# HALOWERK Europe Land – Grassland Share (Parcel Polygon)

> HALOWERK Europe Land – Grassland Share (Parcel Polygon) is a paid API for AI agents from euroland.halowerk.com, paid per call via x402, $0.006/call, status unknown (last checked 2026-09-14).

Returns the share of ESA WorldCover 2021 pixels classified as grassland within a user-supplied WGS84 polygon, covering 30 European countries.

## Facts

- Endpoint: POST https://euroland.halowerk.com/v1/europe-grassland-share-parcel
- Price: $0.006/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/halowerk-europe-land-grassland-share-parcel-polygon-8a0a2d24
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_fUrkC-Ge6-wg8miWagFlf

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-grassland-share-parcel-polygon-8a0a2d24 -d '<json body>'
```

Example prompt: What share of this parcel is classified as grassland? The polygon coordinates are [[-3.2,51.5],[-3.19,51.5],[-3.19,51.51],[-3.2,51.51]] — use ESA WorldCover data for the European land cover analysis.

## When to prefer this

Choose this endpoint when you need grassland land cover share for an irregular polygon boundary (e.g. a real cadastral parcel) rather than a fixed-radius circle. Use it over the circular-buffer grassland endpoint when parcel shape fidelity matters. It is well-suited for compliance, subsidy, or environmental audit workflows where exact parcel geometry is required across European countries covered by ESA WorldCover 2021.

## Known failure modes

- Polygon outside supported European extent (lon -31.5 to 40.5, lat 34 to 72.5) returns an error
- Polygon with fewer than 3 vertices or more than 100 vertices is rejected
- Polygon span exceeding 0.25 degrees is rejected as too large
- Invalid coordinate format or out-of-range values cause validation failure
- Payment failure via x402 protocol prevents endpoint execution

## How this service works

Share of ESA WorldCover 2021 pixels classified as grassland. The service evaluates the bounded polygon supplied by the caller and returns standardized units across all 30 covered countries.

## Output

A standardized fractional or percentage value indicating the share of pixels within the supplied polygon classified as grassland in the ESA WorldCover 2021 dataset, consistent across all 30 covered European countries.

## 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-grassland-share-parcel-polygon-8a0a2d24/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)