Nowadays, the dominant design approach in distributed software is cloud-centric. This comes at the cost of several issues including loss of control over data ownership and privacy, lack of offline availability, poor latency, inefficient use of communication infrastructure, and waste of (powerful) computing resources on the edge. Local-first software presents an alternative approach where data is stored and managed locally and devices primarily communicate in a peer-to-peer manner. However, the decentralized nature of local-first software paired with the unpredictability of interactions driven from the outside world impede reasoning about correctness of such applications. Yet, existing solutions to develop local-first software do not provide safety guarantees and instead expect developers to reason about concurrent interactions in an environment with unreliable network conditions.

In this work, we propose LoRe, a programming language and compiler that automatically verifies developer-supplied safety properties for local-first applications.