# HALOWERK Eastern Land – Hungary Maximum Slope

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

Returns the maximum adjacent-cell surface gradient (steepest slope) across the analysis grid for a given coordinate within Hungary.

## Facts

- Endpoint: POST https://ostland.halowerk.com/v1/hu-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-eastern-land-hungary-maximum-slope-4f1fffad
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ky2Bno8-bGrE3AfmvxeAg

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-eastern-land-hungary-maximum-slope-4f1fffad -d '<json body>'
```

Example prompt: What's the maximum terrain slope gradient at latitude 47.3 and longitude 19.1 in Hungary — I need the steepest adjacent-cell surface gradient for that location.

## When to prefer this

Choose this endpoint when you need the maximum (steepest) slope value specifically for a location in Hungary and want coordinate boundary pre-validation before incurring any cost. Prefer this over generic elevation APIs when you need the maximum adjacent-cell gradient metric specifically, and over regional European terrain APIs when you need Hungary-specific validation guarantees.

## Known failure modes

- Coordinate outside Hungary boundary: rejected before payment with a boundary validation error
- Latitude or longitude outside European coverage range (lat 34–72.5, lon -31.5–40.5): schema validation error
- Missing required latitude or longitude parameter: request rejected with a validation error
- Network or service timeout: no result returned, no charge

## How this service works

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

## Output

A numerical value representing the maximum adjacent-cell surface gradient (steepest slope angle or ratio) across the analysis grid centered on the provided coordinate. The coordinate is validated against Hungary's Natural Earth boundary; requests outside Hungary 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-eastern-land-hungary-maximum-slope-4f1fffad/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from ostland.halowerk.com](https://www.zero.xyz/host/ostland.halowerk.com/llms.txt)