LLM-generated GIS code can look correct but violate geographic rules; GeoContra's contract-based verification catches these semantic errors before they produce wrong spatial analysis.
GeoContra is a verification and repair system that catches geographic errors in AI-generated GIS code. It checks that spatial analysis preserves coordinate systems, topology, units, and geographic plausibility—catching bugs like negative travel times or mismatched coordinate systems that would otherwise produce executable but wrong results.