HALOWERK Europe Land – Mean Surface Slope (Parcel Polygon)

Choose this endpoint when you need a single aggregated slope metric for a custom polygon parcel anywhere across 30 European countries, especially for agricultural, environmental, or land development use cases. Prefer it over raster downloads when you want a ready-to-use scalar value without post-processing. If you need aspect/orientation (south-facing index) or land cover shares rather than raw slope, use the sibling endpoints on the same platform.

• Polygon spans more than 0.25 degrees — request rejected with validation error
• Fewer than 3 coordinate pairs provided — invalid polygon error
• Coordinates fall outside the European coverage area (lat 34–72.5, lon -31.5–40.5) — out-of-coverage error
• Polygon array items with incorrect coordinate ordering or extra items — schema validation failure
• Payment not provided or insufficient — x402 payment required response