LighthouseReckoning is a lightweight LoRa mesh networking library for Arduino-compatible microcontrollers, tested on ESP32 and RP2040 with SX126x radios. Its primary goal is to enable sensor data to reach a central "Home" node through multiple relay nodes. Nodes automatically determine the shortest path to Home by exchanging distance information with their neighbors. Each node only needs to know its immediate neighbors' distances to Home, not the entire network topology. Routing is managed through a distance-vector approach, allowing nodes to forward data hop-by-hop toward the Home node. The system implements hop-by-hop reliability, where each node confirms receipt from its immediate predecessor, offloading end-to-end acknowledgment to local retries. This ensures that only the originating node needs confirmation from its direct neighbor. The library is designed to be non-blocking, allowing for continuous updates in the main loop. It supports automatic multi-hop routing, local packet retries, duplicate detection, and TTL protection. LighthouseReckoning utilizes RadioLib for radio abstraction and is currently tested on specific hardware platforms. Future development aims to enhance protocol features and security.