# HALOWERK Europe Land – Depression Depth (Parcel)

> HALOWERK Europe Land – Depression Depth (Parcel) is a paid API for AI agents from euroland.halowerk.com, paid per call via x402, $0.006/call, status unknown (last checked 2026-09-15).

Returns the positive elevation difference between the neighborhood mean and the center point (depression depth) for a user-supplied WGS84 polygon parcel across 30 European countries.

## Facts

- Endpoint: POST https://euroland.halowerk.com/v1/europe-depression-depth-parcel
- Price: $0.006/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/halowerk-europe-land-depression-depth-parcel-52f82c49
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ypXjybP94l-bnK1CFqzgM

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-europe-land-depression-depth-parcel-52f82c49 -d '<json body>'
```

Example prompt: Can you calculate the depression depth for this parcel of land — the polygon has corners at roughly [9.2, 48.7], [9.21, 48.7], [9.21, 48.71], [9.2, 48.71] — I need to know how much lower the center is compared to the surrounding neighborhood elevation.

## When to prefer this

Choose this endpoint when you need a parcel-level depression depth metric (center vs. neighborhood elevation difference) for a specific user-defined polygon in Europe and want standardized output across 30 countries. Prefer this over circular-buffer siblings when the exact parcel boundary matters (e.g. cadastral parcels, field boundaries). Use it for flood risk, drainage assessment, site suitability, or any analysis where terrain concavity at the parcel level is relevant.

## Known failure modes

- Polygon has fewer than 3 vertices — validation error returned
- Polygon spans more than 0.25 degrees — rejected as exceeding maximum allowed extent
- Coordinates fall outside the covered European extent (longitude -31.5 to 40.5, latitude 34 to 72.5) — no data returned
- Malformed coordinate pairs (wrong order or missing values) — schema validation failure
- Polygon describes a non-closed self-intersecting ring — processing error

## How this service works

Positive difference between the neighborhood mean and center elevation. The service evaluates the bounded polygon supplied by the caller and returns standardized units across all 30 covered countries.

## Output

A standardized numeric value representing the positive elevation difference between the neighborhood mean elevation and the center elevation of the supplied polygon, expressed in consistent units across all 30 covered European countries. A higher value indicates the parcel center is significantly lower than its surroundings (a deeper depression or sink).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "polygon": {
   "type": "array",
   "items": {
    "type": "array",
    "items": [
     {
      "type": "number",
      "maximum": 40.5,
      "minimum": -31.5
     },
     {
      "type": "number",
      "maximum": 72.5,
      "minimum": 34
     }
    ],
    "maxItems": 2,
    "minItems": 2,
    "additionalItems": false
   },
   "maxItems": 100,
   "minItems": 3,
   "description": "WGS84 polygon ring. The closing coordinate is optional; maximum span is 0.25 degrees."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/halowerk-europe-land-depression-depth-parcel-52f82c49/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from euroland.halowerk.com](https://www.zero.xyz/host/euroland.halowerk.com/llms.txt)