# HALOWERK Land Compare – Surface Drainage Tendency (Two-Point Comparison)

> HALOWERK Land Compare – Surface Drainage Tendency (Two-Point Comparison) is a paid API for AI agents from landvergleich.halowerk.com, paid per call via x402, $0.006/call, status unknown (last checked 2026-09-13).

Measures and compares surface drainage tendency at exactly two European coordinates, returning the signed difference and identifying which location drains better.

## Facts

- Endpoint: POST https://landvergleich.halowerk.com/v1/compare-two-drainage-tendency
- Price: $0.006/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/halowerk-land-compare-surface-drainage-tendency-two-point-comparison-49b4f5a1
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_FwUA8Kslv27wlFovlPglN

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-surface-drainage-tendency-two-point-comparison-49b4f5a1 -d '<json body>'
```

Example prompt: Compare the surface drainage tendency between my two candidate farm sites — one at latitude 51.2, longitude 4.4 near Antwerp, and another at latitude 48.8, longitude 2.3 near Paris — and tell me which drains better and by how much.

## When to prefer this

Use this endpoint when you need a direct, signed pairwise comparison of surface drainage tendency between exactly two European sites — ideal for land selection, site assessment, or risk differentiation workflows. Prefer this over ranking endpoints when only two sites are involved and a signed delta is more useful than an ordinal rank.

## Known failure modes

- Coordinates outside European coverage bounds (lat 34–72.5, lon -31.5–40.5) return validation error
- Fewer or more than exactly two location objects in the array are rejected
- Missing required latitude or longitude fields cause schema validation failure
- Ambiguous or near-identical values may yield a negligible or zero difference with no clear winner

## How this service works

Measures surface drainage tendency for exactly two European coordinates with one method and reports the signed difference and winner where meaningful.

## Output

Returns the measured surface drainage tendency value for each of the two input coordinates, the signed numerical difference between them, and an indication of which location has the higher (better) drainage tendency where the difference is meaningful.

## 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-surface-drainage-tendency-two-point-comparison-49b4f5a1/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)