# HALOWERK Southern Land – Greece Built-Up Share

> HALOWERK Southern Land – Greece Built-Up Share is a paid API for AI agents from suedland.halowerk.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-13).

Returns the share of ESA WorldCover 2021 pixels classified as built-up (urban/impervious surface) within the analysis area surrounding a given WGS84 coordinate in Greece.

## Facts

- Endpoint: POST https://suedland.halowerk.com/v1/gr-built-up-share
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/halowerk-southern-land-greece-built-up-share-d78ac1a7
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_cuK5j0WtS1L7vQQ2i0H1N

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-southern-land-greece-built-up-share-d78ac1a7 -d '<json body>'
```

Example prompt: What share of the land around coordinates 37.9755° N, 23.7348° E in Greece is classified as built-up according to ESA WorldCover 2021?

## When to prefer this

Use this endpoint when you need pixel-level built-up land cover statistics for a specific point location within Greece, sourced from the authoritative ESA WorldCover 2021 dataset. Prefer it over general-purpose geocoding or land use APIs when you need ESA WorldCover-specific classifications (not OpenStreetMap or Corine land cover) and when your use case is strictly Greece-scoped. It pairs well with sibling endpoints on the same platform for cropland share, grassland share, soil properties, and elevation statistics.

## Known failure modes

- Coordinate outside Greece boundary (Natural Earth polygon) — request rejected before payment, no result returned
- Coordinate within European bounding box but not in Greece (e.g. Turkey, Italy) — boundary validation fails
- Missing or out-of-range latitude/longitude values — schema validation error
- Network or service unavailability — HTTP 5xx error
- Payment failure or insufficient USDC balance — x402 payment error

## How this service works

Share of ESA WorldCover 2021 pixels classified as built-up. The coordinate is validated against the Natural Earth boundary for Greece; results outside it are rejected before payment.

## Output

A numeric share (fraction or percentage) indicating what proportion of ESA WorldCover 2021 pixels in the analysis area around the submitted coordinate are classified as built-up (urban/impervious surface). The coordinate must fall within the Greece boundary as defined by Natural Earth; requests outside this boundary are rejected before any payment is processed.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "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."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/halowerk-southern-land-greece-built-up-share-d78ac1a7/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from suedland.halowerk.com](https://www.zero.xyz/host/suedland.halowerk.com/llms.txt)