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acheong08/apple-corelocation-experiments

★ 308 · Go · GPL-3.0 · updated Apr 2026

Research dump on how IOS Location Services work

A reverse-engineering research dump on Apple's Wi-Fi Positioning System — the undocumented protobuf API that iOS devices use to crowdsource and query BSSID locations. It's for security researchers and privacy engineers who want to understand (or probe) what Apple collects and how it works, backed by a paper from UMD and a 2010 congressional disclosure.

The protobuf definitions are recovered from actual CoreLocationProtobuf.framework disassembly, not guessed — field names are grounded. The tile coordinate system work is genuinely impressive: tracking down Apple's morton encoding variant, matching it to the HERE Data SDK implementation, and chaining it through OSM tile math to GPS is non-trivial and well-documented. The demo API gives you a working interactive map in one command. The China isolation is noted and handled — separate endpoints, shapefile-based routing, not an afterthought.

This is a research dump, not a library — there's no stable API surface, no versioning, and the README openly calls code incomplete in several places. The tile API investigation is still ongoing as of the last update; some sections end mid-thought. The data-analysis scripts are a mix of Python, SQL, and shell with no documentation on how they chain together or what database schema they expect. Using the WLOC or tile API at scale almost certainly violates Apple's ToS, so production use is a non-starter for most.

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