Developed Unicode-preserving JSON serialization for tool history and reduced tool messages in the Unique-AG/ai repository, focusing on enhancing multilingual support and reliability in backend workflows. Leveraged Python for backend and API development, implementing serialization logic that maintains readable Unicode in LLM-facing payloads and prevents unwanted Unicode escapes during token reduction. Introduced comprehensive regression tests using pytest to cover multilingual content, JSON-sensitive characters, and internal search components, ensuring robust handling of diverse data. The work improved the reliability of tool history processing and reduced encoding-related errors, supporting seamless multilingual workflows and enhancing the overall user experience in data serialization and testing.