# HALOWERK Baltic Land – Poland Built-Up Share

> HALOWERK Baltic Land – Poland Built-Up Share is a paid API for AI agents from baltikum.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 land for a given WGS84 coordinate within Poland.

## Facts

- Endpoint: POST https://baltikum.halowerk.com/v1/pl-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-baltic-land-poland-built-up-share-17473177
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_2x_UZgmxvCS4u03mwL6iV

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-baltic-land-poland-built-up-share-17473177 -d '<json body>'
```

Example prompt: What share of ESA WorldCover 2021 pixels around latitude 52.2297, longitude 21.0122 in Warsaw are classified as built-up?

## When to prefer this

Choose this endpoint when you need a precise, pixel-level built-up land cover fraction specifically for a point within Poland, sourced from the authoritative ESA WorldCover 2021 dataset. It is ideal for urban analysis, site suitability, environmental assessments, or any workflow that requires impervious/built-up surface quantification for Polish locations. The pre-payment coordinate validation against Poland's Natural Earth boundary ensures you are not charged for out-of-scope requests.

## Known failure modes

- Coordinate outside Poland boundary: request rejected before payment, no charge incurred
- Latitude or longitude out of European coverage range (lat 34–72.5, lon -31.5–40.5): validation error
- Malformed or missing coordinate fields: schema validation error
- Coordinate inside European range but outside Poland polygon: boundary rejection error
- Network or upstream data service unavailability: server error response

## How this service works

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

## Output

A numeric value representing the fraction (share) of ESA WorldCover 2021 pixels within the analysis area around the given coordinate that are classified as built-up land. Coordinates outside the Natural Earth boundary for Poland are rejected before 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-baltic-land-poland-built-up-share-17473177/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from baltikum.halowerk.com](https://www.zero.xyz/host/baltikum.halowerk.com/llms.txt)