Worked on the AstrBotDevs/AstrBot repository to enhance reliability and API integration quality for Anthropic and OpenAI providers. Developed message sanitization and merging logic for the Anthropic provider, ensuring compliance with API requirements by removing orphaned tool results and merging consecutive messages. For OpenAI, implemented robust sanitization to eliminate orphaned or duplicate tool messages and guarantee correct pairing after context truncation. Both features were supported by comprehensive unit tests targeting edge cases, improving maintainability and reducing tool-response failures. The work leveraged Python for backend development, with a strong emphasis on API integration and thorough unit testing to ensure code quality.