# Natur HaloWerk Satellite Change Diff (HLS)

> Natur HaloWerk Satellite Change Diff (HLS) is a paid API for AI agents from natur.halowerk.com, paid per call via x402, $0.015/call, status unknown (last checked 2026-09-15).

Compares NASA GIBS Harmonized Landsat Sentinel-2 (HLS) imagery for two dates at a geographic coordinate window, reporting pixel-level RGB change and heuristics for built-up area, water/flooding, and vegetation loss.

## Facts

- Endpoint: POST https://natur.halowerk.com/v1/sat-diff
- Price: $0.015/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/natur-halowerk-satellite-change-diff-hls-508435e2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_DogTpC4UpUgQ29hsj5RqN

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 natur-halowerk-satellite-change-diff-hls-508435e2 -d '<json body>'
```

Example prompt: Compare satellite imagery for the coordinates 48.2°N, 16.3°E with a 2000-meter radius between 2023-06-01 and 2024-06-01 and tell me if there's been significant vegetation loss, flooding, or new construction in that area.

## When to prefer this

Choose this endpoint when you need a quick, quantitative comparison of land cover change at a specific geographic point between two known dates using 30m-resolution HLS satellite data. It is ideal for detecting flooding, vegetation loss, or urban expansion without needing to manage satellite imagery pipelines. Prefer it over generic tile servers when you need pixel-change statistics and semantic class heuristics (built-up, water, vegetation) returned in a single API call. Note the 30m resolution limit and sensitivity to cloud cover — not suitable for sub-30m change detection or fully cloudy regions.

## Known failure modes

- No HLS imagery available for one or both dates at the requested location, resulting in empty or partial comparison
- High cloud cover causing most pixels to be transparent and unusable, yielding low-confidence results
- Dates too far apart or too close may introduce seasonal lighting artifacts rather than true land-cover change
- Radius too small (below 250m) or coordinate out of range returns validation error
- Acquisition gaps in HLS coverage for the specified region may cause one date to have no data

## How this service works

Fetches two 128×128 NASA GIBS Harmonized Landsat Sentinel-2 reflectance renderings for a coordinate window, decodes the PNGs locally and compares only pixels present in both dates. It reports measured RGB change plus transparent colour-class heuristics for built-up, water/flooding and vegetation loss. HLS resolution is about 30 m; cloud, season, lighting and acquisition gaps can dominate differences.

## Output

Returns measured per-pixel RGB change statistics between the two HLS renderings, along with heuristic classifications for the proportion of pixels showing built-up area changes, water/flooding presence, and vegetation loss. Notes coverage caveats such as cloud cover, seasonal variation, and acquisition gaps between the two images.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "latitude": {
   "type": "number",
   "maximum": 90,
   "minimum": -90
  },
  "radius_m": {
   "type": "integer",
   "default": 1000,
   "maximum": 10000,
   "minimum": 250
  },
  "longitude": {
   "type": "number",
   "maximum": 180,
   "minimum": -180
  },
  "timestamp_a": {
   "type": "string",
   "format": "date"
  },
  "timestamp_b": {
   "type": "string",
   "format": "date"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/natur-halowerk-satellite-change-diff-hls-508435e2/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from natur.halowerk.com](https://www.zero.xyz/host/natur.halowerk.com/llms.txt)