Developed an OpenAPI response visibility feature for the wowo-zZ/astron-agent repository, focusing on schema-aware filtering of API response fields. Leveraging Python for backend development, the work introduced the x-display mechanism, allowing precise control over which fields are exposed to clients on a per-schema basis. Validation guardrails were implemented to ensure hidden fields are consistently managed during response processing, reducing the risk of unintended data exposure. This approach enhanced API agility and flexibility, supporting more stable client contracts. The project emphasized robust unit testing and clear semantic commits, laying the foundation for scalable, maintainable API-level visibility controls across endpoints.