From Matthew Panzarino at TechCrunch:

Apple and Google’s engineering teams have banded together to create a decentralized contact tracing tool that will help individuals determine whether they have been exposed to someone with COVID-19.

Contact tracing is a useful tool that helps public health authorities track the spread of the disease and inform the potentially exposed so that they can get tested. It does this by identifying and “following up with” people who have come into contact with a COVID-19-affected person.

The first phase of the project is an API that public health agencies can integrate into their own apps. The next phase is a system-level contact tracing system that will work across iOS and Android devices on an opt-in basis.

The system uses on-board radios on your device to transmit an anonymous ID over short ranges — using Bluetooth beaconing. Servers relay your last 14 days of rotating IDs to other devices, which search for a match. A match is determined based on a threshold of time spent and distance maintained between two devices.

If a match is found with another user that has told the system that they have tested positive, you are notified and can take steps to be tested and to self-quarantine.

This is great news. Any system like this will need deep integration into the operating systems to be effective. Third-party apps can implement some nice features, but the platform itself has to be on board for more widespread adoption. It’s nice to see the two big players in the mobile space cooperating on this level.

They have already started to release some documentation and notes about the APIs. This should be an exciting space to watch over the next few months.