Developed CoAP over TCP (RFC 8323) support for the renesas/zephyr repository, delivering a TCP client implementation and a sample application to demonstrate reliable CoAP communication in embedded systems. The work involved implementing TCP framing, CSM exchange, signaling codes, and blockwise transfer support, enabling robust end-to-end testing with external CoAP servers. Leveraging C programming, Zephyr OS, and network programming expertise, the developer introduced new configuration options and updated documentation to guide integration and usage. These enhancements improved interoperability and deployment reliability for IoT scenarios, providing developers and integrators with clear guidelines and practical tools for reliable CoAP over TCP.