Worked on the harness/mcp-server repository to deliver two core backend features focused on cost management and event handling. Developed enhanced data reporting for the ccm_perspective_grid tool by adding a parameter to include total cost in API responses, improving reporting accuracy and cost visibility. Introduced a new UI events tool for cost categories, implementing validation and event creation to streamline user interactions. Applied targeted code cleanup to address tool-call misconfigurations and updated tests to ensure reliability. Leveraged Go for backend development and API design, utilizing event-driven architecture principles to improve maintainability and user experience within the cost management platform.