# HALOWERK Central Land – CZ Mean Slope

> HALOWERK Central Land – CZ Mean 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 mean first-order surface gradient (slope) at a given WGS84 coordinate within Czechia, derived from grid analysis.

## Facts

- Endpoint: POST https://mitteleuropa.halowerk.com/v1/cz-mean-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-mean-slope-78eea46b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_lhfUqW-jcvdavEwWAAFIj

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-mean-slope-78eea46b -d '<json body>'
```

Example prompt: What is the mean terrain slope at latitude 50.08 and longitude 14.44 in Czechia — I need the average first-order surface gradient for that location.

## When to prefer this

Use this endpoint when you need a mean slope/gradient value for a specific point within Czechia and want a pay-per-call micro-payment model. Prefer this over general-purpose GIS tools when you only need slope for Czech coordinates and want low-latency, per-coordinate pricing. It is part of a suite of terrain and land-surface metrics for Central Europe, so it is well-suited for pipelines that also query elevation, aspect, or soil data for the same region.

## Known failure modes

- Coordinate outside Czechia boundary — rejected with validation error before payment
- Latitude or longitude outside European coverage range (lat 34–72.5, lon -31.5–40.5) — schema validation failure
- Missing required latitude or longitude parameter — request rejected
- Network timeout or upstream DEM data unavailability — service error response
- Payment not completed via x402 protocol — request not processed

## How this service works

Mean first-order 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 mean first-order surface gradient (slope) across the analysis grid centered on the provided coordinate, expressed as a rate of elevation change. Coordinates outside the Czech Republic boundary are rejected before processing.

## 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-mean-slope-78eea46b/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)