Who's On First API

Geographic hierarchy resolution service powered by Who's On First gazetteer data

About Who's On First

Who's On First (WOF) is a gazetteer of places - a comprehensive geographic database covering countries, regions, cities, neighborhoods, and more. It's an open data project that provides consistent, accurate place records with rich metadata and hierarchical relationships.

This API provides a fast, production-ready service for resolving geographic coordinates to their administrative hierarchies using Who's On First data.

Database Statistics

300,767

Total Places

180,225

Localities

56,947

Neighbourhoods

7,194

Constituencies

API Endpoints

Get Geographic Hierarchy

GET /api/v1/hierarchy?lat={latitude}&lon={longitude}

Example:
/api/v1/hierarchy?lat=37.7749&lon=-122.4194
Returns: continent, country, region, county, locality, and neighbourhood

Get Place by ID

GET /api/v1/place/{wof_id}

Example:
/api/v1/place/85922583
Returns: Complete place details with properties and hierarchy

Health Check

GET /health