Developed and delivered support for complex message types in the chat completion protocol for the kvcache-ai/sglang repository, enabling the handling of diverse assistant and tool messages within the /chat/completions endpoint. This work involved router-level changes to improve the extensibility and flexibility of chat workflows, allowing for richer interactions between users and the assistant. The implementation was completed in Rust, leveraging skills in API development, backend engineering, and protocol design. The feature was contributed through a collaborative pull request process, with a focus on code quality and alignment with team practices, and did not include major bug fixes during the period.