Worked on enhancing agent model fallback robustness in the openclaw/openclaw repository, focusing on backend development and error handling using JavaScript and TypeScript. Addressed a critical bug by refining the quota fallback logic to better tolerate differences in session models and manage cooldown events with greater precision. Implemented session overrides and clarified the distinction between rate-limit cooldowns and persistent issues such as authentication or billing errors, preventing premature fallback termination. These improvements increased the reliability and business continuity of the agent system, reduced service interruptions, and improved code maintainability, laying a foundation for higher throughput and future scalability within the platform.