# HALOWERK Land Compare – WorldCover 2020→2021 Dominant Class Transition

> HALOWERK Land Compare – WorldCover 2020→2021 Dominant Class Transition is a paid API for AI agents from landvergleich.halowerk.com, paid per call via x402, $0.008/call, status unknown (last checked 2026-09-15).

Returns the dominant land-cover class transition (ESA WorldCover 2020 v100 → 2021 v200) for a 250-metre analysis area at a given European coordinate.

## Facts

- Endpoint: POST https://landvergleich.halowerk.com/v1/worldcover-2020-2021-class-transition
- Price: $0.008/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/halowerk-land-compare-worldcover-2020-2021-dominant-class-transition-41548445
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Sl-RCzqV-Vi2db2RbKtsd

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-worldcover-2020-2021-dominant-class-transition-41548445 -d '<json body>'
```

Example prompt: What was the dominant land-cover class at latitude 51.5 longitude 10.2 in 2020 and 2021 according to ESA WorldCover, and did it change?

## When to prefer this

Choose this endpoint when you need to detect or audit a dominant land-cover class change at a specific European point between the 2020 and 2021 ESA WorldCover releases. It is the right choice when a single-coordinate class-transition lookup is needed rather than tree-cover share, built-up fraction, or other continuous metrics. Prefer it over the sibling comparison endpoints when the question is categorical (what class was it, did it change?) rather than quantitative (by how much?).

## Known failure modes

- Coordinates outside European coverage bounds (lat 34–72.5, lon -31.5–40.5) will be rejected with a validation error
- Invalid or missing latitude/longitude values return a 400-level error
- Transient server errors may return 5xx responses; retry with backoff
- Payment failure (x402) results in a 402 response requiring valid USDC payment
- Locations at the boundary of coverage may yield incomplete or null class data

## How this service works

Dominant class transition measured from ESA WorldCover 2020 v100 and 2021 v200 for the same 250 metre analysis area. The result is observed map-class change, not a causal claim.

## Output

The endpoint returns the dominant ESA WorldCover land-cover class recorded for the specified 250-metre cell in both 2020 (v100) and 2021 (v200), along with the observed class transition between the two years. This is a map-class change observation, not a causal explanation.

## 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-land-compare-worldcover-2020-2021-dominant-class-transition-41548445/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)