# HALOWERK Baltic Land – Estonia Depression Depth

> HALOWERK Baltic Land – Estonia 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 elevation difference between the neighborhood mean and the center cell elevation (depression depth) for a coordinate within Estonia.

## Facts

- Endpoint: POST https://baltikum.halowerk.com/v1/ee-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-estonia-depression-depth-0f9f87b8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_skFd8EYSCcEi517FEgrlH

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-estonia-depression-depth-0f9f87b8 -d '<json body>'
```

Example prompt: What's the depression depth at latitude 58.3780, longitude 26.7290 in Estonia — specifically the positive difference between the neighborhood mean elevation and the center cell elevation at that point?

## When to prefer this

Choose this endpoint when you need a precise, per-point terrain depression depth metric specifically within Estonia. It is ideal for hydrology, flood risk, drainage planning, or site assessment workflows that require knowing how much lower a specific location sits relative to its immediate surroundings. Prefer it over general DEM APIs when you need Estonia-specific boundary validation and a precomputed neighborhood-mean-vs-center elevation difference rather than raw elevation values.

## Known failure modes

- Coordinate outside Estonia boundary — request rejected before payment with an out-of-bounds error
- Latitude or longitude outside the published European coverage range (lat 34–72.5, lon -31.5–40.5) — validation error
- No elevation data available for the given coordinate — null or error response
- Malformed JSON body or missing required fields — 400-level error
- Payment not processed correctly via x402 protocol — 402 response

## How this service works

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

## Output

A numeric value representing the positive difference in meters between the mean elevation of neighboring grid cells and the center cell elevation at the requested coordinate. A higher value indicates the center sits deeper in a depression relative to its surroundings. Coordinates outside Estonia's Natural Earth boundary 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-estonia-depression-depth-0f9f87b8/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)