  Holographic quantum error-correcting code, the quantum-information structure
hypothesized for the AdS/CFT correspondence, has being attracting increasing
attention in new directions interrelating the studies of quantum gravity and
quantum simulation. In this work, we initiate a novel approach for building
holographic code that can be generally applied in potentially broad and
interdisciplinary contexts. Our approach takes an "opposite" route to the
conventional paradigm that is based on bulk tensor-networks. As illustrated in
an exact model, we start from scalable descriptions of boundary qudits which
can guide succinct quantum-circuit simulations, and rigorously show how the
bulk qudits and the encoding structure emerge from boundary entanglement
patterns. By investigating the entanglement patterns, we systematically unfold
the hypothetical structure for bulk reconstruction and the details of the
Ryu-Takayanagi formula in the formalism of operator-algebra quantum error
correction, demonstrating desired properties that are not yet proved in the
established models. Our work might offer a fresh perspective for the study of
holographic code.
