# HALOWERK Europe Land – Tree Cover Share (Polygon)

> HALOWERK Europe Land – Tree Cover 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 share of ESA WorldCover 2021 pixels classified as tree cover within a user-supplied WGS84 polygon across 30 European countries.

## Facts

- Endpoint: POST https://euroland.halowerk.com/v1/europe-tree-cover-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-tree-cover-share-polygon-36c193a2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_pCFa12aicGx-0cXW7nz4x

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-tree-cover-share-polygon-36c193a2 -d '<json body>'
```

Example prompt: What share of this field is classified as tree cover? The polygon corners are at roughly [10.2,51.3], [10.25,51.3], [10.25,51.35], [10.2,51.35] — use the ESA WorldCover analysis for the parcel.

## When to prefer this

Choose this endpoint when you need ESA WorldCover 2021 tree cover fraction for an arbitrarily shaped land parcel (polygon) in Europe, especially for land due diligence, environmental reporting, or subsidy compliance where exact parcel boundaries matter. Prefer the circular-buffer sibling endpoints if you only have a center point and radius rather than a polygon.

## Known failure modes

- Polygon spans more than 0.25 degrees — request rejected
- Polygon coordinates fall outside the supported European bounding box (longitude −31.5 to 40.5, latitude 34 to 72.5)
- Polygon has fewer than 3 vertices or more than 100 vertices
- Coordinates are malformed or not valid WGS84 values
- Payment failure via x402 protocol prevents execution

## How this service works

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

## Output

A standardized numeric value representing the fraction (or percentage) of ESA WorldCover 2021 pixels within the submitted polygon that are classified as tree cover, 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-tree-cover-share-polygon-36c193a2/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)