Developed principal type identification utilities for the dfinity/new-motoko-base repository, enabling reliable differentiation between canister, self-authenticating user, and reserved principals by inspecting the last byte of each principal’s byte array. The implementation centralized principal type checks, improving code safety and maintainability across the codebase. Comprehensive unit tests were created to validate the accuracy of these utilities for all supported principal types, ensuring robust and predictable behavior. The work was completed using Motoko, with a focus on principal management, smart contract logic, and thorough testing practices. No bugs were reported or fixed during this period, reflecting a focused feature delivery.