Worked on the zed-industries/claude-code-acp repository to enhance system stability by addressing crash risks in streaming and session history replay features. Focused on hardening input handling in TypeScript, the developer implemented robust error handling to guard against undefined input in key functions, preventing potential failures during data processing. Expanded regression and unit testing coverage ensured that edge cases, such as undefined or malformed input, were thoroughly validated. All changes were verified through end-to-end tests and a clean CI build, resulting in improved reliability for ACP integration. The work emphasized error handling, TypeScript best practices, and comprehensive automated testing.