# HALOWERK Baltic Land – Mean Surface Slope (Germany)

> HALOWERK Baltic Land – Mean Surface Slope (Germany) is a paid API for AI agents from baltikum.halowerk.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-15).

Returns the mean first-order surface slope gradient across an analysis grid cell for a given WGS84 coordinate within Germany.

## Facts

- Endpoint: POST https://baltikum.halowerk.com/v1/de-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-baltic-land-mean-surface-slope-germany-15740837
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_L32BiS4WVM2RAszh4owUH

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-baltic-land-mean-surface-slope-germany-15740837 -d '<json body>'
```

Example prompt: What is the mean surface slope at latitude 52.52, longitude 13.41 in Germany? I need the terrain gradient for that location.

## When to prefer this

Choose this endpoint when you need a precise mean surface slope metric for a specific point in Germany, particularly for terrain analysis, site assessment, agricultural planning, or environmental modeling workflows. It is especially useful when Germany-specific validation is required and you want to avoid charges for out-of-bounds coordinates.

## Known failure modes

- Coordinate outside Germany boundary: rejected before payment, returns error indicating invalid location
- Coordinate outside European coverage range (lat 34–72.5, lon -31.5–40.5): schema validation failure
- Missing or malformed latitude/longitude: request validation error
- Service unavailable: HTTP 5xx error

## How this service works

Mean first-order surface gradient across the analysis grid. The coordinate is validated against the Natural Earth boundary for Germany; results outside it are rejected before payment.

## Output

A numeric value representing the mean first-order surface slope gradient (steepness) computed across an analysis grid centered on the requested coordinate. Coordinates outside Germany's Natural Earth boundary are rejected before any payment is charged.

## 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-baltic-land-mean-surface-slope-germany-15740837/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from baltikum.halowerk.com](https://www.zero.xyz/host/baltikum.halowerk.com/llms.txt)