FOAM Space is a project that is addressing the problem of GPS spoofing by creating an alternative network that triangulates location via terrestrial radio beacons rather than satellites. These radio beacons are set up within range of each other to form zones of coverage. It also utilizes blockchain technology, using crypto-economic incentives to encourage running said radio beacons, as well as using NFTs to create immutable certificates of location claims.

Users within range of these zones are able to mint NFTs on the Base Layer 2 rollup, proving that they were in a certain location at a certain time (referred to as Proof of Location). These NFTs— henceforth referred to as FPCs (FOAM Presence Claims)— contain metadata pertinent to their respective claims. Payment for this service provided by the user is denominated in FOAM— the protocol's native token.

The foam-map repository contains the code that is running foamcaster.xyz, a hosted Mapbox map that is populated with FPCs and their associated meta-data. FPC minting events and token events are tracked by the FOAMcaster social media bot, which monitors a number of FOAM-related contracts on Base and Optimism L2s. Code for FOAMcaster can be found in the foamcaster_v2 repository, and published events can be followed on both Twitter/X and Farcaster.