This repository provides a high-precision IP geolocation HTTP API focused on mainland China, capable of resolving IP addresses to province/city/district level using a custom GeoCN database. The server is written in Go, uses MaxMind GeoLite2 databases for ASN and city-level data, and supplements with a custom MMDB for Chinese administrative divisions. It is deployed as a single binary via Docker, with a CI pipeline that weekly rebuilds the image with updated databases. The codebase is monolithic but well-organized, with environment variable configuration, proper error handling, and clean JSON responses. It is primarily an application, not a data research project, though it ships supporting data files for division codes and ASN metadata.