  Graph states are versatile resources for quantum computation and
quantum-enhanced measurement. Their generation illustrates a high level of
control over entanglement. We report on the generation of continuous-variable
graph states of atomic spin ensembles, which form the nodes of the graph. The
edges represent the entanglement structure, which we program by combining
global photon-mediated interactions in an optical cavity with local spin
rotations. By tuning the entanglement between two subsystems, we either
localize correlations within each subsystem or enable Einstein-Podolsky-Rosen
steering. We further engineer a four-mode square graph state, highlighting the
flexibility of our approach. Our method is scalable to larger and more complex
graphs, laying groundwork for measurement-based quantum computation and
advanced protocols in quantum metrology.
