In December 2025, Leon focused on stabilizing the OpenAI Serving Chat pipeline within the jeejeelee/vllm repository, addressing a critical bug that affected the preservation of text and reasoning state during transitions from reasoning to tool calls. By refining backend logic in Python and enhancing AI integration, Leon ensured that token handling and state management were robust, reducing edge-case failures and improving the reliability of tool-call sequences. The work demonstrated careful debugging and adherence to git-based release practices, resulting in a more dependable user experience. Although no new features were added, the depth of the bug fix contributed to overall system stability.