# HALOWERK Baltic Land – Poland Depression Depth

> HALOWERK Baltic Land – Poland Depression Depth 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 the positive difference between neighborhood mean elevation and center-point elevation (depression depth) for a WGS84 coordinate within Poland.

## Facts

- Endpoint: POST https://baltikum.halowerk.com/v1/pl-depression-depth
- 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-depression-depth-4ebd36aa
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_xzTZFdEBe-e1_Vn3RKKAW

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-depression-depth-4ebd36aa -d '<json body>'
```

Example prompt: What's the depression depth at latitude 52.2297 and longitude 21.0122 in Poland — how much lower is that point compared to its surrounding terrain?

## When to prefer this

Choose this endpoint when you need a per-point depression depth metric specifically for locations within Poland, and you want coordinate validation enforced before billing. It is well-suited for hydrological, agricultural, or site-suitability workflows that require knowing whether a terrain point is a local sink relative to its surroundings.

## Known failure modes

- Coordinate outside Poland's Natural Earth boundary — request rejected before payment with a validation error
- Latitude or longitude out of the accepted European range (lat 34–72.5, lon -31.5–40.5) — schema validation failure
- Network timeout or service unavailability — no result returned
- Payment failure via x402 protocol — request not processed

## How this service works

Positive difference between the neighborhood mean and center elevation. The coordinate is validated against the Natural Earth boundary for Poland; results outside it are rejected before payment.

## Output

A numeric value representing the positive elevation difference (in meters) between the mean elevation of the surrounding neighborhood grid cells and the center cell at the given coordinate. If the center is lower than the mean, this depth value is positive (a true depression); coordinates outside Poland's boundary are rejected before any payment is charged.

## 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-depression-depth-4ebd36aa/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)