# HALOWERK Eastern Land – Bulgaria Soil pH (0-5 cm)

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

Returns the mean SoilGrids pH (in H2O) for the 0–5 cm topsoil layer at a given coordinate within Bulgaria.

## Facts

- Endpoint: POST https://ostland.halowerk.com/v1/bg-soil-ph
- 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-eastern-land-bulgaria-soil-ph-0-5-cm-ac363109
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_slrsD01LzaeGXz4M9fj_v

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-bulgaria-soil-ph-0-5-cm-ac363109 -d '<json body>'
```

Example prompt: What's the topsoil pH (0–5 cm, H2O method) at latitude 42.698, longitude 23.322 in Bulgaria? I need it for a soil suitability assessment.

## When to prefer this

Use this endpoint when you need a point-level topsoil pH value (0–5 cm, H2O) for a coordinate known to be within Bulgaria. It combines SoilGrids scientific data with pre-payment boundary validation, making it efficient for Bulgarian-scoped agricultural, environmental, or land-use workflows where you want to avoid paying for out-of-bounds queries.

## Known failure modes

- Coordinate outside Bulgaria boundary — request rejected before payment, error indicating invalid location
- Coordinate within European bounding box but outside Bulgaria — rejected by Natural Earth boundary check
- Malformed or missing latitude/longitude — validation error returned
- Coordinate at sea or non-land area — may return error or null result
- Service unavailable — upstream SoilGrids data not reachable

## How this service works

Mean SoilGrids pH in H2O for the 0-5 cm layer. The coordinate is validated against the Natural Earth boundary for Bulgaria; results outside it are rejected before payment.

## Output

A numeric mean soil pH value (H2O method) for the 0–5 cm topsoil layer at the queried coordinate, sourced from SoilGrids. Coordinates outside Bulgaria's Natural Earth boundary 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-eastern-land-bulgaria-soil-ph-0-5-cm-ac363109/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)