Developed Esxcli command support within the VCSim component of the vmware/govmomi repository, expanding the vSphere Infrastructure Client Simulator’s capabilities for CLI-based testing. This work involved designing and implementing new commands and data types to accurately simulate ESXi CLI operations, allowing developers to test and iterate on automation workflows without requiring access to a live ESXi host. Leveraging Go for core development and XML for data processing, the solution enhanced API simulation and CLI development workflows. The approach enabled more realistic and efficient testing scenarios, supporting faster development cycles and improving the fidelity of simulated vSphere environments for integration testing.