Oso developed an interactive debugger for their declarative logic programming language, Polar, to address the challenges of debugging complex authorization logic in applications. Polar, inspired by Datalog, is designed for fine-grained application authorization but presents unique debugging challenges due to its declarative nature, which lacks traditional imperative debugging tools like stack traces. In response, Oso created a Policy Debugger as part of their Oso Migrate CLI, evolving from their existing Explain tool, to offer a comprehensive view of the decision-making path, including the ability to trace intermediate steps and authorization data snapshots. The debugger is designed to handle Polar's recursive and branching proof model by providing a simplified, interactive UI that allows developers to incrementally explore decision logic, focusing on unexpected results. Built as a terminal-based UI using the ratatui library, the debugger keeps developers integrated within their workflow, enabling them to debug, visualize, and step through policy logic efficiently. Additionally, the Oso Migrate toolkit includes features like parity checks, data snapshotting, request replay, and a test runner to facilitate smooth integration and policy evaluation without requiring deep expertise in logic programming.