# HALOWERK Europe Land – Water & Wetland Share (Polygon)

> HALOWERK Europe Land – Water & Wetland Share (Polygon) 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 combined share of permanent water, herbaceous wetland, and mangrove land cover classes within a user-defined polygon across 30 European countries, derived from ESA WorldCover 2021.

## Facts

- Endpoint: POST https://euroland.halowerk.com/v1/europe-water-wetland-share-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-water-wetland-share-polygon-457994aa
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_eYEhTrT89eNJiOvKnfwbB

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-water-wetland-share-polygon-457994aa -d '<json body>'
```

Example prompt: What share of this plot in the Netherlands is classified as permanent water or wetland? The polygon corners are [4.85, 52.37], [4.87, 52.37], [4.87, 52.39], [4.85, 52.39].

## When to prefer this

Choose this endpoint when you need to quantify the water and wetland land cover fraction for a specific user-defined polygon in Europe, particularly for environmental compliance, land use assessment, or site screening workflows. Prefer it over raster tile services when you need a pre-aggregated scalar metric rather than raw pixel data, and over circular buffer endpoints when the area of interest has an irregular or parcel-specific boundary.

## Known failure modes

- Polygon outside supported 30-country European coverage area returns an error or null result
- Polygon spanning more than 0.25 degrees in any direction is rejected as exceeding maximum span
- Fewer than 3 coordinate pairs provided fails validation (minimum polygon requirement)
- Coordinates provided in wrong order (lat/lon swapped) may return incorrect or out-of-range results
- Malformed polygon ring (non-closed or self-intersecting) may cause a processing error
- Payment not included or insufficient USDC results in 402 Payment Required response

## How this service works

Combined share of permanent water, herbaceous wetland and mangrove classes. The service evaluates the bounded polygon supplied by the caller and returns standardized units across all 30 covered countries.

## Output

A standardized value (fraction or percentage) representing the combined share of ESA WorldCover 2021 pixels classified as permanent water, herbaceous wetland, or mangrove within the supplied polygon, aggregated across the analysis area and returned in standardized units.

## 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-water-wetland-share-polygon-457994aa/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)