# HALOWERK Land Compare – Surface Drainage Tendency Ranking

> HALOWERK Land Compare – Surface Drainage Tendency 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 surface drainage tendency for 2–10 named European sites and returns a ranked list with ties preserved.

## Facts

- Endpoint: POST https://landvergleich.halowerk.com/v1/rank-sites-drainage-tendency
- 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-surface-drainage-tendency-ranking-aa8f607e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_aoLQElIFbGr1aMzBrfjlR

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-surface-drainage-tendency-ranking-aa8f607e -d '<json body>'
```

Example prompt: Can you rank these five European sites by their surface drainage tendency? Site A at 51.5°N, 0.1°W; Site B at 48.9°N, 2.3°E; Site C at 52.4°N, 4.9°E; Site D at 53.6°N, 10.0°E; Site E at 47.1°N, 8.5°E — I need to know which drains best and which worst, with ties shown.

## When to prefer this

Use this endpoint when you need to compare and rank surface drainage tendency across multiple European sites (2–10) simultaneously with ties preserved. Prefer it over pairwise comparison endpoints when you have three or more sites and need a full ordered ranking in a single call. Best suited for site selection, land suitability assessment, or environmental planning workflows within European geographic coverage.

## Known failure modes

- Coordinates outside European coverage bounds (lat 34–72.5°N, lon -31.5–40.5°E) return a validation error
- Fewer than 2 or more than 10 sites in the array cause a schema validation failure
- Missing latitude or longitude on any site object causes a 400-level error
- Site name exceeding 60 characters is rejected
- Network or service unavailability returns a 5xx error

## How this service works

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

## Output

Returns a ranked list of the submitted named sites ordered by their measured surface drainage tendency values, with tied ranks preserved (i.e. sites with equal values share the same rank position). Each entry includes the site name, its drainage tendency metric, 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-surface-drainage-tendency-ranking-aa8f607e/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)