Worked on the openucx/ucx repository to deliver a new feature enabling tokenized data transfers by extending the UCT interface attributes. Focused on API development and system programming in C, the work involved defining token structures for both transmit and receive paths, updating the uct_iface_attr_v2_t structure, and ensuring safe defaults by initializing token_length to zero. The implementation included code cleanups, comment updates, and removal of obsolete conflict markers to maintain code quality. This contribution laid the foundation for more flexible and efficient data paths, supporting higher-throughput workloads and aligning the interface with evolving performance and business requirements.