# HALOWERK Baltic Land – Poland Surface Elevation

> HALOWERK Baltic Land – Poland Surface Elevation is a paid API for AI agents from baltikum.halowerk.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-15).

Returns bilinear-interpolated surface elevation (in metres) from Copernicus DEM GLO-30 for a given WGS84 coordinate, validated against Poland's Natural Earth boundary.

## Facts

- Endpoint: POST https://baltikum.halowerk.com/v1/pl-elevation
- 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-baltic-land-poland-surface-elevation-db87d798
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_btYTERnot-am1Wu0Ekl4l

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-surface-elevation-db87d798 -d '<json body>'
```

Example prompt: What is the surface elevation at latitude 50.06 and longitude 19.94 in Poland — can you look it up using the Copernicus DEM GLO-30 data?

## When to prefer this

Choose this endpoint when you need a precise, single-point terrain elevation for a coordinate within Poland, backed by the high-resolution Copernicus GLO-30 DEM (~30m posting). It is ideal when boundary validation against Poland is required (coordinates outside Poland are rejected before billing). Prefer this over generic global elevation APIs when accuracy within Poland and cost-per-call predictability ($0.003 USDC) matter, and when the Copernicus DEM data lineage is important for your use case.

## Known failure modes

- Coordinate outside Poland boundary: request rejected before payment with a boundary validation error
- Coordinate within European coverage range but outside Poland: rejected by Natural Earth boundary check
- Latitude or longitude outside the published European coverage bounds (lat 34–72.5, lon -31.5–40.5): input validation error
- Malformed or missing latitude/longitude fields: schema validation error
- Service unavailability or upstream DEM data error: HTTP 5xx response

## How this service works

Bilinear surface elevation from Copernicus DEM GLO-30. The coordinate is validated against the Natural Earth boundary for Poland; results outside it are rejected before payment.

## Output

A bilinear-interpolated surface elevation value in metres derived from the Copernicus DEM GLO-30 dataset for the queried WGS84 coordinate. The response is returned only if the coordinate falls within Poland's Natural Earth boundary; out-of-bounds coordinates are rejected before any charge is applied.

## 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-surface-elevation-db87d798/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)