We propose an interactive computational design method for deployable auxetic shells. We realize deployable auxetics as triangular linkages that can be actuated with simple expansive mechanisms to assume a desired freeform target shape. The core feature of these structures is that the target shape is directly and uniquely encoded in the 2D linkage layout. As a consequence, the structure can be fabricated and assembled in the plane and automatically deployed to its 3D target configuration without the need for any scaffold, formwork, or other temporary support structure. We focus on automatic deployment via inflation or gravitational loading for which a rigorous theoretical analysis has been given in prior work. Our paper builds upon these results and presents optimization-based direct manipulation tools to edit and adapt an auxetic linkage structure to effectively explore design alternatives. In addition, our solution enables simulation-based form-finding, where the desired target surface is interactively constructed using the deployment mechanism as a form-finding force. We present several design case studies that demonstrate the effectiveness of our approach and highlight potential applications in architecture.