# HALOWERK Europe Land – Drainage Tendency (Parcel)

> HALOWERK Europe Land – Drainage Tendency (Parcel) is a paid API for AI agents from euroland.halowerk.com, paid per call via x402, $0.006/call, status unknown (last checked 2026-09-15).

Returns the relative runoff/drainage tendency of a user-defined land parcel in Europe, derived from terrain slope and ruggedness metrics, standardized across 30 European countries.

## Facts

- Endpoint: POST https://euroland.halowerk.com/v1/europe-drainage-tendency-parcel
- 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-europe-land-drainage-tendency-parcel-4e61dadf
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_mTPJzFnmxa9bb0abQB5qG

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-europe-land-drainage-tendency-parcel-4e61dadf -d '<json body>'
```

Example prompt: Can you check the drainage tendency for this field parcel in Bavaria — here are the WGS84 corner coordinates forming the polygon: [[11.2,48.1],[11.25,48.1],[11.25,48.13],[11.2,48.13]]?

## When to prefer this

Use this endpoint when you need slope- and ruggedness-derived runoff tendency for a specific bounded land parcel in Europe and require standardized, comparable values across countries. Prefer this over generic elevation APIs when you need a hydrology-relevant terrain metric rather than raw elevation, and over raster download services when you want a single computed score rather than pixel data.

## Known failure modes

- Polygon exceeds maximum 0.25-degree span — returns validation error
- Polygon has fewer than 3 coordinate pairs — rejected as invalid geometry
- Coordinates fall outside Europe coverage bounds (lon -31.5 to 40.5, lat 34 to 72.5) — returns out-of-coverage error
- Malformed coordinate array or non-numeric values — returns schema validation error
- Payment not authorized or insufficient USDC balance — returns 402 Payment Required

## How this service works

Relative runoff tendency derived from slope and ruggedness. The service evaluates the bounded polygon supplied by the caller and returns standardized units across all 30 covered countries.

## Output

A standardized drainage tendency score derived from slope and ruggedness analysis of the input polygon, expressed in consistent units across all 30 covered European countries. The value indicates the relative likelihood of surface runoff versus water retention for the parcel.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "polygon": {
   "type": "array",
   "items": {
    "type": "array",
    "items": [
     {
      "type": "number",
      "maximum": 40.5,
      "minimum": -31.5
     },
     {
      "type": "number",
      "maximum": 72.5,
      "minimum": 34
     }
    ],
    "maxItems": 2,
    "minItems": 2,
    "additionalItems": false
   },
   "maxItems": 100,
   "minItems": 3,
   "description": "WGS84 polygon ring. The closing coordinate is optional; maximum span is 0.25 degrees."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/halowerk-europe-land-drainage-tendency-parcel-4e61dadf/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from euroland.halowerk.com](https://www.zero.xyz/host/euroland.halowerk.com/llms.txt)