Bis[2-(2-pyridylamino)pyridinium] squarate dihydrate

In the title compound, 2C10H10N3+·C4O42−·2H2O, the squarate dianion is centrosymmetric. The organic cation shows an unusual, approximately symmetrical, intra­molecular N⋯H⋯N hydrogen bond. The other hydrogen bonds are conventional N—H⋯O and O—H⋯O links, resulting in chains.