# HALOWERK Land Compare – Mean Slope (Two Locations)

> HALOWERK Land Compare – Mean Slope (Two Locations) is a paid API for AI agents from landvergleich.halowerk.com, paid per call via x402, $0.006/call, status unknown (last checked 2026-09-15).

Computes and compares mean terrain slope for exactly two European coordinate pairs, returning the signed difference and identifying which location is steeper.

## Facts

- Endpoint: POST https://landvergleich.halowerk.com/v1/compare-two-mean-slope
- Price: $0.006/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/halowerk-land-compare-mean-slope-two-locations-a6bd6590
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_DYkRiY_m-DhXSkIGAptno

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-land-compare-mean-slope-two-locations-a6bd6590 -d '<json body>'
```

Example prompt: Compare the mean slope between two locations for me: one at longitude 8.54, latitude 47.37 (Zurich hills) and another at longitude 13.40, latitude 52.52 (Berlin) — tell me which is steeper and by how much.

## When to prefer this

Choose this endpoint when you need a direct pairwise comparison of mean terrain slope for exactly two European locations and want an explicit signed difference and winner — rather than computing raw slope values independently or ranking more than two sites.

## Known failure modes

- Coordinates outside the European coverage bounds (lat 34–72.5, lon -31.5–40.5) will be rejected
- Fewer or more than exactly two location objects will be rejected due to minItems/maxItems constraints
- Missing required longitude or latitude fields returns a validation error
- Malformed numeric values for coordinates cause a 400-level error

## How this service works

Measures mean slope for exactly two European coordinates with one method and reports the signed difference and winner where meaningful.

## Output

Returns the mean slope values for both input coordinates, the signed arithmetic difference between them (location A minus location B), and a winner field indicating which location has the higher mean slope — or indicates no meaningful difference if values are equal.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "locations": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "longitude",
     "latitude"
    ],
    "properties": {
     "name": {
      "type": "string",
      "maxLength": 60,
      "minLength": 1
     },
     "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."
     }
    },
    "additionalProperties": false
   },
   "maxItems": 2,
   "minItems": 2
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/halowerk-land-compare-mean-slope-two-locations-a6bd6590/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from landvergleich.halowerk.com](https://www.zero.xyz/host/landvergleich.halowerk.com/llms.txt)