  $\textit{A priori}$ prediction of phase stability of materials is a
challenging practice, requiring knowledge of all energetically-competing
structures at formation conditions. Large materials repositories
$\unicode{x2014}$ housing properties of both experimental and hypothetical
compounds $\unicode{x2014}$ offer a path to prediction through the construction
of informatics-based, $\textit{ab-initio}$ phase diagrams. However, limited
access to relevant data and software infrastructure has rendered thermodynamic
characterizations largely peripheral, despite their continued success in
dictating synthesizability. Herein, a new module is presented for autonomous
thermodynamic stability analysis implemented within the open-source,
$\textit{ab-initio}$ framework AFLOW. Powered by the AFLUX Search-API,
AFLOW-CHULL leverages data of more than 1.8 million compounds currently
characterized in the AFLOW.org repository and can be employed locally from any
UNIX-like computer. The module integrates a range of functionality: the
identification of stable phases and equivalent structures, phase coexistence,
measures for robust stability, and determination of decomposition reactions. As
a proof-of-concept, thorough thermodynamic characterizations have been
performed for more than 1,300 binary and ternary systems, enabling the
identification of several candidate phases for synthesis based on their
relative stability criterion $\unicode{x2014}$ including 18 promising
$C15_{b}$-type structures and two half-Heuslers. In addition to a full report
included herein, an interactive, online web application has been developed
showcasing the results of the analysis, and is located at
aflow.org/aflow-chull.
