# HALOWERK Nordic Land – Sweden Mean Surface Slope

> HALOWERK Nordic Land – Sweden Mean Surface Slope 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 mean first-order surface gradient (slope) across an analysis grid for a coordinate point validated within Sweden's boundaries.

## Facts

- Endpoint: POST https://nordland.halowerk.com/v1/se-mean-slope
- 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-sweden-mean-surface-slope-b58ae2d2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_WKf8rEt5zdhsj6tr9_iZR

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-sweden-mean-surface-slope-b58ae2d2 -d '<json body>'
```

Example prompt: What's the mean surface slope at latitude 59.33 and longitude 18.07 in Sweden? I need the terrain gradient value for that location.

## When to prefer this

Choose this endpoint when you need mean terrain slope specifically for locations within Sweden, especially when coordinate validation against Sweden's official boundary is required before processing. Ideal for land-use planning, environmental assessment, construction feasibility, or agricultural analysis in Sweden. The pay-per-call x402 pricing ($0.003 USDC) makes it cost-effective for on-demand point queries.

## Known failure modes

- Coordinates outside Sweden's Natural Earth boundary are rejected with a validation error before payment
- Coordinates outside the published European coverage range (lat 34–72.5, lon -31.5–40.5) are rejected
- Network timeout or service unavailability may result in no response
- Invalid or missing latitude/longitude values return a schema validation error

## How this service works

Mean first-order surface gradient across the analysis grid. The coordinate is validated against the Natural Earth boundary for Sweden; results outside it are rejected before payment.

## Output

Returns the mean first-order surface gradient (slope value) computed across the analysis grid for the given coordinate. The coordinate is validated against the Natural Earth boundary for Sweden; requests with coordinates outside Sweden 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-nordic-land-sweden-mean-surface-slope-b58ae2d2/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)