# HALOWERK Land Compare – Depression Depth (Two-Point Pairwise)

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

Measures local depression depth for exactly two European coordinates using a single method, returning the signed difference and identifying which location is deeper.

## Facts

- Endpoint: POST https://landvergleich.halowerk.com/v1/compare-two-depression-depth
- 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-land-compare-depression-depth-two-point-pairwise-f38f1433
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Y7EOMQBd6C5oPli1-nfLF

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-land-compare-depression-depth-two-point-pairwise-f38f1433 -d '<json body>'
```

Example prompt: Compare the local depression depth between these two locations in Europe: one at latitude 51.5, longitude -0.1 (call it 'London') and another at latitude 48.85, longitude 2.35 (call it 'Paris') — tell me which site is deeper and by how much.

## When to prefer this

Choose this endpoint when you need a precise, single-method pairwise comparison of local depression depth for exactly two European locations and want a clean signed difference with a declared winner. Prefer it over the multi-site ranking endpoint when you have exactly two points and need direct head-to-head output rather than a ranked list.

## Known failure modes

- Coordinates outside European coverage bounds (lat 34–72.5, lon -31.5–40.5) will be rejected
- Submitting fewer or more than exactly two location objects causes a validation error
- Missing required latitude or longitude fields returns a schema error
- Network timeout for slow terrain data retrieval
- Identical coordinates may return a zero difference with no clear winner

## How this service works

Measures local depression depth for exactly two European coordinates with one method and reports the signed difference and winner where meaningful.

## Output

Returns the measured local depression depth values for both input coordinates, the signed numerical difference between them, and an indication of which location is the 'winner' (deeper depression), using a single consistent measurement method across both points.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "locations": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "longitude",
     "latitude"
    ],
    "properties": {
     "name": {
      "type": "string",
      "maxLength": 60,
      "minLength": 1
     },
     "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."
     }
    },
    "additionalProperties": false
   },
   "maxItems": 2,
   "minItems": 2
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/halowerk-land-compare-depression-depth-two-point-pairwise-f38f1433/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from landvergleich.halowerk.com](https://www.zero.xyz/host/landvergleich.halowerk.com/llms.txt)