# HALOWERK Eastern Land – Bulgaria Built-Up Land Share

> HALOWERK Eastern Land – Bulgaria Built-Up Land Share is a paid API for AI agents from ostland.halowerk.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-15).

Returns the share of ESA WorldCover 2021 pixels classified as built-up for a given coordinate within Bulgaria.

## Facts

- Endpoint: POST https://ostland.halowerk.com/v1/bg-built-up-share
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/halowerk-eastern-land-bulgaria-built-up-land-share-69b20c47
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_XD485G3_dJsSQ0lzxWEG9

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-eastern-land-bulgaria-built-up-land-share-69b20c47 -d '<json body>'
```

Example prompt: What share of ESA WorldCover 2021 pixels are classified as built-up at latitude 42.6977 and longitude 23.3219 in Bulgaria?

## When to prefer this

Choose this endpoint when you need ESA WorldCover 2021 built-up land cover fractions specifically for locations within Bulgaria, particularly for land assessment, urban density analysis, site suitability screening, or geospatial data enrichment workflows targeting Bulgarian coordinates. It is preferable over generic land cover APIs when Bulgaria-specific boundary validation and pay-per-call pricing ($0.003 USDC) are acceptable, and when WorldCover 2021 pixel-level classification is the desired data source.

## Known failure modes

- Coordinate outside Bulgaria's Natural Earth boundary — request rejected before payment, returning a boundary validation error
- Coordinate within WGS84 European range but outside Bulgaria — rejected by country-level validation
- Malformed or missing latitude/longitude fields — returns schema validation error
- Latitude or longitude outside the published European coverage bounds (lat 34–72.5, lon -31.5–40.5) — returns range 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 Bulgaria; results outside it are rejected before payment.

## Output

A numeric value (fraction or percentage) representing the share of ESA WorldCover 2021 pixels classified as built-up at the queried coordinate. Coordinates outside Bulgaria's Natural Earth boundary 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-eastern-land-bulgaria-built-up-land-share-69b20c47/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from ostland.halowerk.com](https://www.zero.xyz/host/ostland.halowerk.com/llms.txt)