# HALOWERK Land Compare – Local Relief Multi-Site Ranking

> HALOWERK Land Compare – Local Relief Multi-Site 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 local relief (terrain ruggedness) for 2–10 named European sites and returns a ranked list with ties preserved.

## Facts

- Endpoint: POST https://landvergleich.halowerk.com/v1/rank-sites-local-relief
- 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-local-relief-multi-site-ranking-91dd85b5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_IQeBhfi65GtElaaRj1hjO

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-local-relief-multi-site-ranking-91dd85b5 -d '<json body>'
```

Example prompt: Can you rank these five European sites by local terrain relief — Madrid (40.4168, -3.7038), Zurich (47.3769, 8.5417), Prague (50.0755, 14.4378), Warsaw (52.2297, 21.0122), and Lyon (45.7640, 4.8357) — and tell me which has the most rugged terrain and which is the flattest?

## When to prefer this

Use this endpoint when you need to compare local terrain relief across multiple (2–10) European sites simultaneously and want a ranked output with ties preserved. It is preferable over the two-site pairwise endpoints when you have more than two candidates, and preferable over general geospatial APIs when you specifically need local relief as the ranking metric within European coverage.

## Known failure modes

- Coordinates outside European coverage bounds (lat 34–72.5, lon -31.5–40.5) cause validation errors
- Fewer than 2 or more than 10 locations cause schema validation failure
- Missing required latitude or longitude fields trigger a 400 error
- Names exceeding 60 characters are rejected
- Network or upstream terrain data unavailability may return a 5xx error

## How this service works

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

## Output

Returns each named site with its measured local relief value and an ordinal rank (1 = highest relief), with tied values assigned identical ranks and subsequent ranks adjusted accordingly.

## 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-local-relief-multi-site-ranking-91dd85b5/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)