# HALOWERK Nordic Land – SE Depression Depth

> HALOWERK Nordic Land – SE Depression Depth is a paid API for AI agents from nordland.halowerk.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-15).

Returns the positive depth of a topographic depression at a given coordinate in Sweden, computed as the difference between the neighborhood mean elevation and the center-point elevation.

## Facts

- Endpoint: POST https://nordland.halowerk.com/v1/se-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-nordic-land-se-depression-depth-2d69f523
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Ljyn4zR_rgWzfVUQnRpvl

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-nordic-land-se-depression-depth-2d69f523 -d '<json body>'
```

Example prompt: What's the topographic depression depth at latitude 59.33, longitude 18.07 in Sweden — I need to know how much lower that center point is compared to the surrounding neighborhood elevation.

## When to prefer this

Use this endpoint when you need a precise, pay-per-call terrain depression metric for a specific point in Sweden without setting up your own DEM processing pipeline. It is ideal for hydrology, agriculture, construction, or environmental analysis workflows that require on-demand depression depth values validated against Sweden's official boundary.

## Known failure modes

- Coordinate outside Sweden's Natural Earth boundary — request rejected with an error before payment
- Latitude or longitude outside the published European coverage range (lat 34–72.5, lon -31.5–40.5) — validation error
- Elevation data unavailable for the queried location — no result returned
- Negative or zero difference (point is not in a depression) — may return zero or a specific indicator
- Malformed input coordinates — schema validation error

## How this service works

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

## Output

A numeric value representing the depression depth in meters — the positive difference between the neighborhood mean surface elevation and the center-point elevation at the queried coordinate. Coordinates outside Sweden's Natural Earth boundary are rejected before any charge is incurred.

## 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-nordic-land-se-depression-depth-2d69f523/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from nordland.halowerk.com](https://www.zero.xyz/host/nordland.halowerk.com/llms.txt)