this endpoint when you need the maximum surface slope gradient specifically for a point within Czechia and want boundary validation enforced before billing. Prefer this over generic elevation APIs when you require the steepest adjacent-cell gradient metric (not mean slope) from a Copernicus DEM GLO-30 based grid, and when you need guaranteed rejection of out-of-bounds coordinates at no cost.

## Known failure modes

- Coordinate outside Czechia boundary — rejected before payment with a validation error
- Latitude or longitude outside published European coverage range (34–72.5°N, -31.5–40.5°E) — schema validation failure
- Invalid coordinate format or missing required fields — HTTP 400 bad request
- Service unavailable or DEM data not accessible — HTTP 500 or timeout

## How this service works

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

## Output

A numeric value representing the maximum adjacent-cell surface gradient (slope) across the analysis grid centered on the requested coordinate, computed from high-resolution DEM data. Coordinates outside the Natural Earth boundary for Czechia 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-central-land-cz-maximum-surface-slope-207eb85a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from mitteleuropa.halowerk.com](https://www.zero.xyz/host/mitteleuropa.halowerk.com/llms.txt)