WKT → GeoJSON (PostGIS)

Use this skill when your data includes geometries as WKT strings (e.g., "POINT(-87.6 41.8)", "LINESTRING(...)", "POLYGON(...)") and you want a GeoJSON FeatureCollection for map display.

This skill documents the canonical raw SQL pattern for building GeoJSON from WKT using PostGIS.

When to use

• You receive an array of objects like { id, wkt, ... }
• You want GeoJSON directly from Postgres
• You want consistent property shaping and GeoJSON output

Input assumptions

• WKT is valid (or you’ll get PostGIS parse errors)
• The WKT may or may not include an SRID (this pattern assumes no SRID unless you add it)
• Output should be web-map friendly (commonly EPSG:4326)

Canonical SQL pattern

From JSON input (WKT field)