# HALOWERK Southern Land – Portugal Soil CEC (0-5 cm)

> HALOWERK Southern Land – Portugal Soil CEC (0-5 cm) is a paid API for AI agents from suedland.halowerk.com, paid per call via x402, $0.004/call, status unknown (last checked 2026-09-15).

Returns the mean SoilGrids cation exchange capacity (CEC) for the 0–5 cm topsoil layer at a given coordinate within Portugal, validated against the Natural Earth boundary.

## Facts

- Endpoint: POST https://suedland.halowerk.com/v1/pt-soil-cec
- Price: $0.004/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/halowerk-southern-land-portugal-soil-cec-0-5-cm-43e04ab2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_54n3CQ8CFvOTHbamDiGeo

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-southern-land-portugal-soil-cec-0-5-cm-43e04ab2 -d '<json body>'
```

Example prompt: What's the mean cation exchange capacity of the topsoil at latitude 38.716, longitude -9.139 in Portugal — I need the 0–5 cm SoilGrids CEC value for that spot.

## When to prefer this

Use this endpoint when you need the SoilGrids-derived mean CEC specifically for the 0–5 cm topsoil layer at a point location within Portugal. Prefer it over generic soil APIs when you need boundary-validated, per-coordinate lookups for Portugal and are comfortable with micro-payment per call. For other countries or other soil properties (pH, nitrogen, sand, clay), use the sibling endpoints on the same provider.

## Known failure modes

- Coordinate outside Portugal boundary: request rejected before payment with an out-of-bounds error
- Latitude or longitude outside the European coverage range (lat 34–72.5, lon -31.5–40.5): schema validation failure
- Malformed or missing coordinate fields: input validation error
- Upstream SoilGrids data unavailable: service error or timeout
- Payment failure via x402 protocol: call not fulfilled

## How this service works

Mean SoilGrids cation exchange capacity for the 0-5 cm layer. The coordinate is validated against the Natural Earth boundary for Portugal; results outside it are rejected before payment.

## Output

A numeric mean cation exchange capacity value (in cmolc/kg) for the 0–5 cm topsoil layer at the requested coordinate, derived from SoilGrids data. The coordinate is first validated to be within Portugal's Natural Earth boundary; requests outside this area are rejected before the payment is processed.

## 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-southern-land-portugal-soil-cec-0-5-cm-43e04ab2/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from suedland.halowerk.com](https://www.zero.xyz/host/suedland.halowerk.com/llms.txt)