The title mol-ecule, C9H7ClN4OS, is almost planar, with an r.m.s. deviation of 0.034 (2) Å for the mean plane through all the non-H atoms. Intra-molecular N-H⋯O and N-H⋯N hydrogen bonds form S(6) and S(5) ring motifs, respectively. In the crystal, mol-ecules are assembled into inversion dimers through pairs of co-operative N-H⋯Cl inter-actions. These dimers are connected along the b axis by N-H⋯O and N-H⋯S hydrogen bonds, generating layers parallel to (103). The layers are further connected along the a axis into a three-dimensional network, through weak π-π stacking inter-actions [centroid-centroid distance = 3.849 (2) Å].