Worked on the FusionAuth/fusionauth-client-builder repository to enhance API key lifecycle management by introducing explicit expiration timestamps. Developed a feature that adds the expirationInstant field to the APIKey JSON representation, allowing clients and monitoring tools to access precise expiry information for each API key. This update supports improved security auditing and facilitates easier key rotation by making expiration data readily available. The implementation was carried out using Java, with a focus on backend development and robust JSON handling. The work addressed a targeted need for better governance of API keys, contributing to more transparent and manageable API security practices.