  High-quality single crystals of EuAuAs were studied by means of powder x-ray
diffraction, magnetization, magnetic susceptibility, heat capacity, electrical
resistivity and magnetoresistance measurements. The compound crystallizes with
a hexagonal structure of the ZrSiBe type (space group $P6_3/mmc$). It orders
antiferromagnetically below 6 K due to the magnetic moments of divalent Eu
ions. The electrical resistivity exhibits metallic behavior down to 40 K,
followed by a sharp increase at low temperatures. The magnetotransport
isotherms show a distinct metamagnetic-like transition in concert with the
magnetization data. The antiferromagnetic ground state in \mbox{EuAuAs} was
corroborated in the \textit{ab initio} electronic band structure calculations.
Most remarkably, the calculations revealed the presence of nodal line without
spin-orbit coupling and Dirac point with inclusion of spin-orbit coupling. The
\textit{Z}$_2$ invariants under the effective time reversal and inversion
symmetries make this system nontrivial topological material. Our findings,
combined with experimental analysis, makes EuAuAs a plausible candidate for an
antiferromagnetic topological nodal-line semimetal.
