Answer questions about spatial data using DuckDB. Use when the user mentions locations, coordinates, lat/lng, distances, maps, addresses, "near", "within", "closest", geographic names, or spatial file formats (GeoJSON, Shapefile, GeoPackage, GPX, GeoParquet). Also triggers when the user wants to fin

You are answering spatial questions using DuckDB's spatial extension and, when needed, Overture Maps as a free global data source. Question or file: $0 Additional context: ${1: } Step 1 — Understand what the user needs Classify the question: Pattern Data source Key functions "Find X near Y" (no user file) Overture Maps on S3 ST Distance Spheroid , bbox filtering "How far between A and B" Geocode or user data ST Distance Spheroid "Which points fall inside polygons" User files ST Contains "Analyze this GeoJSON/Shapefile/GPX" User file ST Read , measurement functions "Show density/hotspots" User or Overture data H3 hex binning "Convert to GeoJSON/GeoPackage" User file COPY TO (FORMAT GDAL) "Count buildings/roads in area" Overture Maps bbox filtering + aggregation If the question involves real world places, POIs, buildings, roads, or boundaries and the user hasn't provided a file, use Overture Maps — read references/overture.md for S3 paths and schema. For spatial function syntax, read references/functions.md . Step 2 — Write and run the query Always start with: Add extensions as needed: Overture/remote data: LOAD httpfs; CREATE SECRET (TYPE S3, PROVIDER config, REGION 'us west 2'); H3 hex binning: INSTALL h3 FROM community; LOAD h3; Key principles bbox filtering first — When querying Overture, always filter on bbox.xmin/xmax/ymin/ymax before any spatial function. This uses Parquet predicate pushdown and avoids downloading the full dataset. Always set geometry always xy = true — This ensures all spatial functions interpret coordinates as longitude, latitude (the standard for Overture, GeoJSON, and most data sources). Without it, spheroid functions assume latitude first and return wrong results. Use spheroid functions for real world distances — ST Distance Spheroid returns meters on the WGS84 ellipsoid. Plain ST Distance uses planar coordinates and gives meaningless results for lat/lng. Important: spheroid functions ( ST Distance Spheroid , ST Area Spheroid , etc.) require POINT 2D inputs, not generic GEOMETRY . Overture geometry columns are typed GEOMETRY('OGC:CRS84') and cannot be cast directly. Extract coordinates first: CSV with lat/lng needs conversion — ST Point(longitude, latitude) (longitude first). This is the most common gotcha. Run the query in a single bash call: Step 3 — Present results For tabular results: show the data directly For spatial results: consider exporting to GeoJSON for visualization ( COPY TO 'result.geojson' WITH (FORMAT GDAL, DRIVER 'GeoJSON') ) For distance/area results: use human readable units (km for large distances, m for small) For density/hotspot results: describe the pattern and offer to export for visualization If the query fails: duckdb: command not found → delegate to /duckdb skills:install duckdb Missing extension → INSTALL spatial; LOAD spatial; or INSTALL h3 FROM community; LOAD h3; S3 access denied → suggest checking AWS credentials No results with Overture → widen the bbox, check the category spelling, or try a broader search