# HALOWERK Land Compare – Multi-Site Elevation Ranking

> HALOWERK Land Compare – Multi-Site Elevation Ranking is a paid API for AI agents from landvergleich.halowerk.com, paid per call via x402, $0.008/call, status unknown (last checked 2026-09-15).

Measures elevation for two to ten named European sites using WGS84 coordinates and returns a ranked list with ties preserved.

## Facts

- Endpoint: POST https://landvergleich.halowerk.com/v1/rank-sites-elevation
- Price: $0.008/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-multi-site-elevation-ranking-e4d2fa96
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_lCpIRv4lLbat0mlwQIxc7

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-multi-site-elevation-ranking-e4d2fa96 -d '<json body>'
```

Example prompt: Can you rank these five European sites by elevation: Mont Blanc at 45.8326°N 6.8652°E, Zermatt at 46.0207°N 7.7491°E, Innsbruck at 47.2692°N 11.4041°E, Salzburg at 47.8003°N 13.0448°E, and Vienna at 48.2082°N 16.3738°E — highest to lowest, with ties noted?

## When to prefer this

Choose this endpoint when you need to compare and rank elevation across multiple (2–10) European sites simultaneously in a single call, preserving ties. Prefer it over single-coordinate elevation lookups when ranking or ordering is the goal, and over generic elevation APIs when the coverage area is specifically European and the tie-aware ranking output format is needed.

## Known failure modes

- Coordinates outside European coverage bounds (lat 34–72.5°N, lon -31.5–40.5°E) will be rejected
- Fewer than 2 or more than 10 sites submitted will fail validation
- Missing required latitude or longitude fields cause a schema validation error
- Name field exceeding 60 characters will be rejected
- Elevation data unavailable for extremely remote or ocean coordinates within nominal bounds

## How this service works

Measures elevation for two to ten named European sites and ranks the observed values with ties preserved.

## Output

Returns a ranked list of the submitted named European sites ordered by their measured elevation values, with ties preserved in the ranking (equal-elevation sites share the same rank position). Each entry includes the site name, its elevation measurement, and its rank.

## 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": 10,
   "minItems": 2
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/halowerk-land-compare-multi-site-elevation-ranking-e4d2fa96/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)