GitHub project Traccar/traccar-geocoder delivers a fast, self-hosted reverse geocoding service leveraging OpenStreetMap data. Given coordinates, it returns precise addresses including house numbers, streets, cities, and administrative boundaries. Built as part of the Traccar open-source GPS tracking platform, it offers street-level resolution and administrative boundary lookups.

Key features include sub-millisecond query latency via memory-mapped index files, automatic HTTPS with Let's Encrypt, and Docker support for easy deployment. The project consists of a C++ builder component parsing OSM PBF files into a compact binary index and a Rust server serving HTTP/HTTPS queries. Sub-millisecond latency is achieved through this architecture, making it suitable for real-time tracking applications. Deployment is straightforward: Docker Compose setups handle index building and serving, while environment variables control PBF URLs and HTTPS domains.

The Apache 2.0 licensed tool is designed for reliability and scalability in tracking infrastructure.