# HALOWERK Eastern Land – Croatia Drainage Tendency

> HALOWERK Eastern Land – Croatia Drainage Tendency is a paid API for AI agents from ostland.halowerk.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-15).

Returns a relative runoff tendency score derived from terrain slope and ruggedness for a given coordinate within Croatia.

## Facts

- Endpoint: POST https://ostland.halowerk.com/v1/hr-drainage-tendency
- 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-eastern-land-croatia-drainage-tendency-f000e76c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_bA1BEaRZkGqjXJRMW4lj0

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-eastern-land-croatia-drainage-tendency-f000e76c -d '<json body>'
```

Example prompt: What's the relative runoff tendency for the coordinates 45.1°N, 15.4°E in Croatia — I need to know how prone that terrain is to surface drainage based on slope and ruggedness.

## When to prefer this

Choose this endpoint when you need a terrain-derived runoff or drainage tendency score specifically for a point within Croatia, particularly for land assessment, agricultural planning, construction screening, or hydrological risk workflows. It is preferable when you need a fast, per-coordinate computation rather than a raster download, and when slope- and ruggedness-based drainage indexing is the relevant signal (as opposed to soil texture or land cover metrics available on sibling endpoints).

## Known failure modes

- Coordinate outside Croatia boundary — request rejected before payment with a geographic validation error
- Latitude or longitude out of the accepted European coverage range (lat 34–72.5, lon -31.5–40.5) — input validation error
- Malformed or missing coordinate fields — schema validation error
- Service unavailable or timeout — HTTP 5xx error

## How this service works

Relative runoff tendency derived from slope and ruggedness. The coordinate is validated against the Natural Earth boundary for Croatia; results outside it are rejected before payment.

## Output

A numeric relative runoff tendency score derived from terrain slope and ruggedness at the specified coordinate. The coordinate is first validated against the Natural Earth boundary for Croatia; requests outside that boundary are rejected before any charge is made.

## 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-eastern-land-croatia-drainage-tendency-f000e76c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from ostland.halowerk.com](https://www.zero.xyz/host/ostland.halowerk.com/llms.txt)